bluuebunny/crossref_metadata_2025 huggingface dataset:
Are the levels of Cdk4 and Cx43 proteins of porcine oocytes associated with follicular size?
Authors: Antosik Paweł , Kempisty Bartosz , Jackowska Marta , Piotrowska Hanna , Woźna Magdalena , Bukowska Dorota , Bryja Artur , Lianeri Margarita , Brüssow Klaus-Peter , Jaśkowski Jędrzej
Published: May 2011

Gap junction connections are formed by proteins which play an important role in oocyte developmental competency but there is little information on the relationship between follicle size and the expression of genes encoding these proteins. The aim of this study was to investigate the potential association between follicle size and the levels of Cdk4 and Cx43 proteins using western blot analysis and confocal microscopic observations. Cumulus-oocyte complexes (COCs) were collected from puberal gilts (n = 20) of large (>5 mm), medium (3-5 mm), and small (<3 mm) follicles, and stained with BCB. BCB+ COCs, which had finished their growth phase, were cultured in TCM 199 for 44 h. Western blot analysis revealed an increased level of Cdk4 protein in oocytes isolated from large follicles as compared to medium (P < 0.05) and small (P < 0.01) ones. We did not detect differences in Cx43 protein levels in oocytes collected from any follicle class. Confocal microscopic observation revealed a specific membrane and zona pellucida localization of Cdk4 protein in oocytes isolated from large follicles, but an exclusively cytoplasmatic distribution of Cdk4 in oocytes from smaller follicle categories. The effect of follicular size on Cdk4 is indicated by the higher level of Cdk4 protein in oocytes isolated from large follicles and its variable distribution – perhaps resulting from a specific translocation mechanism – in the membrane, zona pellucida, and cytoplasm. IVM may also have a significant effect on Cdk4, as seen from the considerable difference in the expression and localization of Cdk4 protein in oocytes after IVM.
Relative testis size and mating systems in anurans: large testis in multiple-male mating in foam-nesting frogs
Authors: Liao Wen Bo , Mi Zhi Ping , Zhou Cai Quan , Jin Ling , Lou Shang Lin , Han Xian , Ma Jin
Published: May 2011

Comparative studies of the relative testes size in animals show that promiscuous species have relatively larger testes than monogamous species. Sperm competition favours the evolution of larger ejaculates in many animals – they give bigger testes. In the view, we presented data on relative testis mass for 17 Chinese species including 3 polyandrous species. We analyzed relative testis mass within the Chinese data set and combining those data with published data sets on Japanese and African frogs. We found that polyandrous foam nesting species have relatively large testes, suggesting that sperm competition was an important factor affecting the evolution of relative testes size. For 4 polyandrous species testes mass is positively correlated with intensity (males/mating) but not with risk (frequency of polyandrous matings) of sperm competition.
A King, Two Lords, and Three Quadrants
Authors: Eagleton Catherine
Published: May 2011

This paper considers a group of three fourteenth-century English horary quadrants with links to King Richard II and the highest nobility. Building on previous work by Silke Ackermann and John Cherry, it shows how this group of instruments can tell us much about the overlapping significances of medieval instruments—which might at the same time have practical purposes and political significance.
Domestic Adjudication of Sexual and Gender-based Violence in Armed Conflict: Considerations for Prosecutors and Judges
Authors: Kamau Evelyn W.
Published: May 2011

The increased domestication of international core crimes like genocide, crimes against humanity and war crimes has placed national prosecutors and judges on unfamiliar ground. Specifically, though very welcome, the recognition of acts of sexual and gender-based violence (SGBV) as constituting core international crimes poses a further challenge. The circumstances surrounding the commission of SGBV as international core crimes, coupled with their unique elements and manner of proof, makes their domestic prosecution seem that much more difficult. An understanding of how acts of SGBV constitute international core crimes, their constituent elements and the manner of proving them, coupled with how to treat victims and witnesses of SGBV, goes a long way in easing the perceived challenge of domestically prosecuting them. This article is geared towards achieving that and is directed at people who are involved in or are considering carrying out domestic prosecutions and adjudications of SGBV as international core crimes.
The Fatimid Caliph al-Aziz and His Daughter Sitt al-Mulk: A Case of Delayed but Eventual Succession to Rule by a Woman
Authors: Walker Paul E.
Published: May 2011

In his youth the future al-Aziz, then merely the third son of the caliph al-Muizz, acquired a concubine, most likely a Greek-speaking captive, and produced with her a daughter who was to become the famous Sitt al-Mulk. Not only did her mother remain al-Aziz’s favorite long after he rose to the Fatimid throne in 975, she remained so until her death twenty years later, and the daughter continued throughout to hold a claim on his attention many considered unusually intense and extraordinary. This favor, combined with her own political acumen and sharp intelligence, enabled Sitt al-Mulk to exercise authority throughout her lifetime until she finally became the real ruler of the empire upon the disappearance of her eccentric half-brother, al-Hākim, in 1021. Drawing on chronicles written by both Fatimid and anti-Fatimid historians, this article considers the context for Sitt al-Mulk’s rise to power amid the unusual dynamics of the Fatimid royal family. It reveals the implausibility of accounts that attempt to discredit her and demonstrates that when at last she governed the empire, she did so quite competently through a difficult time of transition.
In Reality a Man: Sultan Iltutmish, His Daughter, Raziya, and Gender Ambiguity in Thirteenth Century Northern India
Authors: Gabbay Alyssa
Published: May 2011

