bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology and pathology of the ectoparasitic copepod, Nicothoë astaci (‘lobster louse’) in the European lobster, Homarus gammarus
Authors: WOOTTON EMMA C. , POPE EDWARD C. , VOGAN CLAIRE L. , ROBERTS EMILY C. , DAVIES CHARLOTTE E. , ROWLEY ANDREW F. 
Published: July 2011

SUMMARYEctoparasitic copepods have been reported in a wide range of aquatic animals, including crustacean shellfish. However, with the exception of the salmon louse, Lepeophtheirus salmonis, our knowledge of such parasites in commercial species is rudimentary. The current study examines the morphology and pathology of the parasitic copepod, Nicothoë astaci (the ‘lobster louse’) in its host, the European lobster, Homarus gammarus. Lobsters were sampled from waters surrounding Lundy Island (Bristol Channel, UK) and all individuals collected were found to harbour female adult N. astaci in their gills, with a mean of 47·3 parasites/lobster. The majority of N. astaci were found in the basal region of pleurobranch gills. The parasite was found to attach to gill filaments via its oral sucker, maxillae and maxillipeds, and to feed on host haemolymph (blood) through a funnel-like feeding channel. It caused varying degrees of damage to the host gill, including occlusion of gill filaments and disruption to the vascular system in the central axis. Although there was evidence of extensive host response (haemocytic infiltration) to the parasite, it was displaced from the parasite attachment site and thus was observed in the central gill axis below. The region of gill filament immediately underlying the parasite feeding channel was devoid of such activity suggesting that the parasite interferes with the cellular defence and haemostatic mechanisms of the lobster in order to maintain invasion of the host.
Male gametocyte fecundity and sex ratio of a malaria parasite, Plasmodium mexicanum
Authors: NEAL A. T. 
Published: July 2011

SUMMARYEvolutionary theory predicts that the sex ratio of Plasmodium gametocytes will be determined by the number of gametes produced per male gametocyte (male fecundity), parasite clonal diversity and any factor that reduces male gametes' ability to find and combine with female gametes. Despite the importance of male gametocyte fecundity for sex ratio theory as applied to malaria parasites, few data are available on gamete production by male gametocytes. In this study, exflagellating gametes, a measure of male fecundity, were counted for 866 gametocytes from 26 natural infections of the lizard malaria parasite, Plasmodium mexicanum. The maximum male fecundity observed was 8, but most gametocytes produced 2–3 gametes, a value consistent with the typical sex ratio observed for P. mexicanum. Male gametocytes in infections with higher gametocytaemia had lower fecundity. Male fecundity was not correlated with gametocyte size, but differed among infections, suggesting genetic variation for fecundity. Fecundity and sex ratio were correlated (more female gametocytes with higher fecundity) as predicted by theory. Results agree with evolutionary theory, but also suggest a possible tradeoff between production time and fecundity, which could explain the low fecundity of this species, the variation among infections, and the correlation with gametocytaemia.
Non-existence of radial backward self-similar blow-up solutions with sign change
Authors: Mizoguchi Noriko 
Published: July 2011

We consider a Cauchy problem for a semilinear heat equationwith p > 1. If u(x, t) = (T − t)−1/(p−1)ϕ((T − t)−1/2x) for x ∈ ℝN and t ∈ [0, T),where ϕ ∈ L∞(ℝN) is a solution not identically equal to zero ofthen u is called a backward self-similar solution blowing up at t = T. We show that, for all p > 1, there exists no radial sign-changing solution of (E) which belongs to L∞(ℝN). This implies the non-existence of radial backward self-similar solution with sign change blowing up in finite time.
Normalizing the development of cortisol regulation in maltreated infants through preventive interventions
Authors: Cicchetti Dante , Rogosch Fred A. , Toth Sheree L. , Sturge-Apple Melissa L. 
Published: July 2011

