bluuebunny/crossref_metadata_2025 huggingface dataset:
The Distribution of Arsenate and Arsenite in Shoots and Roots of Holcus lanatus is Influenced by Arsenic Tolerance and Arsenate and Phosphate Supply
Authors: Quaghebeur Mieke , Rengel Zdenko
Published: July 2003

The recent discovery that phytochelatins are important for arsenic (As) detoxification in terrestrial plants results in the necessity to understand As speciation and metabolism in plant material. A hydroponic study was therefore conducted to examine the effects of different levels of phosphate and arsenate [As(V)] on As speciation and distribution in tolerant and non-tolerant clones of Holcus lanatus. Speciation of As in tissue (using high-performance liquid chromatography-inductively coupled plasma mass spectrometry) revealed that the predominant species present were the inorganic As species (As(V) and arsenite [As(III)]), although small levels (<1%) of organic As species (dimethylarsinic acid and monomethylarsonic acid) were detected in shoot material. In roots, the proportion of total As present as As(III) generally increased with increasing levels of As(V) in the nutrient solution, whereas in shoots, the proportion of total As present as As(III) generally decreased with increasing levels of As(V). H. lanatus plants growing in the high-phosphorus (P) (100 μm) solution contained a higher proportion of As(V) (with regard to total As) in both roots and shoots than plants supplied with low P (10 μm); in addition, tolerant clones generally contained a higher proportion of As(V) with regard to total As than non-tolerant clones. The study further revealed that As(V) can be reduced to As(III) in both roots and shoots. Although the reduction capacity was limited, the reduction was closely regulated by As influx for all treatments. The results therefore provide a new understanding about As metabolism in H. lanatus.
Cold Tolerance of C4 photosynthesis in Miscanthus × giganteus: Adaptation in Amounts and Sequence of C4 Photosynthetic Enzymes
Authors: Naidu Shawna L. , Moose Stephen P. , AL-Shoaibi Abdul K. , Raines Christine A. , Long Stephen P.
Published: July 2003

Field-grown Miscanthus × giganteus maintains high photosynthetic quantum yields and biomass productivity in cool temperate climates. It is related to maize (Zea mays) and uses the same NADP-malic enzyme C4 pathway. This study tests the hypothesis that M. × giganteus, in contrast to maize, forms photosynthetically competent leaves at low temperatures with altered amounts of pyruvate orthophosphate dikinase (PPDK) and Rubisco or altered properties of PPDK. Both species were grown at 25°C/20°C or 14°C/11°C (day/night), and leaf photosynthesis was measured from 5°C to 38°C. Protein and steady-state transcript levels for Rubisco, PPDK, and phosphoenolpyruvate carboxylase were assessed and the sequence of C4-PPDK from M. × giganteus was compared with other C4 species. Low temperature growth had no effect on photosynthesis in M. × giganteus, but decreased rates by 80% at all measurement temperatures in maize. Amounts and expression of phosphoenolpyruvate carboxylase were affected little by growth temperature in either species. However, PPDK and Rubisco large subunit decreased >50% and >30%, respectively, in cold-grown maize, whereas these levels remained unaffected by temperature in M. × giganteus. Differences in protein content in maize were not explained by differences in steady-state transcript levels. Several different M. × giganteus C4-PPDK cDNA sequences were found, but putative translated protein sequences did not show conservation of amino acids contributing to cold stability in Flaveria brownii C4-PPDK. The maintenance of PPDK and Rubisco large subunit amounts in M. × giganteus is consistent with the hypothesis that these proteins are critical to maintaining high rates of C4 photosynthesis at low temperature.
Arabidopsis UVH6, a Homolog of Human XPD and Yeast RAD3 DNA Repair Genes, Functions in DNA Repair and Is Essential for Plant Growth
Authors: Liu Zongrang , Hong Suk-Whan , Escobar Mindy , Vierling Elizabeth , Mitchell David L. , Mount David W. , Hall Jennifer D.
Published: July 2003

To evaluate the genetic control of stress responses in Arabidopsis, we have analyzed a mutant (uvh6-1) that exhibits increased sensitivity to UV light, a yellow-green leaf coloration, and mild growth defects. We have mapped the uvh6-1 locus to chromosome I and have identified a candidate gene, AtXPD, within the corresponding region. This gene shows sequence similarity to the human (Homo sapiens) XPD and yeast (Saccharomyces cerevisiae) RAD3 genes required for nucleotide excision repair. We propose that UVH6 is equivalent to AtXPD because uvh6-1 mutants carry a mutation in a conserved residue of AtXPD and because transformation of uvh6-1 mutants with wild-type AtXPD DNA suppresses both UV sensitivity and other defective phenotypes. Furthermore, the UVH6/AtXPD protein appears to play a role in repair of UV photoproducts because the uvh6-1 mutant exhibits a moderate defect in the excision of UV photoproducts. This defect is also suppressed by transformation with UVH6/AtXPD DNA. We have further identified a T-DNA insertion in the UVH6/AtXPD gene (uvh6-2). Plants carrying homozygous insertions were not detected in analyses of progeny from plants heterozygous for the insertion. Thus, homozygous insertions appear to be lethal. We conclude that the UVH6/AtXPD gene is required for UV resistance and is an essential gene in Arabidopsis.
Evidence for Nuclear Processing of Plant Micro RNA and Short Interfering RNA Precursors
Authors: Papp István , Mette M. Florian , Aufsatz Werner , Daxinger Lucia , Schauer Stephen E. , Ray Animesh , van der Winden Johannes , Matzke Marjori , Matzke Antonius J.M.
Published: July 2003

