bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social capital, social currency, and portable assets: The impact of residential mobility on exchanges of social support
Authors: Magdol Lynn , Bessel Diane R. 
Published: December 2004

AbstractWe examined the impact of physical distance on mobilized social capital resources. Social capital theory assumes that physical proximity and residential stability are prerequisites to social capital assets. We tested these assumptions using a two‐wave panel sample from the National Survey of Families and Households consisting of respondents who experienced residential moves between waves. We found local duration since the last move to be beneficial for involvement in social exchanges. Mobility distance was related to deficits for some exchanges but not for others. Rather than a simple dichotomy between material resources that require proximity and nonmaterial resources that do not, we found that emotional and financial support are not affected by mobility distance but that tangible favors and companionship are affected negatively. Although kin exchanges are negatively affected by distant and recent mobility, nonkin exchanges are more extensive for respondents whose kin ties are more distant, suggesting a process of substitutability whereby nonkin may replace kin in the network. Our findings confirm the assumption of social capital theory about distance. They also point to the importance of adding the dimension of distance to exchange theory. Our study demonstrates that place has not lost all relevance in our highly technological postmodern society.
Photosynthetic parameters of birch (Betula pendula Roth) leaves growing in normal and in CO2‐ and O3‐ enriched atmospheres
Authors: EICHELMANN H. , OJA V. , RASULOV B. , PADU E. , BICHELE I. , PETTAI H. , MÖLS T. , KASPAROVA I. , VAPAAVUORI E. , LAISK A. 
Published: December 2004

ABSTRACTTwo silver birch (Betula pendula Roth) clones K1659 and V5952 were grown in open‐top chambers over 3 years (age 7–9 years). The treatments were increased CO2 concentration (+CO2, 72 Pa), increased O3 concentration (+O3, 2 × ambient O3 with seasonal AOT40 up to 28 p.p.m. h) and in combination (+CO2 + O3). Thirty‐seven photosynthetic parameters were measured in the laboratory immediately after excising leaves using a computer‐operated routine of gas exchange and optical measurements. In control leaves the photosynthetic parameters were close to the values widely used in a model (Farquhar, von Caemmerer and Berry, Planta 149, 78–90, 1980). The distribution of chlorophyll between photosystem II and photosystem I, intrinsic quantum yield of electron transport, uncoupled turnover rate of Cyt b6f, Rubisco specificity and Km (CO2) were not influenced by treatments. Net photosynthetic rate responded to +CO2 with a mean increase of 17% in both clones. Dry weight of leaves increased, whereas protein, especially Rubisco content and the related photosynthetic parameters decreased. Averaged over 3 years, eight and 17 mechanistically independent parameters were significantly influenced by the elevated CO2 in clones K1659 and V5952, respectively. The elevated O3 caused a significant decrease in the average photosynthetic rate of clone V5952, but not of clone K1659. The treatment caused changes in one parameter of clone K1659 and in 11 parameters of clone V5952. Results of the combined treatment indicated that +O3 had less effect in the presence of +CO2 than alone. Interestingly, changes in the same photosynthetic parameters were observed in chamberless grown trees of clone V5952 as under +O3 treatment in chambers, but this was not observed for clone K1659. These results suggest that during chronic fumigation, at concentrations below the threshold of visible leaf injuries, ozone influenced the photosynthetic parameters as a general stress factor, in a similar manner to weather conditions that were more stressful outside the chambers. According to this hypothesis, the sensitivity of a species or a clone to ozone is expected to depend on the growth conditions: the plant is less sensitive to ozone if the conditions are close to optimal and it is more sensitive to ozone under conditions of stress.
Monitoring system for the biocontrol agent Pichia anomala strain K using quantitative competitive PCR‐ELOSA
Authors: Pujol M. , De Clercq D. , Cognet S. , Lepoivre P. , Jijakli M. H. 
Published: December 2004

