bluuebunny/crossref_metadata_2025 huggingface dataset:
The Global System of Finance
Authors: Hessling Alexandra , Pahl Hanno
Published: March 2006

Abstract.  In the last decades, revolutionary changes in financial markets, instruments, and institutions have stimulated empirical and theoretical investigations into the interaction of the financial and the “real” side of economic systems. While a considerable body of empirical investigations seems to provide evidence of positive correlations between stock market development and economic growth, there is no consensus in other social sciences as to whether there are two‐way linkages, and if so, how to conceive a possible mechanism of interaction. Particularly, the hypergrowth and ubiquity of financial markets has triggered controversial debates on how to understand today's economic landscape. With the objective of clarifying the relationship between finance and economy, this article restructures the present debate through the lenses of Talcott Parsons's and Niklas Luhmann's theories of social systems. Basic system‐theoretical ideas on social aspects of finance and economy as well as on uncertainty and risk hint at new insights into the global system of finance that might go far beyond explanatory models of causality.
Market Valuation of Tax‐Timing Options: Evidence from Capital Gains Distributions
Authors: CHAY J. B. , CHOI DOSOUNG , PONTIFF JEFFREY
Published: March 2006

We examine a distribution that is taxed as a capital gain rather than as a dividend. Since the distribution induces a realized capital gain while the price change is an unrealized gain, ex‐day return behavior provides evidence of the value of tax‐timing capital gains. We show that investors are compensated 7¢ in unrealized gains for each dollar of realized capital gains, that is, $1 of realized capital gains is equivalent to 93¢ of unrealized gains. An investor with a tax rate on realized gains of 15% has an effective tax rate on unrealized capital gains of 8.6%.
Banks' Advantage in Hedging Liquidity Risk: Theory and Evidence from the Commercial Paper Market
Authors: GATEV EVAN , STRAHAN PHILIP E.
Published: March 2006

Banks have a unique ability to hedge against market‐wide liquidity shocks. Deposit inflows provide funding for loan demand shocks that follow declines in market liquidity. Consequently, banks can insure firms against systematic declines in liquidity at lower cost than other institutions. We provide evidence that when liquidity dries up and commercial paper spreads widen, banks experience funding inflows. These flows allow banks to meet loan demand from borrowers drawing funds from commercial paper backup lines without running down their holdings of liquid assets. We also provide evidence that implicit government support for banks during crises explains these funding flows.
Firm Value and Hedging: Evidence from U.S. Oil and Gas Producers
Authors: JIN YANBO , JORION PHILIPPE
Published: March 2006

This paper studies the hedging activities of 119 U.S. oil and gas producers from 1998 to 2001 and evaluates their effect on firm value. Theories of hedging based on market imperfections imply that hedging should increase the firm's market value (MV). To test this hypothesis, we collect detailed information on the extent of hedging and on the valuation of oil and gas reserves. We verify that hedging reduces the firm's stock price sensitivity to oil and gas prices. Contrary to previous studies, however, we find that hedging does not seem to affect MVs for this industry.
How Do Crises Spread? Evidence from Accessible and Inaccessible Stock Indices
Authors: BOYER BRIAN H. , KUMAGAI TOMOMI , YUAN KATHY
Published: March 2006

We provide empirical evidence that stock market crises are spread globally through asset holdings of international investors. By separating emerging market stocks into two categories, namely, those that are eligible for purchase by foreigners (accessible) and those that are not (inaccessible), we estimate and compare the degree to which accessible and inaccessible stock index returns co‐move with crisis country index returns. Our results show greater co‐movement during high volatility periods, especially for accessible stock index returns, suggesting that crises spread through the asset holdings of international investors rather than through changes in fundamentals.
Mechanical Property and Oxidation Behavior of Self‐Reinforced Si3N4 Doped with Re2O3 (Re=Yb, Lu)
Authors: Tong Xuguang , Li Jianbao , Yang Xiaozhan , Lin Hong , Guo Gangfeng , He Mingsheng
Published: March 2006

In this work, self‐reinforced silicon nitrides with β‐Si3N4 seeds doped with Re2O3 (Re=Yb, Lu) were investigated. Firstly, the two kinds of seeds were obtained by heating α‐Si3N4 powder with Yb2O3 or Lu2O3, respectively. Then the self‐reinforced silicon nitride ceramics were prepared by HP‐sintering of α‐Si3N4 powder, Re2O3 as additive, and the as‐prepared seeds. Oxidation test was carried out at 1400°C in air for 100 h with thermogravimetry analysis (TGA) measurement. Mechanical properties, scanning electronic microscopy microstructures, and X‐ray diffraction patterns were measured before and after oxidation. The results indicated that the introduction of the seeds doped with Re2O3 (Re=Yb, Lu) could obviously increase the toughness and keep the room temperature and high‐temperature strength of the ceramics at high values. After oxidation, the crystalline phase in grain boundary changed and the mechanical properties decreased. TGA showed a parabolic weight gain and the oxidation mechanism was discussed.
Pressureless Densification of Zirconium Diboride with Boron Carbide Additions
Authors: Zhang S. C. , Hilmas G. E. , Fahrenholtz W. G.
Published: March 2006

