bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antiaging effect of Cordyceps sinensis extract
Authors: Ji Deng‐Bo , Ye Jia , Li Chang‐Ling , Wang Yu‐Hua , Zhao Jiong , Cai Shao‐Qing 
Published: September 2008

AbstractThis experiment studied the effect of Cordyceps sinensis extract (CSE) on mice aged by d‐galactose and castrated rats to analyse its antiaging effect. Water maze and step‐down type avoidance tests were used to examine the effect of CSE on learning and memory. CSE shortened escape latency, prolonged step‐down latency and decreased the number of errors in mice aged by d‐galactose. The effect of CSE on the sexual function of castrated rats was evaluated by measuring the penis erection latency, mount latency and ejaculation latency. CSE appeared to shorten penis erection latency and mount latency in castrated rats. The study also measured the effect of CSE on the activity of age‐related enzymes. The results showed that CSE improved the activity of superoxide dismutase, glutathione peroxidase and catalase and lowered the level of lipid peroxidation and monoamine oxidase activity in the aged mice. The study demonstrated that CSE can improve the brain function and antioxidative enzyme activity in mice with d‐galactose‐induced senescence and promote sexual function in castrated rats. All of these findings suggest that CSE has an antiaging effect. Copyright © 2008 John Wiley & Sons, Ltd.
Inhibitory Activities of Cassia tora and its Anthraquinone Constituents on Angiotensin‐Converting Enzyme
Authors: Hyun Sook Kyung , Lee Hyang , Kang Sam Sik , Chung Hae Young , Choi Jae Sue 
Published: September 2008

AbstractAs a component of our program that pertains to the isolation of antihypertensive agents derived from natural products, we screened the bioactivity of seeds from raw and roasted Cassia tora via angiotensin converting enzyme (ACE) inhibitory assays. We found that both of the MeOH extracts from the raw and roasted C. tora exhibited significant inhibitory properties against ACE, demonstrating more than 50% inhibition at a concentration of 163.93 µg/mL. Emodin (3), alaternin (4), gluco‐obtusifolin (5), cassiaside (6), gluco‐aurantioobtusin (7), cassitoroside (8), toralactone gentiobioside (9), and chrysophanol triglucoside (10) had been previously isolated; however, questin (1) and 2‐hydroxyemodin 1‐methylether (2) were isolated from C. tora for the first time in this study. Among them, only anthraquinone glycoside (7) demonstrated marked inhibitory activity against ACE, with an IC50 value of 30.24 ± 0.20 µM. Conversely, aurantioobtusin (7a), obtained from the acid hydrolysis of 7, showed no activity. Further inhibitory kinetics analyzed from Lineweaver‐Burk plots showed 7 to be a competitive inhibitor with a Ki value of 8.3 × 10−5 M. Moreover, compound 7 showed marked inhibitory and scavenging activities with an IC50 value of 49.64 ± 0.37 µM (positive control; trolox: 26.07 ± 1.05 µM) for total reactive oxygen species generation, and 4.60 ± 1.12 µM (positive control; penicillamine: 0.24 ± 0.04 µM) for ONOO−. Copyright © 2008 John Wiley & Sons, Ltd.
Comparative analysis between Chamomilla recutita and corticosteroids on wound healing. An in vitro and in vivo study
Authors: Martins Manoela Domingues , Marques Márcia Martins , Bussadori Sandra Kalil , Martins Marco Antonio Trevizani , Pavesi Vanessa Christina Santos , Mesquita‐Ferrari Raquel Agnelli , Fernandes Kristianne Porta Santos 
Published: September 2008

AbstractThe comparison of chamomile and corticosteroids for treating ulcers was done in vitro and in vivo. The experimental groups were: control; chamomile recutita; triamcinolone acetonide and clobetasol propionate. For the in vitro study the cell viability of fibroblasts cultured for 24 h in media conditioned by the substances was obtained by the MTT reduction analysis. For the in vivo study, 125 male rats were submitted to experimental ulcers treated or not (control) by the substances tested. At 1, 3, 5, 7 and 14 days later 5 animals of each group were sacrificed. The lesions were analyzed by means of clinical observation and histological wound‐healing grading. Data were compared by ANOVA (p ≤ 0.05). All experimental groups presented positive cell viability in 24 h. The cultures treated with chamomile presented the smallest cell viability. All animals of the chamomile group exhibited complete wound healing 9 days before the other groups. Complete repaired lesions were observed after 5 days of treatment only in the chamomile group. Animals treated with chamomile presented significantly faster wound healing in comparison to those treated with corticosteroids. Based on the conditions of this study, we concluded that chamomile in comparison to corticosteroids promotes faster wound healing process. Copyright © 2008 John Wiley & Sons, Ltd.
Top management incentive compensation and knowledge sharing in multinational corporations
Authors: Fey Carl F. , Furu Patrick 
Published: September 2008