Ruler of the Delhi Sultanate in northern India from 1236 to 1240, Raziya is a striking example of a woman who rose to power in a pre-modern Islamic society. It was Raziya’s father’s recognition and cultivation of her wisdom and ruling capacities, as well as his apparent naming of her as his successor, that paved the way for her accession to the throne. This article offers an explanation of how Raziya was able to rule in an environment in which the birth of daughters normally gave rise to disappointment and women had few avenues for authority. It will argue that despite medieval Muslim India’s assigning to women a status separate from and inferior to that of men, a metaphorical space existed in which women could identify or be identified as men. As in many non-Muslim societies, such identification could become a means for a daughter to enter into male sociopolitical spheres.
Coming to terms with sight loss
Authors: Kirkcaldy Andrew , Barr Wally
Published: May 2011

A study using both qualitative and quantitative methods was undertaken to examine the impact of the Royal National Institute of Blind People (RNIB) Finding Your Feet (FYF) programmes on participants. A key component of the study involved looking at any impact attendance may have had on the Quality of Life (QoL) of those taking part. The Birmingham Assessment of Low Vision Focus QoL Questionnaire was used to record data relating to QoL. Sixteen participants completed the questionnaire both before and after their attendance on the programme. Data was analysed alongside transcripts from 17 interviews conducted with participants and observation notes of three separate programmes. Questionnaire results highlighted clear similarities between data gathered for this study and that of other studies, and suggest considerable commonality of experience in people with visual impairment. Qualitative data demonstrate the positive contribution programmes such as FYF can make to the well-being and QoL of participants.
Control strivings in attaining peer-group membership and forming romantic relationships among adolescents with and without visual impairment
Authors: Pfeiffer Jens P. , Pinquart Martin
Published: May 2011

This study compared control striving with regard to two developmental goals in adolescents with visual impairment and sighted peers. A matched-pair design was used with 158 adolescents with visual impairment and 158 sighted peers by using age, gender, habitation (living with ones’ parents vs. other forms of living), and socioeconomic status as matching variables. Adolescents with visual impairment did not differ from sighted peers in control striving with regard to peer-group membership, but they were less active in forming romantic relationships. In addition, there was no difference between the groups in the associations between control strivings and age, gender, goal importance, locus of control, and social support.
Adaptive assessment of young children with visual impairment
Authors: Ruiter Selma , Nakken Han , Janssen Marleen , Van Der Meulen Bieuwe , Looijestijn Paul
Published: May 2011

The aim of this study was to assess the effect of adaptations for children with low vision of the Bayley Scales, a standardized developmental instrument widely used to assess development in young children. Low vision adaptations were made to the procedures, item instructions and play material of the Dutch version of the Bayley Scales of Infant Development — Second Edition (BSID-II), and the Original and Low Vision versions were administered to children with visual impairment over an interval of two weeks. Although quantitative analysis revealed no significant differences between the Original and Low Vision versions of the test in children’s scores, feedback from test administrators indicates that the Low Vision materials make the test easier to administer and more engaging for children.
Design for X-Abilities of a Mechatronic System-A Concurrent Engineering and Graph Theory Based Approach
Authors: Kiran C. Phaneendra , Clement Shibu , Agrawal V.P.
Published: May 2011

Design of a mechatronic system requires multidisciplinary knowledge. A designer should consider product lifecycle issues as well as design and manufacturing strategies simultaneously at conceptual design stage without missing any of the information. The proposed methodology concurrently considers all the x-abilities/design aspects along with interactions without missing any information and hence leads to a high quality product. A methodology which amalgamates concurrent design concepts, graph theory, matrix algebra, and permanent multinomial is proposed. Eight x-abilities namely, miniaturization, intelligence, integration, environment, quality, reliability, manufacturing, and assembly for concurrent design of a mechatronic system and the design parameters under each x-ability are identified. A colored graph useful for visual analysis is proposed. The design index derived is useful for researcher and designer in evaluating the conceptual design alternatives. The proposed step-by-step procedure would be useful for developing a new algorithm for software coding.
Raymond Aron’s political sociology of regime and party
Authors: Scott Alan
Published: May 2011

