bluuebunny/crossref_metadata_2025_split huggingface dataset:
Late Quaternary vegetation and climate history of a perennial river canyon in the Río Salado basin (22°S) of Northern Chile
Authors: Latorre Claudio , Betancourt Julio L. , Arroyo Mary T.K. 
Published: March 2006

AbstractPlant macrofossils from 33 rodent middens sampled at three sites between 2910 and 3150 m elevation in the main canyon of the Río Salado, northern Chile, yield a unique record of vegetation and climate over the past 22,000 cal yr BP. Presence of low-elevation Prepuna taxa throughout the record suggests that mean annual temperature never cooled by more than 5°C and may have been near-modern at 16,270 cal yr BP. Displacements in the lower limits of Andean steppe and Puna taxa indicate that mean annual rainfall was twice modern at 17,520–16,270 cal yr BP. This pluvial event coincides with infilling of paleolake Tauca on the Bolivian Altiplano, increased ENSO activity inferred from a marine core near Lima, abrupt deglaciation in southern Chile, and Heinrich Event 1. Moderate to large increases in precipitation also occurred at 11,770–9550 (Central Atacama Pluvial Event), 7330–6720, 3490–2320 and at 800 cal yr BP. Desiccation occurred at 14,180, 8910–8640, and 4865 cal yr BP. Compared to other midden sites in the region, early Holocene desiccation seems to have happened progressively earlier farther south. Emerging trends from the cumulative midden record in the central Atacama agree at millennial timescales with improved paleolake chronologies for the Bolivian Altiplano, implying common forcing through changes in equatorial Pacific sea-surface temperature gradients.
Climate variability in the Spanish Pyrenees during the last 30,000 yr revealed by the El Portalet sequence
Authors: González-Sampériz P. , Valero-Garcés B.L. , Moreno A. , Jalut G. , García-Ruiz J.M. , Martí-Bono C. , Delgado-Huertas A. , Navas A. , Otto T. , Dedoubat J.J. 
Published: March 2006

AbstractPalynological, sedimentological and stable isotopic analyses of carbonates and organic matter performed on the El Portalet sequence (1802 m a.s.l., 42°48′00ʺN, 0°23′52ʺW) reflect the paleoclimatic evolution and vegetation history in the central-western Spanish Pyrenees over the last 30,000 yr, and provide a high-resolution record for the late glacial period. Our results confirm previous observations that deglaciation occurred earlier in the Pyrenees than in northern European and Alpine sites and point to a glacial readvance from 22,500 to 18,000 cal yr BP, coinciding with the global last glacial maximum. The patterns shown by the new, high-resolution pollen data from this continental sequence, chronologically constrained by 13 AMS 14C dates, seem to correlate with the rapid climate changes recorded in Greenland ice cores during the last glacial–interglacial transition. Abrupt events observed in northern latitudes (Heinrich events 3 to 1, Oldest and Older Dryas stades, Intra-Allerød Cold Period, and 8200 cal yr BP event) were also identified for the first time in a lacustrine sequence from the central-western Pyrenees as cold and arid periods. The coherent response of the vegetation and the lake system to abrupt climate changes implies an efficient translation of climate variability from the North Atlantic to mid latitudes.
α-Tocopherol Plays a Role in Photosynthesis and Macronutrient Homeostasis of the Cyanobacterium Synechocystis sp. PCC 6803 That Is Independent of Its Antioxidant Function
Authors: Sakuragi Yumiko , Maeda Hiroshi , DellaPenna Dean , Bryant Donald A. 
Published: March 2006

