bluuebunny/crossref_metadata_2025_split huggingface dataset:
SNPs of the FADS Gene Cluster are Associated with Polyunsaturated Fatty Acids in a Cohort of Patients with Cardiovascular Disease
Authors: Malerba Giovanni , Schaeffer Linda , Xumerle Luciano , Klopp Norman , Trabetti Elisabetta , Biscuola Michele , Cavallari Ugo , Galavotti Roberta , Martinelli Nicola , Guarini Patrizia , Girelli Domenico , Olivieri Oliviero , Corrocher Roberto , Heinrich Joachim , Pignatti Pier Franco , Illig Thomas 
Published: March 2008

AbstractPolymorphisms of the human Δ‐5 (FADS1) and Δ‐6 (FADS2) desaturase genes have been recently described to be associated with the level of several long‐chain n‐3 and n‐6 polyunsaturated fatty acids (PUFAs) in serum phospholipids. We have genotyped 13 single nucleotide polymorphisms (SNPs) located on the FADS1–FADS2–FADS3 gene cluster (chromosome 11q12–13.1) in 658 Italian adults (78% males; mean age 59.7 ± 11.1 years) participating in the Verona Heart Project. Polymorphisms and statistically inferred haplotypes showed a strong association with arachidonic acid (C20:4n‐6) levels in serum phospholipids and in erythrocyte cell membranes (rs174545 adjusted P value for multiple tests, P < 0.0001 and P < 0.0001, respectively). Other significant associations were observed for linoleic (C18:2n‐6), alpha‐linolenic (C18:3n‐3) and eicosadienoic (C20:2n‐6) acids. Minor allele homozygotes and heterozygotes were associated to higher levels of linoleic, alpha‐linolenic, eicosadienoic and lower levels of arachidonic acid. No significant association was observed for stearidonic (C18:4n‐3), eicosapentaenoic (C20:5n‐3) and docosahexaenoic (C22:6n‐3) acids levels. The observed strong association of FADS gene polymorphisms with the levels of arachidonic acid, which is a precursor of molecules involved in inflammation and immunity processes, suggests that SNPs of the FADS1 and FADS2 gene region are worth studying in diseases related to inflammatory conditions or alterations in the concentration of PUFAs.
Delayed Metabolism of Postprandial Triglyceride‐Rich Lipoproteins in Subjects with Echolucent Carotid Plaques
Authors: Notø Ann‐Trude With , Mathiesen Ellisiv Bøgeberg , Brox Jan , Björkegren Johan , Hansen John‐Bjarne 
Published: March 2008

AbstractSubjects with echolucent carotid plaques have an increased risk of ischemic cerebrovascular events independent of degree of stenosis. Low plasma lipoprotein lipase (LPL) activity promotes a proatherogenic lipid profile, and delayed chylomicron clearance is a risk factor for atherosclerosis. This study was conducted to determine plasma LPL activity and postprandial metabolism of triglycerides in relation to carotid plaque morphology. Plaque echogenicity was assessed by B‐mode ultrasound and analysis of the grey scale median (GSM). Echolucent plaques were defined as GSM ≤ 63 (the median) and echogenic plaques as GSM > 63, and 57 subjects with carotid plaques and 38 subjects without carotid plaques were recruited. Blood samples were collected before and at 2‐h interval for 8 h after a standard high fat meal. LPL activity and mass was determined before and after heparin administration. Postheparin LPL activity was decreased in subjects with echolucent plaques compared to subjects with echogenic plaques (P = 0.06) and to controls (P = 0.04). Plaque echogenicity increased linearly with increasing levels of postheparin LPL activity (P = 0.02) and mass (P = 0.03). Subjects with echolucent plaques had delayed postprandial clearance of chylomicron triglycerides compared to controls (P = 0.04). Low postheparin LPL activity due to attenuated mobilization of LPL from capillary endothelium may play an important role in the formation of echolucent plaques by modulation of postprandial lipids and subsequent fat accumulation in the arterial wall.
Low trans‐Fat Spreads and Shortenings from a Catalyst‐Switching Strategy
Authors: Jackson Michael A. , List Gary R. , Palmquist Debra 
Published: March 2008