This paper provides a critical exposition of Raymond Aron’s analysis of the distinct characteristics of constitutional-pluralist and totalitarian regimes. These regime types are distinguished by the nature of the party system — respectively, multi-party and monopolistic — and their underlying principles. Aron’s approach to the nature of political sociology is, it is argued, deeply influenced by the German — particularly Weberian — understanding of the social sciences as a hermeneutic enterprise concerned with meaning, and by Montesquieu’s analysis of regimes in terms of their (essential) nature, principles and the sources of their potential ‘corruption’. Aron’s analysis provides not only an account of totalitarian regimes in a late, developed stage, but also an analytical snapshot of Western pluralist democracies at the high point of ‘sociological liberalism’. The final section of the paper seeks to identify some differences between Aron’s account of democracy and that contained in contemporary debates on ‘governance’. The striking differences that emerge make Aron’s analysis relevant as an account of a high-tide mark of democracy grounded in a particular mix of party competition and compromise.
Raymond Aron and nuclear war
Authors: Cooper Barry
Published: May 2011

Raymond Aron began his studies of postwar politics by taking into consideration the impact of the atomic bombing of Japan by the United States. As was true of many strategic thinkers after 1945, he was concerned that the new technology would alter the significance of warfare and thus of politics — because, as a student of Clausewitz, Aron was of the view that war and politics were intimately connected. This paper explores the evolution of Aron’s thinking from 1945 until the 1980s and the development and changes in nuclear strategy. Alone in France, and almost alone in Europe, Aron kept abreast of changes in American nuclear strategy and made some insightful, if commonsensical, analyses of the then secret strategic thinking of the Soviets as well as of the European NATO allies of the United States.
On Raymond Aron, passion, identity, and the intricate paths of intellectual filiation
Authors: Greenfeld Liah
Published: May 2011

In this discussion, I reflect on the intellectual kinship between Raymond Aron and other scholars. By parsing this heritage I explore his position as a member of my extended intellectual family. Divergences in our thought and scholarly orientation are analyzed. This article highlights the complex links forged between individual scholars in the chain of cultural development.
Reasons, perceived efficacy and factors associated with complementary and alternative medicine use among Malaysian patients with diabetes mellitus
Authors: Hasan Shahzad S , Loon William Cw , Ahmadi Keivan , Ahmed Syed I , Bukhari Nadeem I
Published: May 2011

This study aimed to evaluate complementary and alternative medicine (CAM) use among Malaysian diabetic patients. Subjects for this case—control study were randomly selected from the pool of patients who were attending diabetes clinics, at the Hospital Tuanku Jaa’far, Seremban, Malaysia. Perceived effect of CAM use, reasons for starting CAM, and sociodemographic factors were collected from patients (n=230). Blood glucose levels were also recorded. Almost half of the study population (49.6%, 114/230) were using CAM together with conventional treatment for diabetes. Thirteen different types of CAM were utilised by the 114 CAM users and herbal medicine (64.9%) was found to be the most commonly used CAM modality. The majority of patients reported quality and safety of CAM (63.2%) and an additional treatment for diabetes (53.5%) as two main reasons for using CAM. About 44% of patients reported that their condition had improved by using CAM (R2=0.512, p=0.004), which was evident by their lowered fasting blood glucose (p=0.045, 7.171 versus 8.767). About 18% perceived their health condition as poor compared to 56% who perceived it as good after commencing CAM use.
Gel-filled (Liqua Care®) therapeutic insoles reduce peak forefoot pressure and increase TcpO2 in individuals with diabetes mellitus and peripheral vascular insufficiency
Authors: Miller Steven , Bain Donald , Siddiqui Tamim , Munro William , Hamill Raymond , Jones Derek , Stang Duncan
Published: May 2011

Objectives

Co-existing diabetes and peripheral vascular disease have increased susceptibility to plantar ulceration. Therapeutic insoles reduce plantar pressure, but the effect on transcutaneous tissue oxygenation (TcpO2) is unknown. This study examines the effect of gel-filled Liqua Care® therapeutic insoles on plantar pressure, and foot TcpO2, in at-risk individuals with diabetes and peripheral vascular insufficiency.

Research design and methods

Ankle brachial pressure index (ABPI) in both lower limbs was measured in patients attending the diabetes centre for complication screening; 21 individuals with ABPI <0.9 and no active ulceration were invited to participate in the study. TcpO 2 was measured at the apex of the great toes both before, and after a 2-week period of Liqua Care® insole use. Recordings of in-shoe pressure measurements without, and with the therapeutic insole were made to ascertain any regional redistribution of plantar pressures (forefoot, midfoot and hindfoot).

Results

A mean reduction in peak forefoot pressure of 54.7 kPa (95% confidence interval (CI) 31.7—77.8 kPa, p<0.01) was observed. Mean great toe TcpO2 increased by 2.92 mmHg (95% CI 0.87—4.97 mmHg, p<0.01).

