bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovations and the role of complementarities in a strategic theory of the firm
Authors: Stieglitz Nils , Heine Klaus 
Published: November 2006

AbstractIn the resource‐based view of strategy and in evolutionary economics, complementary assets play a crucial role in explaining sustainable competitive advantages and innovations. Despite the apparent importance of complementary assets for the understanding of corporate strategy, their creation and the associated managerial problems have been much less discussed. We believe this to be a major weakness in the strategic theory of the firm. Interestingly, problems of coordination and cooperation are center stage in the contract‐based theories of the firm, and we try to integrate some of their insights into a resource‐based perspective. Specifically, we show how complementary assets raise the need for strategic direction by a firm's top management. Moreover, complementary assets magnify internal incentive problems, and their management has an impact on the innovativeness of a firm. Lastly, complementary assets play a crucial role in the internal appropriation of innovative rents. We demonstrate the fruitfulness of our integrated framework by relating some of our findings to the literature on corporate strategy, industry evolution, and organizational structures. Copyright © 2007 John Wiley & Sons, Ltd.
The significance of network resources in the race to enter emerging product markets: the convergence of telephony communications and computer networking, 1989–2001
Authors: Lee Gwendolyn K. 
Published: November 2006

AbstractThis paper focuses on the role of network resources and examines the associated mechanisms that affect the timing of entry into an emerging product market. Linking network theory to market entry research, I analyze the pattern in the structure, relation, and composition of 517 firms' strategic alliances as the firms face the decision of whether and when to enter the networking switches market over a 13‐year period from 1989 to 2001. The context for empirical testing is the voice/data convergence between telephony communications and computer networking technologies during which the industry boundary blurs. Firms that have access to information of high quality, large quantity, and compositional heterogeneity are likely to enter the newly developed market more quickly. However, network configuration lock‐in and network costs may counterbalance the benefits derived from network resources. I discuss the implications of these findings for research on social networks and the timing of market entry. Copyright © 2007 John Wiley & Sons, Ltd.
When is more better? The impact of business scale and scope on long‐term business survival, while controlling for profitability
Authors: Bercovitz Janet , Mitchell Will 
Published: November 2006

AbstractEmpirical research shows that larger businesses tend to survive longer than smaller companies. Little research, though, shows whether size confers survival advantages in addition to the survival benefits of baseline profitability. Moreover, no prior research attempts to disentangle the benefits of organizational capital that accrue from greater scale from those that arise from greater business scope. Thus, we lack a conceptual understanding of the underlying benefits of business size for long‐term survival. We expect business scale and business scope to reflect organizational capital that offers survival benefits, where we conceptualize scale in terms of annual sales revenue and scope in terms of product line breadth and sub‐sector participation within a related business context. We first argue that greater business scale and business scope each enhance long‐term survival, independent of baseline profitability, owing to greater availability of financial resources, organizational routines, and external ties. We then argue that the benefits of scale are greatest for multi‐product businesses, stemming from positive interactive effects of breadth and depth. We find support for these hypotheses with data from 618 firms that operated in the U.S. medical sector between 1978 and 1995. Copyright © 2007 John Wiley & Sons, Ltd.
Investor activism, managerial responsiveness, and corporate social performance
Authors: David Parthiban , Bloom Matt , Hillman Amy J. 
Published: November 2006

AbstractWe study relationships between shareholder proposal activism, managerial response, and corporate social performance (CSP). We find that shareholder proposal activism reduces CSP. We infer that rather than pressuring firms to improve CSP, activism may engender diversion of resources away from CSP into political activities used by managers to resist external pressures and retain discretion. We also find that managers are more likely to settle proposals filed by ‘salient’ shareholders (i.e., those with power, legitimacy, and urgency). Settlement with salient shareholders, however, also reduces CSP, suggesting that managers' responses are symbolic; i.e., they settle with salient shareholders to demonstrate conformance but continue to resist making the substantive changes to core policies that may compromise their discretion. Copyright © 2007 John Wiley & Sons, Ltd.
Arabidopsis thaliana CHX17 gene complements the kha1 deletion phenotypes in Saccharomyces cerevisiae
Authors: Maresova Lydie , Sychrova Hana 
Published: November 2006