A quantitative‐competitive PCR (QC‐PCR) method with enzyme‐linked oligosorbent assay (ELOSA) was developed to monitor Pichia anomala strain K, a biocontrol agent against postharvest diseases on apples. The procedure involved: (i) extraction of strain K DNA; (ii) coamplification of a constant amount of the extracted DNA (containing a strain K DNA marker of 262 base pairs (bp) specifically amplified with SCAR primers K1 and K2) with an internal standard (IS) titration; and (iii) differential hybridization with two specific biotinylated probes either for the target or for the IS sequence on microplate. The IS sequence differed from the target by only a short internal region of 35 bp providing the differential detection between both sequences. Both target and IS sequences proved to be competitive in PCR as well as in sandwich hybridization. Two copies of the target sequence were detected in the strain K genome by means of enzymatic restriction and Southern blot analysis. Varying amounts of strain K cell suspension were quantified in the phosphate buffer used for recovering cells from the apple surface. An accurate estimate of the strain K population was obtained from 103 to 106 yeast cells per apple. The threshold of the method was found to be at 1000 colony‐forming units per apple, which was around 100 times more sensitive than the plating method for monitoring strain K.
Pentobarbital vs chloral hydrate for sedation of children undergoing MRI: efficacy and recovery characteristics
Authors: Malviya Shobha , Voepel‐Lewis Terri , Tait Alan R. , Reynolds Paul I. , Gujar Sachin K. , Gebarski Stephen S. , Petter Eldevik O. 
Published: December 2004

SummaryBackground : Chloral hydrate (CH) sedation for magnetic resonance imaging (MRI) is associated with significant failure rates, adverse events and delayed recovery. Pentobarbital (PB), reportedly produces successful sedation in 98% of children undergoing diagnostic imaging. This study compared the efficacy, adverse events and recovery characteristics of CH vs PB in children undergoing MRI.Methods : With Institutional Review Board approval and written consent, children were randomly assigned to receive intravenous (i.v.) PB (maximum 5 mg·kg−1 in incremental doses) or oral CH (75 mg·kg−1) prior to MRI. Sedation was augmented with 0.05 mg·kg−1 doses of i.v. midazolam (maximum 0.1 mg·kg−1) as necessary. Adverse effects, including hypoxaemia, failed sedation, paradoxical reactions and behavioural changes, the return of baseline activity, and parental satisfaction were documented. The quality of MRI scans was evaluated by a radiologist blinded to the sedation technique.Results : PB facilitated an earlier onset of sedation (P = 0.001), higher sedation scores (P = 0.01), and less need for supplemental midazolam compared with CH. Severe hypoxaemia occurred in two children (6%) in the PB group. Fourteen per cent of the PB group experienced a paradoxical reaction, 9% sedation failure and 11% major motion artefact, compared with 0% (P = 0.05), 3 and 2% (P = NS), respectively, in the CH group. CH and PB were both associated with a high incidence of motor imbalance, and agitation. However, children who received PB had a slower return to baseline activity (P = 0.04).Conclusions : Although PB facilitated a quicker sedation onset and reduced the requirement for supplemental sedation, it produced a higher incidence of paradoxical reaction and prolonged recovery with a similar failure rate compared with CH.
Facial nerve palsy: a complication following anaesthesia in a child with Treacher Collins syndrome
Authors: Duggan Michelle , Ames Warrick , Papsin Blake , Berdock Steven 
Published: December 2004

SummaryWe report a case of facial nerve palsy following anaesthesia in a child with Treacher Collins syndrome. Children in whom intubation is difficult may be at increased risk of this complication.
Genetic modification of photosynthesis with E. coli genes for trehalose synthesis
Authors: Pellny Till K. , Ghannoum Oula , Conroy Jann P. , Schluepmann Henriette , Smeekens Sjef , Andralojc John , Krause Klaus Peter , Goddijn Oscar , Paul Matthew J. 
Published: December 2004

SummaryImprovement in photosynthesis per unit leaf area has been difficult to alter by breeding or genetic modification. We report large changes in photosynthesis in Nicotiana tabacum transformed with E. coli genes for the trehalose pathway. Significantly, photosynthetic capacity (CO2 assimilation at varying light and CO2, and quantum yield of PSII electron transport) per unit leaf area and per leaf dry weight were increased in lines of N. tabacum transformed with the E. coli gene otsA, which encodes trehalose phosphate synthase. In contrast, transformation with otsB, which encodes trehalose phosphate phosphatase or Trec, encoding trehalose phosphate hydrolase, produced the opposite effect. Changes in CO2 assimilation per unit leaf area were closely related to the amount and activity of Rubisco, but not to the maximum activities of other Calvin cycle enzymes. Alterations in photosynthesis were associated with trehalose 6‐phosphate content rather than trehalose. When growth parameters were determined, a greater photosynthetic capacity did not translate into greater relative growth rate or biomass. This was because photosynthetic capacity was negatively related to leaf area and leaf area ratio. In contrast, relative growth rate and biomass were positively related to leaf area. These results demonstrate a novel means of modifying Rubisco content and photosynthesis, and the complexities of regulation of photosynthesis at the whole plant level, with potential benefits to biomass production through improved leaf area.
Emotional modulation of the post‐auricular reflex
Authors: Benning Stephen D. , Patrick Christopher J. , Lang Alan R. 
Published: December 2004