AbstractLow trans fatty acid basestocks suitable for blending with liquid oils to make spreads and shortenings are prepared by using a two‐step hydrogenation process. The first step uses a nickel catalyst to hydrogenate soybean, canola, high‐oleic sunflower, and high‐oleic safflower oils to a predetermined iodine value. At this point in the reaction, the second step commenced. Addition of a platinum catalyst at 80 °C and 73 psi hydrogen pressure allowed for hydrogenation to proceed to iodine values of 40–50. These products had 11–18% trans fatty acid content. These were then blended with soybean oil (5–50% basestock) to give products with bulk properties similar to commercial spreads and shortenings but with about one third the levels of trans fat.
Geometry of Reidemeister classes and twisted Burnside theorem
Authors: Fel'shtyn Alexander , Troitsky Evgenij 
Published: March 2008

AbstractThe purpose of the present mostly expository paper (based mainly on [17, 18, 40, 16, 11]) is to present the current state of the following conjecture of A. Fel'shtyn and R. Hill [13], which is a generalization of the classical Burnside theorem.Let G be a countable discrete group, φ one of its automorphisms, R(φ) the number of φ-conjugacy (or twisted conjugacy) classes, and S(φ) = #Fix the number of φ-invariant equivalence classes of irreducible unitary representations. If one of R(φ) and S(φ) is finite, then it is equal to the other.This conjecture plays a important role in the theory of twisted conjugacy classes (see [26], [10]) and has very important consequences in Dynamics, while its proof needs rather sophisticated results from Functional and Noncommutative Harmonic Analysis.First we prove this conjecture for finitely generated groups of type I and discuss its applications.After that we discuss an important example of an automorphism of a type II1 group which disproves the original formulation of the conjecture.Then we prove a version of the conjecture for a wide class of groups, including almost polycyclic groups (in particular, finitely generated groups of polynomial growth). In this formulation the role of an appropriate dual object plays the finite-dimensional part of the unitary dual. Some counter-examples are discussed.Then we begin a discussion of the general case (which also needs new definition of the dual object) and prove the weak twisted Burnside theorem for general countable discrete groups. For this purpose we prove a noncommutative version of Riesz-Markov-Kakutani representation theorem.Finally we explain why the Reidemeister numbers are always infinite for Baumslag-Solitar groups.
Characterizing C*-algebras of compact operators by generic categorical properties of Hilbert C*-modules
Authors: Frank Michael 
Published: March 2008

AbstractC*-algebrasAof compact operators are characterized as those C*-algebras of coefficients of Hilbert C*-modules for which (i) every boundedA-linear operator between two HilbertA-modules possesses an adjoint operator, (ii) the kernels of all bounded A-linear operators between HilbertA-modules are orthogonal summands, (iii) the images of all boundedA-linear operators with closed range between HilbertA-modules are orthogonal summands, and (iv) for every HilbertA-module every HilbertA-submodule is a topological summand. Thus, the theory of Hilbert C*-modules over C*-algebras of compact operators has similarities with the theory of Hilbert spaces. In passing, we obtain a general closed graph theorem for bounded module operators on arbitrary Hilbert C*-modules.
Absence of contralateral suppression of transiently evoked otoacoustic emissions in fibromyalgia syndrome
Authors: Gunduz B , Bayazit Y A , Celenk F , Sarıdoğan C , Guclu A G , Orcan E , Meray J 
Published: March 2008