Zirconium diboride (ZrB2) was densified (>98% relative density) at temperatures as low as 1850°C by pressureless sintering. Sintering was activated by removing oxide impurities (B2O3 and ZrO2) from particle surfaces. Boron oxide had a high vapor pressure and was removed during heating under a mild vacuum (∼150 mTorr). Zirconia was more persistent and had to be removed by chemical reaction. Both WC and B4C were evaluated as additives to facilitate the removal of ZrO2. Reactions were proposed based on thermodynamic analysis and then confirmed by X‐ray diffraction analysis of reacted powder mixtures. After the preliminary powder studies, densification was studied using either as‐received ZrB2 (surface area ∼1 m2/g) or attrition‐milled ZrB2 (surface area ∼7.5 m2/g) with WC and/or B4C as a sintering aid. ZrB2 containing only WC could be sintered to ∼95% relative density in 4 h at 2050°C under vacuum. In contrast, the addition of B4C allowed for sintering to >98% relative density in 1 h at 1850°C under vacuum.
Patterns of phytoplasma‐infected and infective Scaphoideus titanus leafhoppers in vineyards with high incidence of Flavescence dorée
Authors: Bressan Alberto , Larrue Jean , Padieu Elisabeth Boudon
Published: March 2006

The incidence and transmissibility of Flavescence dorée phytoplasma (FDP) in populations of the vector Scaphoideus titanus Ball (Homoptera: Cicadellidae) were investigated by periodically collecting nymphs and adults of the leafhopper species in four vineyards with high incidence of Flavescence dorée (FD)‐diseased grapevines. Insects were tested individually for FDP with an ELISA procedure, after transmission assays to broadbean seedlings and further transmission to grapevine cuttings. No transmission occurred when early or middle instar nymphs were used to inoculate broadbeans, although a limited number of fifth‐instar nymphs and young adults transmitted the pathogen to broadbean seedlings. However, the same batches of insects transmitted FDP more efficiently to grapevine cuttings during prolonged inoculation periods, confirming the existence of a latent period before infected insects become infective. The proportions of ELISA‐positive individuals in the three categories of insects used for transmission assays reflected the rate of FDP transmission to grapevine cuttings. According to the data obtained by ELISA and from field sampling of first‐instar nymphs, we adapted the proportions of nymph hatching, of infected leafhoppers, and of infective leafhoppers (assuming a conservative latent period in the vector of 30 days) to logistic models as a function of degree‐days. We then discussed the possible use of the model developed for improving vector control decisions in FD‐infected vineyards.
The role of the antennae and maxillary palps in mediating food preference by larvae of the tobacco hornworm, Manduca sexta
Authors: De Boer Gerrit
Published: March 2006

The role of antennae and maxillary palps in mediating food preferences by Manduca sexta (Johan.) (Lepidoptera: Sphingidae) was examined. Fifth‐instar larvae, having different chemosensory organs remaining after microsurgery, were tested in two‐choice feeding assays using three solanaceous host species Lycopersicon esculentum (Mill.), Datura innoxia (Mill.), and Solanum pseudocapsicum (L.), an acceptable non‐host Raphanus sativus (L.) (Cruciferae), and an unacceptable non‐host Pelargonium hortorum (L.H. Bailey) (Geraniaceae). Larvae had a choice between leaf discs of two plant species or between one species and moist filter paper discs (water).

The antennae are fully competent in mediating normal (unimpaired) food preferences for S. pseudocapsicum vs. water and P. hortorum vs. water. Thus, the antennae alone can mediate both acceptance and rejection behaviour. The latter is the first report of such a function in M. sexta. The antennae are partly competent (reduced preference) for S. pseudocapsicum vs. P. hortorum. No antennal competence could be demonstrated using the other plant species tested. The antennae alone are either partly needed (R. sativus vs. water) or not necessary to elicit normal food preferences for the plant species tested.

The maxillary palps are fully competent in mediating normal food preference for S. pseudocapsicum vs. water, and D. innoxia vs. water. The palps are partly competent for S. pseudocapsicum vs. P. hortorum and incompetent for the other plant species tested. Thus, the maxillary palps alone could only mediate acceptance behaviour in this study. The need of the maxillary palps in normal food preferences could not be demonstrated.

Interestingly, the maxillary palps alone can mediate food preferences for two normally rejected plants, R. sativus and P. hortorum. Similar results are reported for two other non‐host plant species, Vigna unguiculata (Walp.) (Leguminosae) and Vinca rosea (L.) (Apocynaceae). Perhaps, the maxillary palps inform M. sexta mostly about feeding stimulatory chemicals common to most plant species.
The effect of temperament and character on response to selective serotonin reuptake inhibitors in panic disorder
Authors: Marchesi C. , Cantoni A. , Fontò S. , Giannelli M. R. , Maggini C.
Published: March 2006

Objective:  In this prospective study, temperament and character were evaluated in patients with panic disorder (PD), before 1 year of medication therapy, to verify whether these factors influenced the outcome of treatment.

Method:  Seventy‐one PD patients were evaluated with the SCID‐IV, the Temperament and Character Inventory (TCI), the SCL‐90, the Ham‐A and the Ham‐D. Patients were treated with pharmacotherapy and were evaluated monthly over 1 year.

Results:  Before treatment, non‐remitted patients showed higher levels of harm avoidance (HA) and lower levels of persistence (P), self‐directedness (SD) and cooperativeness (C), whereas remitted patients showed only higher levels of HA. After controlling the effect of the confounding variables, the likelihood to achieve remission was positively related to SD score (OR = 1.12; P = 0.002), particularly ‘self‐acceptance’ SD dimension (OR = 1.30; P = 0.02).

