bluuebunny/crossref_metadata_2025 huggingface dataset:
Current standards in the diagnostics and therapy of hair diseases – hair consultation
Authors: Blume‐Peytavi Ulrike , Vogt Annika
Published: February 2011

Hair and scalp diseases present an extensive diagnostic and therapeutic task. Treating them is often a challenge for the physician in daily practice. Unclear diagnoses, chronic conditions with long‐lasting therapies and the uncertainty of the patient may often lead to unsatisfying situations for both the patient as well as the doctor. The complaints can be divided into (1) hair loss, (2) increased hair growth and (3) abnormal hair quality. A structured history and the objectification of the clinical findings with the help of standardized diagnostic methods and score systems or classifications enable a diagnosis in most patients already at the first visit. Moreover, such structured processes strengthen the treatment satisfaction and compliance of both the patient and the therapist. In the meantime, diagnostic measures and clinical practice guidelines are available for the most common hair disorders. Expertise in basic psychosomatic care and an empathetic approach to the fears and concerns as well as practical advice for the daily contact with hair disorders should be integrated as separate elements in the management of hair diseases; in most cases they are gratefully welcomed by the patients. The aim of this article is to provide the physician with a guideline for the structured management of a hair patient. An overview of recent new developments and the currently available clinical practice guidelines for diagnosis and therapy of hair disorders is presented.
Cognitive and linguistic abnormalities in benign childhood epilepsy with centrotemporal spikes
Authors: Verrotti A , D’Egidio C , Agostinelli S , Parisi P , Chiarelli F , Coppola G
Published: February 2011

Aim: To assess the cognitive function and language ability in children with benign partial epilepsy with centrotemporal spikes.

Methods: Twenty‐five patients with benign partial epilepsy with centrotemporal spikes were included. They were divided into two subgroups. Group I: 10 patients with rolandic focus who were not treated. Group II: 15 patients with rolandic focus receiving treatment. A third Group of 12 healthy subjects have been studied. All children underwent standardized neuropsychological testing: electroencephalogram recording, Wechsler Intelligence Scale for Children‐revised, Peabody Picture Vocabulary Test‐III (PPVT‐III) and Boston Naming Test (BNT), both during active disease (T1) and 2 years after recovery from epilepsy (T2).

Results: At T1 evaluation, no significant differences in group I and II patients about general intelligence, when compared with controls, were found. Group I and II patients were impaired with respect to controls in the receptive and expressive vocabulary evaluated with PCVT‐III and BNT, respectively. At T2 evaluation, group I and II patients showed a normalization of the language abnormalities.

Conclusion: Deficits of speech‐related abilities can be detected in children with this type of epilepsy: these dysfunctions seem to be independent of the effects of antiepileptic treatment and are reversible after remission of epilepsy.
Testosterone and the child (0–12 years) with Klinefelter syndrome (47XXY): a review
Authors: Fennoy Ilene
Published: February 2011

Aim:  To review the evidence base for providing testosterone therapy in the infant and prepubertal child with Klinefelter syndrome (KS).

Methods:  Major databases were searched to identify articles that addressed the role of testosterone in the development of the male foetus with and without KS and that characterized testicular function in infants with KS.

Results:  Infants with KS have been shown to have an increased frequency of clinical features consistent with deficient testosterone production. However, there are conflicting results regarding whether testosterone levels are low or normal. No direct data address the outcome of therapy in the prepubertal child.

Conclusion:  There is an absence of data that directly address the risks and benefits of testosterone therapy in prepubertal children with KS outside of the entity of microphallus. At this time, there is no other documented benefit for testosterone therapy in these children.
Monitoring of protein catabolism in neonates and young infants post‐cardiac surgery
Authors: Teixeira‐Cintra Monica Akissue Camargo , Monteiro Jacqueline Pontes , Tremeschin Marina , Trevilato Tânia Maria Beltramini , Halperin Mitchell Lewis , Carlotti Ana Paula
Published: February 2011

Aims:  To evaluate cell catabolism by balance of nitrogen and phosphate, and creatinine excretion in children post‐cardiac surgery; to establish protein and energy requirements to minimize catabolism; and to assess nutritional therapy by following these parameters and serial anthropometric measurements.

Methods:  A prospective observational study of children with congenital heart disease undergoing cardiac surgery. Blood samples and 24‐h urine collections were obtained postoperatively for creatinine measurement and nitrogen and phosphate balance. Anthropometric measurements (weight, mid‐arm muscle circumference and triceps skinfold thickness) were obtained preoperatively and at paediatric intensive care unit and hospital discharge.

Results:  Eleven children were studied for 3–10 postoperative days. Anabolism was associated with higher protein and energy intakes compared to catabolism (1.1 vs. 0.1 g/kg/day and 54 vs. 17 kcal/kg/day, respectively). On days with anabolism, phosphate balance was greater compared with that on days with catabolism. Daily creatinine excretion did not correlate with protein balance. Anthropometric measurements did not change significantly over time.