AbstractObjective:To assess contralateral suppression of transiently evoked otoacoustic emissions in patients with fibromyalgia syndrome and normal hearing.Methods:Twenty-four female patients with fibromyalgia syndrome and 24 healthy female controls with normal hearing were assessed using pure tone audiometry and transiently evoked otoacoustic emissions.Results:All patients with fibromyalgia syndrome and all controls had normal hearing on pure tone audiometry. In the patients with fibromyalgia syndrome, the mean transiently evoked otoacoustic emission amplitude was 15.5 ± 4.8 dB. The mean transiently evoked otoacoustic emission amplitudes after contralateral suppression was 15.5 ± 4.9 dB. There was no statistically significant difference between the transiently evoked otoacoustic emission amplitudes measured before and after contralateral suppression (p > 0.05). In the controls, the mean transiently evoked otoacoustic emission amplitude was 12 ± 5 dB. The mean transiently evoked otoacoustic emission amplitudes after contralateral suppression was 11 ± 4.7 dB. There was a statistically significant decrease in transiently evoked otoacoustic emission amplitudes after contralateral suppression (p < 0.01).Conclusion:The mechanisms related to contralateral suppression of transiently evoked otoacoustic emissions seem dysfunctional in fibromyalgia syndrome. This dysfunction may be at the brain stem level, where the medial superior olivary complex is located, or at the synapses of medial superior olivary complex fibres with the outer hair cells in the cochlea. Demonstration of lack of contralateral suppression of transiently evoked otoacoustic emissions can be used as a diagnostic tool in patients with fibromyalgia syndrome.
Increasing dominance of Nile tilapia,Oreochromis niloticus(L) in Lake Victoria, Kenya: Consequences for the Nile perchLates niloticus(L) fishery
Authors: Njiru M. , Ojuok J. , Getabu A. , Jembe T. , Owili M. , Ngugi C. 
Published: March 2008

Nile tilapia, Oreochromis niloticus and Nile perch, Lates niloticus were introduced into Lake Victoria in the 1950s and 1960s. The former was to boost the then declining tilapiine fishery, while the latter was to convert the abundant bony haplochromines to fish flesh. Fish samples were collected by bottom trawling from 1998 to 2000 and in 2004 to 2005 from the Kenya waters of Lake Victoria. The goal was to evaluate the current population characteristics and ecology of the species. Length frequency distribution and size at maturity of Nile tilapia depicted a stable population with high proportions (30%) of mature fish, unlike Nile perch where more than 98% of the individuals were immature. Nile tilapia previously distributed in &lt; 10 m, were caught in areas up to 20 m depth. Catches of Nile tilapia have increased from &lt; 1% in 1970-80s to &gt; 25% in 2005; while Nile perch declined from 95% in 1990s to 58% in 2005.The increase in Nile tilapia catches and its spread into deeper waters is attributed to declining stocks of the predatory Nile perch, availability of suitable food and the species occupying vacant niches left by declining stocks of indigenous species, especially the haplochromines. Increase of anoxic conditions in the lake is also precluding Nile perch thereby affording tilapia refuge. The previously herbivorous tilapia has diversified its diet to include insects and fish. All these factors could be contributing to an increase in Nile tilapia biomass in the lake. If management measures to reduce Nile perch exploitation and its rapid decline are not instituted, the next important demersal commercial fishery in Lake Victoria will probably be Nile tilapia. The establishment of Nile tilapia will be replacing a multimillion-dollar export industry of Nile perch, which will have several economic consequences. However, biodiversity in the lake is expected to increase and thus so will the availability of protein to local communities.
Heterogeneity in physical, chemical and plankton-community structures in Lake Tanganyika.
Authors: Langenberg V. T. , Tumba J.-m. , Tshibangu K. , Lukwesa C. , Chitamwebwa D. , Bwebwa D. , Makasa L. , Roijackers R. 
Published: March 2008

From 28 August to 6 September 1995, we monitored the lake-wide physical, chemical and biological properties of the pelagic waters in Lake Tanganyika. The aim of this study was to examine the spatial environmental variability and its relation to fluctuations in plankton abundance and community assembly.Trade winds had triggered an overall downward tilt of the isotherms; accumulation of warm surface waters and intensified stratification towards the north along with upwelling increased mixing, combined with decreased stratification towards the south. Dissolved oxygen, turbidity, conductivity, phosphorus and chlorophyll-a were higher; whereas temperature and pH were lower in southern than in northern waters. We observed a transition zone (6 to 7°S) where vertical water column structures changed from northern to southern conditions. This did not include the river Rusizi affected regions north of 4°S.High spatial heterogeneity in nutrient supply and degree of mixing had a strong impact on the plankton community. While the northern environments appeared to be based on reduced internal nutrient loading, lower phytoplankton biomass and smaller sized zooplankton with an important role of Cyclopoids, the mixed environments in the south seemed to be based on increased phosphorus availability and larger sized zooplankton dominated by Calanoid grazers.We emphasise that wind-driven formation of a gradual change in physical and chemical properties of the productive zones along the north-south axis of Lake Tanganyika is of importance in regionally determining nutrient flows. This consequently affects plankton community structures and composition, and therefore food web structure and functioning.
A Stochastic Description of the Learning Behaviour of an Individual Subject
Authors: Audley R. J. 
Published: March 2008