The Arabidopsis genome encodes four Dicer-like (DCL) proteins, two of which contain putative nuclear localization signals. This suggests one or more nuclear pathways for processing double-stranded (ds) RNA in plants. To study the subcellular location of processing of nuclear-encoded dsRNA involved in transcriptional silencing, we examined short interfering (si) RNA and micro (mi) RNA accumulation in transgenic Arabidopsis expressing nuclear and cytoplasmic variants of P19, a viral protein that suppresses posttranscriptional gene silencing. P19 binds specifically to DCL-generated 21- to 25-nucleotide (nt) dsRNAs with 2-nt 3′ overhangs and reportedly suppresses the accumulation of all size classes of siRNA. Nuclear P19 resulted in a significant reduction of 21- to 22-nt siRNAs and a 21-nt miRNA, but had a lesser effect on 24-nt siRNAs. Cytoplasmic P19 did not decrease the quantity but resulted in a 2-nt truncation of siRNAs and miRNA. This suggests that the direct products of DCL cleavage of dsRNA precursors of 21- to 22-nt siRNAs and miRNA are present in the nucleus, where their accumulation is partially repressed, and in the cytoplasm, where both normal sized and truncated forms accumulate. DCL1, which contains two putative nuclear localization signals, is required for miRNA production but not siRNA production. DCL1-green fluorescent protein fusion proteins localize to nuclei in transient expression assays, indicating that DCL1 is a nuclear protein. The results are consistent with a model in which dsRNA precursors of miRNAs and at least some 21- to 22-nt siRNAs are processed in the nucleus, the former by nuclear DCL1 and the latter by an unknown nuclear DCL.
Nitric Oxide and Cyclic GMP Are Messengers in the Indole Acetic Acid-Induced Adventitious Rooting Process
Authors: Pagnussat Gabriela Carolina , Lanteri María Luciana , Lamattina Lorenzo
Published: July 2003

This report describes part of the signaling pathway and some of the molecules involved in the auxin-induced adventitious root formation in cucumber (Cucumis sativus). Previous results showed that nitric oxide (NO) mediates the auxin response during adventitious root formation (Pagnussat et al., 2002). To determine the order of action of indole acetic acid (IAA) and NO within the signal transduction pathway and to elucidate the target molecules that are downstream of NO action, cucumber hypocotyl cuttings were submitted to a pretreatment leading to endogenous auxin depletion. The auxin depletion treatment provoked a 3-fold reduction of the root number in comparison to the nondepleted explants. The NO-donor sodium nitroprusside was able to promote adventitious rooting in auxin-depleted explants, whereas the specific NO scavenger cPTIO prevented the effect of sodium nitroprusside. The endogenous NO level was monitored in both control and auxin-depleted explants using a NO-specific fluorescent probe. The NO level was 3.5-fold higher in control (nondepleted) explants than in auxin-depleted ones. The exogenous application of IAA restored the NO concentration to the level found in nondepleted explants. Because NO activates the enzyme guanylate cyclase (GC), we analyzed the involvement of the messenger cGMP in the adventitious root development mediated by IAA and NO. The GC inhibitor LY83583 reduced root development induced by IAA and NO, whereas the cell-permeable cGMP derivative 8-Br-cGMP reversed this effect. The endogenous level of cGMP is regulated by both the synthesis via GC and its degradation by the phosphodiesterase activity. When assayed, the phosphodiesterase inhibitor sildenafil citrate was able to induce adventitious rooting in both nondepleted and auxin-depleted explants. Results indicate that NO operates downstream of IAA promoting adventitious root development through the GC-catalyzed synthesis of cGMP.
Enhanced Low Oxygen Survival in Arabidopsis through Increased Metabolic Flux in the Fermentative Pathway
Authors: Ismond Kathleen P. , Dolferus Rudy , De Pauw Mary , Dennis Elizabeth S. , Good Allen G.
Published: July 2003

We manipulated the enzyme activity levels of the alcohol fermentation pathway, pyruvate decarboxylase (PDC), and alcohol dehydrogenase (ADH) in Arabidopsis using sense and antisense overexpression of the corresponding genes (PDC1, PDC2, and ADH1). Transgenic plants were analyzed for levels of fermentation and evaluated for changes in hypoxic survival. Overexpression of either Arabidopsis PDC1 or PDC2 resulted in improved plant survival. In contrast, overexpression of Arabidopsis ADH1 had no effect on flooding survival. These results support the role of PDC as the control step in ethanol fermentation. Although ADH1 null mutants had decreased hypoxic survival, attempts to reduce the level of PDC activity enough to see an effect on plant survival met with limited success. The combination of flooding survival data and metabolite analysis allows identification of critical metabolic flux points. This information can be used to design transgenic strategies to improve hypoxic tolerance in plants.
Interacting Transcription Factors from the Three-Amino Acid Loop Extension Superclass Regulate Tuber Formation
Authors: Chen Hao , Rosin Faye M. , Prat Salomé , Hannapel David J.
Published: July 2003