Conclusions:  Children with congenital heart disease undergoing cardiac surgery achieved anabolism with >55 kcal/kg/day and >1 g/kg/day of protein. Balance of phosphate was useful to monitor cell breakdown. Anthropometric measurements were not valuable to evaluate nutritional therapy in this population.
Neurological complications and pandemic influenza A (H1N1) virus infection
Authors: Omari Ibrahim , Breuer Oded , Kerem Eitan , Berger Itai
Published: February 2011

Aim:  To report on a different clinical course of pandemic influenza A (H1N1) infection among children who were neurologically impaired before the acute onset of the disease, in comparison with children who were neurologically intact.

Methods:  In a period of 6 months, six children with neurological complications associated with pandemic A (H1N1) infection were identified in a single institution paediatric emergency room. The children suffered from seizures or altered mental status during pandemic A (H1N1) infection. All children underwent extensive clinical and laboratory assessment. Three children were neurologically impaired before the acute onset of the H1N1 infection. The other three were neurologically intact before the acute viral infection.

Results:  In all six patients, pandemic influenza A (H1N1) viral RNA was detected in nasopharyngeal specimens but none in the cerebrospinal fluid. Five children fully recovered or returned to baseline at discharge. The clinical course of the disease and recovery were different between the children who were neurologically impaired before the acute viral infection and those who were neurologically intact.

Conclusions:  It is possible that children with various neurological conditions are in a higher risk to develop further neurological complications during pandemic influenza A (H1N1) infection.
Structural and functional aspects of unique type IV secretory components in the Helicobacter pylori cag‐pathogenicity island
Authors: Cendron Laura , Zanotti Giuseppe
Published: February 2011

Helicobacter pylori cytotoxin‐associated gene‐pathogenicity island (cagPAI) is responsible for the secretion of the CagA effector through a type IV secretion system (T4SS) apparatus, as well as of peptidoglycan and possibly other not yet identified factors. Twenty‐nine different polypeptide chains are encoded by this cluster of genes, although only some of them show a significant similarity with the constitutive elements of well characterized secretion systems from other bacteria. The other cagPAI components represent almost unique proteins in this scenario. The majority of the T4SS include approximately fifteen components, taking into account either the transmembrane complex subunits, ATPases or substrate factors. The composition of the cagPAI is very complex: it includes proteins most likely involved at different levels in the pilus assembly, stabilization and processing of secreted substrate, as well as regulatory particles possibly involved in the control of the entire apparatus. Despite recent findings with respect to components that play a role in the interaction with the host cell, the function of several cagPAI proteins remains unclear or unknown. This is particularly true for those that represent unique members with no clear similarity to those of other T4SS and no obvious evidence of involvement in the secretion of CagA or induction of pro‐inflammatory responses. We summarize what is known about these accessory components, both from a molecular and structural point of view, as well as their putative physiological role.
Silintaphin‐1 – interaction with silicatein during structure‐guiding bio‐silica formation
Authors: Schloßmacher Ute , Wiens Matthias , Schröder Heinz C. , Wang Xiaohong , Jochum Klaus P. , Müller Werner E. G.
Published: February 2011

Silicateins are unique enzymes of sponges (phylum Porifera) that template and catalyze the polymerization of nanoscale silicate to siliceous skeletal elements. These multifunctional spicules are often elaborately shaped, with complex symmetries. They carry an axial proteinaceous filament, consisting of silicatein and the scaffold protein silintaphin‐1, which guides silica deposition and subsequent spicular morphogenesis. In vivo, the synthesis of the axial filament very likely proceeds in three steps: (a) assembly of silicatein monomers to form one pentamer; (b) assembly of pentamers to form fractal‐like structures; and finally (c) assembly of fractal‐like structures to form filaments. The present study was aimed at exploring the effect of self‐assembled complexes of silicatein and silintaphin‐1 on biosilica synthesis in vitro. Hence, in a comparative approach, recombinant silicatein and recombinant silintaphin‐1 were used at different stoichiometric ratios to form axial filaments and to synthesize biosilica. Whereas recombinant silicatein‐α reaggregates to randomly organized structures, coincubation of silicatein‐α and silintaphin‐1 (molecular ratio 4 : 1) resulted in synthetic filaments via fractal‐like patterned self‐assemblies, as observed by electron microscopy. Concurrently, owing to the concerted action of both proteins, the enzymatic activity of silicatein‐α strongly increased by 5.3‐fold (with the substrate tetraethyl orthosilicate), leading to significantly enhanced synthesis of biosilica. These results indicate that silicatein‐α‐mediated biosilicification depends on the concomitant presence of silicatein‐α and silintaphin‐1. Accordingly, silintaphin‐1 might not only enhance the enzymatic activity of silicatein‐α, but also accelerate the nonenzymatic polycondensation of the silica product before releasing the fully synthesized biosiliceous polymer.

Structured digital abstract

 silicatein‐ binds to silicatein‐ by electronmicroscopy (Viewinteraction)

 silicatein‐ and silintaphin‐1 bind by electronmicroscopy (Viewinteraction)
Impact of Hypertension, Aging, and Antihypertensive Treatment on the Morphology of the Pudendal Artery
Authors: Hannan Johanna L. , Blaser Mark C. , Pang Judith J. , Adams Stephen M. , Pang Stephen C. , Adams Michael A.
Published: February 2011

Introduction

Aging and hypertension increase the risk of erectile dysfunction (ED) and cardiovascular disease. Arterial insufficiency is likely a primary factor in hypertension-related ED. Given the dominance of internal pudendal arteries in controlling penile vascular resistance, pathological changes in this vessel would be critical for inducing ED in aged hypertensives.

