bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes
Authors: Zhou Qi , Wang Jun , Huang Ling , Nie Wenhui , Wang Jinhuan , Liu Yan , Zhao Xiangyi , Yang Fengtang , Wang Wen 
Published: June 2008

Abstract
Background
The regular mammalian X and Y chromosomes diverged from each other at least 166 to 148 million years ago, leaving few traces of their early evolution, including degeneration of the Y chromosome and evolution of dosage compensation.

Results
We studied the intriguing case of black muntjac, in which a recent X-autosome fusion and a subsequent large autosomal inversion within just the past 0.5 million years have led to inheritance patterns identical to the traditional X-Y (neo-sex chromosomes). We compared patterns of genome evolution in 35-kilobase noncoding regions and 23 gene pairs on the homologous neo-sex chromosomes. We found that neo-Y alleles have accumulated more mutations, comprising a wide variety of mutation types, which indicates cessation of recombination and is consistent with an ongoing neo-Y degeneration process. Putative deleterious mutations were observed in coding regions of eight investigated genes as well as cis-regulatory regions of two housekeeping genes. In vivo assays characterized a neo-Y insertion in the promoter of the CLTC gene that causes a significant reduction in allelic expression. A neo-Y-linked deletion in the 3'-untranslated region of gene SNX22 abolished a microRNA target site. Finally, expression analyses revealed complex patterns of expression divergence between neo-Y and neo-X alleles.

Conclusion
The nascent neo-sex chromosome system of black muntjacs is a valuable model in which to study the evolution of sex chromosomes in mammals. Our results illustrate the degeneration scenarios in various genomic regions. Of particular importance, we report - for the first time - that regulatory mutations were probably able to accelerate the degeneration process of Y and contribute to further evolution of dosage compensation.
Chondroitin sulfate disaccharide stimulates microglia to adopt a novel regulatory phenotype
Authors: Ebert Stefanie , Schoeberl Tobias , Walczak Yana , Stoecker Katharina , Stempfl Thomas , Moehle Christoph , Weber Bernhard H F , Langmann Thomas 
Published: June 2008

AbstractA disaccharide degradation product of chondrotin sulfate proteoglycan-disaccharide (CSPG-DS) has been implicated previously in the inhibition of neurodegeneration by influencing microglia activation. In this study, genome-wide microarray analysis was used to identify specific gene expression profiles of CSPG-DS-stimulated BV-2 microglia-like cells. Gene products involved in phagocytosis, detoxification, migration, immune regulation, and antigen presentation were found to be altered significantly. These findings were replicated and compared with IFN-γ-stimulated primary microglia using real-time quantitative RT-PCR validation. Importantly, a unique transcriptional phenotype with anti-inflammatory and IFN-γ counter-regulatory properties partially related to alternatively activated macrophages was identified. Using functional cell assays, we found that CSPG-DS-stimulated microglia possess increased phagocytic capacity but lack direct cytotoxic effects such as secretion of NO. Furthermore, conditioned media from CSPG-DS-treated microglia did not diminish the viability or cause apoptosis of cultured photoreceptor cells and partially rescued these cells from IFN-γ-induced apoptosis. Taken together, our data provide a unique transcript dataset and important in vitro findings about the functional properties of CSPG-DS-activated microglia. These might be starting points to explore the in vivo role of CSPG-DS as a bioactive microglia regulator and its potential, therapeutic application in immune-related, neurodegenerative disorders.
Regulation of cytosolic phospholipase A2α by hsp90 and a p54 kinase in okadaic acid-stimulated macrophages
Authors: Tucker Dawn E , Gijón Miguel A , Spencer Diane M , Qiu Zhi-Hua , Gelb Michael H , Leslie Christina C 
Published: June 2008