Abstract
α-Tocopherol is synthesized exclusively in oxygenic phototrophs and is known to function as a lipid-soluble antioxidant. Here, we report that α-tocopherol also has a novel function independent of its antioxidant properties in the cyanobacterium Synechocystis sp. PCC 6803. The photoautotrophic growth rates of wild type and mutants impaired in α-tocopherol biosynthesis are identical, but the mutants exhibit elevated photosynthetic activities and glycogen levels. When grown photomixotrophically with glucose (Glc), however, these mutants cease growth within 24 h and exhibit a global macronutrient starvation response associated with nitrogen, sulfur, and carbon, as shown by decreased phycobiliprotein content (35% of the wild-type level) and accumulation of the nblA1-nblA2, sbpA, sigB, sigE, and sigH transcripts. Photosystem II activity and carboxysome synthesis are lost in the tocopherol mutants within 24 h of photomixotrophic growth, and the abundance of carboxysome gene (rbcL, ccmK1, ccmL) and ndhF4 transcripts decreases to undetectable levels. These results suggest that α-tocopherol plays an important role in optimizing photosynthetic activity and macronutrient homeostasis in Synechocystis sp. PCC 6803. Several lines of evidence indicate that increased oxidative stress in the tocopherol mutants is unlikely to be the underlying cause of photosystem II inactivation and Glc-induced lethality. Interestingly, insertional inactivation of the pmgA gene, which encodes a putative serine-threonine kinase similar to RsbW and RsbT in Bacillus subtilis, results in a similar increase in glycogen and Glc-induced lethality. Based on these results, we propose that α-tocopherol plays a nonantioxidant regulatory role in photosynthesis and macronutrient homeostasis through a signal transduction pathway that also involves PmgA.
Gene Expression Profiling Using cDNA Microarray Analysis of the Sexual Reproduction Stage of the Unicellular Charophycean Alga Closterium peracerosum-strigosum-littorale Complex
Authors: Sekimoto Hiroyuki , Tanabe Yoichi , Tsuchikane Yuki , Shirosaki Hiroshi , Fukuda Hiroo , Demura Taku , Ito Motomi 
Published: March 2006

Abstract
The desmid Closterium peracerosum-strigosum-littorale complex, which is the closest unicellular sister to land plants, is the best characterized of the charophycean green algae with respect to the process of sexual reproduction. To elucidate the molecular mechanism of intercellular communication during sexual reproduction, we created a normalized cDNA library from mixed cells of the sexual and the vegetative phases and generated a cDNA microarray. In total, 3,236 expressed sequence tags, which were classified into 1,615 nonredundant groups, were generated for cDNA microarray construction. Candidate genes for key factors involved in fertilization, such as those that encode putative receptor-like protein kinase, leucine-rich-repeat receptor-like protein, and sex pheromone homologs, were up-regulated during sexual reproduction and/or by the addition of the purified sex pheromones, and the expression patterns of these genes were confirmed by quantitative real-time polymerase chain reaction analysis. This first transcriptome profile of Closterium will provide critical clues as to the mechanism and evolution of intercellular communication between the egg and sperm cells of land plants.
Structural Investigation of Disordered Stress Proteins. Comparison of Full-Length Dehydrins with Isolated Peptides of Their Conserved Segments
Authors: Mouillon Jean-Marie , Gustafsson Petter , Harryson Pia 
Published: March 2006

Abstract
Dehydrins constitute a class of intrinsically disordered proteins that are expressed under conditions of water-related stress. Characteristic of the dehydrins are some highly conserved stretches of seven to 17 residues that are repetitively scattered in their sequences, the K-, S-, Y-, and Lys-rich segments. In this study, we investigate the putative role of these segments in promoting structure. The analysis is based on comparative analysis of four full-length dehydrins from Arabidopsis (Arabidopsis thaliana; Cor47, Lti29, Lti30, and Rab18) and isolated peptide mimics of the K-, Y-, and Lys-rich segments. In physiological buffer, the circular dichroism spectra of the full-length dehydrins reveal overall disordered structures with a variable content of poly-Pro helices, a type of elongated secondary structure relying on bridging water molecules. Similar disordered structures are observed for the isolated peptides of the conserved segments. Interestingly, neither the full-length dehydrins nor their conserved segments are able to adopt specific structure in response to altered temperature, one of the factors that regulate their expression in vivo. There is also no structural response to the addition of metal ions, increased protein concentration, or the protein-stabilizing salt Na2SO4. Taken together, these observations indicate that the dehydrins are not in equilibrium with high-energy folded structures. The result suggests that the dehydrins are highly evolved proteins, selected to maintain high configurational flexibility and to resist unspecific collapse and aggregation. The role of the conserved segments is thus not to promote tertiary structure, but to exert their biological function more locally upon interaction with specific biological targets, for example, by acting as beads on a string for specific recognition, interaction with membranes, or intermolecular scaffolding. In this perspective, it is notable that the Lys-rich segment in Cor47 and Lti29 shows sequence similarity with the animal chaperone HSP90.
Discrepancies between prescribed daily doses and WHO defined daily doses of antibacterials at a university hospital
Authors: Muller Arno , Monnet Dominique L. , Talon Daniel , Hénon Thierry , Bertrand Xavier 
Published: March 2006