Using the yeast (Saccharomyces cerevisiae) two-hybrid system and a potato (Solanum tuberosum) KNOX protein, designated POTH1, as bait, we have identified seven distinct interacting proteins from a stolon library of potato. All seven cDNAs are members of the BEL1-like family of transcription factors. Among these proteins, there are at least four regions of high sequence conservation including the homeodomain, the proline-tyrosine-proline three-amino acid loop extension, the SKY box, and a 120-amino acid region upstream from the homeodomain. Through deletion analysis, we identified a protein-binding domain present in the carboxy end of the KNOX domain of POTH1. The protein-binding domain in the BEL1 protein is located in the amino-terminal one-half of the 120-residue conserved region of the BELs. RNA-blot analysis showed differential patterns of RNA accumulation for the BELs in various potato organs. The level of StBEL5 mRNA increased in response to a short-day photoperiod in both leaves and stolons. Similar to sense mutants of POTH1, transgenic lines that overexpressed StBEL5 exhibited enhanced tuber formation even under noninductive conditions. Unlike POTH1 sense lines, however, these BEL lines did not exhibit the extreme leaf and stem morphology characteristic of KNOX overexpressers and displayed a more rapid rate of growth than control plants. Both StBEL5 and POTH1 sense lines exhibited an increase in cytokinin levels in shoot tips. StBEL5 lines also exhibited a decrease in the levels of GA 20-oxidase1 mRNA in stolon tips from long-day plants. Our results demonstrate an interaction between KNOX and BEL1-like transcription factors of potato that may potentially regulate processes of development.
Viviparous1 Alters Global Gene Expression Patterns through Regulation of Abscisic Acid Signaling
Authors: Suzuki Masaharu , Ketterling Matthew G. , Li Qin-Bao , McCarty Donald R.
Published: July 2003

Maize (Zea mays) Viviparous1 (VP1) and Arabidopsis ABI3 are orthologous transcription factors that regulate key aspects of plant seed development and ABA signaling. To understand VP1-regulated gene expression on a global scale, we have performed oligomicroarray analysis of transgenic Arabidopsis carrying 35S::VP1 in an abi3 null mutant background. We have identified 353 VP1/ABA-regulated genes by GeneChip analysis. Seventy-three percent of the genes were affected by both VP1 and ABA in vegetative tissues, indicating a tight coupling between ABA signaling and VP1 function. A large number of seed-specific genes were ectopically expressed in vegetative tissue of 35S::VP1 plants consistent with evidence that VP1 and ABI3 are key determinants of seed-specific expression. ABI5, a positive regulator of ABA signaling, was activated by VP1, indicating conservation of the feed-forward pathway mediated by ABI3. ABA induction of ABI1 and ABI2, negative regulators of ABA signaling, was strongly inhibited by VP1, revealing a second pathway of feed-forward regulation. These results indicate that VP1 strongly modifies ABA signaling through feed-forward regulation of ABI1/ABI5-related genes. Of the 32 bZIP transcription factors represented on the GeneChip, genes in the ABI5 clade were specifically coregulated by ABA and VP1. Statistical analysis of 5′ upstream sequences of the VP1/ABA-regulated genes identified consensus abscisic responsive elements as an enriched element, indicating that many of the genes could be direct targets of the ABI5-related bZIPs. The Sph element is an enriched sequence motif in promoters of genes co-activated by ABA and VP1 but not in promoters of genes activated by ABA alone. This analysis reveals that distinct combinatorial patterns of promoter elements distinguish subclasses of VP1/ABA coregulated genes.
Molecular and Biochemical Characterization of VR-EILs Encoding Mung Bean ETHYLENE INSENSITIVE3-LIKE Proteins
Authors: Lee Jae-Hoon , Kim Woo Taek
Published: July 2003

ETHYLENE INSENSITIVE3 (EIN3) is a transcription factor involved in the ethylene signal transduction pathway in Arabidopsis. Two full-length cDNA clones, pVR-EIL1 and pVR-EIL2, encoding EIN3-LIKE proteins were isolated by reverse transcriptase-polymerase chain reaction and by screening the cDNA library of mung bean (Vigna radiata) hypocotyls. VR-EIL1 and VR-EIL2 share 70% identity and display varying degrees of sequence conservation (39%–65%) with previously isolated EIN3 homologs from Arabidopsis, tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum) plants. Gel retardation assay revealed that both VR-EILs were able to interact specifically with optimal binding sequence-1, the recently identified optimal binding sequence for tobacco TEIL, with the binding of VR-EIL2 being more efficient than that of VR-EIL1. Transient expression analysis using a VR-EIL::smGFP fusion gene in onion (Allium cepa) epidermal cells indicated that the VR-EIL proteins were effectively targeted to the nucleus. The fusion protein of VR-EIL2 with GAL4 DNA-binding domain strongly activated transcription of a reporter gene in yeast cells, and an essential domain for transcription-stimulating activity was localized to the amino-terminal acidic region that consists of 50 amino acid residues. In contrast with what has been previously found in EIN3- and TEIL-overexpressing Arabidopsis plants, transgenic tobacco seedlings expressing the VR-EIL genes under the control of cauliflower mosaic virus 35S promoter did not exhibit a constitutive triple response. Instead, they displayed a markedly enhanced proliferation of root hairs, one of the typical ethylene response phenotypes, and increased sensitivity to exogenous ethylene. In addition, the pathogenesis-related (PR) genes encoding β-1,3-glucanase, osmotin, and PR1 were constitutively expressed in 35S::VR-EIL lines without added ethylene, and were hyperinduced in response to ethylene treatment. These results indicate that VR-EILs are functional in tobacco cells, thereby effectively transactivating the GCC-box-containing PR genes and enhancing sensitivity to ethylene. The possible physiological role of VR-EILs is discussed in the light of the suggestion that they are active components of the ethylene-signaling pathway and their heterologous expressions constitutively turn on a subset of ethylene responses in tobacco plants.
The Function of Ascorbate Oxidase in Tobacco
Authors: Pignocchi Cristina , Fletcher John M. , Wilkinson Joy E. , Barnes Jeremy D. , Foyer Christine H.
Published: July 2003