AbstractAtChx17p is a putative K+/H+ exchanger from Arabidopsis thaliana, expressed in the roots and probably involved in K+ acquisition and homeostasis. AtCHX17 cDNA complements the phenotypes of the kha1Δ mutation in S. cerevisiae cells: a growth defect at increased pH and hygromycin sensitivity. The localization of GFP‐tagged AtChx17 protein in yeast cells is similar to that of ScKha1p: a bold dotted pattern inside the cells resembling the Golgi fluorescence markers. These results show that (a) the proteins AtChx17 and ScKha1 could have similar functions and (b) S. cerevisiae kha1 deletion mutants could serve for the heterologous expression and characterization of plant transporters. The results of this work are evidence that a S. cerevisiae strain with deletions of genes encoding alkali–metal–cation/H+ antiporters (i.e. Nha1p, Nhx1p, Kha1p) could be an ideal tool for expression and functional analysis of any type of similar plant antiporters (plasma membrane, endosomal/prevacuolar and Golgi). Copyright © 2006 John Wiley & Sons, Ltd.
Oxygen and carbon source‐regulated expression of PDC and ADH genes in the respiratory yeast Pichia anomala
Authors: Fredlund Elisabeth , Beerlage Christiane , Melin Petter , Schnürer Johan , Passoth Volkmar 
Published: November 2006

AbstractWe amplified, sequenced and studied the transcriptional regulation of genes of the alcoholic fermentation pathway in the biocontrol and non‐Saccharomyces wine yeast, Pichia anomala. Two ADH isogenes, PaADH1 and PaADH2, and one PDC gene, PaPDC1, were amplified from genomic P. anomala DNA by a two‐step PCR approach, using degenerated primers against conserved regions of the respective genes for cloning core regions, and PCR‐based gene walking for cloning the respective 5′ and 3′‐ends. According to sequence analysis, ADH1 and PDC1 are most likely cytoplasmatic proteins, while ADH2 is most probably localized in the mitochondria. PaADH1 was expressed during aerobic growth on glucose, ethanol and succinate, but was nine‐fold upregulated in response to oxygen limitation when grown on glucose. The gene seems to be involved in both production and consumption of ethanol. Only low expression of PaADH2 was detected during growth on glucose and ethanol, but it was highly expressed during growth on the non‐fermentable carbon source succinate and repressed by the addition of glucose. PaPDC1 was expressed during aerobic growth on glucose and was upregulated four‐fold in response to oxygen limitation. PaPDC1 expression was lower in cells grown on ethanol and succinate than on glucose and was up‐ regulated two‐ and four‐fold, respectively, after glucose addition. Our results demonstrate that transcription of genes of the fermentative pathway is regulated by hypoxia and carbon source but posttranscriptional regulation may play a major role in regulating the metabolic flux. Copyright © 2006 John Wiley & Sons, Ltd.
Lipids of dermatophytes II. Effect of growth condition on the lipid composition and membrane transport ofMicrosporum gypseum
Authors: Larroya Saroj , Khuller Gopal K. 
Published: November 2006

AbstractSupplementation of glucose‐containing medium with ethanol and replacement of glucose by glycerol in the Sabouraud’s growth medium ofMicrosporum gypseum altered the levels of total phospholipids as well as their apolar and polar head groups. The levels of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) increased under these growth conditions; also, the ratio of unsaturated/saturated phospholipid fatty acids decreased on ethanol supplementation but increased in the presence of glycerol. Steady state accumulation of labelled amino acids (glycine, lysine and aspartic acid) was affected under these conditions.
Incorporation oftrans fatty acids into submandibular salivary gland lipids
Authors: Alam Syed Q. , Alam Bassima S. , Banerji Arnold 
Published: November 2006