Conclusions

These insoles may prevent new and recurrent pedal ulceration in at-risk patients with diabetes and peripheral vascular disease.
Oxidative DNA damage: antioxidant response in postprandial hyperglycaemia in type 2 diabetes mellitus
Authors: Al-Aubaidy Hayder A , Jelinek Herbert F
Published: May 2011

The mechanism by which postprandial glucose load and sudden cardiac death are linked is not fully understood. This study compares the postprandial response of 8-hydroxy-deoxy-guanosine (8-OHdG)and erythrocyte glutathione (GSH) in control and type 2 diabetes groups. 8-OHdG was significantly elevated in type 2 diabetic patients (824.1±331.2 and 1087±273.1 pg/ml at the first and second hours respectively, p<0.05, versus 600.4±214.4 pg/ml at baseline) following a glucose load. This was associated with a significant reduction in the level of erythrocyte GSH after the first hour (59.1±9 mg/100ml; p<0.001) compared with the basal level (72.1±9 mg/100ml), followed by a significant elevation in the second hour (71.5±11.1 mg/100ml; p<0.001) compared with the first hour, bringing the GSH level only back to base level. The increase in 8-OHdG in people with type 2 diabetes during the postprandial period further supports previous evidence of a defective antioxidant response and greater risk of heart attack due to blood vessel endothelial cell damage and smooth muscle proliferation.
Evaluation of the diabetic foot according to Wagner’s classification in a rural teaching hospital
Authors: Jawed Mohammad Akther  , Imran Ali Khan  , Shahpurkar Vinay V , Khanam Najnin , Zahiruddin Quazi Syed
Published: May 2011

Diabetic foot is a common, preventable complication of diabetes mellitus. This was a prospective study (April 2004 to October 2005) of 55 diabetic foot patients attending surgical out and in-patient departments at a rural hospital in Mahrastra, India. To determine the prevalence of diabetic foot amongst our patients with diabetes and the associated risk factors. All patients underwent medical assessment, including foot examination, those with diabetic foot answered an interviewer-administered questionnaire on foot healthcare practices. Symptoms, examination findings, glycaemic control, duration and classification of diabetes, occupation and smoking habits were cross studied with diabetic foot according to Wagner’s grading. The prevalence of diabetic foot was 11% and 84% of patients were men. The commonest presentation was Wagner’s grade 2 diabetic foot (34.5%) and most patients (69%) worked outside. The majority of patients with Wagner’s grade 2—5 had uncontrolled diabetes. Neuropathic and vasculopathic components were major predictors of diabetic foot. More than half (64.5%) of our patients were ignorant of foot healthcare practices. Patients with diabetes at this rural clinic need to be better informed on how to examine and care for their feet. They would also benefit from measures to help them improve glycaemic control.
Obesity in the pathogenesis of type 2 diabetes
Authors: Day Caroline , Bailey Clifford J
Published: May 2011

Obesity, and especially visceral adiposity, escalates the development of insulin resistance and type 2 diabetes. Excess adipose tissue contributes to a chronic increase in circulating fatty acids reducing the usage of glucose as a source of cellular energy. Excess fatty acids also result in increased deposition of fat in muscle and liver, and increased metabolites such as diacylglycerol and ceramide which activate isoforms of protein kinase C that impede cellular insulin signalling. Chronically raised lipid levels also impair islet beta cell function, acting in conjuction with insulin resistance to aggravate hyperglycaemia. The detrimental effects of several adipokines such as TNFα, IL6 and RBP4, which are produced in excess by an increased adipose mass, and reduced production of adiponectin are further mechanisms through which obesity potentiates the development of type 2 diabetes.
Dietary antioxidant interventions in type 2 diabetes patients: a meta-analysis
Authors: Akbar Sarah , Bellary Srikanth , Griffiths Helen R
Published: May 2011

An imbalance between reactive oxygen species (ROS) production and antioxidant scavenging has been implicated in type 2 diabetes. ROS are a byproduct in type 2 diabetes, generated during protein glycation and as a consequence of advanced glycation end-products-receptor binding; they impair insulin signalling pathways and induce cytotoxicity in pancreatic beta cells. Neutralisation of oxidants by increased antioxidant availability may mitigate these effects. Several human intervention studies have been undertaken to determine whether dietary antioxidants exert beneficial effects for type 2 diabetes patients. This paper describes a systematic review and meta-analysis of the effects of dietary supplementation with antioxidant vitamins C or E on (1) plasma glucose and insulin concentrations, as an indicator of the capacity for antioxidant to interfere with disease process and (2) on glycated haemoglobin A1C as a measure of antioxidant effects on posttranslational protein modification implicated in disease complications. Combined analysis of 14 studies that met inclusion criteria revealed that dietary antioxidant supplementation did not affect plasma glucose or insulin levels, suggesting that they could not interfere with the pathogenesis of insulin resistance. However, HbA1C levels were significantly reduced by antioxidant supplementation, suggesting that antioxidants may have some benefit in protecting against the complications of type 2 diabetes.
Moveout inversion of wide-azimuth P-wave data for tilted TI media
Authors: Wang Xiaoxiang , Tsvankin Ilya
Published: May 2011