AbstractLongitudinal effects of child maltreatment on cortisol regulation in infants from age 1 to 3 years were investigated in the context of a randomized preventive intervention trial. Thirteen-month-old infants from maltreating families (N= 91) and their mothers were randomly assigned to one of three intervention conditions: child–parent psychotherapy, psychoeducational parenting intervention, and a control group involving standard community services (CS). A fourth group of infants from nonmaltreating families (N= 52) and their mothers comprised a nonmaltreated comparison (NC) group. The two active interventions were combined into one maltreated intervention (MI) group for statistical analyses. Saliva samples were obtained from children at 10:00 a.m. before beginning a laboratory observation session with their mothers when the children were 13 months of age (preintervention), 19 months (midintervention), 26 months (postintervention), and 38 months (1-year postintervention follow-up). At the initial assessment, no significant differences among groups in morning cortisol were observed. Latent growth curve analyses examined trajectories of cortisol regulation over time. Beginning at midintervention, divergence was found among the groups. Whereas the MI group remained indistinguishable from the NC group across time, the CS group progressively evinced lower levels of morning cortisol, statistically differing from the MI and NC groups. Results highlight the value of psychosocial interventions for early child maltreatment in normalizing biological regulatory processes.
The impact of allostatic load on maternal sympathovagal functioning in stressful child contexts: Implications for problematic parenting
Authors: Sturge-Apple Melissa L. , Skibo Michael A. , Rogosch Fred A. , Ignjatovic Zeljko , Heinzelman Wendi 
Published: July 2011

AbstractThe present study applies an allostatic load framework to an examination of the relationship between maternal psychosocial risk factors and maladaptive parenting behaviors. Specifically, the implications of low socioeconomic status and maternal depressive symptoms for maternal sympathovagal functioning during young children's distress were examined, as well as whether that functioning was, in turn, associated with maternal insensitivity, hostility, intrusiveness, and disengagement during mother–child dyadic interaction. Consistent with an allostatic framework, three patterns of sympathovagal functioning were expected to emerge: normative arousal, hyperarousal, and hypoarousal profiles. Furthermore, meaningful associations between maternal psychosocial risk factors, maladaptive parenting behaviors, and the three profiles of sympathovagal functioning were anticipated. Participants included 153 mother–toddler dyads recruited proportionately from lower and middle socioeconomic status backgrounds. Mothers’ sympathovagal response to their child's distress was assessed during the Strange Situation paradigm, and mothers’ parenting behavior was assessed during a dyadic free-play interaction. As hypothesized, normative arousal, hyperarousal, and hypoarousal profiles of maternal sympathovagal functioning were identified. Maternal depressive symptomatology predicted the hyperarousal profile, whereas socioeconomic adversity predicted hypoarousal. Moreover, allostatic load profiles were differentially associated with problematic parenting behaviors. These findings underscore the role of physiological dysregulation as a mechanism in the relationship between proximal risk factors and actual maladaptive parenting behaviors.
Allostasis and allostatic load in the context of poverty in early childhood
Authors: Blair Clancy , Raver C. Cybele , Granger Douglas , Mills-Koonce Roger , Hibel Leah ,   The Family Life Project Key Investigators
Published: July 2011

AbstractThis paper examined the relation of early environmental adversity associated with poverty to child resting or basal level of cortisol in a prospective longitudinal sample of 1135 children seen at 7, 15, 24, 35, and 48 months of age. We found main effects for poor housing quality, African American ethnicity, and low positive caregiving behavior in which each was uniquely associated with an overall higher level of cortisol from age 7 to 48 months. We also found that two aspects of the early environment in the context of poverty, adult exits from the home and perceived economic insufficiency, were related to salivary cortisol in a time-dependent manner. The effect for the first of these, exits from the home, was consistent with the principle of allostatic load in which the effects of adversity on stress physiology accumulate over time. The effect for perceived economic insufficiency was one in which insufficiency was associated with higher levels of cortisol in infancy but with a typical but steeper decline in cortisol with age at subsequent time points.
Maternal responsiveness moderates the relationship between allostatic load and working memory
Authors: Doan Stacey N. , Evans Gary W. 
Published: July 2011