AbstractThree groups of rats were fed diets containing 20% corn oil, 20% margarine stock (MS) or 19% MS +1% corn oil. Diets were fed for 12 weeks, 1 week of pregnancy, 3 weeks of lactation and 8 weeks post‐weaning. The incorporation oftrans‐octadecenoate into various lipids of the submandibular salivary gland (SMSG) homogenates and plasma membranes was studied.Trans octadecenoate was incorporated into all the lipid fractions studied. Its levels were the highest in phosphatidylethanolamine. The double bond index of phospholipid fatty acids in the plasma membranes of the SMSG was substantially lower in the group fed 20% MS. The fluorescence polarization of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) was generally higher in the membranes of SMSG from rats fed MS than that of the other two groups, thus indicating lower fluidity. Also, the breakpoints in fluorescence polarization were at a higher temperature in the membranes from rats fed MS as compared with those fed corn oil. Lower fluidity of plasma membranes of SMSG observed in rats fed 20% MS may result in modification of the activities of membrane‐bound enzymes.
A mild, rapid, and efficient method of lipid extraction for use in determining vitamin E/lipid ratios
Authors: Burton Graham W. , Webb Ann , Ingold Keith U. 
Published: November 2006

AbstractA new, general method for lipid extraction and measurement of vitamin E/total lipid ratios in tissue and cell samples has been developed. The new extraction procedure use a combination of sodium dodecylsulfate, ethanol andn‐heptane, and is mild, clean, convenient, efficient and rapid (≤5 min). The efficiency of the new method has been confirmed for human plasma, red blood cells and rat liver homogenate by the comparison of the yields of vitamin E, O‐acyl lipid and cholesterol with the yields obtained following conventional extraction procedures. Extraction efficiency also has been confirmed for multilamenllar vesicles composed of known quantities of vitamin E, egg lecithin and cholesterol.
Rapid and convenient separation of phospholipids and non phosphorus lipids from rat heart using silica cartridges
Authors: Juaneda Pierre , Rocquelin Gerard 
Published: November 2006

AbstractThe separation of non phosphorus lipids and phospholipids of rat heart using Sep‐pack Silica cartridges is described. No cartridge preparation is necessary before utilization. The separation of lipid extracts is very fast. A complete partition of non phosphorus lipids and phospholipid is obtained.
A colorimetric assay of pancreatic lipase: Rapid detection of lipase and colipase separated by gel filtration
Authors: Roberts Johnna , Stella Valentino J. , Decedue Charles J. 
Published: November 2006

AbstractA rapid assay for pancreatic lipase (E.C., glycerol‐ester hydrolase 3.1.1.3) is described. The assay is based on the color change of a pH indicator as butyric acid is released from the substrate tributyrin. A mixture made with tributyrin and the water soluble components of the assay is ideally suited for use as a rapid test as, for example, when assaying chromatography fractions. Quantitative data can be obtained by measuring the disappearance of absorbance at 557 nm versus a blank reaction. The assay has been used in the rapid preparation of colipase‐free lipase and colipase.
Effect of type of diet and feeding status on modulation of hepatic HMG‐CoA reductase in rats
Authors: Kelley Michael J. , Story Jon A. 
Published: November 2006

AbstractThe effect of diet type and feeding status on hepatic HMG‐CoA reductase (HMGR) [mevalonate: NADP+ oxidoreductase (acylating CoA); EC 1.1.1.34] was studied in rats. Animals fed a ground, commercial, stock diet exhibited higher expressed and total activities of HMGR in the fed state than animals fed a semi‐purified diet. The differences did not appear in meal‐trained animals when measured before the onset of the meal after a 22‐hr fast. When expressed activity was taken as a per cent of total activity, fed animals from both diet groups used about 10% of their available activity. When animals on commercial diets were fasted, 20% of the activity was expressed. Fasted animals on the semi‐purified diet also increased the per cent of expressed reductase activity, but this increase was not as great (13.3%).These data suggest that, in the rat, regulation of cholesterol synthesis in response to decreased total HMGR during fasting and increased levels after a meal results from alterations in the percentage of enzyme which is expressed. The semi‐purified diet used here resulted in consistently lower levels of HMG‐CoA reductase activity than the commercial diet regardless of feeding pattern.
Distribution of glycosphingolipids of monkey small and large intestinal mucosa
Authors: Dahiya Rajvir , Brown Michael D. , Brasitus Thomas A. 
Published: November 2006