Currently TTI (transversely isotropic with a tilted symmetry axis) models are widely used for velocity analysis and imaging in many exploration areas. We develop a 3D parameter-estimation algorithm for TTI media composed of homogeneous layers separated by plane dipping interfaces. The input data include P-wave NMO ellipses and time slopes (horizontal slownesses of the zero-offset rays) combined with borehole information. If the symmetry axis is perpendicular to the bottom of each layer, it is possible to estimate the interval symmetry-direction velocity VP0 , anisotropy parameter [Formula: see text], and the reflector orientation using a single constraint — the reflector depth. The algorithm can tolerate small [Formula: see text] deviation of the symmetry axis from the reflector normal. However, as is the case for the 2D problem, the parameter [Formula: see text] can seldom be obtained without nonhyperbolic moveout inversion. If the symmetry axis deviates from the reflector normal but is confined to the dip plane, stable parameter estimation requires specifying a relationship between the tilt and dip in each layer. When the tilt represents a free parameter, the input data have to be supplemented by wide-azimuth VSP traveltimes with the offset reaching at least 1/4 of the maximum reflector depth. Moreover, the additional angle coverage provided by VSP data may help resolve the parameter [Formula: see text] in the upper part of the model. The developed methodology can be used to build an accurate initial anisotropic velocity model for processing of wide-azimuth surveys.
Parameterization of elastic stress sensitivity in shales
Authors: Pervukhina Marina , Gurevich Boris , Golodoniuc Pavel , Dewhurst David N.
Published: May 2011

Stress dependency and anisotropy of dynamic elastic properties of shales is important for a number of geophysical applications, including seismic interpretation, fluid identification, and 4D seismic monitoring. Using Sayers-Kachanov formalism, we developed a new model for transversely isotropic (TI) media that describes stress sensitivity behavior of all five elastic coefficients using four physically meaningful parameters. The model is used to parameterize elastic properties of about 20 shales obtained from laboratory measurements and the literature. The four fitting parameters, namely, specific tangential compliance of a single crack, ratio of normal to tangential compliances, characteristic pressure, and crack orientation anisotropy parameter, show moderate to good correlations with the depth from which the shale was extracted. With increasing depth, the tangential compliance exponentially decreases. The crack orientation anisotropy parameter broadly increases with depth for most of the shales, indicating that cracks are getting more aligned in the bedding plane. The ratio of normal to shear compliance and characteristic pressure decreases with depth to 2500 m and then increases below this to 3600 m. The suggested model allows us to evaluate the stress dependency of all five elastic compliances of a TI medium, even if only some of them are known. This may allow the reconstruction of the stress dependency of all five elastic compliances of a shale from log data, for example.
Boundary attenuation angles for inhomogeneous plane waves in anisotropic dissipative media
Authors: Červený Vlastislav , Pšenčík Ivan
Published: May 2011

We study behavior of attenuation (inhomogeneity) angles [Formula: see text], i.e., angles between real and imaginary parts of the slowness vectors of inhomogeneous plane waves propagating in isotropic or anisotropic, perfectly elastic or viscoelastic, unbounded media. The angle [Formula: see text] never exceeds the boundary attenuation angle [Formula: see text]. In isotropic viscoelastic media [Formula: see text]; in anisotropic viscoelastic media [Formula: see text] may be greater than, equal to, or less than [Formula: see text]. Plane waves with [Formula: see text] do not exist. Because [Formula: see text] in anisotropic viscoelastic media is usually not known a priori, the commonly used specification of an inhomogeneous plane wave by the attenuation angle [Formula: see text] may lead to serious problems. If [Formula: see text] is chosen close to [Formula: see text] or even larger, indeterminate, unstable or even nonphysical results are obtained. We study properties of [Formula: see text] and show that the approach based on the mixed specification of the slowness vector fully avoids the problems mentioned above. The approach allows exact determination of [Formula: see text] and removes instabilities known from the use of the specification of the slowness vector by [Formula: see text]. For [Formula: see text], the approach yields zero phase velocity, i.e., the corresponding wave is a nonpropagating wave mode. The use of the mixed specification leads to the explanation of the deviation of [Formula: see text] from [Formula: see text] as a consequence of different orientations of energy-flux and propagation vectors in anisotropic media. The approach is universal; it may be used for isotropic or anisotropic, perfectly elastic or viscoelastic media, and for homogeneous and inhomogeneous waves, including strongly inhomogeneous waves, like evanescent waves.
A comparison of the dispersion relations for anisotropic elastodynamic finite-difference grids
Authors: Bernth Henrik , Chapman Chris
Published: May 2011

Several staggered grid schemes have been suggested for performing finite-difference calculations for the elastic wave equations. In this paper, the dispersion relationships and related computational requirements for the Lebedev and rotated staggered grids for anisotropic, elastic, finite-difference calculations in smooth models are analyzed and compared. These grids are related to a popular staggered grid for the isotropic problem, the Virieux grid. The Lebedev grid decomposes into Virieux grids, two in two dimensions and four in three dimensions, which decouple in isotropic media. Therefore the Lebedev scheme will have twice or four times the computational requirements, memory, and CPU as the Virieux grid but can be used with general anisotropy. In two dimensions, the rotated staggered grid is exactly equivalent to the Lebedev grid, but in three dimensions it is fundamentally different. The numerical dispersion in finite-difference grids depends on the direction of propagation and the grid type and parameters. A joint numerical dispersion relation for the two grids types in the isotropic case is derived. In order to compare the computational requirements for the two grid types, the dispersion, averaged over propagation direction and medium velocity are calculated. Setting the parameters so the average dispersion is equal for the two grids, the computational requirements of the two grid types are compared. In three dimensions, the rotated staggered grid requires at least 20% more memory for the field data and at least twice as many number of floating point operations and memory accesses, so the Lebedev grid is more efficient and is to be preferred.
An analytic model for the stress-induced anisotropy of dry rocks
Authors: Gurevich Boris , Pervukhina Marina , Makarynska Dina
Published: May 2011

