bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon dynamics in successional and afforested spruce stands in Thuringia and the Alps
Authors: THUILLE ANGELIKA , SCHULZE ERNST‐DETLEF 
Published: December 2005

AbstractChanges in the carbon stocks of stem biomass, organic layers and the upper 50 cm of the mineral soil during succession and afforestation of spruce (Picea abies) on former grassland were examined along six chronosequences in Thuringia and the Alps. Three chronosequences were established on calcareous and three on acidic bedrocks. Stand elevation and mean annual precipitation of the chronosequences were different. Maximum stand age was 93 years on acid and 112 years on calcareous bedrocks. Stem biomass increased with stand age and reached values of 250–400 t C ha−1 in the oldest successional stands. On acidic bedrocks, the organic layers accumulated linearly during forest succession at a rate of 0.34 t C ha−1 yr−1. On calcareous bedrocks, a maximum carbon stock in the humus layers was reached at an age of 60 years.Total carbon stocks in stem biomass, organic layers and the mineral soil increased during forest development from 75 t C ha−1 in the meadows to 350 t C ha−1 in the oldest successional forest stands (2.75 t C ha−1 yr−1). Carbon sequestration occurred in stem biomass and in the organic layers (0.34 t C ha−1 yr−1on acid bedrock), while mineral soil carbon stocks declined.Mineral soil carbon stocks were larger in areas with higher precipitation. During forest succession, mineral soil carbon stocks of the upper 50 cm decreased until they reached approximately 80% of the meadow level and increased slightly thereafter. Carbon dynamics in soil layers were examined by a process model. Results showed that sustained input of meadow fine roots is the factor, which most likely reduces carbon losses in the upper 10 cm. Carbon losses in 10–20 cm depth were lower on acidic than on calcareous bedrocks. In this depth, continuous dissolved organic carbon inputs and low soil respiration rates could promote carbon sequestration following initial carbon loss.At least 80 years are necessary to regain former stock levels in the mineral soil. Despite the comparatively larger amount of carbon stored in the regrowing vegetation, afforestation projects under the Kyoto protocol should also aim at the preservation or increase of carbon in the mineral soil regarding its greater stability of compared with stocks in biomass and humus layers. If grassland afforestation is planned, suitable management options and a sufficient rotation length should be chosen to achieve these objectives. Maintenance of grass cover reduces the initial loss.
Contrasting stream water NO3− and Ca2+ in two nearly adjacent catchments: the role of soil Ca and forest vegetation
Authors: CHRISTOPHER SHEILA F. , PAGE BLAIR D. , CAMPBELL JOHN L. , MITCHELL MYRON J. 
Published: December 2005

AbstractTwo nearly adjacent subcatchments, located in the Adirondack Mountains of New York State, US, with similar atmospheric inputs of N (0.6 kmol ha−1 yr−1), but markedly different stream water solute concentrations, provided a unique opportunity to evaluate the mechanisms causing this variation. Subcatchment 14 (S14) had much greater stream water Ca2+ and NO3− concentrations (851 and 73 μmolc L−1, respectively) than Subcatchment 15 (S15) (427 and 26 μmolc L−1, respectively). To elucidate factors affecting the variability in stream water concentrations, soil and forest floor samples from each subcatchment were analyzed for total elemental cations and extractable N species. Mineral soil samples were also analyzed for exchangeable cations. Tree species composition was characterized in each subcatchment and potential differences in land use history and hydrology were also assessed. Compared with S15, soils in S14 had significantly higher total elemental Ca2+ in the forest floor (380 vs. 84 μmol g−1), Bs horizon (e.g. 1361 vs. 576 μmol g−1) and C horizon (1340 vs. 717 μmol g−1). Exchangeable Ca2+ was also significantly higher in the mineral soil (64 μmol g−1 in S14 vs. 8 μmol g−1 in S15). Extractable NO3− was higher in S14 compared with S15 in both the forest floor (0.1 vs. 0.01 μmol g−1) and Bs horizon (0.2 vs. 0.07 μmol g−1) while extractable NH4+ was higher in S14 vs. S15 in the forest floor (7 vs. 5 μmol g−1). The total basal area of ‘base‐rich indicator’ tree species (e.g. sugar maple, American basswood, eastern hophornbeam) was significantly greater in S14 compared with S15, which had species characteristic of sites with lower base concentrations (e.g. American beech and eastern white pine). The disparity in stream water Ca2+ and NO3−, concentrations and fluxes between S14 and S15 were explained by differences in tree species composition and soil properties rather than differences in land use or hydrology. The marked difference in soil Ca2+ concentrations in S14 vs. S15 corresponded to the higher stream water Ca2+ and the larger contribution of base‐rich tree species to the overstory biomass in S14. Soil under such species is associated with higher net mineralization and nitrification and likely contributed to the higher NO3− concentrations in the drainage waters of S14 vs. S15. Studies investigating differences in spatial and temporal patterns of the effects of chronic N deposition on surface water chemistry need to account for changes in tree species composition and how vegetation composition is influenced by soil properties, as well as climatic and biotic changes.
Are Chilean coastal forests pre‐Pleistocene relicts? Evidence from foliar physiognomy, palaeoclimate, and phytogeography
Authors: Hinojosa Luis Felipe , Armesto Juan J. , Villagrán Carolina 
Published: December 2005