Aim

We assessed the age-related impact of hypertension and its treatment on erectile function and pudendal artery structure in young and old spontaneously hypertensive rats (SHRs).

Methods

Erectile responses were monitored in 15- and 77-week-old SHR and Wistar Kyoto (WKY) rats using apomorphine (80 mg/kg). At sacrifice, the vasculature was perfusion-fixed and aorta, renal, mesenteric, and internal pudendal arteries assessed morphometrically using light and electron microscopy. A separate group of 15-week SHR were treated with enalapril and hydrochlorothiazide (30 mg/kg/day, 2 weeks) followed by 2 weeks off treatment, after which the same vessels were assessed morphometrically. Arterial pressures were determined using radiotelemetry.

Main Outcomes Measured

Erectile function, vessel morphology (lumen diameter, wall thickness, cross-sectional area, extracellular matrix [ECM]) and arterial pressure.

Results

Erectile responses were similar in young SHR and WKY (1.7 ± 0.80 vs. 1.4 ± 0.85) but declined significantly in aged SHR (0.3 ± 0.49). Vascular aging in SHR was associated with striking pudendal remodeling, characterized by marked neointimal proliferation and disruptions of the internal elastic lamina. This remodeling involved thickening of the medial layer (35 ± 6.0 µm vs. 81 ± 3.5 µm, P < 0.01), decreased lumen diameter (282 ± 6.3 µm vs. 250 ± 12.4 µm, P < 0.05) and increased ECM (10 ± 2.0 µm2 vs. 26 ± 10.6 µm2, P < 0.001). In old pudendals, there were significantly more round synthetic smooth muscle cells bordering the intima and in the neointima. Antihypertensive treatment decreased the wall : lumen ratio in young SHR pudendal arteries (−17%).

Conclusions

Vascular aging in SHR with ED involved distinctive pathogenic remodeling in the internal pudendal artery. In young SHR, brief antihypertensive therapy was able to regress this abnormal morphology.
MIXING TASTE ILLUSIONS: THE EFFECT OF MIRACULIN ON BINARY AND TRINARY MIXTURES
Authors: CAPITANIO ANTONELLA , LUCCI GIULIANA , TOMMASI LUCA
Published: February 2011

Miraculin, the extract of miracle fruit (Richadella dulcifica or Synsepalum dulcificum), is a taste‐modifying protein, its effect consisting in a temporary and almost complete replacement of sour taste with sweet taste. Despite psychophysical investigations were carried out in the past, very little is known about the effect of this molecule on taste interactions. We investigated the changes induced by miraculin on the gustatory sensations evoked by isolated tastants (citric acid, caffeine, NaCl and sucrose) and by binary and trinary mixtures that included a sour tastant (citric acid). We confirmed the effects of miraculin on citric acid, both as a single tastant and in mixtures. In mixtures including a salty tastant, the “illusory sweetness” induced by miraculin significantly reduced saltiness. Variable effects were shown on the perception of bitterness, although mostly in the direction of bitterness suppression. Finally, contrary to previous results, miraculin added sweetness in mixtures that included a sweet tastant.

PRATICAL APPLICATIONS

The taste‐modifying protein miraculin has been known since long time due to its surprising property of transforming sourness into sweetness. Here, we put at test the properties of miraculin in mixtures, proving that its sweetness‐inducing effect has an impact also on saltiness and bitterness, provided that the mixture includes a sour tastant (citric acid). In all mixtures containing NaCl (sour‐salty, sour‐salty‐bitter and sour‐salty‐sweet), saltiness was significantly reduced, suggesting a suppressive interaction between miraculin‐induced sweetness and NaCl. Similarly, although less strongly, the bitterness (of caffeine) was suppressed in two mixtures out of three (sour‐bitter and sour‐bitter‐sweet).
POSSIBILITY FOR A STRAWBERRY JAM SENSORY STANDARD
Authors: KOPPEL K. , TIMBERG L. , SALUMETS A. , PAALME T.
Published: February 2011

Sensory and instrumental characteristics of 25 commercial strawberry jam samples manufactured in 11 countries were compared to determine whether the development of a sensory or origin standard for strawberry jams was practical. Appearance, texture and flavor attributes were evaluated by sensory analysis. Color, hardness, sugar and acid profile, pH, dry weight and Brix of the samples were measured using instrumental means. The sweet attribute was correlated with total sugars (0.88), glucose (0.68), sucrose content (0.71), Brix (0.89) and dry weight of the samples (0.91). Sensory properties indicated three clusters of jams: (1) sweet, red‐colored jams holding a high‐fruit content; (2) jams containing artificial aromas and a granular structure; and (3) brown‐colored jams that were somewhat bitter, sour and astringent. Those clusters were independent of country of origin, thus a Protected Designation of Origin standard does not seem appropriate. However, a sensory standard based on color, sweetness and natural strawberry identity appears possible.