A stochastic process for the description of learning behaviour in a two-choice situation, a special case of a family of processes given in an earlier paper, is introduced. It can be used to describe individual learning data, including both the choice sequence and the latency of the choices within the description. This has the advantage that parameter estimates may be based separately on the latencies and on the choice sequence, and the agreement between these estimates can be taken as an indication of the validity of the stochastic description. The process is fitted to fifty learning trials of an albino rat. Only two parameters are employed in the description of the sequence of choices made by the subject, and a further one to include the response latencies. No generality is claimed for the success of the particular process employed in this one example, which is given only as an illustration of the possible value of the method.
Sensory Factors in the Voluntary Application of Pressure
Authors: Provins K. A. 
Published: March 2008

The experiments described attempt to assess the extent of sensory control of voluntary movements of the forearm and finger when the contractions of the muscles concerned are approximately isometric. In the first two experiments, records were obtained of the accuracy with which subjects were able to reproduce a particular pressure with the ulnar border of the hand at different pressure values and rates of application. Results show a statistically significant increase in error of reproduction of pressure as the pressure applied decreases and the rate of application is increased. In the third experiment, using an applied force of 25 gms. weight, a significant difference in accuracy of reproduction of finger pressure between the maximum and a slower rate of application is also shown, but not when the digital nerves are blocked by a local anaesthetic. Furthermore, there is no significant difference in accuracy of reproduction of finger pressure between the anaesthetized and unanaesthetized condition at the fastest rate of application. On the other hand, at the slow rate of application, there is an increasingly significant difference between the anæsthetized and unanaethetized condition as the applied force is reduced below 400 gms. weight, in favour of the control condition. In the fourth experiment, subjects were trained to apply a force of 25 gms. weight using a small area of skin on the palmar surface of the index finger, then tested for their ability to reproduce the same force before and after changing the size of the area of application. Results show a marked change in applied force corresponding to the change in size of skin area used. It is concluded that below an applied force of about 400 gms. weight, the maximum accuracy in reproduction of finger pressure is dependent upon cutaneous receptors. The results of these experiments are discussed in relation to evidence from other experimental, clinical and animal studies and it is suggested that the major function of afferent impulses from a limb in the initiation of voluntary movements is probably facilitatory rather than sensory.
The Error Power Spectrum as a Technique for Assessing the Performance of the Human Operator in a Simple Task
Authors: Sutton G. G. 
Published: March 2008

The measurement of performance of a human operator in a closed loop control system is considered; it is suggested that the power spectrum of the fluctuations of his tracking error (or error spectral density curve) gives a useful picture of performance and the equipment and technique for producing such a curve is described briefly. As an example of the technique the power spectra obtained on several subjects performing a simple task with a pressure joystick are given and the implications of the shape of the curve are discussed.
Experimental Disorientation in the Horizontal Plane
Authors: Piercy Malcolm 
Published: March 2008

Twenty-eight subjects were examined on a visual matching task for their ability to maintain an orientation with respect to a particular direction in the horizontal plane following a voluntary rotary body movement through 180 degrees. Each subject was examined with respect to eight different directions. Numerous gross errors occurred when visual information was reduced to the display of an arrow indicating a direction and a second arrow manipulated by the subject. The magnitude and distribution of the errors suggest that, under the conditions of this experiment, visual information as to direction in the horizontal plane is analysed according to the two horizontal dimensions defined by the sagittal and coronal planes of the head. In correcting for the rotary body movement, failure may occur with respect to either or both of these two dimensions. The frequency of a failure to make any correction at all (i.e. 180-degree errors) is consistent with independent failure in each of the two horizontal dimensions. Failure is markedly more frequent in the fore-aft dimension than in the left-right dimension. It is suggested that this may be explained in terms of the ambiguous spatial significance of vertical disposition on the retina and the possibility of contamination between the two systems of conceptual analysis which identify the vertical and the fore-aft dimensions of visual space. It is demonstrated that when minimal “landmarks” are provided they tend to be utilized as reference points in attempts to maintain orientation, even when the subject is aware that the “landmarks” are misleading. Such a use of “landmarks” does not suppress the previously mentioned mechanism of dimensional orientation. The relevance of these results to normal human orientation is discussed.
The Timing of Bar-Pressing Behaviour
Authors: Trotter J. R. 
Published: March 2008