AbstractA large literature now exists on emotional modulation of the startle blink reflex. The current study examined affective modulation of the post‐auricular reflex, which can be measured in relation to the same noise probe used to evoke the startle reflex. We recorded the post‐auricular reflex during viewing of pictures that varied systematically in emotional valence, content, and intensity. A significant linear valence modulation effect was found, with pleasant pictures potentiating and aversive pictures inhibiting the post‐auricular reflex in comparison with neutral pictures. This modulatory effect did not vary as a function of picture content, but it was most robust for highly intense emotional pictures. Implications for the assessment of basic emotional action tendencies are discussed.
Intraductal papillary mucinous neoplasm of the pancreas in a patient with attenuated familial adenomatous polyposis
Authors: Chetty R , Salahshor S , Bapat B , Berk T , Croitoru M , Gallinger S 
Published: December 2004

A 67 year old man with a clinical diagnosis of attenuated familial adenomatous polyposis (AFAP) and a past history of synchronous colon cancers in the transverse colon was also found to have an intraductal papillary mucinous neoplasm (IPMN) of the pancreas. In addition, several foci of heterotopic gastric oxyntic mucosa were noted in the duodenum, interspersed with flat and polypoid adenomas. The duodenal adenomas showed low grade dysplasia, loss of adenomatous polyposis coli (APC) protein expression, but retention of β catenin staining, localised to the nucleus and cytoplasm. The IPMN in the pancreas showed an identical immunohistochemical profile to the duodenal adenomas. The heterotopic gastric foci in the duodenum were negative for the APC protein, and β catenin staining was membranous in location. Although the patient did not show germline truncating APC mutations or mutations in the MYH gene, the past history, clinical features, and immunohistochemical profile of the various lesions suggest strongly that the IPMN is part of the spectrum of lesions encountered in AFAP. Whether the heterotopic oxyntic gastric mucosa in the duodenum is also related is unclear, but it may represent a forme fruste of fundic gland polyps.
GRAPH SOLUTIONS OF NONLINEAR HYPERBOLIC SYSTEMS
Authors: LEFLOCH PHILIPPE G. 
Published: December 2004

For nonlinear hyperbolic systems of partial differential equations in one-space dimension (in either conservative or non-conservative form) we introduce a geometric framework in which solutions are sought as (continuous) parametrized graphs(t,s) ↦ (X,U)(t,s) satisfying ∂sX ≥ 0, rather than (discontinuous) functions (t,x) ↦ u(t,x). On one hand, we generalize an idea by Dal Maso, LeFloch, and Murat who used a family of traveling wave profiles to define non-conservative products, and we define the notion of graph solution subordinate to a family of Riemann graphs. The latter naturally encodes the graph of the solution to the Riemann problem, which should be determined from an augmented model taking into account small-scale physics and providing an internal structure to the shock waves.In a second definition, we write an evolution equation on the graphs directly and we introduce the notion of graph solution subordinate to a diffusion matrix, which merges together the hyperbolic equations (in the "non-vertical" parts of the graphs) with the traveling wave equation of the augmented model (in the "vertical" parts).We consider the Cauchy problem within the class of graph solutions. The graph solution to the Cauchy problem is constructed by completion of the discontinuities of the entropy solution. The uniqueness is established by applying a general uniqueness theorem due to Baiti, LeFloch, and Piccoli. The proposed geometric framework illustrates the importance of the uniform distance between graphs to deal with solutions of nonlinear hyperbolic problems.
High resolution electron microscopy of the high‐Tc Superconductor Bi2+xSr2Ca1‐xCu2O8+δ
Authors: Zhou W. , Kirkland A. I. , Mackay K. D. , Armstrong A. R. , Harrison M. R. , Jefferson D. A. , Liang W. Y. , Edwards P. P. 
Published: December 2004