Conclusions:  Our data suggest that in PD: i) the evaluation of personality, using the Cloninger's model, confirms the presence of personality pathology as one predictor of non‐response to treatment; ii) in patients with low SD a combination of medication and cognitive‐behaviour therapy should be the most effective treatment.
Prevalence of Toxoplasma infection in first‐episode schizophrenia and comparison between Toxoplasma‐seropositive and Toxoplasma‐seronegative schizophrenia
Authors: Wang H.‐L. , Wang G.‐H. , Li Q.‐Y. , Shu C. , Jiang M.‐S. , Guo Y.
Published: March 2006

Objective:  To compare the prevalence of Toxoplasma infection between the first‐episode schizophrenia and the controls and to compare the clinical features between the Toxoplasma‐seronegative and Toxoplasma‐seropositive patients with schizophrenia.

Method:  The rate of serum reactivity toToxoplasma in 600 schizophrenia, 600 affective disorders, and 400 controls was investigated. The clinical symptoms of the schizophrenia patients were scored and compared.

Results:  The rate of IgG antibody, not IgM in the schizophrenia patients, was higher than the control groups, and the odds ratio of schizophrenia associated with IgG antibody was 2.22–5.12. The affective disorders did not differ in the rate of IgG or IgM antibody from the normal or the physical disease control. The seropositive schizophrenia patients had higher scores on the positive subscale and three components of Positive and Negative Symptoms Scale than the seronegative patients.

Conclusion:  This study lent further weight to the hypothesis that exposure to Toxoplasma may be a risk factor for schizophrenia.
Experimental evaluation of cyadox phototoxicity to Balb/c mouse skin
Authors: He Qinghua , Fang Guijie , Wang Yulian , Wei Zhichao , Wang Daju , Zhou Shiqi , Fan Shengxian , Yuan Zanghui
Published: March 2006

Background: Cyadox is a veterinary drug mainly used as an effective antimicrobial promoter in animal husbandry. It was reported that the other quinoxaline‐1,4‐dioxide compounds had phototoxicity, but only few data are reported on phototoxicity of cyadox. This study was performed to evaluate the phototoxicity of cyadox on skin.

Methods: Eighty mice were equally divided into eight groups. Five groups with ultraviolet A (UVA) irradiation for 2 h (21 J/cm2) were administered at doses of 0, 10, 50, 200 mg/kg cyadox and 50 mg/kg olaquindox, respectively, and others as controls without irradiation administered at doses of 0, 200 mg/kg cyadox and 50 mg/kg olaquindox, respectively. Drugs were administered by gavage once daily with a suspension in 0.8% carboxymethyl‐cellulose for consecutive 4 days. After administration, a recovery period of 7 days was arranged. Histopathological examination of auricular skin was performed on days 5 and 12. Measurement of auricular thickness, gross pathology and erythema score were conducted once daily.

Results: Cyadox groups (200, 50 and 10 mg/kg) with irradiation had erythema and oedema of auricular skin with dose–response relationship, which gradually convalesced after dosing and irradiation ceased. Severe erythema, oedema and necrosis of auricles were observed on olaquindox group with irradiation.

Conclusion: The phototoxicity of cyadox was mild and reversible, which demonstrated a good safety profile of cyadox in terms of phototoxicity.
Biological effect of far‐infrared therapy on increasing skin microcirculation in rats
Authors: Yu Shi‐Yau , Chiu Jen‐Hwey , Yang Shiaw‐Der , Hsu Yu‐Chen , Lui Wing‐Yiu , Wu Chew‐Wun
Published: March 2006

Background/purpose: Insufficient microcirculation of skin leads to acute and chronic tissue ischemia in cases of trauma, reconstructive surgery, diabetes mellitus and peripheral arterial occlusive disease. The autonomic nervous system and nitric oxide (NO) play important roles in maintaining blood perfusion of the skin. Far‐infrared (FIR) therapy provides low energy of light emitted from an artificial radiator and has been used to treat many vascular‐related disorders. Nevertheless, the mechanisms through which FIR works remain unclear. The present study aims to test the hypothesis that the effect of FIR is through increasing skin microcirculation by a mechanism other than its thermal effect.

Methods: Sixty rats were used in the present study. A WS™ TY301 FIR emitter was placed 20 cm above the rats. Skin temperature and blood flow were continuously measured by a K‐type thermocouple. Under laboratory control, the abdominal skin temperature steadily increased from 38–39°C, and was kept at constant temperature. Skin microcirculation was measured with a continuous laser Doppler flowmeter.

Results: There was no significant change of skin blood flow during FIR treatment. Skin blood flow increased significantly soon after the removal of the FIR emitter. The stimulating effect on skin blood flow was more significant in the rats treated with FIR for 45 min and could be sustained as long as 60 min. These findings suggested a non‐thermic biological effect of FIR on skin microcirculation. The promotive effect of FIR on increasing skin blood flow was not influenced by pretreatment of APP (atropine, propranolol and phentolamine), but was suppressed by pretreatment with NG‐nitro‐l‐arginine methyl ester (an endothelial nitric oxide synthase inhibitor).