AbstractThe ganglioside and neutral glycosphingolipid composition of adult monkey small and large intestinal mucosa were characterized and compared. GM3, GM2 and GD1A were found to be the principal gangliosides in each of these tissues. Dihexosylceramide was the major neutral glycosphingolipid of both organs. The total content of gangliosides and neutral glycolipids/ceramide, however, was ca. four‐fold and two‐fold higher, respectively, in small intestinal than colonic mucosa.While all glycosphingolipids examined contained hydroxy and nonhydroxy fatty acids, the former fatty acids accounted for 60–90% of the total fatty acids in both organs. Sphingosine was the predominant long chain base of ceramide, mono‐, di‐, tri‐ and tetrahexosylceramide, whereas phytosphingosine was the major base of GM3 in both tissues. The results of these studies demonstrate that while many similarities of monkey small and large intestinal glycosphingolipids exist, qualitative and quantitative differences are present along the length of the monkey gut. These differences may be at least partially responsible for certain of the well‐recognized variations in normal physiological and pathological processes that occur in these organs.
Distribution of glycosphingolipids and ceramide of rat small intestinal mucosa
Authors: Dahiya Rajvir , Brasitus Thomas A. 
Published: November 2006

AbstractPrevious studies have suggested that glycosphingolipids may be involved in a number of physiological functions of the small intestinal mucosa. Regional variations in many of these processes exist along the length of this organ. In the present studies, the glycosphingolipid and ceramide composition of the proximal, middle and distal thirds of the rat small intestine were characterized and compared. Mono‐ and trihexosylceramide were the major neutral glycolipids and hematoside (GM3), the principal ganglioside of this organ. Monohexosylceramide was the major glycolipid of the proximal segment, whereas trihexosylceramide predominated in the distal segments. The total content of neutral glycolipids, ceramide and gangliosides as well as the content of the individual glycosphingolipids and ceramide were highest in the distal segment, intermediate in the middle and lowest in the proximal segment. Additionally, regional variations were noted in the fatty acid composition of the major glycosphingolipids. These differences in the composition of glycolipids and ceramide along the length of the intestine may be responsible, at least partially, for the regional functional specialization seen in this organ.
Retention of linoleic acid in carcass lipids of rats fed different levels of essential fatty acids
Authors: Becker Wulf , Bruce Ake 
Published: November 2006

AbstractRats of an inbred Sprague‐Dawley strain were fed purified diets with low (0.3% of total energy), normal (3%) or high (10%) content of essential fatty acids (EFA) for at least three generations. Two 30‐days‐old rats with similar weights were chosen from one litter. One was killed; weight increase and food consumption of the other rat was measured for 15 days. Total lipid content and fatty acid composition in total lipid and lipid classes were determined in both rats. Seven pairs of rats from each group were treated in the same way. Calculations based an amount of linoleic acid ingested and retained in the carcass lipids showed that 50% of the ingested linoleic acid was retained in the low EFA rats compared to 10–15% in the normal and high EFA rats.
Formation of complexes between lecithin and apovitellenin I, an avian egg‐yolk apoprotein
Authors: Fretheim K. , Sleigh R. W. , Burley R. W. 
Published: November 2006

AbstractIn a study of lipid‐protein interactions in egg yolk, it was found that L‐α‐dipalmitoyl lecithin gave two distinct noncovalent complexes (A and B) with apovitellenin I, an apoprotein in the major yolk lipoprotein. Interaction took place under widely varied conditions, and yolk lecithin gave similar complexes. Complex A, which was formed within minutes, consisted of round particles of about 9 nm diameter. Complex B, which was formed more slowly, consisted of larger, particles. Possibly resembling curved discs, with diameter of 30–40 nm. The preparation and some properties of these complexes are described. It is suggested that they may be suitable for an extensive study of phospholipid‐protein interactions in yolk.
Effect of total parenteral nutrition with linoleic acid‐rich emulsions on tissue ω6 and ω3 fatty acids in the rat
Authors: Innis Sheila M. 
Published: November 2006