PRACTICAL APPLICATIONS

Strawberry flavoring and strawberry jams are used widely in various food products including pastries, dairy products and confectionery. Product developers, technologists and scientists in the food industry can benefit if a standard for the strawberry jam product category can be developed that are not dependent on country of origin.
TONGUE–PALATE INTERACTIONS DURING SWALLOWING
Authors: KIESER JULES , BOLTER CHRIS , RANIGA NITIN , WADDELL J. NEIL , SWAIN MICHAEL , FARLAND GUY
Published: February 2011

Investigating the sequence and magnitude of tongue movements against the hard palate during swallowing is basic to understanding the process by which the bolus is moved from the front of the mouth to the pharynx. Here we outline the basic muscular anatomy of the tongue, and we report on specific pressure patterns generated at three positions along the midline: at the front, middle and back of the hard palate. We show that there are sharp amplitudinal changes from positive to negative pressures at all three locations. While these pressure patterns show large interindividual variations, they appear to be consistent within individuals, irrespective of bolus size or consistency. Tentatively, we are able to identify three basic patterns; Type I, squeezer – a mostly positive pressure cascade from the front to the back of mouth; Type II, slider – characterized by an effortless and extended swallow, and Type III, slapper – large positive and negative pressure fluctuations during each swallow. Finally, we found that the most variability in pressure fluctuations occurred in the front of the mouth, from which we conclude that the front of the tongue has a predominant organisational role, whereas the back of the tongue is mostly propulsional.

PRACTICAL APPLICATIONS

While tongue pressure patterns during liquid swallowing vary greatly between persons, they appear to be highly specific within individuals. While some individuals have seemingly effortless swallows, others are more forceful and either squeeze their bolus or apply rapidly changing positive and negative forces to it. The results presented here also show that these patterns remain conserved irrespective of bolus consistency or volume, suggesting that novel foodstuffs might have to be individually designed with three swallowing types in mind. We also show maximum variation at the front of the tongue, emphasising an organisational rather than purely propulsional role for this area. This knowledge will be useful in designing and formulating new food products, particularly for those suffering from dysphagia, an inability to swallow normally.
TEXTURE PERCEIVED ON INULIN‐ENRICHED LOW‐FAT SEMISOLID DAIRY DESSERTS. RHEOLOGICAL AND STRUCTURAL BASIS
Authors: BAYARRI SARA , GONZÁLEZ‐TOMÁS LUIS , HERNANDO ISABEL , LLUCH Ma ANGELES , COSTELL ELVIRA
Published: February 2011

The aim of the present work is to study whether the perceived texture of low‐fat dairy desserts with inulin of different average chain lengths, can be explained by the rheological parameters and by structural characteristics. Creaminess, roughness and mouth coating of low‐fat samples with short‐chain or native inulin added, did not differ in the intensity of these attributes with respect to whole‐milk sample, although their visual consistency and thickness were perceived as significantly lower of that of whole‐milk sample. The addition of long‐chain inulin gives rise to a low‐fat product with the same thickness intensity as the full‐fat sample, though less creamy, rougher and with more mouth coating. Both flow and viscoelastic rheological indices values were related with differences in thickness observed among samples, but not with the variation in creaminess or roughness. The latter attributes could be explained by the presence of the inulin aggregates observed by microstructure analysis and detected by particle size distribution measurements.

PRACTICAL APPLICATIONS

Although mechanical and rheological properties are the predominant stimuli affecting texture perception in most foods, to match the rheological behavior of different samples does not guarantee matching the texture perceived. The aim of this work was to explain differences on the perceived texture of starch‐based dairy desserts with inulin of different average chain lengths added. The results have shown that although rheological data were able to explain the differences in thickness perceived, structural information is needed to understand differences in creaminess and roughness.
Verbascosides from Olive Mill Waste Water: Assessment of Their Bioaccessibility and Intestinal Uptake Using an In Vitro Digestion/Caco‐2 Model System
Authors: Cardinali Angela , Linsalata Vito , Lattanzio Vincenzo , Ferruzzi Mario G.
Published: February 2011

Abstract:  Olive mill wastewater (OMWW) is an agricultural waste material produced in high quantities in the Mediterranean basin. OMWW may be an inexpensive source of health promoting phytochemicals with potential economic value including many low molecular weight compounds such as verbascosides. While promising as antioxidants in vitro, little information is available on the potential absorption of verbascosides by humans. The main objective of the present study was to characterize the verbascoside content and potential for their bioavailability from a partially purified phenolic fraction (IP) of OMWW. The IP was obtained after ultrafiltration step at 5000 Dalton and gel filtration low‐pressure chromatography (LH20) of OMWW. RP‐HPLC analysis identified several soluble phenolics compounds including verbascoside and isoverbascoside as major components of OMWW fractions. The potential for bioavailability of these polyphenols was estimated by using both in vitro digestion and Caco‐2 human intestinal cell models. In vitro digestive recoveries (bioaccessibility) were found to be 35.5%± 0.55% for verbascoside and 9.2%± 0.94% for isoverbascoside highlighting potential sensitivity of these phenolics to gastric and small intestinal digestive conditions. Accumulation of verbascosides by highly differentiated Caco‐2 monolayers was linear between 10 and 100 μM of verbascoside and isoverbascoside from IP extract. Uptake of verbascoside and isoverbascoside was rapid with peak accumulation occurring after 30 min with total accumulation efficiency of 0.1% and 0.2% providing intracellular levels of 130 and 80 pmol/mg cell protein for verbascoside and isoverbascoside, respectively. Combined, these data suggest that verbascosides present in OMWW are bioaccessible and provides a rationale for subsequent in vivo studies on the bioavailability and bioactivity of OMWW components.
Regional Distribution and Prospects of Potash in China
Authors: Mianping ZHENG , Yongsheng ZHANG , Heran YUAN , Xifang LIU , Wenxi CHEN , Jinsuo LI
Published: February 2011