Conclusion: In conclusion, FIR therapy exerts a NO‐related biological effect to increase skin microcirculation in rats. This might bring into perspective the clinical application of FIR to treat ischemic disease by augmenting l‐arginine/NO pathway.
Biological effects of simulated ultraviolet daylight: a new approach to investigate daily photoprotection
Authors: Seité Sophie , Medaisko Chantal , Christiaens François , Bredoux Catherine , Compan Delphine , Zucchi Hélène , Lombard Danièle , Fourtanier Anny
Published: March 2006

Background: The irradiance of standard ultraviolet daylight (UV‐DL) is representative of most frequently encountered UV exposure conditions and simulators of UV‐DL can now be used to properly investigate the biological effects of a non‐extreme UV radiation. One of the characteristics of the simulated UV‐DL used in this study is its dUVA to dUVB irradiance ratio, which amounts to 24, instead of close to 10, for the simulated zenithal UV radiation (UV‐SSR).

Purpose/Methods: The aim of our study was to compare photobiological effects induced, in human skin, by acute and semi‐chronic exposure to simulated UV‐DL with those induced by UV‐SSR.

Results: Differences between UV doses needed to induce given biological effects after exposure to simulated UV‐DL compared with UV‐SSR indicate that the spectral distribution of the UV spectrum is of primary importance with regard to biological endpoints in the epidermis (SBC, p53, thymine dimers, Langerhans cells, and melanocyte alterations, etc.) and in the dermis (collagen, tenascin, etc.).

Significant biological damage was noticed after 19 cumulative exposures to 0.5 minimum erythemal dose (MED) of UV‐DL over 4 weeks. 0.5 MED of UV‐DL corresponds to 1/9 of the daily typical dose received in Paris in April, emphasizing the need for an efficient daily UV protection.

Conclusion: Simulated UV daylight is a relevant new tool for daily photoprotection studies.
Internalized Pseudomonas Exotoxin A can Exploit Multiple Pathways to Reach the Endoplasmic Reticulum
Authors: Smith Daniel C. , Spooner Robert A. , Watson Peter D. , Murray James L. , Hodge Thomas W. , Amessou Mohamed , Johannes Ludger , Lord J. Michael , Roberts Lynne M.
Published: March 2006

Receptor‐mediated internalization to the endoplasmic reticulum (ER) and subsequent retro‐translocation to the cytosol are essential sequential processes required for the intoxication of mammalian cells by Pseudomonas exotoxin A (PEx). The toxin binds the α2‐macroglobulin receptor/low‐density lipoprotein receptor‐related protein. Here, we show that in HeLa cells, PEx recruits a proportion of this receptor to detergent‐resistant microdomains (DRMs). Uptake of receptor‐bound PEx involves transport steps both directly from early endosomes to the trans‐Golgi network (TGN) independently of Rab9 function and from late endosomes to the TGN in a Rab9‐dependent manner. Furthermore, treatments that simultaneously perturb both Arf1‐dependent and Rab6‐dependent retrograde pathways show that PEx can use multiple routes to reach the ER. The Rab6‐dependent route has only been described previously for cargo with lipid‐sorting signals. These findings suggest that partial localization of PEx within DRM permits a choice of trafficking routes consistent with a model that DRM‐associated toxins reach the ER on a lipid‐dependent sorting pathway whilst non‐DRM‐associated PEx exploits the previously characterized KDEL receptor‐mediated uptake pathway. Thus, unexpectedly, an ER‐directed toxin with a proteinaceous receptor shows promiscuity in its intracellular trafficking pathways, exploiting routes controlled by both lipid‐ and protein‐sorting signals.
Farming with Your Hoe in a Sack: Condom Attitudes, Access, and Use in Rural Tanzania
Authors: Plummer Mary L. , Wight Daniel , Wamoyi Joyce , Mshana Gerry , Hayes Richard J. , Ross David A.
Published: March 2006

This study examines condom knowledge, attitudes, access, and practices in rural Mwanza, Tanzania. From 1999–2002, six researchers carried out participant observation in nine villages for a total of 158 person‐weeks. Many villagers perceived condoms negatively for multiple reasons, for example, the method's association with infection or promiscuity, reduced male sexual pleasure, and cultural understandings of meaningful sex. Men controlled the terms of sexual encounters and reported that they would use condoms only with risky partners, but few perceived their partners as such. Use of condoms appeared to be very low, primarily as a result of limited demand, although barriers to access also existed. These qualitative findings contrast with inconsistent survey reports of relatively high condom use in the same population. Intervention efforts should address the tradeoff between possible short‐ and long‐term consequences of condom use, particularly for men, for example, reduced pleasure versus reduced HIV risk. If possible, surveys should assess the validity of reported condom use through comparison with other data, including qualitative findings and distribution/sales records.
Turning policy into practice: more difficult than it seems. The case of breastfeeding education
Authors: Smale Mary , Renfrew Mary J. , Marshall Joyce L. , Spiby Helen
Published: March 2006