The function of the apoplastic enzyme ascorbate oxidase (AO) was investigated in tobacco (Nicotiana tabacum). The abundance of AO mRNA was up-regulated by light. Cytosolic ascorbate peroxidase (APX1) transcripts were also highest in the light. In contrast, l-galactono-γ-lactone dehydrogenase, stromal APX, and thylakoid APX transcripts remained constant over the day/night cycle. Salicylic acid inhibited growth, increased expression of the pathogenesis-related protein (PR) 1a, and decreased AO transcript abundance. In contrast, the application of auxin enhanced growth and increased AO and PR 1a gene expression. Therefore, AO transcript abundance varied in a manner similar to hormone-mediated changes in plant growth. To study the effects of modified AO expression on growth, transformed tobacco plants expressing AO in the sense and antisense orientations were generated. The resultant large changes in apoplastic AO activity in the transformed tobacco plants had little effect on whole leaf ascorbate (AA) content, but they had dramatic effects on apoplastic AA levels. Enhanced AO activity oxidized the apoplastic AA pool, whereas decreased AO activity increased the amount of AA compared with dehydroascorbate. A relationship was observed between AO activity and plant height and biomass. Native AO transcript levels were no longer subject to light/dark regulation in AO sense and antisense plants. Taken together, these data show that there is an interaction between hormone, redox, and light signals at the level of the apoplast via modulation of ion of AA content.
Regulation of Arabidopsis COPINE 1 Gene Expression in Response to Pathogens and Abiotic Stimuli
Authors: Jambunathan Niranjani , McNellis Timothy W.
Published: July 2003

The copines are a widely distributed class of calcium-dependent, phospholipid-binding proteins of undetermined biological function. Mutation of the Arabidopsis CPN1 (COPINE 1) gene causes a humidity-sensitive lesion mimic phenotype with increased resistance to a bacterial and an oomyceteous pathogen, constitutive pathogenesis-related gene expression, and an accelerated hypersensitive cell death defense response. Here, we show that the disease resistance phenotype of the cpn1-1 mutant was also temperature sensitive, demonstrate increased CPN1 gene transcript accumulation in wild-type plants under low-humidity conditions, and present a detailed analysis of CPN1 gene transcript accumulation in response to bacterial pathogens. In wild-type plants, CPN1 transcript accumulation was rapidly, locally, and transiently induced by both avirulent and virulent strains of Pseudomonas syringae pv tomato bacteria. However, induction of CPN1 transcript accumulation by avirulent bacteria was much faster and stronger than that induced by virulent bacteria. Bacterial induction of CPN1 transcript accumulation was dependent on a functional type III bacterial protein secretion system. In planta expression of the avrRpt2 avirulence gene was sufficient to trigger rapid CPN1 transcript accumulation. CPN1 transcript accumulation was induced by salicylic acid treatment but was not observed during lesion formation in the lesion mimic mutants lsd1 and lsd5. These results are consistent with CPN1 playing a role in plant disease resistance responses, possibly as a suppressor of defense responses including the hypersensitive cell death defense response. The results also suggest that CPN1 may represent a link between plant disease resistance and plant acclimation to low-humidity and low-temperature conditions.
Mitochondrial Phosphatidylserine Decarboxylase from Higher Plants. Functional Complementation in Yeast, Localization in Plants, and Overexpression in Arabidopsis
Authors: Rontein Denis , Wu Wen-I , Voelker Dennis R. , Hanson Andrew D.
Published: July 2003