One of the main causes of azimuthal anisotropy in sedimentary rocks is anisotropy of tectonic stresses in the earth’s crust. We have developed an analytic model for seismic anisotropy caused by the application of a small anisotropic stress. We first considered an isotropic linearly elastic medium (porous or nonporous) permeated by a distribution of discontinuities with random (isotropic) orientation (such as randomly oriented compliant grain contacts or cracks). The geometry of individual discontinuities is not specified. Instead, their behavior is defined by a ratio B of the normal to tangential excess compliances. When this isotropic rock is subjected to a small compressive stress (isotropic or anisotropic), the number of cracks along a particular plane is reduced in proportion to the normal stress traction acting on that plane. This effect is modeled using the Sayers-Kachanov noninteractive approximation. The model predicts that such anisotropic crack closure yields elliptical anisotropy, regardless of the value of the compliance ratio B. It also predicts the ratio of Thomsen’s anisotropy parameters [Formula: see text] as a function of the compliance ratio B and Poisson’s ratio of the unstressed rock. A comparison of the model predictions with the results of laboratory measurements indicates a reasonable agreement for moderate magnitudes of uniaxial stress (as high as 30 MPa). These results can be used for differentiating stress-induced anisotropy from that caused by aligned fractures. Conversely, if the cause of anisotropy is known, then the anisotropy pattern allows one to estimate P-wave anisotropy from S-wave anisotropy.
Geomechanical and ultrasonic characterization of a Norwegian Sea shale
Authors: Dewhurst David N. , Siggins Anthony F. , Sarout Joël , Raven Mark D. , Nordgård-Bolås Hege M.
Published: May 2011

Anisotropy of velocity in shaly overburden is known to cause significant problems for geophysical interpretation, including depth conversion and fluid identification. In addition, mechanical and dynamic elastic shale behavior is not well understood because few tests have been performed on well-preserved samples. Multiple stage triaxial tests were performed upon horizontal core plugs of a shale from the Norwegian Sea with a view to evaluating rock strength and the evolution of ultrasonic response during rock deformation. In addition, standard rock physical properties were characterized as well as composition. The shale microfabric is seen to be strongly laminated, with alternating thick clay-rich laminae and thin silt-rich laminae. Occasional microfractures are also noted parallel to these laminations. The shale has low friction coefficient and cohesive strength, and shows anisotropy of these parameters when the maximum principal stress is oriented parallel to and at 45° to the microfabric. The orientation of the maximum principal stress parallel to the intrinsic fabric and microcracks was seen to significantly impact on velocity normal to the fabric as stress parallel to the fabric increased. S-wave anisotropy was significantly affected by the increasing stress anisotropy. Stress orientation with respect to fabric orientation was therefore found to be an important control on the degree of anisotropy of dynamic elastic properties in this shale.
Endocrine Parameters and Phenotypes of the Growth Hormone Receptor Gene Disrupted (GHR−/−) Mouse
Authors: List Edward O. , Sackmann-Sala Lucila , Berryman Darlene E. , Funk Kevin , Kelder Bruce , Gosney Elahu S. , Okada Shigeru , Ding Juan , Cruz-Topete Diana , Kopchick John J.
Published: May 2011

Disruption of the GH receptor (GHR) gene eliminates GH-induced intracellular signaling and, thus, its biological actions. Therefore, the GHR gene disrupted mouse (GHR−/−) has been and is a valuable tool for helping to define various parameters of GH physiology. Since its creation in 1995, this mouse strain has been used by our laboratory and others for numerous studies ranging from growth to aging. Some of the most notable discoveries are their extreme insulin sensitivity in the presence of obesity. Also, the animals have an extended lifespan, which has generated a large number of investigations into the roles of GH and IGF-I in the aging process. This review summarizes the many results derived from the GHR−/− mice. We have attempted to present the findings in the context of current knowledge regarding GH action and, where applicable, to discuss how these mice compare to GH insensitivity syndrome in humans.
Fluorescent Chemosensors for Chromium(III) Ions and the Cr3+/Cr2+ Ratio
Authors: de los Rios Alejandra , Mal Prasenjit , Meixner Alfred J , Khoptyar Dmitry , Schmittel Michael
Published: May 2011

The shielded linear trisphenanthroline 1 is utilized as a triple reassurance probe and as an ON–OFF–ON signaling unit (after addition of Cu2+) for the detection and quantification of Cr3+ ions. The analogous monophenanthroline 2 served as a ratiometric fluorescent chemosensor for analyzing the Cr3+/Cr2+ ratio.
Self-assembled Gels of Amphiphilic Sequential Peptide in Water and Organic Solvents
Authors: Cai Rong , Zhao Ying , Ogura Kempei , Tanaka Masayoshi , Kinoshita Takatoshi , Cai Qing
Published: May 2011