Breastfeeding is increasingly recognized as a health policy priority. To achieve real change in breastfeeding rates, those who advise and support childbearing women need to be appropriately educated and trained so that they do not disrupt breastfeeding. The aim of this study was to conduct a needs analysis about breastfeeding training among a range of people who advise and support breastfeeding women, including breastfeeding women themselves, to contribute to future provision of education. A qualitative, interview‐based study was conducted in one northern UK city with practitioners who support breastfeeding, and breastfeeding women, selected using purposive sampling. Individual (n = 73) and group (n = 9) interviews were conducted. Detailed notes were returned to each respondent for checking. Information was organized into themes. Coding was charted to enable comparison by theme and case. Four main themes emerged: perspectives of breastfeeding women; feeling (un)prepared to support breastfeeding; fragmentation of knowledge; and provision of education about breastfeeding. A deficit in education and training for all professional groups was identified. There was little evidence of informal shared learning among professional groups, and no evidence of usual mechanisms to ensure education and practice standards. Doctors received very little formal education; most relied on other health professionals to provide this expertise. Students encountered a chaotic learning environment where it was not possible to observe sound, consistent practice. Voluntary breastfeeding supporters felt well‐prepared. The results call into question the potential for health services to respond to policy recommendations that support increased rates of breastfeeding.
Civic Engagement Among Low‐Income and Low‐Wealth Families: In Their Words
Authors: McBride Amanda Moore , Sherraden Margaret S. , Pritzker Suzanne
Published: March 2006

Abstract:Using in‐depth interviews, we explored civic engagement that included volunteering through religious organizations, neighboring, involvement in children's activities, and contributing. The sample consisted of 84 low‐income, low‐wealth families. Findings indicate that although people of limited resources may be engaged, they face substantial challenges to active engagement. Data are suggestive of a modified life cycle theory, a resource or “stakeholding” theory, and institutional theories regarding challenges to engagement. In the context of the study's limitations, implications are discussed for measurement, research, and interventions.
Micro‐focus X‐ray computed tomography images of the 3D structure of the cranium of a fetus with asymmetric double malformation
Authors: Shibata Takashi , Matsumoto Sumiko , Nagano Teiko , Sasaki Hiroshi
Published: March 2006

ABSTRACT    Reconstructed micro computed tomography (Micro‐CT, µ‐CT) images have revealed the detailed three‐dimensional structure of the cranium of human fetal congenital anomalies for the first time. The objects were a head and a cervix of female autosite and a parasite consisting of only a head conjoined to the scapular region of the autosite of an asymmetric double malformation (asymmetric conjoined twins, heteropagus twinning) at a gestational age of 8 months. The cranium of the autosite was normal, but that of the parasite was characterized by otocephaly (agnathia, synotia, and monorhina) and almost all the cranial bones were of an abnormal shape. It is suggested that a part of occipital bone (the basioccipital and exoccipital bones), the vomer and cribriform plate were absent and this resulted in the fusion and overlapping of bilateral temporal and craniofacial bones that should have been adjacent to them. This resulted in a reformation and relocation of most of the cranial bones. Micro‐CT is a useful tool to visualize the detailed bone structure which has not been clarified by the conventional dissection methods and other imaging technologies and is a powerful instrument for studying congenital anomalies.
Leptin deficiency causes pycnotic change in fetal cingulate cortical cells
Authors: Udagawa Jun , Nimura Masayuki , Kagohashi Yukiko , Otani Hiroki
Published: March 2006

ABSTRACT    Leptin is an obese gene product, and leptin‐deficient ob/ob mice develop hyperphagia and reduced locomotor activity. Leptin is thought to be related to brain development, because leptin receptors are widely expressed in the brain, and because brain weight as well as brain protein and DNA contents were reduced in adult ob/ob mice. In this study, we investigated the effect of leptin on the fetal cingulate cortex, since the leptin receptor is expressed in the neurons of the cingulate cortex, which is involved in emotion as well as in sensory, motor, and cognitive processes. The ob/ob fetuses had more pycnotic cells than wild‐type fetuses in the cingulate cortex at embryonic day (E) 18. Many pycnotic cells were observed in the intermediate zone of the cingulate cortex. Most cells observed in this area were neuronal lineage cells, while few undifferentiated cells and oligodendrocyte precursor cells were found. At E18 there was no significant difference in the rostrocaudal length of the corpus callosum, which contains the neuronal projection from the cingulate cortex, between ob/ob and wild‐type fetuses. We also showed that the length of the cerebrum was greater and the width of the cerebrum and cerebellum were lesser in ob/ob fetuses than in wild‐type at E16. These results suggest an increased cell death in neuronal lineage cells in the intermediate zone of the cingulate cortex in leptin‐deficient ob/ob mice. Leptin deficiency may also alter the gross morphology of the brain in development, but not the formation of the corpus callosum.
Cleft lip and palate in mice treated with 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin: a morphological in vivo study
Authors: Yamada Tomohiro , Mishima Katsuaki , Fujiwara Kumiko , Imura Hideto , Sugahara Toshio
Published: March 2006