AbstractAim We ask whether contemporary forests of the Chilean Coastal Range can be considered to be direct and conservative descendants of pre‐Pleistocene palaeofloras that occurred in southern South America from the Palaeogene to early Neogene periods (65–10 Ma), maintaining foliar physiognomies that do not match their present‐day climate. We also identify the most likely ancestors of present‐day coastal forests.Location Coastal Range of south‐central Chile (33–40° S).Methods We compared leaf morphology between five representative modern floras from mid‐latitude forests of the Chilean Coastal Range, and 14 Palaeogene–early Neogene palaeofloras from southern South America. We also compared the composition of biogeographical elements (defined by the modern distribution of plant genera) between fossil and present‐day assemblages. Palaeoclimatic reconstructions were based on a canonical correspondence analysis between leaf morphology of modern assemblages and eight climatic variables, and tested by a Monte Carlo permutation test. We compared the relative positions of fossil and modern floras on the environmental vector space defined by Canoco, and on axes defined by instrumental and estimated temperature and precipitation data.Results According to foliar characters, Palaeogene palaeofloras were strikingly divergent from present‐day coastal forests of central Chile. In contrast, two extant forest floras of the Chilean Coastal Range have a foliar morphology that resembles some late Eocene to early Miocene mixed palaeofloras, at least 23 Myr older. These two modern sites are representative of an area of the Coastal Range (36–37° S) that has been highlighted for its relictual character. None of the 14 fossil floras corresponded exactly to the modern composition of phytogeographic elements, although correspondence analyses showed that mixed and Neogene subtropical fossil floras were compositionally close to the extant woody floras of coastal forests in central Chile.Main Conclusions Contemporary forests of the Chilean Coastal Range exhibit strong physiognomic resemblance to the mixed palaeofloras from 33°57′ to 41°15′ S, which may be the closest ancestor of the deciduous and endemic‐rich Maulino forest, presently restricted to coastal areas between 36° and 38° S. In turn, the Neogene subtropical palaeoflora that occurred in the Proto‐Andean foothills of central Chile is the likely predecessor of Mediterranean‐type sclerophyllous forests of central Chile (32–33° S). Despite foliar resemblance between the late pre‐Pleistocene and extant forest floras, our palaeoclimatic reconstructions suggest that modern assemblages exist under climatic conditions that do not match their foliar physiognomy. We attribute this convergence in foliar morphology to the ‘evolutionary inertia’ of surviving lineages, favoured by the buffering effect of the coastal environment on climatic variability.
The Suppressor of Cytokine Signalling 3, SOCS3, may be One Critical Modulator of Seasonal Body Weight Changes in the Siberian Hamster, Phodopus sungorus
Authors: Tups A. , Barrett P. , Ross A. W. , Morgan P. J. , Klingenspor M. , Mercer J. G. 
Published: December 2005