Plants are known to synthesize ethanolamine (Etn) moieties by decarboxylation of free serine (Ser), but there is also some evidence for phosphatidyl-Ser (Ptd-Ser) decarboxylation. Database searches identified diverse plant cDNAs and an Arabidopsis gene encoding 50-kD proteins homologous to yeast (Saccharomyces cerevisiae) and mammalian mitochondrial Ptd-Ser decarboxylases (PSDs). Like the latter, the plant proteins have putative mitochondrial targeting and inner membrane sorting sequences and contain near the C terminus a Glycine-Serine-Threonine motif corresponding to the site of proteolysis and catalytic pyruvoyl residue formation. A truncated tomato (Lycopersicon esculentum) cDNA lacking the targeting sequence and a chimeric construct in which the targeting and sorting sequences were replaced by those from yeast PSD1 both complemented the Etn requirement of a yeast psd1 psd2 mutant, and PSD activity was detected in the mitochondria of the complemented cells. Immunoblot analysis of potato (Solanum tuberosum) mitochondria demonstrated that PSD is located in mitochondrial membranes, and mRNA analysis in Arabidopsis showed that the mitochondrial PSD gene is expressed at low levels throughout the plant. An Arabidopsis knockup mutant grew normally but had 6- to 13-fold more mitochondrial PSD mRNA and 9-fold more mitochondrial PSD activity. Total membrane PSD activity was, however, unchanged in the mutant, showing mitochondrial activity to be a minor part of the total. These results establish that plants can synthesize Etn moieties via a phospholipid pathway and have both mitochondrial and extramitochondrial PSDs. They also indicate that mitochondrial PSD is an important housekeeping enzyme whose expression is strongly regulated at the transcriptional level.
The Tn Antigen-Specific Lectin from Ground Ivy Is an Insecticidal Protein with an Unusual Physiology
Authors: Wang Weifang , Hause Bettina , Peumans Willy J. , Smagghe Guy , Mackie Anne , Fraser Robin , Van Damme Els J.M.
Published: July 2003

Leaves of ground ivy (Glechoma hederacea) contain a lectin (called Gleheda) that is structurally and evolutionary related to the classical legume lectins. Screening of a population of wild plants revealed that Gleheda accounts for more than one-third of the total leaf protein in some clones, whereas it cannot be detected in other clones growing in the same environment. Gleheda is predominantly expressed in the leaves where it accumulates during early leaf maturation. The lectin is not uniformly distributed over the leaves but exhibits a unique localization pattern characterized by an almost exclusive confinement to a single layer of palisade parenchyma cells. Insect feeding trials demonstrated that Gleheda is a potent insecticidal protein for larvae of the Colorado potato beetle (Leptinotarsa decemlineata). Because Gleheda is not cytotoxic, it is suggested that the insecticidal activity is linked to the carbohydrate-binding specificity of the lectin, which as could be demonstrated by agglutination assays with different types of polyagglutinable human erythrocytes is specifically directed against the Tn antigen structure (N-acetylgalactosamine O-linked to serine or threonine residues of proteins).
Deviant Talk in Adolescent Friendships: A Step Toward Measuring a Pathogenic Attractor Process
Authors: Granic Isabela , Dishion Thomas J.
Published: July 2003

Deviant talk in adolescent friendships has been previously found to predict escalations in substance use, delinquency, and violence. The current paper extends past work on deviant talk by examining its dynamic, self‐organizing properties. From the direct observations of peer interactions, a simple measure was developed that indicated whether, as an interaction unfolded, deviant talk bouts became longer in duration (indicating an attractor state). Participants included 102 high‐risk adolescents and their friends. A time‐series of the duration of each successive deviant talk bout over the course of an interaction was created for all dyads. Slope values were derived from the time‐series and used as an index of attractor strength. As hypothesized, the attractor index predicted serious authority conflict (arrests, school expulsion) and drug abuse three years later, after controlling for prior problem behavior, family coercion and deviant peer associations. The findings suggest that the process by which adolescents become increasingly absorbed in deviant talk is an important underlying mechanism in the development of serious antisocial behavior.
Mother–Son Positive Synchrony in Middle Childhood: Relation to Antisocial Behavior
Authors: Criss Michael M. , Shaw Daniel S. , Ingoldsby Erin M.
Published: July 2003

The aim of the present investigation was to examine mother–son positive synchrony and its link to child and best friend antisocial behavior in middle childhood. Data were collected from 122 families with 10‐year‐old children during home assessments. Positive synchrony was rated during a parent–child discussion task. Data were also gathered on parent–child openness and conflict, harsh discipline, parental monitoring, and the child's social information processing. Four domains of child adjustment were assessed: antisocial behavior (ages 8 and 10), best friend antisocial behavior (ages 8 and 10), social skills (age 10), and anxiety/depression (age 10). The results indicated that observed positive synchrony was related significantly to measures tapping parenting, parent–child conflict, and child social information processing, as well as to youth and best friend antisocial behavior. The associations between synchrony and antisocial behavior remained significant after controlling for prior youth adjustment and other child and parenting factors. Developmental implications and suggestions for future research are discussed.
Change in Parents’ Monitoring Knowledge: Links with Parenting, Relationship Quality, Adolescent Beliefs, and Antisocial Behavior
Authors: Laird Robert D. , Pettit Gregory S. , Dodge Kenneth A. , Bates John E.
Published: July 2003