China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi‐stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in “quasi, cratons (continental block)”; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.
New Primitive Fossil Earwig from Daohugou, Inner Mongolia, China (Insecta: Dermaptera: Archidermaptera)
Authors: Jingxia ZHAO , Chungkun SHIH , Dong REN , Yunyun ZHAO
Published: February 2011

A new genus and species Palaeodermapteron dicranum gen. et sp. nov. of the subfamily Dermapterinae and family Dermapteridae is described from the Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia in China. This article documents the earliest record of fossil earwig, extending the earwig existence to the Middle Jurassic. Detailed description and illustration of the specimen along with a brief review of the subfamily Dermapterinae are given. Evolutional trend of earwig morphology and its associated living environment are also discussed.
Internal Structure of Cambrian Fossil Embryo Markuelia Revealed in the Light of Synchrotron Radiation X‐ray Tomographic Microscopy
Authors: Gong CHENG , Fan PENG , Baichuan DUAN , Xiping DONG
Published: February 2011

In the light of Synchrotron Radiation X‐ray Tomographic Microscopy (SRXTM), the internal structure of Markuelia hunanensis is revealed. In one example, vitrification and peeling show the annuli hidden under the chorion. Sectioning and 3‐D reconstruction display an intact digestive tract from the inverted introvert to the terminal anus. The inverted introvert forms a rugby cavum. The following digestive tract is rope‐like coiling, parallel to the body axis, about 650 μm in length, and uniform in diameter (∼80 μm). An exquisitely preserved pipe‐like structure is hidden in the middle of the rope‐like structure, diameter 20–40 μm, with a length of ∼120 μm. We interpret this pipe‐like structure as the possible epidermis of the gut and its surroundings as the possible residue of musculature, similar to that in Priapulans. The two symmetrical rod‐shape structures connecting the body wall and digestive tract are interpreted as the possible retractor muscles. After comparing the well preserved Left‐form and Right‐form Body of Markuelia, we suggest that they may represent a dimorphism. Counted directly, one sample of Markuelia hunanensis possesses 62 annulations and the other 68.
New Data on the Mineralogy of Chromite from the Nuggihalli Schist Belt, Western Dharwar Craton, Karnataka, India: Petrogenetic Implications
Authors: RAJU Perumala V.S. , BABU Elapavalooru V.S.S.K. , MERKLE Roland K.W.
Published: February 2011

The occurrence of rhythmic layering of chromite and host serpentinites in the deformed layered igneous complexes has been noticed in the Nuggihalli schist belt (NSB) in the western Dharwar craton, Karnataka, South India. For this study, the chromitite rock samples were collected from Jambur, Tagadur, Bhakatarhalli, Ranganbetta and Byrapur in the NSB. Petrography and ore microscopic studies on chromite show intense cataclasis and alteration to ferritchromite. The ferritchromite compositions are characterized by higher Cr number (Cr/[Cr+Al]) (0.68–0.98) and lower Mg number (Mg/[Mg+Fe]) (0.33–0.82) ratios in ferritchromite compared to that of parent chromite. The formation process for the ferritchromite is thought to be related to the exchange of Mg, Al, Cr, and Fe between the chromite, surrounding silicates (serpentines, chlorites), and fluid during serpentinization.
Geochemical Characteristics and Geological Significance of Early Permian Baya'ertuhushuo Gabbro in South Great Xing'an Range
Authors: Jianfeng LIU , Xiaoguo CHI , Zhi ZHAO , Xingzhou ZHANG , Zhihong MA , Tiefu WANG , Zhaochu HU
Published: February 2011

Field geological investigation and geochemical analysis are carried out on Baya'ertuhushuo Gabbro in South Great Xing'an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a component of an ophiolite suite as previously thought. Zircon laser ablation inductively coupled plasma mass spectroscopy (LA‐ICP‐MS) U‐Pb dating indicates the gabbro was formed in 274–275 Ma, just as the widespread volcanic rocks of Dashizhai Formation (P1d), monzogranites and miarolitic alkali‐feldspar granites in the study area. The gabbro has SiO2 content between 47.23 wt% and 50.17 wt%, high MgO and FeOT contents of 6.95–11.29 wt% and 7.32–12.24 wt%, respectively, and it belongs to low‐K tholeiitic series in the SiO2‐K2O diagram. The Chondrite‐normalized rare earth element (REE) patterns and primitive mantle‐normalized spider diagrams of the gabbro are similar to those of Normal Mid‐Ocean Ridge Basalt (N‐MORB) except for the enrichment of large ion lithophile elements (LILE), such as Rb, Ba and K. In trace element tectonic discriminative diagrams, the samples are mainly plotted in the N‐MORB field, and Zircon in situ Lu‐Hf isotopic analysis also indicates the gabbro originated from depleted mantle. Through synthetic studies of the geochemical characteristics and petrogenesis of Baya'ertuhushuo gabbro, volcanic rocks of Dashizhai Formation and granitoids in the area, it is suggested that the early Permian magmatism in the Xilinhot‐Xiwuqi area formed in the tectonic setting of asthenosphere upwelling, which was caused by breaking‐off of the subducted Paleo‐Asian Ocean slab.
Geochemistry of Ore‐bearing Lamprophyre from the Cu‐Ni Deposit in Dhi Samir, Yemen
Authors: Liyan ZUO , Rongfu PEI , Kaiye SHUAI , Fengqi YANG , Riwei ZHU , Liemeng ZHANG
Published: February 2011