Aims The defined daily doses (DDD) defined by the WHO are widely used as an indicator to measure antibiotic use in the hospital setting. However, discrepancies exist between countries in terms of antibiotic dosage. The aim of the present study was to compare, for each antibacterial agent available at our university hospital, the prescribed daily doses (PDD) with the DDD.Methods Data were extracted from the pharmacy computer system. Antibiotic use was expressed in DDD per 1000 patient days. We also calculated the ratio of number of DDD : number of treatment‐days and estimated the average PDD for each antibiotic and route of administration.Results The average PDD did not correspond to the DDD for many classes of antibiotics. If fluoroquinolones and cephalosporins were prescribed at a dosage close to the DDD, other antimicrobial classes such as penicillins, aminoglycosides or macrolides were not. Overall, the number of DDD overestimated the number of treatment days by 40%. For the most consumed antibiotic at our hospital, i.e. oral amoxicillin‐clavulanic acid, the PDD was three times the DDD.Conclusions Our study shows that, except for the fluoroquinolones and the cephalosporins, the number of DDD did not correctly reflect the number of antibiotic treatment days at our hospital. This does not invalidate the systematic approach of the WHO and hospitals should use the DDDs to make national and international comparisons of their antibiotic use. However, each hospital should define and validate its own indicators to describe the local exposures to antibiotics and to study the relationship with resistance.
Sublytic complement C5b-9 complexes induce thrombospondin-1 production in rat glomerular mesangial cells via PI3-k/Akt: association with activation of latent transforming growth factor-β1
Authors: Gao L , Qiu W , Wang Y , Xu W , Xu J , Tong J 
Published: March 2006

SummaryMesangial cell proliferation is a common cellular response to a variety of different types of glomerular injury. Complement C5b-9 is a prime candidate to mediate mesangial cell proliferation, especially sublytic C5b-9, which can induce the production of multiple inflammatory factors and cytokines. Transforming growth factor (TGF)-β1 plays a major role in the accumulation of extracellular matrix (ECM), while thrombospondin (TSP)-1 has been identified as an activator of latent TGF-β1 in an in vitro system. Using rat glomerular mesangial cells (GMCs) as a model system, we assessed the effect of sublytic C5b-9 on the expression of TSP-1 and TGF-β1 and explored the relevant pathway of signal transduction. First, we ensured the concentrations of anti-Thy1 antibody and complement, which were regarded as a sublytic C5b-9 dose, and examined whether the sublytic C5b-9 induced expression of TSP-1 in rat GMCs which, in turn, activated latent TGF-β1 by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Then, we investigated the role of the PI3-k/Akt pathway in sublytic C5b-9-induced TSP-1 production in rat GMCs by Western blot analysis. The addition of sublytic C5b-9 (5% anti-Thy1 antibody and 4% normal serum) to rat GMCs induced activation of latent TGF-β1 via TSP-1. The addition of sublytic C5b-9 apparently increased the protein of Akt phosphorylation, whereas PI3-k inhibitor LY294002 could clearly reduce the increase of TSP-1 induced by sublytic C5b-9. These results indicate that TSP-1 is an activator of latent TGF-β1 in sublytic C5b-9-induced rat GMCs; furthermore, the PI3-k/Akt signal transduction pathway may play a key role in sublytic C5b-9-induced TSP-1 production.
The dependence of clustering on galaxy properties
Authors: Li Cheng , Kauffmann Guinevere , Jing Y. P. , White Simon D. M. , Börner Gerhard , Cheng F. Z. 
Published: March 2006