AbstractGrowing interest has emerged in viewing the multinational corporation as a knowledge creating and diffusing entity. The importance of sharing knowledge across organizational and national boundaries has been established in previous research. However, the question of which organizational policies lead to knowledge sharing between multinational units is still not fully understood. In particular, the link between compensation mechanisms and knowledge sharing has not received attention in previous studies. By studying 164 foreign‐owned subsidiaries located in Finland and China, this article attempts to identify the relationship between subsidiary bonus pay based on MNC‐wide performance and knowledge sharing between different units of the MNC. In line with the knowledge‐based perspective of the firm, the results suggest that incentive pay based on the collective performance of the MNC leads to greater knowledge sharing. Copyright © 2008 John Wiley & Sons, Ltd.
Institutions, resources, and entry strategies in emerging economies
Authors: Meyer Klaus E. , Estrin Saul , Bhaumik Sumon Kumar , Peng Mike W. 
Published: September 2008

AbstractWe investigate the impact of market‐supporting institutions on business strategies by analyzing the entry strategies of foreign investors entering emerging economies. We apply and advance the institution‐based view of strategy by integrating it with resource‐based considerations. In particular, we show how resource‐seeking strategies are pursued using different entry modes in different institutional contexts. Alternative modes of entry—greenfield, acquisition, and joint venture (JV)—allow firms to overcome different kinds of market inefficiencies related to both characteristics of the resources and to the institutional context. In a weaker institutional framework, JVs are used to access many resources, but in a stronger institutional framework, JVs become less important while acquisitions can play a more important role in accessing resources that are intangible and organizationally embedded. Combining survey and archival data from four emerging economies, India, Vietnam, South Africa, and Egypt, we provide empirical support for our hypotheses. Copyright © 2008 John Wiley & Sons, Ltd.
What passes as a rigorous case study?
Authors: Gibbert Michael , Ruigrok Winfried , Wicki Barbara 
Published: September 2008

AbstractThis article investigates the methodological sophistication of case studies as a tool for generating and testing theory by analyzing case studies published during the period 1995–2000 in 10 influential management journals. We find that case studies emphasized external validity at the expense of the two more fundamental quality measures, internal and construct validity. Comparing case studies published in the three highest‐ranking journals with the other seven, we reveal strategies that may be useful for authors wishing to conduct methodologically rigorous case study research. Copyright © 2008 John Wiley & Sons, Ltd.
Appropriability, preemption, and firm performance
Authors: Ceccagnoli Marco 
Published: September 2008

AbstractThe impact of strategies used to appropriate innovation rents on firm performance is analyzed using a sample of U.S. public manufacturing firms. Stronger appropriability at the firm level, achieved through patent protection or the ownership of specialized complementary assets, leads to superior economic performance, as measured by the stock market valuation of a firm's R& D assets. Among commonly used ‘nonconventional’ patent strategies, preemptive patenting allows incumbents to strengthen their market power. Consistent with theory, such effect is higher for incumbents with higher ex ante market power and facing a higher threat of entry, and lower when R& D competition is characterized by the discovery of drastic innovations. Copyright © 2008 John Wiley & Sons, Ltd.
Capacity rationalization and exit strategies
Authors: Wood Andrew 
Published: September 2008

AbstractA case study of the response to chronic excess capacity in a small competitive industry (the manufacturing of clay bricks) permits a generalization of Bower's concentration hypothesis. Barriers to exit produced a free rider problem where only smaller and lower quality brick plants were shut when the efficient solution demanded major closures. The exit logjam was resolved by the strategic actions of growth‐maximizing managers. They used major acquisitions as the basis for substantial reductions in firm and industry capacity while growing their own market share. The fall in industry capacity enabled other firms to follow suit while maintaining their market share as predicted by prospect theory. Copyright © 2008 John Wiley & Sons, Ltd.
ANTI-COMMUTING REAL HYPERSURFACES IN COMPLEX TWO-PLANE GRASSMANNIANS
Authors: JEONG IMSOON , LEE HYUN JIN , SUH YOUNG JIN 
Published: September 2008