An amphiphilic peptide designed with serine as a polar residue showed gelation in both water and organic solvents. This sequential peptide has a strong tendency to adopt β-sheet conformation in these solvents. Such gels of β-sheet peptide based on hierarchical self-assembly consist of nanofiber construction because of the β-sheet structure, and because of crosslinking attributable to hydrogen bonding among hydroxy groups of the serine side chain.
Synthesis and Properties of 9,10-Anthrylene-substituted Phenyleneethynylene Dyes for Dye-sensitized Solar Cell
Authors: Yang Xin , Fang Jing-Kun , Suzuma Yoshinori , Xu Feng , Orita Akihiro , Otera Junzo , Kajiyama Shingo , Koumura Nagatoshi , Hara Kohjiro
Published: May 2011

A series of 9,10-anthrylene-substituted phenyleneethynylenes having Ph2N and CN groups were synthesized. A dye-sensitized solar cell fabricated by both Ph2N- and CN-substituted derivative exhibited the highest performance of photo-to-current energy conversion.
Photocurrent Generated from Nanoelectrode Consisting of Dye, Titania Gel, and Carbon Nanotube
Authors: Nishikiori Hiromasa , Ohta Takuma , Yamakami Tomohiko , Endo Morinobu , Fujii Tsuneo
Published: May 2011

The dye- and titania gel-modified multiwalled carbon nanotube nanoelectrodes were prepared by sol–gel at room temperature. The photoelectric conversion properties of the nanoelectrodes were examined by simple spectroscopic and electric measurements. The photocurrent spectrum originated from the absorption of the dye. The open-circuit voltage was due to the semiconducting characteristics of the titania gel. The experimental results indicated electron transport from the dye excited states to the carbon nanotubes through the titania gel.
Template Synthesis of Freestanding Nanostructural Membrane of Polyaniline
Authors: Liu Zhao , Zhai Dongyuan , Pan Lijia , Qiu Hao , Li Wenbo , Ding Xiaomei , Shi Yi
Published: May 2011

A reactive template method was used to synthesize large, flexible, freestanding nanostructural membranes of a conductive polymer, polyaniline. The resulting membranes are constructed of textured nanofibers with diameters about 100 nm. Such a flexible nanostructural membrane has great potential in applications in supercapacitors, lithium batteries, sensors, memories, and artificial muscles.
Factors influencing delay time and coronary arterial density during coronary angiography with DSCT
Authors: Tang Lijun , Zhu Xiaomei , Xu Yi , Yu Tongfu , Xu Hai , Tang Jinhua , Dogra Vikram , Wang Dehang
Published: May 2011

Background

CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image.

Purpose

To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT.

Material and Methods

One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight × height/3600]1/2) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density.

Results

Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651–0.110 × HR + 1.902 × gender + 0.394 × TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42–4.099 × HR–3.293 × weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density.

Conclusion

Delay time is influenced by HR, gender and TCD. Coronary arterial density also changes with HR and weight. So HR, gender, TCD and weight can be used to adjust flow rate and dosage of contrast media before administration of contrast media during coronary CT angiography.
Pathological 99mTc-sestamibi myocardial perfusion scintigraphy is independently associated with emerging cardiac events in elderly patients with known or suspected coronary artery disease
Authors: Bucerius Jan , Joe Alexius Y , Herder Ellen , Brockmann Holger , Biermann Kim , Palmedo Holger , Tiemann Klaus , Biersack Hans-Jürgen
Published: May 2011

Background

Only few data are available regarding the prognostic impact of myocardial perfusion scintigraphy with 99mTc-sestamibi (MPS) regarding emerging cardiac events in elderly patients

Purpose

To evaluate the prognostic value of MPS regarding emerging cardiac events in patients aged ≥70 years with known or suspected coronary artery disease (CAD).

Material and Methods

One hundred and thirty-three patients (74.6 ± 3.7 years) who underwent exercise or pharmacological stress/rest MPS were included in this analysis. Semi-quantitative visual interpretation of MPS images was performed and Summed-Stress- (SSS), Summed-Difference- (SDS), and Summed-Rest Scores (SRS) were calculated. Multivariate logistic regression analyses were calculated for evaluation of the independent prognostic impact of MPS results and several cardiac-related patient characteristics with regard to emerging cardiac events. Kaplan-Meier survival- and log rank analyses were calculated for assessment of cardiac event-free survival.

Results

Pathological SSS (OR: 3.3), angina (OR: 2.7) and ischemic ECG (OR: 3.0) were independently associated with cardiac events. Patients with pathological SSS (p = 0.005) and ischemic ECG (p = 0.012) had a significantly lower incidence of cardiac event-free survival.