The structure of the 85 K Bi‐Sr‐Ca‐Cu‐O superconductor has been investigated by means of high resolution electron microscopy combined with image simulation. An ordered one‐in‐five substitution of calcium by bismuth ions is proposed as the explanation for the observed superlattice formation. magnified image
The synthesis of metallocene‐labelled drugs for biological assays
Authors: Lavastre I , Besançon J , Brossier P , Moise C 
Published: December 2004

AbstractSeveral drugs (amphetamine, desipramine, nortriptyline, phenobarbital) have been labelled with metallocenic fragments in order to develop a new immunoassay method. The metallocenic fragments are cymantrenic or benchrotrenic derivatives: the linkage between the organic and organometallic moieties has been achieved by reactions between amino and acidic functional groups. All the products (metallohaptens), purified by different chromatography techniques, have been fully characterized by IR and 1H NMR spectroscopy and their mass spectra.
An international intercomparison exercise for total mercury in seawater
Authors: Cossa D , Courau P 
Published: December 2004

AbstractTwo 30 dm3 coastal seawater samples were collected in September 1983. One was acidified, homogenized and divided among 50 500‐cm3 glass ampoules. The second was spiked with 612ng of mercury added as methylmercury chloride, acidified, homogenized and divided among 50 500‐cm3 glass ampoules. All these operations were performed under a mercury‐free atmosphere. A single sample from each set was sent to each of 37 laboratories; 21 of them submitted their results of a ‘total’ mercury concentation determination. The consensus values and their confidence limits are 6.0 ± 1.6 and 24.2 ± 2.8 ng dm−3 for the natural and the spiked samples respectively. Eleven laboratories reported reliable quantitative results (within ± 2SD) for the natural (unspiked) sample, and 12 for the spiked sample. In addition, ten laboratories give sets of results within ± 2SD of the consensus values. Storage for up to four months of methylmercury spiked samples with 1.4% nitric acid (0.3 mol dm−3) at room temperature is, alone, an unsuitable treatment for releasing mercury from its monomethyl compounds.
Tributyltin levels in French Mediterranean coastal waters
Authors: Alzieu Claude , Michel Pierre , Sanjuan Jane , Averty Bernard 
Published: December 2004

AbstractTributyltin (TBT) and its degradation products were measured in seawater samples in 1988 and 1989 at different locations of the French Mediterranean coast, including harbours, marinas and mariculture areas. Higher levels of TBT contamination were found in harbour (2–833 ng dm−3) and marina waters (18–736 ng dm−3) compared with mariculture areas (<2–111 ng dm−3). Geographical distribution of TBT degradation products showed that a TBT hot spot finally results in a diffuse contamination of dibutyltin (DBT) and monobutyltin (MBT), even far distant from input areas.
Electrically conducting organometallic polymers
Authors: Nalwa Hari S. 
Published: December 2004

AbstractPolyacetylene, which exhibits metallic‐like electrical conductivity upon redox doping, led to the development of a new class of electronic materials. Metallic conductivity in polyacetylene originates from the mobility of charge‐carriers along the highly conjugated π‐electron carbon backbone. On the other hand, organometallic polymer backbones comprising transition‐metal ions and highly conjugated ligands may themselves produce intrinsically conducting materials due to the increased molecular orbital interaction between metal atoms via ligands. For decades organometallic polymers have been the subject of great scientific interest due to their unique electrical properties and many potential uses. Following the discovery of polyacetylene, the cofacially joined metallophthalocyanine polymers emerged as a new class of electrically conducting polymers. This important class of conducting organometallic polymers now includes a wide variety of materials such as poly(metalyne), poly(metallophthalocyanines), metal poly(benzodithiolene), poly(metalloethylene tetrathiolate), poly(metal tetrathio‐oxalate), etc. Depending upon the molecular structures, many organometallic polymers are intrinsic conductors while in others metallic‐like conductivity is induced by a molecular doping process. The superiority of electrically conducting organometallic polymers is manifest in their excellent environmental stability and processability. Conducting organometallic polymers have a wide range of applications in electrocatalysis, photovoltaics, sensors and fuel‐cell technology.
Preparation and characterization of diphenyllead(IV) and triphenyllead(IV) complexes with N‐protected amino‐acids and the dipeptides
Authors: Sandhu G K , Kaur H 
Published: December 2004