A longitudinal prospective design was used to examine antisocial behavior, two aspects of the parent–child relationship, inept parenting, and adolescents’ beliefs in the appropriateness of monitoring as predictors of parents’ monitoring and change in monitoring during the high school years. A total of 426 adolescents provided reports of their parents’ monitoring knowledge during four yearly assessments beginning the summer before entering grade 9. Greater concurrent levels of monitoring knowledge were associated with less antisocial behavior, more parent‐reported relationship enjoy‐ment, adolescents and parents spending more time together, and adolescents reporting stronger beliefs in the appropriateness of parental monitoring. Weaker knowledge beliefs predicted increases in monitoring knowledge over time. More antisocial behavior problems were linked to lower levels of knowledge through less enjoyable parent–adolescent relationships, parents and adolescents spending less time together, and adolescents reporting weaker monitoring beliefs. Discussion focuses on processes linking antisocial behavior problems with low levels of monitoring knowledge.
Boys’ Maladaptive Social Information Processing, Family Emotional Climate, and Pathways to Early Conduct Problems
Authors: Schultz David , Shaw Daniel S.
Published: July 2003

Maladaptive social information processing characterizes many children with behavioral adjustment difficulties. Yet, we know little about the antecedents of maladaptive social information processing. The present study examined the relations between early family risk and later maladaptive social information processing and conduct problems in a sample of 178 economically disadvantaged boys. Early childhood assessments of socioeconomic disadvantage (low SES, single parent status, low maternal education) and maternal depression predicted boys’ maladaptive response generation and conduct problems at age 10, accounting for 6% and 14% of the variances, respectively, but not hostile attribution bias. Maladaptive response generation also fit a model of significant partial mediation of the effects of socioeconomic disadvantage on conduct problems. Results suggest the importance of the family's emotional climate during children's early development for their later adjustment.
Export–Oriented Foreign Direct Investment and Local Content Requirement
Authors: Lahiri Sajal , Ono Yoshiyasu
Published: July 2003

We develop a model in which foreign firms locate in a host country and export their produce to another (consuming) country. We consider both exogenous and endogenous numbers of foreign firms. These firms compete with domestic firms in the consuming country under oligopoly. Unemployment exists in both countries. We analyse the conflict of interest between the two countries on the level of local content for the foreign firms. Under free entry of foreign firms, the consuming country may want a less severe restriction on local contents than the host country, but not so when the number of foreign firms is exogenous.
Has Productivity Contributed to China's Growth?
Authors: Wu Yanrui
Published: July 2003

This paper applies an extended Solow approach to examine the role of productivity in China's economic growth. The extended Solow approach allows the decomposition of output growth into factor contributions, technological progress and efficiency change. It is found that total factor productivity (TFP) has on average contributed to 13.5 percent of China's economic growth in the past two decades. This contribution is mainly due to technological progress which tends to accelerate over time. However, during 1982–97 efficiency change due to catch–up has been very volatile, reflecting the uncertainties associated with economic reforms and transition in China.
Consumption, Housing Rents and Housing Price: A Test Of A Real Estate Pricing Model Using Hong Kong Data
Authors: Cheung Francis K. , Ni Shawn , Siu Alan
Published: July 2003

The present study investigates whether Hong Kong's volatile real estate market is consistent with a non–linear consumption–based–asset–pricing model. It finds that the asset–pricing model is not rejected for some types of properties. However, the differentials between the returns to residential properties and risk–free rate are too large to be explained by the model.
Basic Needs, Property Rights and Degradation Of Commons
Authors: Hazari Bharat R. , Kumar Ajai
Published: July 2003

A major problem in many developing countries is the degradation of commons. This degradation has occurred on account of the lack of fulfilment of the basic needs of the poor, free riding and ill–defined property rights. As these goods are essential for the survival of these people, they have to access these items from commons. This results in regular raids to common land for resources and also to private houses (for example, in New Delhi) which are not guarded for water. A variant of the agricultural household model is used to analyse the above problem. Several propositions are established and it is demonstrated that degradation can occur at both a low and high price of basic needs. This result has important policy implications as it demonstrates that land or common degradation cannot be solved by just using the price system. Properly defined property rights and provision of basic goods in kind may resolve the problem of degradation of commons.
How Labour Markets affect Trade Policies and Trade: The Case of the Foreign Labour Union
Authors: Fung K. C.
Published: July 2003

This paper highlights the point that the presence of a foreign union affects significantly the characterization of domestic trade policies, and thus, trade. Specifically, both the objective functions of the foreign union and the nature of interactions between the foreign firm and the foreign union are important determinants of the sign and magnitudes of the domestic trade policies. The importance of the foreign union effect holds regardless of whether the domestic trade policies are politically motivated or whether they are set to maximize national welfare. The foreign union effect is also present with or without a domestic producer.
Land and Urban Unemployment
Authors: Wei Gu , Yabuuchi Shigemi
Published: July 2003

This paper re–examines the effects of expansion of land itself on unemployment and welfare in the mobile–capital Harris–Todaro model with land in agriculture. We show the possibility of immiserization and the harmful effects on employment contrary to the conventional results.
The Long–Term Effectiveness of the Hong Kong Employees Retraining Programme
Authors: Chan William , Suen Wing
Published: July 2003

The Employees Retraining Programme in Hong Kong was promoted as the solution to structural unemployment resulting from rapid transformation of the economy. However, our study of the labour market performance of a group of trainees shows no evidence of any positive programme effect, more than three years after the completion of training, when compared to a group of job searchers. In particular, full time training is found to be less effective than part time training, and training in general skills is significantly less effective than training in specific occupational skills. This suggests problems in the design and implementation of retraining in Hong Kong.
Resurrecting Old–Fashioned Foundationalism
Authors: Barnes Gordon
Published: July 2003