AbstractA substantial amount of research has demonstrated the deleterious effects of chronic stress on memory. However, much less is known about protective factors. In the current study we test the role of maternal responsiveness in buffering the effects of childhood allostatic load on subsequent adolescent working memory. Allostatic load is a marker of cumulative stress on the body that is caused by mobilization of multiple physiological systems in response to chronic environmental demands. Results of the study suggest that allostatic load negatively affects working memory, but that this effect is significantly attenuated in children with responsive mothers.
Hypocortisolism as a potential marker of allostatic load in children: Associations with family risk and internalizing disorders
Authors: Badanes Lisa S. , Watamura Sarah Enos , Hankin Benjamin L. 
Published: July 2011

AbstractAlthough the majority of research attention to the hypothalamic–pituitary–adrenal (HPA) axis in stress-related disorders and as a marker of allostatic load has focused on overactivation of this stress system, theory and data clearly indicate that underactivation is also an important type of dysregulation. In the current study we focused on low cortisol, exploring a constellation of risk factors including stress exposure, maternal depression, and attenuated basal and stress reactive cortisol in two samples of children. The first sample was comprised of 110 preschoolers living in high-stress environments. Cortisol was assessed across the day at home and at child care as well as across two stress paradigms. These data were used to classify whether children's HPA axis activity was attenuated. Serious family financial strain, maternal depression, and attenuated cortisol all made unique contributions in models predicting current clinical levels of internalizing symptoms as rated by mothers and teachers. The second sample was 166 third, sixth, and ninth graders studied five times across a 1-year period. Maternal and child depression were determined through structured clinical interviews, and stress exposure was assessed via checklist and interview techniques with the child and parent. Cortisol was assessed multiple times across a lab visit at Time 1, and these data were combined into a single continuous measure. Cortisol concentrations across the lab visit interacted with stress exposure across the year such that children with lower average cortisol at Time 1 and increased stress across the 12 months showed elevated levels of internalizing symptoms. Based on these and related data we propose that prior to puberty low cortisol may be an important marker of allostatic load, particularly for risk of depression and anxiety.
Social encounters in daily life and 2-year changes in metabolic risk factors in young women
Authors: Ross Kharah , Martin Tara , Chen Edith , Miller Gregory E. 
Published: July 2011

AbstractResearch shows that poor social ties increase risks of morbidity and mortality from cardiovascular disease (CVD). However, little is known about the nature of everyday social encounters that give rise to this association, or when in the course of development they begin to shape disease-relevant biological processes. In this study, 122 adolescent females recorded the qualities of their everyday social interactions using electronic diaries. At the same time we measured components of the metabolic syndrome, a precursor to CVD that includes central adiposity, high blood pressure, insulin resistance, and lipid dysregulation. Metabolic symptoms were reassessed 12 and 24 months later. Hierarchical linear modeling revealed an association between negative social interactions and metabolic symptom trajectories. To the extent that participants had more intense negative social encounters in daily life, they showed increasing scores on a composite indicator of metabolic risk over 2 years. This association was independent of a variety of potential confounders, and persisted when symptoms of depression and broader personality traits were controlled. There was no association between positive social encounters and metabolic risk trajectories. These findings suggest that even in otherwise healthy adolescents, abrasive social encounters may accelerate the progression of early stages of CVD.
Inhibition of the chlorinating activity of myeloperoxidase by tempol: revisiting the kinetics and mechanisms
Authors: Queiroz Raphael F. , Vaz Sandra M. , Augusto Ohara 
Published: July 2011

The nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) reduces tissue injury in animal models of inflammation by mechanisms that are not completely understood. MPO (myeloperoxidase), which plays a fundamental role in oxidant production by neutrophils, is an important target for anti-inflammatory action. By amplifying the oxidative potential of H2O2, MPO produces hypochlorous acid and radicals through the oxidizing intermediates MPO-I [MPO-porphyrin•+-Fe(IV)=O] and MPO-II [MPO-porphyrin-Fe(IV)=O]. Previously, we reported that tempol reacts with MPO-I and MPO-II with second-order rate constants similar to those of tyrosine. However, we noticed that tempol inhibits the chlorinating activity of MPO, in contrast with tyrosine. Thus we studied the inhibition of MPO-mediated taurine chlorination by tempol at pH 7.4 and re-determined the kinetic constants of the reactions of tempol with MPO-I (k=3.5×105 M−1·s−1) and MPO-II, the kinetics of which indicated a binding interaction (K=2.0×10−5 M; k=3.6×10−2 s−1). Also, we showed that tempol reacts extremely slowly with hypochlorous acid (k=0.29 and 0.054 M−1·s−1 at pH 5.4 and 7.4 respectively). The results demonstrated that tempol acts mostly as a reversible inhibitor of MPO by trapping it as MPO-II and the MPO-II–tempol complex, which are not within the chlorinating cycle. After turnover, a minor fraction of MPO is irreversibly inactivated, probably due to its reaction with the oxammonium cation resulting from tempol oxidation. Kinetic modelling indicated that taurine reacts with enzyme-bound hypochlorous acid. Our investigation complements a comprehensive study reported while the present study was underway [Rees, Bottle, Fairfull-Smith, Malle, Whitelock and Davies (2009) Biochem. J. 421, 79–86].
Diurnal variability in orthostatic tachycardia: implications for the postural tachycardia syndrome
Authors: Brewster Jordan A. , Garland Emily M. , Biaggioni Italo , Black Bonnie K. , Ling John F. , Shibao Cyndya A. , Robertson David , Raj Satish R. 
Published: July 2011

Patients with POTS (postural tachycardia syndrome) have excessive orthostatic tachycardia (&gt;30 beats/min) when standing from a supine position. HR (heart rate) and BP (blood pressure) are known to exhibit diurnal variability, but the role of diurnal variability in orthostatic changes of HR and BP is not known. In the present study, we tested the hypothesis that there is diurnal variation of orthostatic HR and BP in patients with POTS and healthy controls. Patients with POTS (n=54) and healthy volunteers (n=26) were admitted to the Clinical Research Center. Supine and standing (5 min) HR and BP were obtained in the evening on the day of admission and in the following morning. Overall, standing HR was significantly higher in the morning (102±3 beats/min) than in the evening (93±2 beats/min; P&lt;0.001). Standing HR was higher in the morning in both POTS patients (108±4 beats/min in the morning compared with 100±3 beats/min in the evening; P=0.012) and controls (89±3 beats/min in the morning compared with 80±2 beats/min in the evening; P=0.005) when analysed separately. There was no diurnal variability in orthostatic BP in POTS. A greater number of subjects met the POTS HR criterion in the morning compared with the evening (P=0.008). There was significant diurnal variability in orthostatic tachycardia, with a great orthostatic tachycardia in the morning compared with the evening in both patients with POTS and healthy subjects. Given the importance of orthostatic tachycardia in diagnosing POTS, this diurnal variability should be considered in the clinic as it may affect the diagnosis of POTS.
Exaggerated natriuresis during clamping of systemic NO supply in healthy young men
Authors: Simonsen Jane A. , Rasmussen Mona S. , Vach Werner , Høilund-Carlsen Poul F. , Bie Peter 
Published: July 2011