AbstractIn resident mouse peritoneal macrophages, group IVA cytosolic phospholipase A2 (cPLA2α) mediates arachidonic acid (AA) release and eicosanoid production in response to diverse agonists such as A23187, phorbol myristate acetate, zymosan, and the enterotoxin, okadaic acid (OA). cPLA2α is regulated by phosphorylation and by calcium that binds to the C2 domain and induces translocation from the cytosol to membranes. In contrast, OA activates cPLA2α-induced AA release and translocation to the Golgi in macrophages without an apparent increase in calcium. Inhibitors of heat shock protein 90 (hsp90), geldanamycin, and herbimycin blocked AA release in response to OA but not to A23187, PMA, or zymosan. OA, but not the other agonists, induced activation of a cytosolic serine/threonine 54-kDa kinase (p54), which phosphorylated cPLA2α in in-gel kinase assays and was associated with cPLA2α in immunoprecipitates. Activation of the p54 kinase was inhibited by geldanamycin. The kinase coimmunoprecipitated with hsp90 in unstimulated macrophages, and OA induced its loss from hsp90, concomitant with its association with cPLA2α. The results demonstrate a role for hsp90 in regulating cPLA2α-mediated AA release that involves association of a p54 kinase with cPLA2α upon OA stimulation.
Recruitment of the inflammatory subset of monocytes to sites of ischemia induces angiogenesis in a monocyte chemoattractant protein-1-dependent fashion
Authors: Capoccia Benjamin J , Gregory Alyssa D , Link Daniel C 
Published: June 2008

AbstractThere is accumulating evidence that delivery of bone marrow cells to sites of ischemia by direct local injection or mobilization into the blood can stimulate angiogenesis. This has stimulated tremendous interest in the translational potential of angiogenic cell population(s) in the bone marrow to mediate therapeutic angiogenesis. However, the mechanisms by which these cells stimulate angiogenesis are unclear. Herein, we show that the inflammatory subset of monocytes is selectively mobilized into blood after surgical induction of hindlimb ischemia in mice and is selectively recruited to ischemic muscle. Adoptive-transfer studies show that delivery of a small number of inflammatory monocytes early (within 48 h) of induction of ischemia results in a marked increase in the local production of MCP-1, which in turn, is associated with a secondary, more robust wave of monocyte recruitment. Studies of mice genetically deficient in MCP-1 or CCR2 indicate that although not required for the early recruitment of monocytes, the secondary wave of monocyte recruitment and subsequent stimulation of angiogenesis are dependent on CCR2 signaling. Collectively, these data suggest a novel role for MCP-1 in the inflammatory, angiogenic response to ischemia.
The Frank–Starling mechanism in vertebrate cardiac myocytes
Authors: Shiels Holly A. , White Ed 
Published: June 2008

SUMMARYThe Frank–Starling law of the heart applies to all classes of vertebrates. It describes how stretch of cardiac muscle, up to an optimum length, increases contractility thereby linking cardiac ejection to cardiac filling. The cellular mechanisms underlying the Frank–Starling response include an increase in myofilament sensitivity for Ca2+, decreased myofilament lattice spacing and increased thin filament cooperativity. Stretching of mammalian, amphibian and fish cardiac myocytes reveal that the functional peak of the sarcomere length (SL)–tension relationship occurs at longer SL in the non-mammalian classes. These findings correlate with in vivo cardiac function as non-mammalian vertebrates, such as fish,vary stroke volume to a relatively larger extent than mammals. Thus, it seems the length-dependent properties of individual myocytes are modified to accommodate differences in organ function, and the high extensibility of certain hearts is matched by the extensibility of their myocytes. Reasons for the differences between classes are still to be elucidated, however, the structure of mammalian ventricular myocytes, with larger widths and higher levels of passive stiffness than those from other vertebrate classes may be implicated.
The free-flight response ofDrosophilato motion of the visual environment
Authors: Mronz Markus , Lehmann Fritz-Olaf 
Published: June 2008

SUMMARYIn the present study we investigated the behavioural strategies with which freely flying fruit flies (Drosophila) control their flight trajectories during active optomotor stimulation in a free-flight arena. We measured forward, turning and climbing velocities of single flies using high-speed video analysis and estimated the output of a`Hassenstein–Reichardt' elementary motion detector (EMD) array and the fly's gaze to evaluate flight behaviour in response to a rotating visual panorama. In a stationary visual environment, flight is characterized by flight saccades during which the animals turn on average 120° within 130 ms. In a rotating environment, the fly's behaviour typically changes towards distinct, concentric circular flight paths where the radius of the paths increases with increasing arena velocity. The EMD simulation suggests that this behaviour is driven by a rotation-sensitive EMD detector system that minimizes retinal slip on each compound eye, whereas an expansion-sensitive EMD system with a laterally centred visual focus potentially helps to achieve centring response on the circular flight path. We developed a numerical model based on force balance between horizontal, vertical and lateral forces that allows predictions of flight path curvature at a given locomotor capacity of the fly. The model suggests that turning flight in Drosophila is constrained by the production of centripetal forces needed to avoid side-slip movements. At maximum horizontal velocity this force may account for up to 70%of the fly's body weight during yaw turning. Altogether, our analyses are widely consistent with previous studies on Drosophila free flight and those on the optomotor response under tethered flight conditions.
Oxygen consumption by a coral reef sponge
Authors: Hadas Eran , Ilan Micha , Shpigel Muki 
Published: June 2008