ABSTRACT    It is well‐known that TCDD (2,3,7,8, tetrachloridedibenzo‐p‐dioxin) induces cleft palates (CPs) in pregnant C57BL mice. However, it is unclear if TCDD is a possible teratogen for cleft lip. We examined maxillofacial malformations including cleft lip in three animal strains: A/J mice, C57BL/6J mice and ICR mice. The A/J mouse develops cleft lip and palate spontaneously at a 5–10% rate. TCDD was administered in olive oil on gestation day (GD) 12.5 with gastric tubes at 10 µg/kg, 20 µg/kg, or 40 µg/kg to examine the dose–response, and on a single day from GD 8.5–14.5 to examine the timing effects of TCDD administration on lip and palate formation. Furthermore, the palatal shelf movements during GD 8.5–14.5 were observed with a stereoscopic microscope. All embryos had cleft palates when the TCDD was administered just before palatogenesis (GD11.5‐GD12.5). With respect to the TCDD effects, there were large differences among the strains. In the A/J mice, the difference between a lethal dose and a dose that could induce a cleft palate was close. Cleft lips were not induced, even when the TCDD was given just before labiogenesis. Morphologically, both palatal shelves contacted perfectly along their lengths, but separated and formed cleft palates. In conclusion, TCDD is a strong inducer of cleft palates, and interferes with the fusion phase of the secondary palate, but has no effect on the lip.
Susceptibility of newborn rats to 3‐ethylphenol and 4‐ethylphenol compared with that of young rats
Authors: Takahashi Mika , Hirata‐Koizumi Mutsuko , Nishimura Nobuo , Ito Yoshihiko , Sunaga Masao , Fujii Sakiko , Kamata Eiichi , Hasegawa Ryuichi , Ema Makoto
Published: March 2006

ABSTRACT    Newborn rat studies were conducted with oral administration of 3‐ethylphenol (3EP) and 4‐ethylphenol (4EP) on postnatal days (PND) 4–21 to allow comparison of no observed adverse effect level (NOAEL) and unequivocally toxic level (UETL) with those from 28‐day studies of young rats starting at 5–6 weeks of age. In the newborn rat studies, slightly lowered body weight was observed after 3EP treatment, and deaths, hypoactivity, Straub tail, deep respiration and delayed righting reflex were clearly observed after 4EP treatment. In the young rat studies, salivation, staggering gait, changes in the liver including high values of liver weight and alanine aminotransferase or total cholesterol and the lesions in the forestomach were clearly observed after 3EP and 4EP treatments. NOAELs of 3EP and 4EP in the newborn rat studies appeared to be almost 3 times lower than those in the young rat studies. As a clear toxicity of 3EP was not observed in newborn rats, UETLs were not established for 3EP. Regarding 4EP, UETL of young rats was 4–5 times higher than that of newborn rats. In conclusion, newborn rats were 3–5 times more susceptible to 3EP and 4EP than young rats.
In vitro embryotoxicity testing of metals for dental use by differentiation of embryonic stem cell test
Authors: Imai Koichi , Nakamura Masaaki
Published: March 2006

ABSTRACT    We examined embryotoxicity using the embryonic stem cell test (EST) protocol. Tests were conducted using standard reagents for the atomic absorption measurement of 11 metal ions, silver, cobalt, chromium, copper, mercury, nickel, palladium, antimony, tin, vanadium, and zinc from among metals comprising dental alloys. In addition, for four metals like silver, cobalt, chromium, and nickel, the tests were also conducted using a test solution extracted from powder in the cell culture medium. The embryotoxic potential was obtained from a biostatistics‐based prediction model, which was calculated from three endpoints, the ID50, IC50ES and IC503T3. Data with the standard reagents showed that chromium and mercury ions corresponded to class 3, that is, having a strong embryotoxicity, while antimony, tin, and vanadium ions exhibited a weak embryotoxicity. The other metal ions demonstrated no embryotoxicity. On the other hand, when extracts of metal powder in cell culture solutions were used, silver exhibited a weak embryotoxicity while all other metals exhibited no embryotoxicity. In the future, it will be important to clarify the embryotoxicity of the many dental materials that are in use today. In addition, it is necessary to develop substances to ensure they have no toxicity before use in dental applications.
Population‐based case‐control study of oxoline acid use during pregnancy for birth outcomes
Authors: Dudás István , Puhó Erzsébet , Czeizel Andrew E.
Published: March 2006

ABSTRACT    The objective of the study was to check the effect of oxoline acid, a bactericidal drug for the treatment of urinary tract infection during pregnancy, on congenital abnormalities of informative offspring and fetal development. Human data of oxoline acid use during pregnancy have not been reported, but the use of this quinolone derivative is not recommended during pregnancy by the US Food and Drug Administration. The teratogenic and fetotoxic potential of oxoline acid was evaluated in the population‐based large data set of the Hungarian Case‐Control Surveillance of Congenital Abnormalities between 1980 and 1996. Observed and expected numbers of congenital abnormalities were compared in the newborn infants and fetus of case mothers with oxoline acid treatment. In addition, gestational age and birthweight were evaluated in control newborn infants born to mothers with or without oxoline acid treatment. Of 38 151 newborn infants without any congenital abnormalities (control group), 13 (0.03%) had mothers who were treated with oxoline acid, while of 22 843 cases with congenital abnormalities, five (0.02%) had mothers who were treated with oxoline acid during pregnancy (POR with 95% CI: 0.6, 0.2–1.8). The comparison of observed and expected number of different congenital abnormalities did not show the teratogenic potential of oxoline acid. There was a 0.9 weak shorter gestational age without a smaller birthweight in the newborn infants born to mothers with oxoline acid treatment. Our data did not indicate teratogenic and fetotoxic effect of oxoline acid, however, the number of cases and controls was limited.
A 10-Year Longitudinal Investigation of Strategy, Systems, and Environment on Innovation in Family Firms
Authors: Craig Justin B. L. , Moores Ken
Published: March 2006