Book reviewed in this article:

M DePaul (ed), Resurrecting Old–Fashioned Foundationalism
A First Assessment of Some Measures of Core Inflation for the Euro Area
Authors: Vega Juan-Luis , Wynne Mark A.
Published: July 2003

Core inflation plays an important role in the deliberations of monetary policy-makers. In this paper we evaluate a number of measures of core inflation constructed using euro-area data. In addition to the traditional exclusion-type core measures, we examine two newer ones, documenting their properties and evaluating their performance in terms of their ability to track underlying or trend inflation in real time. We focus on core measures derived from the Harmonized Index of Consumer Prices (HICP) as the European Central Bank has chosen to define its mandate for price stability in terms of this index, and because this is the only index of consumer prices that is compiled in a comparable manner across all members of the European Union. We document significant excess kurtosis in the cross-section distribution of price changes in the euro area, and show that several categories of prices are more volatile than those typically excluded from traditional measures of core inflation. Contrary to what one might expect, traditional measures of core inflation are not significantly less volatile than headline measures.We document the superior performance of alternative measures of core inflation in tracking trend inflation on average, but show that none of the various measures of core gave significant advance warning of the pickup in trend inflation at the beginning of 1999.
Measuring Monetary Policy in Germany: A Structural Vector Error Correction Approach
Authors: Brüggemann Imke
Published: July 2003

A structural vector error correction (SVEC) model is used to investigate several monetary policy issues. While being data-oriented the SVEC framework allows structural modeling of the short-run and long-run properties of the data. The statistical model is estimated with monthly German data for 1975-98 where a structural break is detected in 1984. After splitting the sample, three stable long-run relations are found in each subsample which can be interpreted in terms of a moneydemand equation, a policy rule and a relation for real output, respectively. Since the cointegration restrictions imply a particular shape of the long-run covariance matrix this information can be used to distinguish between permanent and transitory innovations in the estimated system. Additional restrictions are introduced to identify a monetary policy shock.
Monetary Policy, Agency Costs and Output Dynamics
Authors: Linnemann Ludger , Schabert Andreas
Published: July 2003

This paper examines the role of financial market imperfections for output reactions to nominal interest rate shocks. Empirical evidence shows a humpshaped impulse response function of output and suggests that credit supply co-moves with output. A monetary business cycle model with staggered price setting is presented where the firms’ outlays for capital and labor must be covered by the sum of net worth of entrepreneurs and loans in the form of debt contracts. These properties are shown to generate a hump-shaped impulse response of output, which takes on the smooth and persistent appearance of the empirical output response when nominal wages are set in a staggered way, too.
Monetary Policy Shocks and Heterogeneous Finance Decisions: A Model of Hidden Effort Choice and Financial Intermediation
Authors: Dietrich Diemo
Published: July 2003

The paper investigates how monetary policy shocks influence the composition of firms’ external finance given that firms are heterogeneous. Heterogeneity stems from differences in the availability of internal funds and in the monitoring costs associated with bank finance. These costs are determined by the intensity of the lending relationship. By using a delegated monitoring approach it is found that bank loans serve as a substitute for internal funds if the lending relationship is sufficiently close. Moreover, banks with strong credit ties to their customers are not only able to protect borrowers from liquidity constraints following a monetary tightening but are even able to extend their business lending.
Competition Necessarily Tends to Produce Excess: The Experience of Free Banking in Switzerland
Authors: Neldner Manfred
Published: July 2003

According to McCulloch, Longfield and Loyd, a free banking system is always prone to overissues of bank notes. Their view is supported by the free banking era in Switzerland (1826-1907), where, due to competitive pressures within the banking community and the absence of note-brand loyalty on the part of the general public, overissues (causing a rise in the foreign exchange rates above the upper gold and silver points) finally became permanent. Free competition, therefore, had to give way to collusive action and, in 1907 (with the open consent of the issuing banks), to the establishment of the Swiss National Bank.
Cell Therapy of α-Sarcoglycan Null Dystrophic Mice Through Intra-Arterial Delivery of Mesoangioblasts
Authors: Sampaolesi Maurilio , Torrente Yvan , Innocenzi Anna , Tonlorenzi Rossana , D'Antona Giuseppe , Pellegrino M. Antonietta , Barresi Rita , Bresolin Nereo , De Angelis M. Gabriella Cusella , Campbell Kevin P. , Bottinelli Roberto , Cossu Giulio
Published: July 2003

Preclinical or clinical trials for muscular dystrophies have met with modest success, mainly because of inefficient delivery of viral vectors or donor cells to dystrophic muscles. We report here that intra-arterial delivery of wild-type mesoangioblasts, a class of vessel-associated stem cells, corrects morphologically and functionally the dystrophic phenotype of virtually all downstream muscles in adult immunocompetent α-sarcoglycan (α-SG) null mice, a model organism for limb-girdle muscular dystrophy. When mesoangioblasts isolated from juvenile dystrophic mice and transduced with a lentiviral vector expressing α-SG were injected into the femoral artery of dystrophic mice, they reconstituted skeletal muscle in a manner similar to that seen in wild-type cells. The success of this protocol was mainly due to widespread distribution of donor stem cells through the capillary network, a distinct advantage of this strategy over previous approaches.
Vaccinations for Adult Solid-Organ Transplant Recipients: Current Recommendations and Protocols
Authors: Duchini Andrea , Goss John A. , Karpen Saul , Pockros Paul J.
Published: July 2003

