The role of oxytocin in mother-infant relations : a systematic review of human studies

Background: Oxytocin is associated with the establishment and quality of maternal behavior in animal models. Parallel investigations in humans are now under way. This article reviews the current research examining the role of oxytocin in mother-infant relations, attachment, and bonding in humans. Methods: A systematic search was made of three electronic databases and other bibliographic sources for published research studies that examined oxytocin and mother-infant relations in humans, including attachment, maternal behavior, parenting, and mother-infant relations. Results: Eight studies were identified, all of which were unique in their methodologies, populations studied, and measures used. Seven studies found significant and strong associations between levels or patterns of oxytocin and aspects of mother-infant relations or attachment. Conclusions: Oxytocin appears to be of crucial importance for understanding mother-infant relationships. The findings of this review suggest that the pioneering, but preliminary, research undertaken to date is promising and that replication with larger samples is needed. Research that draws on more robust measures of attachment and bonding, as well as improved measures of oxytocin that include both central and peripheral levels, will elucidate the role of oxytocin in human mother-infant relationships. As the production of oxytocin is by no means restricted to mothers, the extension of the oxytocin studies to fathering, as well as to alloparental caregiving, would be an intriguing next step.

Flexible multibody approach in forward dynamic simulation of locomotive strains in human skeleton with flexible lower body bones

A method for bone strain estimation is examined in this article. The flexibility of a single bone in an otherwise rigid human skeleton model has been studied previously by various authors. However, in the previous studies, the effect of the flexibility of multiple bones on the musculoskeletal model behavior was ignored. This study describes a simulation method that can be used to estimate the bone strains at both tibias and femurs of a 65-year old Caucasian male subject. The verification of the method is performed by the comparison of the results with other studies available in literature. The results of the study show good correlation with the results of previous empirical studies. A damping effect of the flexible bones on the model is also studied in this paper.

Browsing behavior mimicking attacks on popular web sites for large botnets

With the significant growth of botnets, application layer DDoS attacks are much easier to launch using large botnet, and false negative is always a problem for intrusion detection systems in real practice. In this paper, we propose a novel application layer DDoS attack tool, which mimics human browsing behavior following three statistical distributions, the Zipf-like distribution for web page popularity, the Pareto distribution for page request time interval for an individual browser, and the inverse Gaussian distribution for length of browsing path. A Markov model is established for individual bot to generate attack request traffic. Our experiments indicated that the attack traffic that generated by the proposed tool is pretty similar to the real traffic. As a result, the current statistics based detection algorithms will result high false negative rate in general. In order to counter this kind of attacks, we discussed a few preliminary solutions at the end of this paper.

Individual, social, and physical environment factors associated with electronic media use among children : sedentary behavior at home

Background: Individual, home social and physical environment correlates of electronic media (EM) use among children were examined and pattern of differences on school and weekend days.
Methods: Youth (n = 298) aged 11 to 12 years self-reported time spent using EM (TV, video/DVD, computer use, and electronic games) on a typical school and a weekend day, each dichotomized at the median to indicate heavy and light EM users. Anthropometric measurements were taken. Logistic regression examined correlates of EM use.
Results: In total, 87% of participants exceeded electronic media use recommendations of ≤ 2 hrs/day. Watching TV during breakfast (OR = 3.17) and after school (OR = 2.07), watching TV with mother (OR = 1.96), no rule(s) limiting time for computer game usage (OR = 2.30), having multiple (OR = 2.99) EM devices in the bedroom and BMI (OR = 1.15) were associated with higher odds of being heavy EM user on a school day. Boys (OR = 2.35) and participants who usually watched TV at midday (OR = 2.91) and late at night (OR = 2.04) had higher odds of being a heavy EM user on the weekend.
Conclusions: Efforts to modify children’s EM use should focus on a mix of intervention strategies that address patterns and reinforcement of TV viewing, household rules limiting screen time, and the presence of EM devices in the child’s bedroom.