This article studies innovation in family firms, filling in some gaps in existent literature. The research addresses the idea of shifting leadership, different mechanisms of facilitating communication, and the importance to the firm of technical progress, linking each to innovation. Shifting leadership is addressed through the longitudinal design. Communication mechanisms are monitored through two constructs: scope of information and timeliness of information. Technical progress is included in an environmental uncertainty factor technoeconomic uncertainty. The findings suggest that linkages between established family firms and innovation may be substantially stronger than currently assumed by many.
Ecological importance of Neotyphodium spp. grass endophytes in agroecosystems
Authors: Malinowski Dariusz P. , Belesky David P.
Published: March 2006

Neotyphodium spp. fungal endophytes form symbiotic associations with agronomic grasses with expression ranging from mutualistic to parasitic. In general, endophyte infection frequencies seem more variable in natural compared to pastoral situations, suggesting that expression and benefits attributable to endophyte infection depend on the resource environment in which the host–endophyte complex was formed and the conditions under which it is being grown. Emerging evidence suggests that expression is not always mutualistic or beneficial to the host in terms of productivity and persistence in resource‐limited environments. Expression of host–endophyte associations will vary depending on resource availability and environmental conditions that influence host physiology and growth, and herbivore behavior. New research suggest alkaloids and secondary metabolites produced by host–endophyte associations can have physiological functions in addition to acting as herbivore deterrents. Novel host–endophyte associations are being created that maintain insect and disease resistance, while having minimal detrimental impact on mammalian herbivores. The influence of host–endophyte associations on sward composition and soil food webs is only now coming to light. While novel endophyte associations and their attendant mechanisms can be considered beneficial in some respect, the associations may not be as adaptable to stressful or marginal resource environments and could have long‐term ecological impacts measured in terms of persistence and total productivity of the sward. We review the extensive published work on host–endophyte interactions and illustrate the complexity of host–endophyte associations and their interactions with environment, and the range of responses that occur.
Nuclear magnetic resonance studies of CXC chemokine receptor 4 allosteric peptide agonists in solution
Authors: Baryshnikova O.K. , Rainey J.K. , Sykes B.D.
Published: March 2006

Abstract:  CXC chemokine receptor 4 (CXCR4) is an important pharmacological target due to its involvement in HIV‐1 pathogenesis and cancer metastasis. Two recently discovered allosteric agonists that bind and activate CXCR4, the ASLW and RSVM peptides, were analyzed using solution nuclear magnetic resonance spectroscopy. Both peptides assumed an extended backbone conformation with several well‐defined local motifs in the regions from residues 5 to 8 and 9 to 12. The local structures in the region of residues 5–8 were different for agonists studied here and natural ligands. The local structure in the region 9–12 was adopted by the entire ensemble of the ASLW peptide structures and by the subset of conformations for the RSVM peptide. The same turn was found in full‐length stromal derived factor (SDF)‐1 and in the small family of the SDF‐1 N‐terminal 17‐mer. Similar examples in literature suggest the relevance of nascent structures in peptides to their biologically relevant conformations. The significance of found local structures and implications for further drug design are discussed.
Antifungal activity of human salivary mucin‐derived peptide, MUC7 12‐mer, in a murine model of oral candidiasis
Authors: Muralidharan R. , Bobek L.A.
Published: March 2006

Abstract:  Previous studies have shown that peptides derived from the N‐terminal region of the low molecular mass human salivary mucin, MUC7, possess potent in vitro cidal activity against Candida albicans and other medically important fungi. MUC7 12‐mer (residues 40–51 of the parent MUC7) peptide, having the optimal size and a net charge of +6, was found to be anticandidal in human saliva (clarified and unclarified), and its candidacidal potency was found to be superior to that of histatin 5 12‐mer (Hsn5 12‐mer). We have, therefore, explored the candidacidal potency of MUC7 12‐mer (l and d isomers) and Hsn5 12‐mer peptides in vivo. In vitro killing assay was performed to establish killing activity of the peptides against C. albicans prior to in vivo experiments. A murine model of oral candidiasis that has the characteristics of oral thrush in humans was employed for the in vivo studies, based on a previous protocol. Upon candidal induction, antifungal treatment application using agents emulsified in Pluronic F127 was performed for six consecutive days. Amphotericin B and clotrimazole emulsified in the same delivery system were used as positive control drugs. Candidacidal efficacy was evaluated microbiologically and histopathologically. Results demonstrated a considerable reduction of fungal burden by the MUC7 12‐mer peptides (l and d), comparable to control drugs, and this effect was statistically significant, unlike the effect seen with Hsn5 12‐mer. Murine oral candidiasis model employed in this study is suitable to test the candidacidal agents employing Pluronic F127. In conclusion, MUC7 12‐mer appears to be a promising candidate as an antifungal agent for oral candidiasis.
Bond Graph Based Approach to Passive Teleoperation of a Hydraulic Backhoe
Authors: Krishnaswamy Kailash , Li Perry Y.
Published: March 2006