The time spent by a rat in a bar-pressing situation is made up of active time spent n pressing, eating time, and extra time spent in other activities. With a well trained rat, active time and extra time are small, and eating time mainly determines the rate of reward delivery. Active time is affected by a change of weight on the bar, the time between reward deliveries is affected by the amount of reward, and the extra time is affected by extinction conditions. There is not a one-to-one correspondence between periods of activity at the knob and rewards. The term “response” and some variables based on it are given empirical referents, which show that much research and theorizing on bar-pressing behaviour has been concerned with only a small selection of the rat's bar-pressing activities. Some reasons for this restriction are the use of the simple weighted bar, the lack of a rationale for bar-pressing research, and the practice of not watching the rat during an experiment.
After-Images from Retina and Brain
Authors: Oswald Ian 
Published: March 2008

The evidence pointing to the retinal origin of after-images is considered. The reports of the occurrence of after-images from visual images of hallucinatory vividness are reviewed. Experimental results are presented to indicate that a complementarily coloured afterimage may arise following the exposure of the temporarily blind retina to a coloured stimulus. After-images, or after-effects, from vivid images are described in seventeen persons (mostly possessors of “number-forms”). They are found to move with the eyes and to show, in some persons, a degree of conformity with Emmert's Law which, while considerable, is less than that of after-images of real stimuli. In the case of one “eidetic” subject, the after-images from neither real nor imaged stimuli conformed with Emmert's Law. In some persons, after-images of images occur in complementary colours. The retinal origin of after-images is affirmed, but that they can occur occasionally as a purely central phenomenon is acknowledged. The possible learned or inherent nature of after-images of central origin is discussed.
The E.E.G., Visual Imagery and Attention
Authors: Oswald Ian 
Published: March 2008

The claim that persons may be broadly classified into imaginal types on the basis of their E.E.G. records is examined. It is found that a given individual may show a different “type” of E.E.G. from one occasion to the next. A group of persons, known to indulge spontaneously in certain recognizable varieties of vivid visual imagery, contained the same proportion of the different E.E.G. “types” as a large control sample. It was found that subjects could experience changing or static visual images without any blocking of the alpha rhythm providing that difficulty was not experienced in perceiving the images. Flat E.E.G. records were not found to be associated with regular respiration. It is proposed that the previously reported association between alpha blocking and the appearance of visual imagery could have arisen from the fact that difficulty in thinking (a) activates mechanisms which desynchronize E.E.G. potentials, (b) provokes the emergence of visual images.
Method of Serial Extrapolation
Authors: Beloff J. 
Published: March 2008

A psychophysical procedure is proposed for measuring a subject's power of discerning “lawfulness,” “regularity,” “invariance” in a stimulus sequence. The task consists of supplying the next term in a given series. The method is tested by applying it to a visual series consisting of lines subdivided in geometric progression. The effect upon accuracy of judgement is investigated by varying the settings of the stimulus, in particular the rate of increase or gradient of the series and the number of segments given prior to extrapolation, and of presenting the next-but-one position in the series, thereby converting the task into one of interpolation. Where possible, quantitative predictions are made concerning these variables on the basis of certain explicit assumptions. Results show that accuracy decreases, as predicted, as the gradient of the series increases, but does not seem to be affected by adding to the number of terms presented. Interpolation shows a reduction in variable error compared with extrapolation more or less as required by theory. Finally, discrepancies in the findings are discussed with special reference to their bearing on the validity of the method.