Abstract
We use a sample of ∼200 000 galaxies drawn from the Sloan Digital Sky Survey (SDSS) with 0.01 &lt; z &lt; 0.3 and −23 &lt; M  0.1r &lt; −16 to study how clustering depends on properties such as stellar mass (M*), colour (g−r), 4000-Å break strength (D4000), concentration index (C), and stellar surface mass density (μ*). Our measurements of wp(rp) as a function of the r-band luminosity are in excellent agreement with the previous two-degree Field Galaxy Redshift Survey and SDSS analyses. We compute wp(rp) as a function of stellar mass and we find that more-massive galaxies cluster more strongly than less-massive galaxies, with the difference increasing above the characteristic stellar mass M* of the Schechter mass function. We then divide our sample according to colour, 4000-Å break strength, concentration and surface density. As expected, galaxies with redder colours, larger 4000-Å break strengths, higher concentrations and larger surface mass densities cluster more strongly. The clustering differences are largest on small scales and for low-mass galaxies. At fixed stellar mass, the dependences of clustering on colour and 4000-Å break strength are similar. Different results are obtained when galaxies are split by concentration or surface density. The dependence of wp(rp) on g−r and D4000 extends out to physical scales that are significantly larger than those of individual dark matter haloes (&gt;5 h−1 Mpc). This large-scale clustering dependence is not seen for the parameters C or μ*. On small scales (&lt;1 h−1 Mpc), the amplitude of the correlation function is constant for ‘young’ galaxies with 1.1 &lt; D4000 &lt; 1.5 and a steeply rising function of age for ‘older’ galaxies with D4000 &gt; 1.5. In contrast, the dependence of the amplitude of wp(rp) on concentration on scales less than 1 h−1 Mpc is strongest for disc-dominated galaxies with C &lt; 2.6. This demonstrates that different processes are required to explain environmental trends in the structure and in the star formation history of galaxies.
Effects of Genotypes and Plant Density on Yield, Yield Components and Photosynthesis in Bt Transgenic Cotton
Authors: Dong H. Z. , Li W. J. , Tang W. , Li Z. H. , Zhang D. M. 
Published: March 2006

AbstractBt (Bacillus thuringiensis) transgenic cotton (Gossypium hirsutumL.), including the introduced, indigenous Chinese non‐hybrid and hybrid cotton, is spreading very rapidly in China. Agronomic and photosynthetic performance as well as the optimum plant density for planting Bt cotton may vary with genotypes. With three types of commercial Bt cotton varieties, two field experiments were conducted to study yield performance and leaf photosynthetic rate (Pn) during 2000 and 2001, and yield interaction between variety and plant density during 2001 and 2002 in Yellow River region in northern China. The first experiment showed that the indigenous Chinese Bt cotton significantly differed from the introduced Bt cotton (IBtC) in plant growth and yield components. As a result of manipulation of boll numbers, boll weight and lint percentage, there was no significant difference in lint yield between Chinese non‐hybrid Bt cotton (CBtC) and the IBtC, but two Chinese hybrid Bt cotton (HBtC) varieties exhibited significantly higher lint yield than all other varieties in either 2000 or 2001. Hybrid cotton SCRC15 showed a one‐peak curvilinear change in diurnal course of Pn throughout the growing season, while non‐hybrid cotton 33B and SCRC16 exhibited severe mid‐day depression in Pn in squaring, flowering or boll‐setting stage. The second experiment showed that the main effect of plant population on lint yield was not significant, and yield difference among all treatments was derived from varieties and the interaction between plant density and variety. The optimal plant densities in terms of lint yield for the introduced, indigenous CBtC and HBtC genotypes were 6.0, 4.5 and 3.0 plants m−2respectively.
Constructing families and kinship through donor insemination
Authors: Hargreaves Katrina 
Published: March 2006

AbstractThis paper presents some central findings of an exploratory qualitative study of New Zealand families with children conceived by donor insemination (DI). Drawing on social anthropological and sociological theorising about kinship and contemporary Western families, the paper explores the ways in which parents and their kin actively construct parent‐child relationships and kin connections through the notions of biological and social ties, nature and nurture. The paper discusses three major themes emerging from the data: the social construction of the ‘natural facts’ of procreation, physical resemblance, and the construction of families through choice, not biology. Whilst the primacy of biological or genetic connection is a powerful cultural theme, particularly evident in the ambiguities and uncertainties for social fathers and their kin, these families also deconstruct this notion. Drawing simultaneously on the power of social and biological connection, using biology as a metaphor for social relations, or by privileging social ties and the formation of families through choice, over time these families strategically establish themselves as the sole parents and kin of their children conceived by DI.
The politics of end‐of‐life decision‐making: computerised decision‐support tools, physicians’ jurisdiction and morality
Authors: Jennings Beth 
Published: March 2006