AbstractIn this paper we give a nonexistence theorem for real hypersurfaces in complex two-plane Grassmannians G2(ℂm+2) with anti-commuting shape operator.
Ethanol extract ofPsoralea corylifoliaL. and its main constituent, bakuchiol, reduce bone loss in ovariectomised Sprague–Dawley rats
Authors: Lim Sun-Hye , Ha Tae-Youl , Kim Sung-Ran , Ahn Jiyun , Park Hyun Jin , Kim Suna 
Published: September 2008

The aim of the present study was to investigate whether ethanol extracts ofPsoralea corylifoliaL. (PCE) and its active component protect against bone loss in ovariectomised rats. We screened oestrogenic activities of the main extract fractions usingin vitroassays and identified bakuchiol as the most active oestrogenic component by HPLC and LC/MS, and then demonstrated that bakuchiol had strong binding affinity for oestrogen receptor (ER) α. Seventy female Sprague–Dawley rats were assigned to either a sham-operated group (n10) or an ovariectomised group (n60). The ovariectomised group was subdivided into six groups, each containing ten rats: vehicle group, two bakuchiol-treated groups (dose of 15 mg/kg per d or 30 mg/kg per d; ten rats for each group), two PCE-supplemented groups (0·25 % or 0·5 % extracts of diets; ten rats for each group) and a 17β-oestradiol (E2)-treated group (20 μg/kg per d). We recorded weight and feed intake every week, and killed all animals after 6 weeks. Blood was collected, and the uterus, kidneys and livers were removed. Bakuchiol has a three-fold higher binding affinity for ERα than for ERβ. Bakuchiol and PCE treatments had no uterotrophic activity even though they demonstrated oestrogenic activity in thein vitroassays. Bakuchiol and PCE treatments reduced postmenopausal bone loss by increasing alkaline phosphatase, Ca concentrations, serum E2 concentration and bone mineral density, and by decreasing the inorganic P level. The present study indicated that bakuchiol and PCE treatments could protect against bone loss.
Timing of volcanism and evolution of the northern Kenya Rift
Authors: McDOUGALL IAN , BROWN FRANCIS H. 
Published: September 2008

AbstractThe northern Kenya Rift is bounded on the west by uplands of Turkana which comprise horst-like blocks that include metamorphic basement rocks, locally overlain unconformably by the Cretaceous Lubur Sandstone, in turn overlain by predominantly volcanic sequences in which relatively thin sedimentary packages occur. Amphibolite facies crystalline rocks of the basement yield Early Palaeozoic K–Ar cooling ages reflecting the Pan-African Orogeny. Volcanism in Turkana was initiated through voluminous eruptions of transitional tholeiitic basalts commencing about 36 Ma ago in the Late Eocene, with some evidence for concomitant rhyolitic volcanism. Volcanism became dominantly rhyolitic in the interval from about 27 to 23 Ma ago, but remained bimodal as basaltic lavas are also known from this period. From about 19 to 15 Ma or younger, basaltic volcanism again dominated, often alkaline in nature, with thin but significant sedimentary sequences interleaved that have yielded important vertebrate faunal assemblages. Parallels exist between the volcanic history recorded in Turkana and that found in the Nabwal Hills east of Lake Turkana. In the southern Turkana region, oil exploration by seismic methods and deep drill holes has shown the existence of northerly-trending half-graben with up to 7 km of fill, and that these developed from at least Oligocene and possibly Late Eocene times. This suggests that the widespread basaltic volcanism at about 36 Ma ago (Late Eocene) heralds an earlier initiation of the Kenya Rift in northern Kenya than most workers have previously suggested.
Bubble-induced skin-friction drag reduction and the abrupt transition to air-layer drag reduction
Authors: ELBING BRIAN R. , WINKEL ERIC S. , LAY KEARY A. , CECCIO STEVEN L. , DOWLING DAVID R. , PERLIN MARC 
Published: September 2008