Magmatic Cu‐Ni sulfide deposits are generally associated with mafic‐ultramafic rocks and it has not been reported that lamprophyre is one of the surrounding rocks of Cu‐Ni sulfide deposits. The Dhi Samir deposit in Yemen, however, is a rare example of Cu‐Ni deposits which are hosted in lamprophyre dikes. In this paper, comprehensive research is made on petrology, petrochemistry and isotope geochemistry for Cu‐Ni‐bearing rocks in the Dhi Samir area and the results show that dark rocks related to Cu‐Ni orebodies are sodium‐weak potassium and belong to calc‐alkaline series lamprophyre, especially camptonite, characterized by enriched alkali, iron and titanium. In these rocks large‐ion‐lithophile elements are obviously concentrated, while high field strength elements slightly depleted, showing clear negative anomalies of Ta and Nb, and weak deficiency of Ti. The ΣREE is very high (225.67–290.05 ppm) and the REE partition curves are flat and right‐inclined, featuring a LREE‐enriched pattern with low negative Eu anomalies. Study of magmatic source areas indicates that the rocks have low (87Sr/86Sr) and high εNd(t), and the magmas were probably derived from the enriched mantle I (EM‐I) end‐member. Based on the LA‐ICPMS on zircon U‐Pb isotope dating, the lamprophyre in the Dhi Samir mining area has an age of 602±2.6 Ma, indicating that the rock was formed in the late Proterozoic and in an intraplate setting due to magmatism of an extensional environment in the post‐Pan‐Africa orogeny.
A Kinematic Thermal Model for Descending Slabs with Velocity Boundary Layers: A Case Study for the Tonga Subducting Slab
Authors: Keliang ZHANG , Dongping WEI
Published: February 2011

For the purpose of investigating the influence of metastable olivine (MO) phase transformations on both deep seismicity and stagnation of slabs, we constructed a 2‐dimensional finite element thermal model for a 120 Ma‐old 50° dipping oceanic lithosphere descending at 10 cm/yr with velocity boundary layers, which would mitigate the interference of constant velocity field for the slab. The resulting temperatures show that most of intermediate and deep earthquakes occurring within the Tonga slab are occurring inside the 800°C and 1200°C isotherm, respectively. The elevation of olivine transformation near ∼410 km and respective persistence of metastable olivine and spinel within the transition zone and beneath 660 km would thus result in bimodal positive, zonal, negative density anomalies, respectively. These results together with the resulting pressure anomalies may reflect the stress pattern of the Tonga slab: (i) slab pull force exerts above a depth of ∼230 km; (ii) MO existence changes the buoyancy force within the transition zone and facilitates slab stagnation at a depth of 660 km; (iii) as the subducting materials accumulated over 660 km, deepest earthquakes occur due to MO transformation; (iv) a flattened ‘slab’ may penetrate into the lower mantle due to the density increment of Sp transformation.
Formation Mechanism of the Changxing Formation Gas Reservoir in the Yuanba Gas Field, Sichuan Basin, China
Authors: Shengxiang LONG , Renchun HUANG , Hongtao LI , Yuchun YOU , Guoping LIU , Zhenrui BAI
Published: February 2011

In a very gentle platform‐margin paleogeographic environment, platform‐margin reef flat fades carbonate reservoir rocks were developed in the Changxing Formation of Yuanba field. Later weak structural evolution and diagenetic evolution caused the Changxing Formation to form lithologic traps, with good reservoirs such as dissolved bioclastic dolostone and dissolved pore dolostone. The Changxing Formation gas reservoir is a pseudo‐layered porous lithologic gas reservoir under pressure depletion drive, with high H2S and moderate CO2 contents. This paper predictes that the conducting system for the Changxing Formation gas reservoir is possibly composed of the pores and microfractures in the Changxing Formation reservoir, the top erosional surface of the Changxing Formation, as well as the micropores and microfractures in the underlying formations. The Changxing Formation reservoir has experienced 3 hydrocarbon charging stages. This paper suggests that diffusion is the major formation mechanism for this gas reservoir. In the Middle and Late Yanshanian, the Yuanba area entered the major gas charging stage. The gas migrated mainly through diffusion and with the assistance of seepage flow in small faults and microfractures from the source rocks and the other oil‐bearing strata to the Changxing Formation carbonate reservoir rocks, forming lithologic gas pools. In the Himalayan Epoch, the lithologic traps were uplifted as a whole without strong modification or overlapping, and were favorable for gas preservation.
Using the theory of planned behaviour to understand binge drinking: The importance of beliefs for developing interventions
Authors: French David P. , Cooke Richard
Published: February 2011

Objectives.  To elicit students’ salient beliefs in relation to binge drinking, and to examine the extent to which individual salient beliefs predict theory of planned behaviour (TPB) constructs in relation to binge drink, and actual drinking behaviour assessed later that evening.