AbstractThe Siberian hamster, Phodopus sungorus, exhibits a remarkable cycle of body weight, reproduction and leptin sensitivity in response to a seasonal change in photoperiod. In the present study, we investigated the hypothesis that the suppressor of cytokine signalling 3 (SOCS3) plays a critical role in the regulation of the seasonal body weight cycle. We analysed arcuate nucleus SOCS3 gene expression in short day length (SD; 8 : 16 h light/dark) acclimated Siberian hamsters that were transferred back to long day length (LD; 16 : 8 h light/dark) and in hamsters that spontaneously became photorefractory to SD induced by prolonged exposure. SD acclimated hamsters that were transferred back to LD for 1, 2, 3, 4 or 6 weeks, increased arcuate nucleus SOCS3 gene expression to the LD level within 2 weeks, and maintained this higher level thereafter. The early increase of SOCS3 gene expression preceded the LD‐induced rise in body weight by approximately 3 weeks. Hamsters kept in SD for an extended period (25 weeks), began to become refractory to SD and to increase body weight. By this time, there was no difference in level of SOCS3 gene expression between LD and SD photoperiods, although body weight was still suppressed in SD hamsters. Finally, we addressed whether SOCS3 gene expression is related to SD‐induced gonadal regression or to body weight decrease by comparing Siberian hamsters with Syrian hamsters. The latter exhibited substantial SD‐induced gonadal regression but only limited seasonal changes in body weight. Acclimation to either LD or SD for 14 weeks had no effect on SOCS3 gene expression. This implies that arcuate nucleus SOCS3 gene expression is unlikely to be related to seasonal cycles in reproductive activity. Taken together, the findings further strengthen our hypothesis that SOCS3 may be one molecular trigger of seasonal cycles in body weight.
Targets of the master regulator of biofilm formation in Bacillus subtilis
Authors: Chu Frances , Kearns Daniel B. , Branda Steven S. , Kolter Roberto , Losick Richard 
Published: December 2005

SummaryWild strains of the spore‐forming bacterium Bacillus subtilis are capable of forming architecturally complex communities of cells. The formation of these biofilms is mediated in part by the 15‐gene exopolysaccharide operon, epsA‐O, which is under the direct negative control of the SinR repressor. We report the identification of an additional operon, yqxM‐sipW‐tasA, that is required for biofilm formation and is under the direct negative control of SinR. We now show that all three members of the operon are required for the formation of robust biofilms and that SinR is a potent repressor of the operon that acts by binding to multiple sites in the promoter region. Genome‐wide analysis of SinR‐controlled transcription indicates that the epsA‐O and yqxM‐sipW‐tasA operons constitute many of the most strongly controlled genes in the SinR regulon. These findings reinforce the view that SinR is a master regulator for biofilm formation and further suggest that a principal biological function of SinR is to govern the assembly of complex multicellular communities.
Stromatolite reef crusts, Early Cretaceous, Spain: bacterial origin of in situ‐precipitated peloid microspar?
Authors: RIDING ROBERT , TOMÁS SARA 
Published: December 2005

AbstractPeloidal crusts are significant components of Early Cretaceous (Aptian) reef carbonates in eastern Spain. The crusts form steep‐sided laminated deposits on coral and other skeletal surfaces. Their microfabric consists almost entirely of silt‐sized peloids in fenestral microspar matrix. This microfabric contrasts with more poorly sorted and generally finer grained detrital wackestone–packstone fabrics of the adjacent reef matrix. Scarcity of incorporated grains indicates that the crusts did not trap many particles. It is proposed that the crusts are stromatolites and that peloids and inter‐peloid space were created concurrently by bacterial degradation of organic matter. As they developed, inter‐peloid voids were protected from infiltration of extraneous sediment by the organic‐rich exterior surface of the stromatolite. Even spacing of the peloids within microspar may reflect self‐organization of bacterial colonies in the decaying organic matrix. Compressed and partly amalgamated peloids marginal to burrows in the stromatolites suggest that the peloid fabrics were initially only partially lithified. The grainstone‐like peloid fabric is therefore interpreted as having formed in situ by very early diagenetic processes driven by heterotrophic bacteria.
Localization of a flavonoid biosynthetic polyphenol oxidase in vacuoles
Authors: Ono Eiichiro , Hatayama Masayoshi , Isono Yuri , Sato Takuya , Watanabe Ryoko , Yonekura‐Sakakibara Keiko , Fukuchi‐Mizutani Masako , Tanaka Yoshikazu , Kusumi Takaaki , Nishino Tokuzo , Nakayama Toru 
Published: December 2005