AbstractWith the increasing corporate and governmental rationalisation of medical care, the mandate of efficiency has caused many to fear that concern for the individual patient will be replaced with impersonal, rule‐governed allocation of medical resources. Largely ignored is the role of moral principles in medical decision‐making. This analysis comes from an ethnographic study conducted from 1999–2001 in three US Intensive Care Units, two of which were using the computerised decision‐support tool, APACHE III (Acute Physiological and Chronic Health Evaluation III), which notably predicts the probability that a patient will die. It was found that the use of APACHE presents a paradox regarding concern for the individual patient. To maintain jurisdiction over the care of patients, physicians share the data with the payers and regulators of care to prove they are using resources effectively and efficiently, yet they use the system in conjunction with moral principles to justify treating each patient as unique. Thus, concern for the individual patient is not lessened with the use of this system. However, physicians do not share the data with patients or surrogate decision‐makers because they fear they will be viewed as more interested in profits than patients.
Early admission to stroke unit influences clinical outcome
Authors: Silvestrelli G. , Parnetti L. , Paciaroni M. , Caso V. , Corea F. , Vitali R. , Capocchi G. , Agnelli G. 
Published: March 2006

An improvement in patient arrival time to stroke unit (SU) is recommended, since earlier stroke management seems to improve ‘per se’ functional outcome. The objective of this study was to determine if early admission influences the outcome, reduces disability and mortality at discharge and three months later independent of tlirombolytic treatment.Consecutive acute stroke patients admitted to SU between January 1st 2000 and December 31st 2003 were studied in order to analyze the actual role of acute management independent specific pharmacological treatment, we excluded subjects who underwent rt‐PA.35.8% of 2,041 consecutive stroke patients arrived within 3 hours; 62.4% within 6 hours; 37.6% arrived later. Approximately 80% of the <6 hour patients presented a National Institutes of Health Stroke Scale (NIHSS) >4 and modified Rankin Scale (mRS) score >2 in comparison with 60% of the >6 hour patients. In hospital (8.7%) and three‐month (7.3%) mortality in <3 hour patients were not significantly different from what observed in >3 hour patients (6.8% and 6.1% respectively) while functional outcome after three months was better in <3 hour patients (NIHSS: 34.6 vs 15.2; mRS: 32.9% vs 16.8%). Old age, history of TIA, cardioembolic etiology, severity of neurological deficit and hemorrhagic stroke type all led to earlier arrival time. Admission within 3 hours ‘per se’ improves outcome and reduced disability at three months.
Forage preferences in two species of prairie dog (Cynomys parvidens and Cynomus ludovicianus): implications for hibernation and facultative heterothermy
Authors: Lehmer E. M. , Biggins D. E. , Antolin M. F. 
Published: March 2006

AbstractSeveral laboratory studies have shown that the ingestion of dietary linoleic (18:2 ω6) acid before winter can promote deep and continuous torpor, whereas excess consumption of α‐linolenic acid (18:3 ω3) can interfere with an animal's ability to reach and maintain low body temperatures during torpor. As mammalian heterotherms obtain linoleic and α‐linolenic acid strictly from the diet, diet selection has been proposed as a mechanism that allows hibernators to ingest levels of linoleic and α‐linolenic acid that promote favorable torpor patterns. Here diet, dietary nutrient content and patterns of forage preference of a representative hibernator, the Utah prairie dog Cynomys parvidens, and a facultative heterotherm, the black‐tailed prairie dog Cynomys ludovicianus, were examined under natural field conditions. Diets of black‐tailed (BTPD) and Utah prairie dogs (UTPD) differed across seasons (BTPD F26,108=9.59, P<0.01; UTPD F38,80=3.25, P<0.01) and elevations (BTPD F26,108=20.15, P<0.01; UTPD F38,80=20.51, P<0.01), and forage preference indices indicate that neither species randomly selected plant species relative to their abundance on colonies in any season. Black‐tailed prairie dogs did not consume or avoid consumption of plant species based on levels of total lipids, linoleic acid, α‐linolenic acid or nitrogen. Considering only the plants consumed, black‐tailed prairie dogs appeared to prefer plants with low levels of α‐linolenic acid (F1,19=5.81, P=0.03), but there were no detectable relationships between preference and other nutrients. Utah prairie dogs consumed plants higher in α‐linolenic acid (t=1.98, P=0.05) and avoided plants high in linoleic acid (t=−2.02, P=0.04), but consumption‐avoidance decisions did not appear to be related to nitrogen or total lipids. Of the plants consumed, Utah prairie dogs again preferred plants high in α‐linolenic acid (F1,17=4.62, P=0.05). Levels of linoleic and α‐linolenic acid were positively correlated in plants consumed by prairie dogs (BTPD Pearson r=0.66, P<0.01; UTPD Pearson r=0.79, P<0.01), reducing the opportunity for independent selection of either lipid.