To investigate the phenomena of skin-friction drag reduction in a turbulent boundary layer (TBL) at large scales and high Reynolds numbers, a set of experiments has been conducted at the US Navy's William B. Morgan Large Cavitation Channel (LCC). Drag reduction was achieved by injecting gas (air) from a line source through the wall of a nearly zero-pressure-gradient TBL that formed on a flat-plate test model that was either hydraulically smooth or fully rough. Two distinct drag-reduction phenomena were investigated; bubble drag reduction (BDR) and air-layer drag reduction (ALDR).The streamwise distribution of skin-friction drag reduction was monitored with six skin-friction balances at downstream-distance-based Reynolds numbers to 220 million and at test speeds to 20.0ms−1. Near-wall bulk void fraction was measured at twelve streamwise locations with impedance probes, and near-wall (0 <Y< 5mm) bubble populations were estimated with a bubble imaging system. The instrument suite was used to investigate the scaling of BDR and the requirements necessary to achieve ALDR.Results from the BDR experiments indicate that: significant drag reduction (>25%) is limited to the first few metres downstream of injection; marginal improvement was possible with a porous-plate versus an open-slot injector design; BDR has negligible sensitivity to surface tension; bubble size is independent of surface tension downstream of injection; BDR is insensitive to boundary-layer thickness at the injection location; and no synergetic effect is observed with compound injection. Using these data, previous BDR scaling methods are investigated, but data collapse is observed only with the ‘initial zone’ scaling, which provides little information on downstream persistence of BDR.ALDR was investigated with a series of experiments that included a slow increase in the volumetric flux of air injected at free-stream speeds to 15.3ms−1. These results indicated that there are three distinct regions associated with drag reduction with air injection: Region I, BDR; Region II, transition between BDR and ALDR; and Region III, ALDR. In addition, once ALDR was established: friction drag reduction in excess of 80% was observed over the entire smooth model for speeds to 15.3ms−1; the critical volumetric flux of air required to achieve ALDR was observed to be approximately proportional to the square of the free-stream speed; slightly higher injection rates were required for ALDR if the surface tension was decreased; stable air layers were formed at free-stream speeds to 12.5ms−1with the surface fully roughened (though approximately 50% greater volumetric air flux was required); and ALDR was sensitive to the inflow conditions. The sensitivity to the inflow conditions can be mitigated by employing a small faired step (10mm height in the experiment) that helps to create a fixed separation line.
Gonad development and spawning in one and two year old mussels (Mytilus edulis) from Western Norway
Authors: Duinker Arne , Håland Liv , Hovgaard Peter , Mortensen Stein 
Published: September 2008

Sexual maturation and spawning was followed in one and two year old rope cultured mussels (Mytilus edulis) from April to December. Development of gonad and storage tissue was followed using descriptive categories from histology, and development of total soft tissue was followed using meat yield and condition index.Both age groups were mature both during spring and autumn and had similar patterns of spawning and maturation. April and May were characterized by scattered spawning activity and accumulation of storage reserves at the same time, resulting in relative constant condition indices during this period. This was followed by ripening of the gonads and an increase in condition index that culminated in a spawning in late June. Parts of the population then entered a resting phase, while a part of the population underwent new maturation towards an autumn spawning in September. In December all the mussels had started the winter maturation.Condition index and meat yield were higher throughout the season in the one year old mussels. This was probably due to the sum of several factors, including differences in specific feeding rates and biomass density, rather than spawning.The present study is the first to compare the reproductive patterns over time of one and two year old mussels with reliable age determination, and provide information that there are no obvious differences in neither timing of gonad development nor spawning patterns between the age-classes.
Frequency and risk factors for toxoplasmosis in ovines of various regions of the State of Colima, Mexico
Authors: CABALLERO-ORTEGA H. , PALMA J. M. , GARCÍA-MÁRQUEZ L. J. , GILDO-CÁRDENAS A. , CORREA D. 
Published: September 2008

SUMMARYInfection of ewes byToxoplasma gondiimay induce abortions, thus it has consequences for sheep production. Colima, Western State of Mexico, has favourable climatic conditions for transmission and both domestic and wild cats live there. The aim of this study was to determine the frequency of specific antibodies in sheep from the coast, a mountain, and a hill of Colima. Serum samples from 351 sheep were tested by a previously standardized indirect ELISA. The frequency of infection was estimated and the farm location and flock size, as well as the animals' age and sex were analysed as risk factors for toxoplasmosis. The frequency of antibodies depended on the altitude, being higher at sea level than at 1200 metres above sea level (OR=3·77, 95% CI=1·79–7·94,P<0·0001), and the size of the flock, being higher in the large ones (OR=2·23, 95% CI=1·35–3·71,P=0·002). Older animals were more frequently positive and with a stronger response than young ones (OR=1·77, 95% CI=1·07–2·93,P=0·016). No differences were observed between male and female sheep. In conclusion, toxoplasmosis is present in sheep of Colima with variations related to altitude, flock size and age.
A proof of Pesin's formula
Authors: Mañé Ricardo 
Published: September 2008