Design.  Longitudinal, over a single evening.

Methods.  192 students were recruited as they entered a campus bar at the beginning of the evening. They completed questionnaires with open‐ended questions eliciting beliefs concerning binge drinking, and ratings scales assessing standard TPB constructs in relation to binge drinking. At the end of the evening, 181 completed a second questionnaire and recorded the number of alcoholic drinks they had consumed.

Results.  Beliefs were reliably coded (all kappas ≥0.79). Students with higher intentions to binge drink were more likely to believe that their friends approved of binge drinking, and that (lack of) money would make it difficult. Students who reported drinking more alcohol at the end of the evening were more likely to believe that getting drunk is an advantage/what they would like about binge drinking tonight, that their sports teams would approve, and that celebrating, drinking patterns, and environment would make it easy to binge drink.

Conclusions.  The present study has identified the individually salient beliefs relating to drinking behaviour that the TPB states should be addressed by interventions to alter behaviour, and which that should be assessed as mediators in intervention research. As a whole, these findings highlight the importance of perceived peer norms in binge drinking in this population, and support the idea of interventions to challenge the perception of social pressure to binge drink.
Ageing reduces the compensatory vasodilatation during hypoxic exercise: the role of nitric oxide
Authors: Casey Darren P. , Walker Branton G. , Curry Timothy B. , Joyner Michael J.
Published: February 2011

Non‐technical summary  In young healthy humans, the combination of exercise and hypoxia produces a compensatory vasodilatation to ensure the maintenance of oxygen to the active muscles. We have previously demonstrated that nitric oxide (NO) is a major factor responsible for the compensatory vasodilatation. In this paper we show that the compensatory vasodilator response to hypoxic exercise is attenuated in older adults due to less NO signalling. These findings provide important information on the impact of ageing and the role of NO in the regulation of skeletal muscle blood flow during conditions of reduced oxygen availability.
L-Curve Based Tikhonov’s Regularization Method for Determining Relaxation Modulus From Creep Test
Authors: Zhu Yaoting , Sun Lu , Xu Huilin
Published: February 2011

A numerical method for directly obtaining discrete relaxation modulus from static creep tests data is developed for linear viscoelastic asphalt mixtures. To overcome the ill-posedness of interconversion between creep compliance and relaxation modulus, Volterra integral equations of the second kind and L-curve based Tikhonov’s regularization method are used to construct the computational scheme of parameter estimation. A numerical case study is presented to demonstrate the efficiency of the regularization method, which takes into account different step lengths and noise levels. It indicates that the computed results are accurate and robust at different noise levels. Compared with other existing methods, the L-curve based Tikhonov’s regularization method provides the best parameter estimates in dealing with both the numerical case study and the experiment data. The method can be used to extract viscoelastic parameters of asphalt mixtures from creep tests effectively and robustly.
Projection-Based Control of Parallel Mechanisms
Authors: Aghili Farhad
Published: February 2011

The unifying idea for most model-based control approaches for parallel mechanism is to derive a minimal-order dynamics model of the system and then design the corresponding controller. The problem with such a control approach is that the controller needs to change its structure whenever the mechanical system changes its number of degrees-of-freedom. This paper presents a projection-based control scheme for parallel mechanism that works whether the system is overactuated or not; it does not require derivation of the minimal-order dynamics model. Since the dimension of the projection matrix is fixed, the projection-based controller does not need to change its structure whenever the mechanical system changes its number of degrees-of-freedom. The controller also allows to specify lower and upper bounds on the actuator forces/torques, making it suitable not only for the control of parallel manipulators with limited force/torque capability of the actuators but also for backlash-free control of parallel manipulators as well as for control of tendon driven parallel manipulators. The stability of the projection-based controllers is rigourously proved, while the condition for the controllability of parallel manipulators is also derived in detail. Finally, experimental results obtained from a simple parallel mechanism, which changes its degrees-of-freedom, are appended. The results also demonstrate that the maximum actuator torque can be reduced by 20% if the actuator saturation is taken into account by the controller.
Thermovibrational Instability in a Fluid Saturated Anisotropic Porous Medium
Authors: Saravanan S. , Sivakumar T.
Published: February 2011

A comprehensive investigation is made to understand the effect of harmonic vibration on the onset of convection in a horizontal anisotropic porous layer heated either from below or from above. The layer is subject to vertical mechanical vibrations of arbitrary amplitude and frequency. The porous medium is assumed to be both mechanically and thermally anisotropic, and Brinkman’s law is invoked to model the momentum balance. Both continued fraction and Hill’s infinite determinant methods are used to determine the convective instability threshold with the aid of Floquet theory. The synchronous and subharmonic resonant regions of dynamic instability are determined and their critical boundaries are found. The results show that anisotropy in permeability favors convection whereas that in thermal conductivity suppresses it with a wider cellular pattern at the instability threshold. The influence of vibration parameters and heating condition on the anisotropy effects and the competition between the synchronous and subharmonic modes are discussed. This study also reveals the existence of a closed disconnected instability region in certain areas of the parameter space for the first time in literature.
Prediction of Thermal Conductivity and Convective Heat Transfer Coefficient of Nanofluids by Local Composition Theory
Authors: Hosseini M. S. , Mohebbi A. , Ghader S.
Published: February 2011