Adsorption, lubrication, and wear of lubricin on model surfaces : polymer brush-like behavior of a glycoprotein

Using a surface force apparatus, we have measured the normal and friction forces between layers of the human glycoprotein lubricin, the major boundary lubricant in articular joints, adsorbed from buffered saline solution on various hydrophilic and hydrophobic surfaces: i), negatively charged mica, ii), positively charged poly-lysine and aminothiol, and iii), hydrophobic alkanethiol monolayers. On all these surfaces lubricin forms dense adsorbed layers of thickness 60–100 nm. The normal force between two surfaces is always repulsive and resembles the steric entropic force measured between layers of end-grafted polymer brushes. This is the microscopic mechanism behind the antiadhesive properties showed by lubricin in clinical tests. For pressures up to ∼6 atm, lubricin lubricates hydrophilic surfaces, in particular negatively charged mica (friction coefficient μ = 0.02–0.04), much better than hydrophobic surfaces (μ > 0.3). At higher pressures, the friction coefficient is higher (μ > 0.2) for all surfaces considered and the lubricin layers rearrange under shear. However, the glycoprotein still protects the underlying substrate from damage up to much higher pressures. These results support recent suggestions that boundary lubrication and wear protection in articular joints are due to the presence of a biological polyelectrolyte on the cartilage surfaces.

Driving down daily step counts: the impact of being driven to school on physical activity and sedentary behavior

This study investigated whether being driven to school was associated with lower weekday and weekend step counts, less active out-of-school leisure pursuits, and more sedentary behavior. Boys aged 10–13 years (n = 384) and girls aged 9–13 years (n = 500) attending 25 Australian primary schools wore a pedometer and completed a travel diary for one week. Parents and children completed surveys capturing leisure activity, screen time, and sociodemographics. Commute distance was objectively measured. Car travel was the most frequent mode of school transportation (boys: 51%, girls: 58%). After adjustment (sociodemographics, commute distance, and school clustering) children who were driven recorded fewer weekday steps than those who walked (girls: –1,393 steps p < .001, boys: –1,569 steps, p = .009) and participated in fewer active leisure activities (girls only: p = .043). There were no differences in weekend steps or screen time. Being driven to and from school is associated with less weekday pedometer-determined physical activity in 9- to 13-year-old elementary-school children. Encouraging children, especially girls, to walk to and from school (even for part of the way for those living further distances) could protect the health and well-being of those children who are insufficiently active.

Sex-linked neuroanatomical basis of human altruistic cooperativeness

Human altruistic cooperativeness, one of the most important components of our highly organized society, is along with a greatly enlarged brain relative to body size a spectacular outlier in the animal world. The "social-brain hypothesis" suggests that human brain expansion reflects an increased necessity for information processing to create social reciprocity and cooperation in our complex society. The present study showed that the young adult females (n = 66) showed greater Cooperativeness as well as larger relative global and regional gray matter volumes (GMVs) than the matched males (n = 89), particularly in the social-brain regions including bilateral posterior inferior frontal and left anterior medial prefrontal cortices. Moreover, in females, higher cooperativeness was tightly coupled with the larger relative total GMV and more specifically with the regional GMV in most of the regions revealing larger in female sex-dimorphism. The global and most of regional correlations between GMV and Cooperativeness were significantly specific to female. These results suggest that sexually dimorphic factors may affect the neurodevelopment of these "social-brain" regions, leading to higher cooperativeness in females. The present findings may also have an implication for the pathophysiology of autism; characterized by severe dysfunction in social reciprocity, abnormalities in social-brain, and disproportionately low probability in females.

Associations between behavior regulation, competence, physical activity, and health for adolescent females

This study investigated the association between the different types of behavior regulation and competence on sport and physical activity (PA) and perceived health, and the influence of school year level (ie, year 7 and year 11) and setting (ie, metropolitan and rural) on these relationships.

