Understanding the relevance of national culture in international business research: a quantitative analysis

This review is a comprehensive quantitative analysis of the International Business literature whose focus is on national culture. The analysis relies on a broad range of bibliometric techniques as productivity rankings, citation analysis (individual and cumulative), study of collaborative research patterns, and analysis of the knowledge base. It provides insights on (I) faculty and institutional research productivity and performance; (II) articles, institutions, and scholars’ influence in the contents of the field and its research agenda; and (III) national and international collaborative research trends. The study also explores the body of literature that has exerted the greatest impact on the researched set of selected articles.info:eu-repo/semantics/publishedVersio

Regulation of Ace2-dependent genes requires components of the PBF complex in schizosaccharomyces pombe

The division cycle of unicellular yeasts is completed with the activation of a cell separation program that results in the dissolution of the septum assembled during cytokinesis between the 2 daughter cells, allowing them to become independent entities. Expression of the eng1+ and agn1+ genes, encoding the hydrolytic enzymes responsible for septum degradation, is activated at the end of each cell cycle by the transcription factor Ace2. Periodic ace2+ expression is regulated by the transcriptional complex PBF (PCB Binding Factor), composed of the forkhead-like proteins Sep1 and Fkh2 and the MADS box-like protein Mbx1. In this report, we show that Ace2-dependent genes contain several combinations of motifs for Ace2 and PBF binding in their promoters. Thus, Ace2, Fkh2 and Sep1 were found to bind in vivo to the eng1+ promoter. Ace2 binding was coincident with maximum level of eng1+ expression, whereas Fkh2 binding was maximal when mRNA levels were low, supporting the notion that they play opposing roles. In addition, we found that the expression of eng1+ and agn1+ was differentially affected by mutations in PBF components. Interestingly, agn1+ was a major target of Mbx1, since its ectopic expression resulted in the suppression of Mbx1 deletion phenotypes. Our results reveal a complex regulation system through which the transcription factors Ace2, Fkh2, Sep1 and Mbx1 in combination control the expression of the genes involved in separation at the end of the cell division cycle

Solid-phase extraction and high-performance liquid chromatographic determination of polyphenols in apple musts and ciders

An improved analytical method was developed for the determination of polyphenols in the apple products must and cider. Phenolic compounds were fractionated into neutral and acidic groups by means of a solid-phase extraction method. The analytical method proposed was effective for the quantitation of phenolic compounds; recoveries between 84% and 111% were obtained, and the relative standard deviation was usually less than 5%

Phenolic Profile of Asturian (Spain) Natural Cider

The polyphenolic composition of natural ciders from the Asturian community (Spain), during 2 consecutive years, was analyzed by RP-HPLC and the photodiode-array detection system, without previous extraction (direct injection). A total of 16 phenolic compounds (catechol, tyrosol, protocatechuic acid, hydrocaffeic acid, chlorogenic acid, hydrocoumaric acid, ferulic acid, (-)-epicatechin, (+)-catechin, procyanidins B2 and B5, phloretin-2¢-xyloglucoside, phloridzin, hyperin, avicularin, and quercitrin) were identified and quantified. A fourth quercetin derivative, one dihydrochalcone-related compound, two unknown procyanidins, three hydroxycinnamic derivatives, and two unknown compounds were also found. Among the low-molecular-mass polyphenols analyzed, hydrocaffeic acid was the most abundant compound, representing more than 80% of the total polyphenolic acids. Procyanidins were the most important family among the flavonoid compounds. Discriminant analysis was allowed to correctly classify more than 93% of the ciders, according to the harvest year; the most discriminant variables were an unknown procyanidin and quercitrin

Characterization of beet necrotic yellow vein furovirus from Spanish sugar beets

Rhizomania is a viral disease, caused by beet necrotic yellow vein furovirus (BNYVV), which was detected in Spanish sugar beets in 1988, it being focused on the Castilla y León region. BNYVV has five RNA fragments with specific functions, and the different composition and proportion of RNA in the virions allow their separation and the characterization of their activities during the development of the disease. Thirty–six samples of sugar beet rootlets and frozen pulps from three different sugar beet zones of Castilla y León were analyzed by DAS-ELISA and Immunocapture-Reverse Transcription-Polymerase Chain Reaction (IC-RT-PCR) using specific primers. The identity of the cDNA products was confirmed by nested- PCR and restriction fragment length polymorphism (RFLP). The uniformity of the patterns obtained by RFLP analyses with nine endonucleases showed the existence of a unique strain of BNYVV in 80,000 Ha of crop surface which could be explained by a recent arrival of the rhizomania disease to this region. The isolates studied were more similar to type A, which has been previously described in BNYVV, but a nonexpected cleavage site for this molecular group was observed with endonuclease Hinc II on the RNA-2 IC-RT-PCR product (nt 2133–3293) in the thirty–six Spanish samples and also in a North American strain taken as reference. The use of frozen pulps obtained as a previous step to the industrial extraction of sugar avoids problems due to erratic distribution of the virus in the roots, provides repetitive results for a particular sample, and facilitates epidemiological and distributional studies on rhizomania disease

Gene expression analysis of the biocontrol fungus Trichoderma harzianum in the presence of tomato plants, chitin, or glucose using a high-density oligonucleotide microarray

<p>Abstract</p> <p>Background</p> <p>It has recently been shown that the <it>Trichoderma </it>fungal species used for biocontrol of plant diseases are capable of interacting with plant roots directly, behaving as symbiotic microorganisms. With a view to providing further information at transcriptomic level about the early response of <it>Trichoderma </it>to a host plant, we developed a high-density oligonucleotide (HDO) microarray encompassing 14,081 Expressed Sequence Tag (EST)-based transcripts from eight <it>Trichoderma </it>spp. and 9,121 genome-derived transcripts of <it>T. reesei</it>, and we have used this microarray to examine the gene expression of <it>T. harzianum </it>either alone or in the presence of tomato plants, chitin, or glucose.</p> <p>Results</p> <p>Global microarray analysis revealed 1,617 probe sets showing differential expression in <it>T. harzianum </it>mycelia under at least one of the culture conditions tested as compared with one another. Hierarchical clustering and heat map representation showed that the expression patterns obtained in glucose medium clustered separately from the expression patterns observed in the presence of tomato plants and chitin. Annotations using the Blast2GO suite identified 85 of the 257 transcripts whose probe sets afforded up-regulated expression in response to tomato plants. Some of these transcripts were predicted to encode proteins related to <it>Trichoderma</it>-host (fungus or plant) associations, such as Sm1/Elp1 protein, proteases P6281 and PRA1, enchochitinase CHIT42, or QID74 protein, although previously uncharacterized genes were also identified, including those responsible for the possible biosynthesis of nitric oxide, xenobiotic detoxification, mycelium development, or those related to the formation of infection structures in plant tissues.</p> <p>Conclusion</p> <p>The effectiveness of the <it>Trichoderma </it>HDO microarray to detect different gene responses under different growth conditions in the fungus <it>T. harzianum </it>strongly indicates that this tool should be useful for further assays that include different stages of plant colonization, as well as for expression studies in other <it>Trichoderma </it>spp. represented on it. Using this microarray, we have been able to define a number of genes probably involved in the transcriptional response of <it>T. harzianum </it>within the first hours of contact with tomato plant roots, which may provide new insights into the mechanisms and roles of this fungus in the <it>Trichoderma</it>-plant interaction.</p