Recipients of solid-organ transplantation are at risk of severe infections due to their life-long immunosuppression. Despite emerging evidence that vaccinations are safe and effective among immunosuppressed patients, most vaccines are still underutilized in these patients. The efficacy, safety, and protocols of several vaccines in this patient population are poorly understood. Timing of vaccination appears to be critical because response to vaccinations is decreased in patients with end-stage organ disease and in the first 6 months after transplantation. For these reasons, the primary immunizations should be given before transplantation, as early as possible during the course of disease. Vaccination strategy should include vaccination of household contacts and health care workers at transplant centers unless contraindicated. No conclusive data are available on the use of immunoadjuvants and screening for protective titers. Most vaccines appear to be safe in solid-organ transplantation recipients, but live vaccines should be avoided until further studies are available. The risk of rejection appears minimal. Recommended vaccines include pneumovax, hepatitis A and B, influenza, and tetanus-diphtheria. We outline specific protocols and recommendations in this particular patient population. Specific contraindications exist for other vaccines, such as yellow fever, oral polio vaccine, bacillus Calmette-Guerin, and vaccinia. We conclude that solid-organ recipients will benefit from consistent immunization practices. Further studies are recommended to improve established protocols in this patient population.
Receptors, Mediators, and Mechanisms Involved in Bacterial Sepsis and Septic Shock
Authors: Van Amersfoort Edwin S. , Van Berkel Theo J. C. , Kuiper Johan
Published: July 2003

Bacterial sepsis and septic shock result from the overproduction of inflammatory mediators as a consequence of the interaction of the immune system with bacteria and bacterial wall constituents in the body. Bacterial cell wall constituents such as lipopolysaccharide, peptidoglycans, and lipoteichoic acid are particularly responsible for the deleterious effects of bacteria. These constituents interact in the body with a large number of proteins and receptors, and this interaction determines the eventual inflammatory effect of the compounds. Within the circulation bacterial constituents interact with proteins such as plasma lipoproteins and lipopolysaccharide binding protein. The interaction of the bacterial constituents with receptors on the surface of mononuclear cells is mainly responsible for the induction of proinflammatory mediators by the bacterial constituents. The role of individual receptors such as the toll-like receptors and CD14 in the induction of proinflammatory cytokines and adhesion molecules is discussed in detail. In addition, the roles of a number of other receptors that bind bacterial compounds such as scavenger receptors and their modulating role in inflammation are described. Finally, the therapies for the treatment of bacterial sepsis and septic shock are discussed in relation to the action of the aforementioned receptors and proteins.
Versatility of Aminoglycosides and Prospects for Their Future
Authors: Vakulenko Sergei B. , Mobashery Shahriar
Published: July 2003

Aminoglycoside antibiotics have had a major impact on our ability to treat bacterial infections for the past half century. Whereas the interest in these versatile antibiotics continues to be high, their clinical utility has been compromised by widespread instances of resistance. The multitude of mechanisms of resistance is disconcerting but also illuminates how nature can manifest resistance when bacteria are confronted by antibiotics. This article reviews the most recent knowledge about the mechanisms of aminoglycoside action and the mechanisms of resistance to these antibiotics.
Production of Eicosanoids and Other Oxylipins by Pathogenic Eukaryotic Microbes
Authors: Noverr Mairi C. , Erb-Downward John R. , Huffnagle Gary B.
Published: July 2003

Oxylipins are oxygenated metabolites of fatty acids. Eicosanoids are a subset of oxylipins and include the prostaglandins and leukotrienes, which are potent regulators of host immune responses. Host cells are one source of eicosanoids and oxylipins during infection; however, another potential source of eicosanoids is the pathogen itself. A broad range of pathogenic fungi, protozoa, and helminths produce eicosanoids and other oxylipins by novel synthesis pathways. Why do these organisms produce oxylipins? Accumulating data suggest that phase change and differentiation in these organisms are controlled by oxylipins, including prostaglandins and lipoxygenase products. The precise role of pathogen-derived eicosanoids in pathogenesis remains to be determined, but the potential link between pathogen eicosanoids and the development of TH2 responses in the host is intriguing. Mammalian prostaglandins and leukotrienes have been studied extensively, and these molecules can modulate Th1 versus Th2 immune responses, chemokine production, phagocytosis, lymphocyte proliferation, and leukocyte chemotaxis. Thus, eicosanoids and oxylipins (host or microbe) may be mediators of a direct host-pathogen “cross-talk” that promotes chronic infection and hypersensitivity disease, common features of infection by eukaryotic pathogens.
Managing Occupational Risks for Hepatitis C Transmission in the Health Care Setting
Authors: Henderson David K.
Published: July 2003

Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of “acute hepatitis C syndrome” that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.