NO (nitric oxide) may be involved in fluid homoeostasis. We hypothesized that increases in NO synthesis contribute to acute, saline-induced natriuresis, which, therefore, should be blunted when NO availability is stabilized. Young men were studied during simultaneous infusions of L-NAME [NG-nitro-L-arginine methyl ester; bolus of 750 μg·kg−1 of body weight and 8.3 μg·min−1·kg−1 of body weight] and SNP (sodium nitroprusside), the latter at a rate preventing L-NAME from increasing total peripheral resistance (‘NO-clamping’). Slow volume expansion (saline, 20 μmol of NaCl·min−1·kg−1 of body weight for 3 h) was performed with and without concomitant NO-clamping. NO-clamping itself decreased RPF (renal plasma flow; P~0.02) and tended to decrease arterial blood pressure [MABP (mean arterial blood pressure)]. Volume expansion markedly decreased the plasma levels of renin, AngII (angiotensin II) and aldosterone (all P&lt;0.001), while MABP (oscillometry), heart rate, cardiac output (impedance cardiography), RPF (by p-aminohippurate), GFR [glomerular filtration rate; by using 51Cr-labelled EDTA] and plasma [Na+] and [K+] remained constant. Volume expansion increased sodium excretion (P&lt;0.02) at constant filtered load, but more so during NO-clamping than during control (+184% compared with 52%; P&lt;0.0001). Urinary nitrate/nitrite excretion increased during volume expansion; plasma cGMP and plasma vasopressin were unchanged. The results demonstrate that NO-clamping augments sodium excretion in response to volume expansion at constant MABP and GFR, reduced RPF and decreased renin system activity, a response termed hypernatriuresis. The results indicate that mediator(s) other than MABP, RPF, GFR and renin system activity contribute significantly to the homoeostatic response to saline loading, but the specific mechanisms of hypernatriuresis remain obscure.
A Grid-enabled web portal for NMR structure refinement with AMBER
Authors: Bertini Ivano , Case David A. , Ferella Lucio , Giachetti Andrea , Rosato Antonio 
Published: July 2011

Abstract
Motivation: The typical workflow for NMR structure determination involves collecting thousands of conformational restraints, calculating a bundle of 20–40 conformers in agreement with them and refining the energetics of these conformers. The structure calculation step employs simulated annealing based on molecular dynamics (MD) simulations with very simplified force fields. The value of refining the calculated conformers using restrained MD (rMD) simulations with state-of-art force fields is documented. This refinement however presents various subtleties, from the proper formatting of conformational restraints to the definition of suitable protocols.
Results: We describe a web interface to set up and run calculations with the AMBER package, which we called AMPS-NMR (AMBER-based Portal Server for NMR structures). The interface allows the refinement of NMR structures through rMD. Some predefined protocols are provided for this purpose, which can be personalized; it is also possible to create an entirely new protocol. AMPS-NMR can handle various restraint types. Standard rMD refinement in explicit water of the structures of three different proteins are shown as examples. AMPS-NMR additionally includes a workspace for the user to store different calculations. As an ancillary service, a web interface to AnteChamber is available, enabling the calculation of force field parameters for organic molecules such as ligands in protein–ligand adducts.
Availability and Implementation: AMPS-NMR is embedded within the NMR services of the WeNMR project and is available at http://py-enmr.cerm.unifi.it/access/index/amps-nmr; its use requires registration with a digital certificate.
Contact: ivanobertini@cerm.unifi.it
Supplementary information: Supplementary data are available at Bioinformatics online.
NASP: a parallel program for identifying evolutionarily conserved nucleic acid secondary structures from nucleotide sequence alignments
Authors: Semegni J. Y. , Wamalwa M. , Gaujoux R. , Harkins G. W. , Gray A. , Martin D. P. 
Published: July 2011

Abstract
Summary:Many natural nucleic acid sequences have evolutionarily conserved secondary structures with diverse biological functions. A reliable computational tool for identifying such structures would be very useful in guiding experimental analyses of their biological functions. NASP (Nucleic Acid Structure Predictor) is a program that takes into account thermodynamic stability, Boltzmann base pair probabilities, alignment uncertainty, covarying sites and evolutionary conservation to identify biologically relevant secondary structures within multiple sequence alignments. Unique to NASP is the consideration of all this information together with a recursive permutation-based approach to progressively identify and list the most conserved probable secondary structures that are likely to have the greatest biological relevance. By focusing on identifying only evolutionarily conserved structures, NASP forgoes the prediction of complete nucleotide folds but outperforms various other secondary structure prediction methods in its ability to selectively identify actual base pairings.
Availability: Downloable and web-based versions of NASP are freely available at http://web.cbio.uct.ac.za/~yves/nasp_portal.php
Contact: yves@cbio.uct.ac.za
Supplementary information: Supplementary data are available at Bioinformatics online.