SummaryAureusidin synthase, a polyphenol oxidase (PPO), specifically catalyzes the oxidative formation of aurones from chalcones, which are plant flavonoids, and is responsible for the yellow coloration of snapdragon (Antirrhinum majus) flowers. All known PPOs have been found to be localized in plastids, whereas flavonoid biosynthesis is thought to take place in the cytoplasm [or on the cytoplasmic surface of the endoplasmic reticulum (ER)]. However, the primary structural characteristics of aureusidin synthase and some of its molecular properties argue against localization of the enzyme in plastids and the cytoplasm. In this study, the subcellular localization of the enzyme in petal cells of the yellow snapdragon was investigated. Sucrose‐density gradient and differential centrifugation analyses suggested that the enzyme (the 39‐kDa mature form) is not located in plastids or on the ER. Transient assays using a green fluorescent protein (GFP) chimera fused with the putative propeptide of the PPO precursor suggested that the enzyme was localized within the vacuole lumen. We also found that the necessary information for vacuolar targeting of the PPO was encoded within the 53‐residue N‐terminal sequence (NTPP), but not in the C‐terminal sequence of the precursor. NTPP‐mediated ER‐to‐Golgi trafficking to vacuoles was confirmed by means of the co‐expression of an NTPP‐GFP chimera with a dominant negative mutant of the Arabidopsis GTPase Sar1 or with a monomeric red fluorescent protein (mRFP)‐fused Golgi marker (an H+‐translocating inorganic pyrophosphatase of Arabidopsis). We identified a sequence‐specific vacuolar sorting determinant in the NTPP of the precursor. We have demonstrated the biosynthesis of a flavonoid skeleton in vacuoles. The findings of this metabolic compartmentation may provide a strategy for overcoming the biochemical instability of the precursor chalcones in the cytoplasm, thus leading to the efficient accumulation of aurones in the flower.
The pherophorins: common, versatile building blocks in the evolution of extracellular matrix architecture in Volvocales
Authors: Hallmann Armin 
Published: December 2005

SummaryGreen algae of the order Volvocales provide an unrivalled opportunity for exploring the transition from unicellularity to multicellularity. They range from unicells, like Chlamydomonas, through homocytic colonial forms with increasing cooperation of individual cells, like Gonium or Pandorina, to heterocytic multicellular forms with different cell types and a complete division of labour, like Volvox. A fundamental requirement for the evolution of multicellularity is the development of a complex, multifunctional extracellular matrix (ECM). The ECM has many functions, which can change under developmental control or as a result of environmental factors. Here molecular data from 15 novel proteins are presented. These proteins have been identified in Chlamydomonas reinhardtii, Gonium pectorale, Pandorina morum and Volvox carteri, and all belong to a single protein family, the pherophorins. Pherophorin‐V1 is shown to be a glycoprotein localized to the ‘cellular zone’ of the V. carteri ECM. Pherophorin‐V1 and ‐V2 mRNAs are strongly induced not only by the sex inducer, which triggers sexual development at extremely low concentrations, but also by mechanical wounding. Like the extensins of higher plants, which are also developmentally controlled or sometimes inducible by wounding, the pherophorins contain a (hydroxy‐)proline‐rich (HR) rod‐like domain and are abundant within the extracellular compartment. In contrast to most extensins, pherophorins have additional globular A and B domains on both ends of the HR domains. Therefore pherophorins most closely resemble a particular class of higher plant extensin, the solanaceous lectins (e.g. potato lectin), suggesting multivalent carbohydrate‐binding functions are present within the A and B domains and are responsible for cross‐linking. Our results suggest that pherophorins are used as the building blocks for the extracellular scaffold throughout the Volvocales, with the characteristic mesh sizes in different ECM structures being a result of the highly diverse extensions of the HR domains. Pherophorins have therefore been a versatile element during the evolution of ECM architecture in these green algae.
Novel polymorphisms in exons 6 and 7 of A/B alleles detected by polymerase chain reaction–single strand conformation polymorphism
Authors: Chen Y. J. , Chen P. S. , Liu H. M. , Lyou J. Y. , Hu H. Y. , Lin J. S. , Tzeng C. H. 
Published: December 2005

Background and Objectives  The ABO blood group system is the most important blood group system in transfusion medicine. In addition to the major A, B and O alleles, many rare alleles have been defined. Polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and analysis by PCR sequence specific primers (SSP) are commonly conducted for genotyping but have the limitation of being unable to detect unknown substitution(s) in amplified DNA fragments, whereas PCR–single strand conformation polymorphism (SSCP) can be used for both.Materials and Methods  Three‐hundred unrelated blood donors of the AB phenotype were enrolled. Four pairs of primers were designed to constitute two sets of multiplex PCRs: this amplifies four fragments spanning the entire exon 6 and its immediate flanking regions, nucleotides 432–1065, as well as the 3′ untranslated region of exon 7 of the ABO gene. The SSCP electrophoresis was carried out on a 12·5% polyacrylamide gel in a GenePhor electrophoresis unit. For those with unexpected banding patterns, SSCP analyses were performed in duplicate and samples were cloned and sequenced for exons 6 and 7.Results  Seven samples were noted to have six variant alleles, of which five have not been previously reported in the literature. Of these five novel variants, four were derived from the B allele, while the other derived from the A allele.Conclusions  By using PCR–SSCP, five novel A/B alleles were found.
Cuff filling volumes and pressures in pediatric laryngeal mask airways
Authors: MAINO PAULO , DULLENKOPF ALEXANDER , KELLER CHRISTIAN , BERNET‐BUETTIKER VERA , WEISS MARKUS 
Published: December 2005