AbstractThe effect of total parenteral nutrition (TPN) with lipid emulsions containing ca. 48% 18∶2ω6 plus 8% 18∶3ω3 (Intralipid®) or 76% 18∶2ω6 plus 0.5% 18∶3ω3 (Liposyn®) on the fatty acid composition of liver and plasma triglyceride and phospholipid (PL) was studied in the rat. Plasma PL showed a clear influence of the egg PL present in the infused lipid, suggesting replacement of endogenous lipoprotein PL. The incorporation of 20 and 22 carbon ω6 and ω3 fatty acids was reduced in liver phosphatidylcholine of rats infused with either Intralipid or Liposyn. Phosphatidylethanolamine was much less affected and showed reduced 20∶4ω6 and 20∶5ω3 in the Liposyn group only. Reduction in levels of long chain essential fatty acid metabolites was compensated for by an increased content of saturated fatty acids. There was no accumulation of 18∶2ω6 or 18∶3ω3 in liver PL. The similarity between the effects of Intralipid and Liposyn supports the conclusion that 18∶2ω6, not 18∶3ω3, was responsible. The data suggest that intravenous administration of high levels of 18∶2ω6 in parenteral lipid reduces desaturation/elongation of essential fatty acids but does not competitively inhibit esterification of other fatty acids into PL.
Effects of essential fatty acid administration on cardiovascular responses to stress in the rat
Authors: Mills David E. , Ward Ron P. 
Published: November 2006

AbstractThis study examined the effects of 18∶2(n−6), 18∶3(n−6), 20∶4(n−6) and 18∶3(n−3) on cardiovascular responses to isolation stress in male rats. Group‐acclimated rats were fasted for 2 days, then placed on a fat‐free diet. Two wk later animals were divided into six groups (six animals per group) and given eight‐wk intraperitoneal osmotic pumps releasing 1.47×10−7 mol/hr of either olive oil (OL), or of 18∶2(n−6), 18∶3(n−6), 20∶4(n−6) or 18∶3(n−3) in OL. Another group received dummy pumps. Two wk after pump implantation, animals were isolated for four wk. Blood pressure (BP), heart rate and body weight were followed before and during stress. Following the stress period, animals were assessed for cardiovascular reactivity to norepinephrine (NOR) and angiotensin (ANG).Prior to isolation, 18∶3(n−6) lowered BP vs OL (p<0.01). Stress increased BP within 24 hr in all groups except 18∶3(n−6) and 20∶4(n−6). Treatment with 20∶4(n−6) vs OL prevented the BP rise (p<0.001) only for the first two wk of stress. Administration of 18∶3(n−6) vs OL prevented any BP increase over the four‐wk stress period (p<0.001). Stress increased heart rate in all groups except 20∶4(n−6). Heart rate was lowered by 18∶3(n−6) vs OL (p<0.01) before and during stress. Vascular reactivity to NOR was unaffected by treatment, but OL and 18∶3(n−6) decreased responses to ANG infusion. These data suggest that 18∶3(n−6) supplementation attenuates cardiovascular responses to chronic stress, and that Δ6‐ and Δ5‐desaturase activity are inhibited during chronic psychological stress.
Acetate and mevalonate labeling studies with developingCuphea lutea seeds
Authors: Singh Sheo S. , Nee Thomas Y. , Pollard Michael R. 
Published: November 2006

AbstractCuphea seeds contain large amounts of medium chain (C8 to C14) fatty acids, mainly as triacylglycerols. The biosynthesis of these lipids was studied in vivo by incubating developingCuphea lutea seeds with labeled acetate. Incorporation of label into triacylglycerols and into medium chain fatty acids occurred principally during the period of endogenous lipid deposition, but some label was encountered in these products even during seed dehydration. At this later stage palmitate and oleate were the dominant labeled fatty acids. During the period of rapid endogenous lipid deposition acyl lipids other than triacylglycerols were minor labeled components. The labeling patterns were consistent with the Kennedy pathway for triacylglycerol biosynthesis. The fatty acid composition of the acyl‐CoA pool was similar to the total lipid fatty acid composition, but the acyl‐ACP pool contained relatively more short chain acyl groups. Squalene was labeled from acetate throughout the period of seed development, but labeled sterols were not detected. Using [2‐14C]mevalonic acid lactone as substrate, squalene was the principal labeled product. Small amounts of label were found in free sterols. However, in terms of mass, free sterol dominated over squalene. The possibility of two independent sites of isoprenoid biosynthesis in the developing embryo is discussed.