SUMMARY
Oxygen consumption of the Red Sea coral reef sponge Negombata magnifica was measured using both incubation and steady-state methods. The latter method was found to be the more reliable because sponge activity remained stable over time. Oxygen consumption rate was measured during three levels of sponge activity: full activity, reduced activity and basal activity(starved). It was found that the active oxygen consumption rate of N. magnifica averaged 37.3±4.6 nmol O2min–1 g–1 wet mass, which is within the upper range reported for other tropical marine sponges. Fully active N. magnifica individuals consumed an average of 41.8±3.2 nmol O2 min–1 g–1 wet mass. The mean basal respiration rate was 20.2±1.2 nmol O2min–1 g–1 wet mass, which is 51.6±2.5% of the active respiration rate. Therefore, the oxygen used for water pumping was calculated to be at most 10.6±1.8 nmol O2 min–1 g–1 wet mass, which is 25.1±3.6% of the total respiration. Combined oxygen used for maintenance and water pumping activity was calculated to be 30.8 nmol O2 min–1 g–1 wet mass, which is approximately 74% of the sponge's total oxygen requirement. The remaining oxygen is directed to other physiological activities, mainly the energy requirement of growth. These findings suggest that only a relatively minor amount of energy is potentially available for growth, and thus might be a factor in controlling the growth rate of N. magnifica in oligotrophic coral reefs.
Wing kinematics measurement and aerodynamics of hovering droneflies
Authors: Liu Yanpeng , Sun Mao 
Published: June 2008

SUMMARYThe time courses of wing and body kinematics of three freely hovering droneflies (Eristalis tenax) were measured using 3D high-speed video,and the morphological parameters of the wings and body of the insects were also measured. The measured wing kinematics was used in a Navier–Stokes solver to compute the aerodynamic forces and moments acting on the insects. The time courses of the geometrical angle of attack and the deviation angle of the wing are considerably different from that of fruit flies recently measured using the same approach. The angle of attack is approximately constant in the mid portions of a half-stroke (a downstroke or upstroke) and varies rapidly during the stroke reversal. The deviation angle is relatively small and is higher at the beginning and the end of a half-stroke and lower at the middle of the half-stroke, giving a shallow U-shaped wing-tip trajectory. For all three insects considered, the computed vertical force is approximately equal to the insect weight (the difference is less than 6% of the weight) and the computed horizontal force and pitching moment about the center of mass of the insect are approximately zero. The computed results satisfying the equilibrium flight conditions, especially the moment balance condition, validate the computation model. The lift principle is mainly used to produce the weight-supporting vertical force, unlike the fruit flies who use both lift and drag principles to generate the vertical force; the vertical force is mainly due to the delayed stall mechanism. The magnitude of the inertia power is larger than that of the aerodynamic power, and the largest possible effect of elastic storage amounts to a reduction of flight power by around 40%, much larger than in the case of the fruit fly.
Navigational abilities of homing pigeons deprived of olfactory or trigeminally mediated magnetic information when young
Authors: Gagliardo Anna , Ioalè Paolo , Savini Maria , Wild Martin 
Published: June 2008