AbstractThe diphenyllead(IV) derivatives of N‐benzoyl‐(glycine, DL‐alanine); N‐formyl and N‐acetyl‐L‐phenylalanine; N‐monochloroacetyl‐L‐phenylalanine; N‐benzoyl‐(glycylglycine, DL‐alanylglycine), and N‐formyl‐ N‐acetyl‐ and N‐monochloroacetyl‐(L‐phenylalanylglycine) have been prepared in 1:2 molar ratio by reaction of diphenyllead dichloride with the appropriate amino‐acid or dipeptide. Corresponding triphenyllead(IV) derivatives have been prepared in 1:1 molar ratio by reaction of triphenyllead chloride with the thallium(I) salts of the amino‐acid or the dipeptide. These complexes have been characterized by elemental analysis, IR and 1H NMR spectral studies. A polymeric hexacoordinated octahedral structure for diphenyllead(IV), and a five‐coordinated distorted trigonalbipyramidal chain‐type structure for triphenyllead(IV), complexes is confirmed by IR spectra. The carboxylate group acts in a bidentate manner, not as in diorgano and triorganotin(IV) complexes with these acids, where it is monodentate. The available bonding sites such as amide and peptide carbonyl (CO) and amide and peptide nitrogen atoms are not involved in bonding with lead (IV) and thus are available for bonding with the biological systems. The presence of different N‐protecting groups does not affect the coordination sites around lead(IV). The triphenyllead(IV) compounds are relatively more stable than the diphenyllead(IV) compounds.
Disproportionation of triorganotin species, R3SnX
Authors: Blunden Steven J , Harston Paul , Hill Robin , Wardell James L 
Published: December 2004

AbstractTriorganotin compounds, R3SnX, have found extensive use as a biological agents in such areas as agrochemicals, marine antifoulants and timber preservatives. In contrast, di(R2SnX2) and tetraorganotin derivatives (R4Sn) possess less biological activity than do their triorganotin counterparts. It has been shown that disproportionation of R3SnX species (i.e. to produce R2SnX2 and R4Sn) can occur especially when X is a chelating or bridging group such as oxide, carboxylate, hydroxy ketone or hydroxyquinoline. This process has implications for the industrial applications and analysis of R3SnX compounds.
Mass spectrometric studies on the decomposition of trialkylgallium on gaas surfaces
Authors: Ohki Yoshimasa , Hiratani Yuji 
Published: December 2004

AbstractThe thermal decomposition of trimethylgallium [(CH3)3Ga] and triethylgallium [(C2H5)3Ga] on gallium arsenide (GaAs) surfaces was studied under an ultra‐high vacuum using mass spectrometry. It was observed that the decomposition process of (CH3)3Ga and (C2H5)3Ga depends on the arsenic coverage of the substrate surface. On a (100)‐oriented surface, increasing the arsenic coverage basically enhances the decomposition of (CH3)3Ga and (C2H5)3Ga to gallium atoms above 350 and 300°C, respectively. The decomposition of (CH3)3Ga proceeds by emitting CH3 radicals. On a surface with low arsenic coverage, the decomposition of (CH3)3Ga is imperfect and fewer than three methyl groups of alkylgallium are desorbed. On a (111)B‐oriented surface, however, an increase in the surface arsenic coverage suppresses the decomposition of alkylgallium, which is different from the case for a (100) surface.
Wavelength dependence in photochemical vapor deposition of aluminum film using dimethylaluminum hydride
Authors: Hanabusa Mitsuga , Ikeda Masashi 
Published: December 2004

AbstractIn photochemical vapor deposition of aluminum film on silicon using dimethylaluminum hydride, (CH3)2AlH, a surface reaction dominated below a (CH3)2AlH pressure of 0.3 m Torr at 200°C, which was induced only with the 160 nm band emitted from a deuterium lamp. A gas‐phase reaction occurred above 0.3 mTorr at 200°C, which could be induced by both 160 nm and 240 nm emission bands from the lamp. To distinguish between surface ad gas‐phase reactions, a thickness profile was used. At 240°C the surface reaction could be induced even by the 240 nm band, while the deposits formed under illumination of the two bands were thinner than those obtained with only the 240 nm band, indicating occurrence of vacuum ultraviolet (VUV)‐enhanced desorption. The mechanism responsible for the observed wavelength dependence in unclear. The electrical resistivity of the films deposited at 200°C was 4.5 μΩ cm, which did not change with wavelength.