Human operated, hydraulic actuated machines are widely used in many high-power applications. Improving productivity, safety and task quality (e.g., haptic feedback in a teleoperated scenario) has been the focus of past research. For robotic systems that interact with the physical environments, passivity is a useful property for ensuring safety and interaction stability. While passivity is a well utilized concept in electromechanical robotic systems, investigation of electrohydraulic control systems that enforce this passivity property are rare. This paper proposes and experimentally demonstrates a teleoperation control algorithm that renders a hydraulic backhoe/force feedback joystick system as a two-port, coordinated, passive machine. By fully accounting for the fluid compressibility, inertia dynamics and nonlinearity, coordination performance is much improved over a previous scheme in which the coordination control approximates the hydraulic system by its kinematic behavior. This is accomplished by a novel bond graph based three step design methodology: (1) energetically invariant transformation of the system into a pair of “shape” and “locked” subsystems; (2) inversion of the shape system bond graph to derive the coordination control law; (3) use of the locked system bond graph to derive an appropriate control law to achieve a target locked system dynamics while ensuring the passivity property of the coordinated system. The proposed passive control law has been experimentally verified for its bilateral energy transfer ability and performance enhancements.
Haptic Manipulation of Serial-Chain Virtual Mechanisms
Authors: Constantinescu Daniela , Salcudean Septimiu E. , Croft Elizabeth A.
Published: March 2006

This paper presents an approach for providing realistic force feedback to users manipulating serial-chain virtual mechanisms. In the proposed approach, a haptic device controller is designed that penalizes users’ motion along the directions resisted by the virtual joints. The resisted directions span the nullspace the Jacobian of the virtual mechanism computed at the users’ hand, and are derived via a singular value decomposition-based algorithm. Haptic numerical performance is achieved by computing the resisted directions on the graphics processor, and by using them on the haptics processor to derive the control signal that restricts users’ motion as required by the virtual joints. The performance of the proposed approach is validated through experimental manipulations of links with unrestricted and with restricted motion within a planar virtual world.
Development of a Second Generation In-Flight Icing Simulation Code
Authors: Beaugendre Héloïse , Morency François , Habashi Wagdi G.
Published: March 2006

Two-dimensional and quasi-3D in-flight ice accretion simulation codes have been widely used by the aerospace industry for the last two decades as an aid to the certification process. The present paper proposes an efficient numerical method for calculating ice shapes on simple or complex 3D geometries. The resulting ice simulation system, FENSAP-ICE, is built in a modular fashion to successively solve each flow, impingement and accretion via field models based on partial differential equations (PDEs). The FENSAP-ICE system results are compared to other numerical and experimental results on 2D and slightly complex 3D geometries. It is concluded that FENSAP-ICE gives results in agreement with other code calculation results, for the geometries available in the open literature.
Electrohydrodynamics of Thin Flowing Films
Authors: Griffing Evan M. , George Bankoff S. , Miksis Michael J. , Schluter Robert A.
Published: March 2006

Thin films of oil flowing down a nearly-vertical plate were subjected to a strong normal electrostatic field. Steady-state height profiles were measured by fluorescence imaging. For electrode potentials less than that required to produce an instability, the two-dimensional response of the interface was <1%. Calculations of the fluid height coupled with the electric field solution were identical to uncoupled calculations for electric fields below the stability threshold. Pressure profiles under the film and three-dimensional effects are also discussed.
Numerical Calculation of Pressure Fluctuations in the Volute of a Centrifugal Fan
Authors: Ballesteros-Tajadura Rafael , Velarde-Suárez Sandra , Hurtado-Cruz Juan Pablo , Santolaria-Morros Carlos
Published: March 2006

In this work, a numerical model has been applied in order to obtain the wall pressure fluctuations at the volute of an industrial centrifugal fan. The numerical results have been compared to experimental results obtained in the same machine. A three-dimensional numerical simulation of the complete unsteady flow on the whole impeller-volute configuration has been carried out using the computational fluid dynamics code FLUENT®. This code has been employed to calculate the time-dependent pressure both in the impeller and in the volute. In this way, the pressure fluctuations in some locations over the volute wall have been obtained. The power spectra of these fluctuations have been obtained, showing an important peak at the blade passing frequency. The amplitude of this peak presents the highest values near the volute tongue, but the spatial pattern over the volute extension is different depending on the operating conditions. A good agreement has been found between the numerical and the experimental results.
Power Assessment of Flowing Compressed Air
Authors: Cai Maolin , Kawashima Kenji , Kagawa Toshiharu
Published: March 2006

This study proposes a new concept for quantifying the energy of flowing compressed air, called air power. Air power is defined as the work-producing potential of compressed air, and its definition and general equation are presented. The properties of air power are also discussed. Air power is comprised of two components, transmission power and expansion power, while air temperature and kinetic energy can generally be neglected.
Prediction of Fluid Inertance in Nonuniform Passageways
Authors: Johnston D. Nigel
Published: March 2006

The dynamic response, stability, and noise characteristics of fluid components and systems can be strongly influenced by the inertance of the fluid in passageways, which are often of complex geometry. The inertance is a parameter that has often proved to be very difficult to accurately quantify, either theoretically or experimentally. This paper presents a method of numerical calculation of the inertance in a passageway, assuming inviscid, incompressible flow and zero mean flow. The method is simple to apply and can be applied to geometries of arbitrary complexity. Two simple but unorthodox ways of calculating inertance using a computational fluid dynamics and a finite element solid-modeling package are also demonstrated. Results are presented for a simple cylindrical orifice, a simple spool valve, and a conical poppet valve. The effect of the inertance on the response of a poppet valve is demonstrated.