SUMMARY
Anatomical evidence and conditioning experiments have recently suggested that magnetoreceptors are located in the upper beak of homing pigeons, where they are innervated by the ophthalmic branch of the trigeminal nerve. These findings have raised the issue of whether the trigeminally mediated magnetoreception is involved in the navigational mechanisms of homing pigeons. Recent data have shown that, in inexperienced pigeons, section of the ophthalmic branch of the trigeminal nerve does not impair navigational abilities, whereas the navigational performance of inexperienced pigeons is disrupted after section of the olfactory nerve. Nevertheless, the issue of whether the stimuli available during development of the navigational mechanism can influence the types of cues used in determining the direction of displacement remains unresolved. To address this issue, we surgically deprived young pigeons of either olfactory or trigeminally mediated magnetic information, and then later tested their navigational abilities subsequent to an intensive training flight program of up to 10 km in different directions. The birds deprived of trigeminally mediated magnetic information when young developed navigational abilities at the same level as intact control pigeons,whereas the olfactory deprived pigeons displayed randomly scattered initial orientation and poor homing performance. Our data show that olfactory cues are needed for the development of navigational abilities from unfamiliar locations and that the lack of magnetic information does not affect the development of homing abilities.
Modulation, individual variation and the role of lingual sensory afferents in the control of prey transport in the lizardPogona vitticeps
Authors: Schaerlaeken Vicky , Herrel Anthony , Meyers J. J. 
Published: June 2008

SUMMARYMost organisms feed on a variety of food items that may differ dramatically in their physical and behavioural characteristics (e.g. mobility, mass,texture, etc.). Thus the ability to modulate prey transport behaviour in accordance with the characteristics of the food appears crucial. Consequently,prey reduction and transport movements must be adjusted to the natural variation in material properties of the food, between and within feeding sequences and transport cycles. Here we describe an investigation of (1) the ability of the agamid lizard Pogona vitticeps to modulate prey transport kinematics when feeding on a range of food items differing in their physical characteristics and (2) the role of sensory feedback in controlling jaw and tongue movements by bilateral transection of the lingual trigeminal sensory afferents. Our findings demonstrate that P. vitticepsmodulates the kinematics of its feeding behaviour in response to the mechanical demands imposed by different food types. In addition, transection of the trigeminal sensory afferents has an effect on the movements of jaws and tongue during transport, and increases the duration of transport cycles needed to process a given food type. However, after transection, transport cycles were still different for different food types suggesting that other sources of sensory information are also used to modulate prey transport in the lizard P. vitticeps.
The compression and expansion waves of the forward and backward flows: An in-vitro arterial model
Authors: Feng J , Khir A W 
Published: June 2008

Although the propagation of arterial waves of forward flows has been studied before, that of backward flows has not been thoroughly investigated. The aim of this research is to investigate the propagation of the compression and expansion waves of backward flows in terms of wave speed and dissipation, in flexible tubes. The aim is also to compare the propagation of these waves with those of forward flows. A piston pump generated a flow waveform in the shape of approximately half-sinusoid, in flexible tubes (12 mm and 16 mm diameter). The pump produced flow in either the forward or the backward direction by moving the piston forward, in a ‘pushing action’ or backward, in a ‘pulling action’, using a graphite brushes d.c. motor. Pressure and flow were measured at intervals of 5 cm along each tube and wave speed was determined using the PU-loop method. The simultaneous measurements of diameter were also taken at the same position of the pressure and flow in the 16 mm tube. Wave intensity analysis was used to determine the magnitude of the pressure and velocity waveforms and wave intensity in the forward and backward directions. Under the same initial experimental conditions, wave speed was higher during the pulling action (backward flow) than during the pushing action (forward flow). The amplitudes of pressure and velocity in the pulling action were significantly higher than those in the pushing action. The tube diameter was approximately 20 per cent smaller in the pulling action than in the pushing action in the 16 mm tube. The compression and expansion waves resulting from the pushing and pulling actions dissipated exponentially along the travelling distance, and their dissipation was greater in the smaller than in the larger tubes. Local wave speed in flexible tubes is flow direction- and wave nature-dependent and is greater with expansion than with compression waves. Wave dissipation has an inverse relationship with the vessel diameter, and dissipation of the expansion wave of the pulling action was greater than that of the pushing action.
Contingency Theory and Public Bureaucracies
Authors: Greenwood Royston , Hinings C.R. 
Published: June 2008