In this study, a new method based on the local composition theory has been developed to predict thermal conductivity, convective heat transfer coefficient, and viscosity of nanofluids. The nonrandom two liquid (NRTL) model is used for this purpose. The effects of temperature and particle volume concentration on thermal conductivity, convective heat transfer coefficient, and viscosity are investigated. The adjustable parameters of the NRTL model were obtained by fitting with experimental data. The results of the local composition theory are compared with the experimental data of CuO/water, Al2O3/water, TiO2/water, Cu/water, Au/water, Ni/water, TiO2/ethylene glycol, and Al/ethylene glycol (EG) nanofluids and a good agreement between the theory and the experimental data is observed. The absolute average deviation of the model for thermal conductivity was 1.51% in comparison to 42% in conventional models. This parameter for viscosity and convective heat transfer coefficient were 2.91% and 2.13%, respectively. Moreover, a new equation for calculating convective heat transfer coefficient of nanofluids is proposed and tested.
Natural Convection in a Quadrantal Cavity Heated and Cooled on Adjacent Walls
Authors: Aydin Orhan , Yesiloz Gurkan
Published: February 2011

In this study, experimental and numerical analyses of natural convection in a quadrantal cavity heated and cooled on adjacent walls have been made to examine heat and fluid flow. Experimental studies involve the use of the particle tracing method that enables us to visualize the flow pattern in the enclosure. Numerical solutions are obtained using a commercial computational fluid dynamics package, FLUENT, using the finite volume method. Water is used as the working fluid. Effects of the Rayleigh number, Ra, on the Nusselt number, Nu, as well as velocity and temperature fields are investigated for the range of Ra from 103 to 107. A new approach is suggested to overcome the singularity at the corner joining the differentially heated isothermal walls when determining Nu. This novel approach is justified through the purely analytical conduction solution. The experimental and numerical results are shown to agree fairly well. Finally, a correlation for Nu is developed.
Tensorial Parameterization of Rotation and Motion
Authors: Bauchau Olivier A. , Li Leihong
Published: February 2011

The parameterizations of rotation and motion are the subject of continuous research and development in many theoretical and applied fields of mechanics such as rigid body, structural, and multibody dynamics. Tensor analysis expresses the invariance of the laws of physics with respect to the change of basis and change of frame operations. Consequently, it is imperative to formulate mechanics problems in terms of tensorial quantities. This paper presents formal proofs that rotation and motion parameterizations are tensors if and only if they are parallel to the eigenvectors of the rotation and motion tensors, respectively, associated with their unit eigenvalues. Furthermore, it also establishes that the tangent operators of rotation and motion are of a tensorial nature if and only if they are expressed in terms of the vectorial parameterizations of rotation and motion, respectively. Finally, important tensor identities are shown to hold for all vectorial parameterization of rotation and motion.
A Novel Approach for the Inspection of Flexible Parts Without the Use of Special Fixtures
Authors: Abenhaim Gad N. , Tahan Antoine S. , Desrochers Alain , Maranzana Roland
Published: February 2011

In a free state, flexible parts may have different shapes compared to their computer-aided design (CAD) model. Such parts may likewise undergo large deformations depending on their space orientation. These conditions severely restrict the feasibility of inspecting flexible parts without restricting the deformations of the part and therefore require dedicated and expensive tools such as a conformation jig or a fixture to maintain the integrity of the part. To address these challenges, this paper proposes a new inspection method, the iterative displacement inspection (IDI) algorithm, that evaluates profile variations without the need for specialized fixtures. This study examines 32 models of simulated manufactured parts to show that the IDI algorithm can iteratively deform the meshed CAD model until it resembles the scanned manufactured part, which enables their comparison. The method deforms the mesh in such a manner so as to ensure its smoothness. This way, neither surface defects nor the measurement noise of the scanned parts are concealed during the matching process. As a result, the case studies illustrate that the method’s error essentially only represents the scanned part’s measurement noise. The inspection results, therefore, solely reflect the effect of variations from the manufacturing process itself and not the deformation of the part.
Investigations on CFD Simulations for Predicting Windage Power Losses in Spur Gears
Authors: Marchesse Y. , Changenet C. , Ville F. , Velex P.
Published: February 2011

In this paper, a computational fluid dynamics (CFD) code is applied to two- and three-dimensional simulations of windage power loss generated by spur gears rotating in air. Emphasis is placed on the various meshes associated with the finite volume method and on the choice of turbulence model. Comparing CFD predictions with the power losses measured on a specific test rig, it is shown that the fluid ejection in the radial direction must be included in order to reproduce the experimental evidence. The relative importance of the losses generated by the gear front and rear faces along with those due to the teeth is discussed. The volumetric flow rate expelled by the teeth is analyzed and the influence of flanges is highlighted.