SummaryBackground : Hyperinflation of LMA cuffs carries the risk of airway morbidity by exerting pressure on laryngeal and pharyngeal structures. Cuff hyperinflation in LMAs can result from nitrous oxide diffusion into the LMA cuff and from deliberate manual cuff inflation.Methods : In an in vitro set up, maximum recommended cuff filling volumes for size 1, 1.5, 2, 2.5, 3 disposable LMAs from different manufacturers [SoftSeal LMA (Portex); Unique LMA (Intavent); Marshall LAD, LaryngoSeal (Tyco)] and reusable Classic and ProSeal LMAs (Intavent) were inflated into completely emptied LMA‐cuffs and into LMA‐cuffs at resting volume. Cuff pressures were measured using a cuff manometer. Experiments were performed eight times using two exemplars of each brand/size.Results : Maximum recommended cuff filling volumes for pediatric LMAs resulted in hyperinflation (cuff pressure >60 cmH2O) in almost all LMAs, starting with emptied cuff. Starting from resting cuff volume, the maximum recommended inflation volume resulted in cuff pressures of >120 cmH2O in all LMAs and sizes except in the ProSeal size 3 (101 ± 1 cmH2O).Conclusions : Since the volume of air which is effectively required depends on several factors and varies between patients, the cuffs should be inflated only with the minimum volume of air required to form an effective seal with the respiratory and gastrointestinal tracts and the cuff pressure should be controlled.
Spinal anesthesia in children with isobaric local anesthetics: Report on 307 patients under 13 years of age
Authors: IMBELLONI LUIZ EDUARDO , VIEIRA ENEIDA MARIA , SPERNI FRANCINE , GUIZELLINI ROSA HELENA , TOLENTINO ANA PAULA 
Published: December 2005

SummaryBackground:  Spinal anesthesia in expert hands is an excellent method for children for appropriate surgery. The aim of this study was to evaluate the effects of spinal anesthesia with isobaric solutions in 307 consecutive cases from May 2001 to August 2002.Methods:  In this prospective study, 307 patients from 0 to 12 years of age were scheduled for spinal anesthesia with enantiomeric mixture of bupivacaine (S75 : 25R) 0.5% or racemic bupivacaine 0.5% or lidocaine 2% without glucose, for surgery compatible with the technique. The following were assessed: latency of analgesia, motor block, maximum length and duration of sensory blockade, cardiovascular changes, incidence of headache or transient neurological symptoms and cost.Results:  The onset of sensory block occurred at 2.36 ± 0.95 min. Duration of surgery was 1.29 ± 0.83 h and the duration of stay in the postanesthesia care unit was 39.72 ± 26.84 min. The highest level of analgesia ranged from T9 to T4 (mean T6). Onset of motor block was <2 min in all children and each had a modified Bromage score of 3 at the beginning of the surgery. At the end of the surgery 9% had score 3, 16%, score 2, 46%, score 1 and 29%, zero. Seventy five percent of all patients recovered from motor block 1 or zero at the end of the surgery. Patients older than 1  year were able to walk in 3.79 ± 0.73 h. There was no case of oxygen desaturation. Hypotension and bradycardia occurred in one patient. Spinal anesthesia failed in five patients. Three children developed postdural puncture headache (PDPH), the youngest aged 2 years. PDPH in all three was mild or moderate. Transient radicular symptoms were not observed. The final cost of the spinal anesthesia was R$49.00 compared with a mean cost of general anesthesia of R$105.00.Conclusions:  Spinal anesthesia continues to gain acceptance as an alternative to general anesthesia in children. There has also been an increased use of spinal anesthesia for other surgical procedures including lower extremity orthopedic procedures as well as specific surgery procedures above the umbilicus and in patients past the neonatal period. Spinal anesthesia in children is a special method suitable for use only by anesthesiologists, expert in administering spinal anesthesia for adults. It was 54% less than the cost of general anesthesia.