The study of organizational bureaucracies has in recent years taken the form of ‘contingency theory’ a theory which rests upon the assumption that organizational characteristics have to be shaped to meet situational circumstances. The theory implies that the extent to which an organization secures a ‘goodness of fit’ between situational circumstances and structural characteristics will determine the level of organizational performance. Child summarizes it as follows: contingency theory ‘regards the design of an effective organization as necessarily having to be adapted to cope with the “contingencies” which derive from the circumstances of environment, technology, scale, resources and other factors in the situation in which an organization is operating’.
It is interesting that not one of the major contributions to contingency theory has considered the existence of elected representatives, to whom an organization is subordinated, and who are themselves accountable to a wider electorate, as being a significant contingency operating upon government bureaucracies. Blau has studied several government agencies in the United States, covering personnel agencies finance departments and employment security agencies; Meyer examined finance authorities; Hage and Aiken studied sixteen social welfare agencies; Hall and Pugh et al. covered both public and private bureaucracies.
Increased Plasma Apolipoprotein C-III Concentration Independently Predicts Cardiovascular Mortality: The Hoorn Study
Authors: Scheffer Peter G , Teerlink Tom , Dekker Jacqueline M , Bos Griët , Nijpels Giel , Diamant Michaela , Kostense Piet J , Stehouwer Coen D A , Heine Robert J 
Published: June 2008

AbstractBackground: Hypertriglyceridemia is a cardiovascular risk factor. Apolipoprotein C-III (apoC-III) is an important determinant of the catabolic rate of triglyceride-rich lipoproteins. The aim of this study was to investigate the prognostic value of plasma apoC-III concentrations for cardiovascular mortality.Methods: We performed this prospective study in 2244 subjects (ages 49–77 years) who participated in the Hoorn Study. During a mean follow-up of 15 years, 504 individuals died: 231 of cardiovascular disease, 180 of cancer, and 93 of other causes. Cardiovascular disease risk factors and plasma apoC-III concentrations were measured at baseline.Results: The age- and sex-adjusted plasma apoC-III concentration was prospectively associated with cardiovascular mortality (P &lt; 0.001). After adjustment for traditional risk factors, including fasting triglycerides, the hazard ratio (95% CI) for cardiovascular death between the highest and the lowest quartile of apoC-III was 1.85 (1.02–3.38). High concentrations of apoC-III did not appear to be associated with noncardiovascular mortality.Conclusions: In this general population cohort, a high apoC-III concentration in plasma, independently of fasting triglycerides and other traditional risk factors, predicts cardiovascular mortality.
Diagnostic Accuracy of Serum Ceruloplasmin in Wilson Disease: Determination of Sensitivity and Specificity by ROC Curve Analysis among ATP7B-Genotyped Subjects
Authors: Mak Chloe M , Lam Ching-Wan , Tam Sidney 
Published: June 2008

AbstractBackground: A serum ceruloplasmin concentration below 0.20 g/L is conventionally considered as one of the major diagnostic criteria for Wilson disease. This decision threshold has not been fully validated for its diagnostic characteristics, however. In this study, we evaluated various decision thresholds of serum ceruloplasmin concentration in the diagnosis of Wilson disease based on genotype-verified Wilson disease patients, carriers, and normal individuals.Methods: Serum ceruloplasmin concentration was measured by a nephelometric method in 57 Wilson disease patients and 71 family members (49 heterozygotes and 22 wild-type homozygotes), a validation group of 25 subjects clinically suspected of Wilson disease, and 690 normal individuals. We performed ROC analysis using Analyze-it software and confirmed the genotypes by direct DNA sequencing of ATP7B.Results: Serum ceruloplasmin concentrations &lt;0.20, 0.14, and 0.10 g/L showed positive predictive values of 48.3%, 100%, and 100%, respectively, and negative predictive values of 98.7%, 97.1%, and 91.9%. In the validation group, a serum ceruloplasmin threshold of 0.14 g/L rendered 100% sensitivity and specificity. Forty of 690 healthy subjects had serum ceruloplasmin concentrations &lt;0.20 g/L; however, these 40 individuals had normal genotypes by DNA sequencing, and none of the 40 had ceruloplasmin concentrations &lt;0.14 g/L.Conclusions: The diagnostic accuracy for Wilson disease using a serum ceruloplasmin concentration of 0.14 g/L as the local decision threshold was better than that using a threshold of 0.20 g/L. We suggest that laboratories providing ceruloplasmin assays determine decision thresholds based on local populations.