AbstractLet f: M → M be a diffeomorphism of a compact manifold M and let χ:M → R be defined by putting χ(x) equal to the sum of the non-negative characteristic exponents of f at x, each being counted with its multiplicity. If μ is an f-invariant probability of M which is absolutely continuous relative to Lebesgue measure, then Pesin has proved the entropy, hμ(f), is given by We prove this formula without using the theory of stable manifolds.
On the classification of Markov chains by finite equivalence
Authors: Parry William , Tuncel Selim 
Published: September 2008

AbstractWe consider a certain analytic function β (t) which is an invariant of finite equivalence between two finite state Markov chains. If two such chains P, Q have the same β-function we wish to prove that they are finitely equivalent. To this end we show that U(t)Pt = QtU (t) has a nontrivial matrix solution U over the ring (exp) of integral combinations of exponential functions. In fact we can force U(t) to be strictly positiveat any specified t0. If U(t) has entries from (exp), the sub-semi-ring of positive integral combinations of exponential functions, then P, Q are finitely equivalent. Many examples reinforce the conjecture that U(t) may always be chosen over (exp) when P, Q have the same β-function. We relate the β-function to topological entropy, measure entropy and information variance.
The modified Lax and two-dimensional Toda lattice equations associated with simple Lie algebras
Authors: Wilson George 
Published: September 2008

AbstractWe associate to each complex simple Lie algebra g a hierarchy of evolution equations; in the simplest case g = sl(2) they are the modified KdV equations. These new equations are related to the two-dimensional Toda lattice equations associated with g in the same way that the modified KdV equations are related to the sinh-Gordon equation.
Maximally highly proximal generators of minimal flows
Authors: Auslander Joseph , van der Woude Jaap 
Published: September 2008

AbstractWe study minimal flows and their extensions by means of the associated maximally highly proximal flows. These, in turn, can be represented by highly proximal generators, which are certain subsets of the universal minimal flow. From this point of view we obtain information on relative disjointness, coalescence, the Bronstein property, and RIC extensions.
An amenable equivalence relation is generated by a single transformation
Authors: Connes A. , Feldman J. , Weiss B. 
Published: September 2008

AbstractWe prove that for any amenable non-singular countable equivalence relation R⊂X×X, there exists a non-singular transformation T of X such that, up to a null set:It follows that any two Cartan subalgebras of a hyperfinite factor are conjugate by an automorphism.
An alternative approach to the ergodic theory of measured foliations on surfaces
Authors: Rees Mary 
Published: September 2008

AbstractWe consider measured foliations on surfaces, and interval exchanges. We give alternative proofs of the following theorems first proved by Masur and (independently) Veech. The action of the diffeomorphism group of the surface on the projective space of measured foliations (with respect to a natural ‘Lebesgue’ measure) is ergodic. Almost all measured foliations are uniquely ergodic. Almost all interval exchanges (again, with respect to a natural ‘Lebesgue’ measure) are uniquely ergodic.
Integrable geodesic flows on homogeneous spaces
Authors: Thimm A. 
Published: September 2008

AbstractA method is exposed which allows the construction of families of first integrals in involution for Hamiltonian systems which are invariant under the Hamiltonian action of a Lie group G. This is applied to invariant Hamiltonian systems on the tangent bundles of certain homogeneous spaces M = G/K. It is proved, for example, that every such invariant Hamiltonian system is completely integrable if M is a real or complex Grassmannian manifold or SU(n + 1)/SO(n + 1) or a distance sphere in ℂPn+1. In particular, the geodesic flows of these homogeneous spaces are integrable.
The bifurcation of periodic orbits of one-dimensional maps
Authors: Block Louis , Hart David 
Published: September 2008

AbstractThe bifurcation of C1-continuous families of maps of the interval or circle is studied. It is shown, for example, that period-tripling cannot occur. This yields topological properties of the stratification of C1(I, I) induced by the Sarkovskii order, and corresponding bifurcation properties.