Conclusion

Pathological MPS is independently associated with emerging cardiac events predicting a significantly lower incidence of cardiac event-free survival in patients aged ≥70 years.
Phantom and cadaver measurements of dose and dose distribution in micro-CT of the chest in mice
Authors: Rodt Thomas , Luepke Matthias , Boehm Claudia , von Falck Christian , Stamm Georg , Borlak Jürgen , Seifert Hermann , Galanski Michael
Published: May 2011

Background

Micro-computed tomography (CT) allows high-resolution imaging of the chest in mice for small animal research with a significant radiation dose applied.

Purpose

To report on measurement of the applied radiation dose using different scan protocols in micro-CT of the chest in mice.

Material and Methods

Repetitive dose measurements were performed for four different micro-CT protocols (with/without respiratory gating) and for micro-CT fluoroscopy used for chest imaging. Measurements were carried out using thermoluminescence dosimeters (TLD) in mouse cadavers and in a PMMA phantom allowing measurement of the radiation dose in the direct path of rays and assessment of scattered radiation.

Results

The dose measured inside and outside the chests of the cadavers varied between 190 und 210 mGy, respectively. The expected mean doses in mice in the direct path of rays for the four examined micro-CT protocols varied between 170 and 280 mGy. The mean values for 1 and 5 minutes of fluoroscopy were 17 mGy and 105 mGy, respectively.

Conclusion

The measured dose values are similar to the dose values for micro-CT of the chest reported so far. A relevant dose can be delivered by micro-CT of the chest, which could possibly interact with small animal studies. Therefore, the applied dose for a specific protocol should be known and adverse radiation effects be considered.
Multidetector computed tomography evaluation of bony fragments and donor sites in acute patellar dislocation
Authors: Peltola Erno K , Koskinen Seppo K
Published: May 2011

Background

Patellar dislocation is frequently associated with bony fragments that are difficult to see on radiographs. MRI or MDCT are often used to rule out or characterize these bony fragments.

Purpose

To assess the use of MDCT for locating bony fragments and donor sites in patients with acute patellar dislocation, and to test whether sizes and quantity of bony fragments differ between first-time dislocations and recurrent dislocations.

Material and Methods

Retrospective data from two hospitals during a 96-month period were collected, and a total of 46 patients (mean age 27 years, range 9–69 years) that had sustained an acute patellar dislocation (22 first-time, 24 recurrent) were identified. Size, location and donor site of bony fragments were evaluated on MDCT images. Surgical correlation was available for 22 of 46 patients.

Results

On MDCT images, the likely donor site could be identified in 62 of 71 (87%) bony fragments. Of the bony fragments that were seen on MDCT images, 40 of 68 (59%) were not seen on AP and lateral views of the conventional radiographs. There was no significant difference in size of bony fragments between first-time or recurrent dislocators (p = 0.77). The average number of bony fragments were 2.1 and 1.0 in first-time and recurrent dislocators, respectively. The location and donor site of bony fragments was similar between two patients groups.

Conclusion

MDCT is a suitable imaging method to locate bony fragments and donor sites. The number of bony fragments seems to be higher in first-time dislocators than recurrent dislocators, otherwise findings between the two patient groups were similar.
The assessment of breast cancer response to neoadjuvant chemotherapy: comparison of magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography
Authors: Park Jeong Seon , Moon Woo Kyung , Lyou Chae Yeon , Cho Nariya , Kang Keon Wook , Chung June-Key
Published: May 2011

Background

Neoadjuvant chemotherapy for locally advanced breast cancer is a widely accepted treatment. For assessment of the tumor response after chemotherapy, both magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) are promising methods.

Purpose

To retrospectively compare MRI and PET in the assessment of tumor response to neoadjuvant chemotherapy for primary breast cancer with the pathologic response as the reference standard.

Material and Methods

Between August 2006 and May 2008, 32 women with breast cancer underwent concurrent MRI and PET before and after neoadjuvant chemotherapy. For response assessment, we calculated the changes in the maximum diameters of the tumor (ΔDmax) on MRI, and the changes in the standard uptake values (ΔSUV) on PET. The correlation between the ΔDmax and ΔSUV was analyzed using Pearson's correlation coefficient. The correspondence rates between each imaging modality and pathologic assessment were calculated. For prediction of the pathologic complete response (pCR), the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analyzed using the McNemar test.

Results

The pathologic assessment of tumor response to neoadjuvant chemotherapy identified eight complete responses (25.0%), 10 partial responses (31.2%), and 14 non-responses (43.8%). The change in size on MRI was moderately correlated with the change in SUV on PET (r = 0.574, p = 0.001). The correspondence rate of response assessment was 75.0% (24/32) between MRI and pathologic response and 53.1% (17/32) between PET and pathologic response. For the pCR, specificity (95.8% vs. 62.5%) and PPV (83.3% vs. 47.1%) were statistically higher on MRI than PET (p < 0.05), while sensitivity (100.0% vs. 62.5%) and NPV (100.0% vs. 88.5%) on PET tended to be higher than MRI.

Conclusion

Before and after neoadjuvant chemotherapy for breast cancer, the ΔDmax of MRI correlated moderately with the ΔSUV on PET. For prediction of the pCR, MRI proved to be a more specific modality than PET.