Effects of alloying elements on the corrosion behavior and biocompatibility of biodegradable magnesium alloys: a review

Magnesium (Mg) based alloys have been extensively considered for their use as biodegradable implant materials. However, controlling their corrosion rate in the physiological environment of the human body is still a significant challenge. One of the most effective approaches to address this challenge is to carefully select alloying compositions with enhanced corrosion resistance and mechanical properties when designing the Mg alloys. This paper comprehensively reviews research progress on the development of Mg alloys as biodegradable implant materials, highlighting the effects of alloying elements including aluminum (Al), calcium (Ca), lithium (Li), manganese (Mn), zinc (Zn), zirconium (Zr), strontium (Sr) and rare earth elements (REEs) on the corrosion resistance and biocompatibility of Mg alloys, from the viewpoint of the design and utilization of Mg biomaterials. The REEs covered in this review include cerium (Ce), erbium (Er), lanthanum (La), gadolinium (Gd), neodymium (Nd) and yttrium (Y). The effects of alloying elements on the microstructure, corrosion behavior and biocompatibility of Mg alloys have been critically summarized based on specific aspects of the physiological environment, namely the electrochemical effect and the biological behavior. This journal is © the Partner Organisations 2014.

Oxytocin enhances the appropriate use of human social cues by the domestic dog (Canis familiaris) in an object choice task

It has been postulated that the neuropeptide, oxytocin, is involved in human-dog bonding. This may explain why dogs, compared to wolves, are such good performers on object choice tasks, which test their ability to attend to, and use, human social cues in order to find hidden food treats. The objective of this study was to investigate the effect of intranasal oxytocin administration, which is known to increase social cognition in humans, on domestic dogs' ability to perform such a task. We hypothesised that dogs would perform better on the task after an intranasal treatment of oxytocin. Sixty-two (31 males and 31 females) pet dogs completed the experiment over two different testing sessions, 5-15 days apart. Intranasal oxytocin or a saline control was administered 45 min before each session. All dogs received both treatments in a pseudo-randomised, counterbalanced order. Data were collected as scores out of ten for each of the four blocks of trials in each session. Two blocks of trials were conducted using a momentary distal pointing cue and two using a gazing cue, given by the experimenter. Oxytocin enhanced performance using momentary distal pointing cues, and this enhanced level of performance was maintained over 5-15 days time in the absence of oxytocin. Oxytocin also decreased aversion to gazing cues, in that performance was below chance levels after saline administration but at chance levels after oxytocin administration.

Predicting physical activity intention and behavior in school-age children

Two studies were conducted to predict physical activity in school-aged children. Study 1 tested the utility of an integrated model in predicting physical activity (PA) intention and behavior-the theory of planned behavior (TPB) and self-efficacy theory. Six hundred and forty-five New Zealand children (aged 11-13 years) completed measures corresponding to the integrated model and a self-reported measure of PA one week later. Perceived behavioral control (PBC) and subjective norm were the two strongest predictors of intentions. Task efficacy and barrier efficacy were the two strongest predictors of PA. A second study (Study 2) was conducted to determine whether the self-efficacy measures could discriminate objectively measured PA levels. Sixty-seven Canadian children (aged 11-13 years) completed task and barrier self-efficacy measures. The following week, children classified as 'high' (n = 11) and 'lower' (n = 7) for both task and barrier efficacy wore an Actical® monitor for seven consecutive days to provide activity-related energy expenditure (AEE) data. Results showed that children with high efficacy expended significantly greater AEE than their lower efficacious counterparts. Findings from these two studies provide support for the use of self-efficacy interventions as a potentially useful means of increasing PA levels among school-aged children.

Sport consumer behavior research: improving our game

Sport consumer behavior (SCB) research continues to grow in both popularity and sophistication. A guiding principle in much of this research has focused on the nature of sport-related experiences and the benefits sport consumers derive from these experiences. This emphasis has generated new knowledge and insights into the needs and wants of sport consumers. Although these efforts have contributed to the field's understanding of SCB, the vast majority of this research has centered on psychological phenomena and the evaluative and affective components of these sport experiences. Approaches to this work have also narrowed, with SCB research predominately relying on cross-sectional studies and attitudinal surveys to collect information. This has resulted in limited findings that seldom account for how various situational or environmental factors might influence attitudinal data patterns at the individual and group level. This special issues seeks to deepen our understanding of SCB by providing seven papers that demonstrate or validate findings using multiple studies or data collections.

Performance assessment, vulnerability, human capital, and the allocation of aid among developing countries

Developing country performance with respect to economic policies and institutional behavior is a common criterion for the allocation of aid among recipient countries. This paper examines how performance is used, arguing that performance is too narrowly defined. A more appropriate definition is one that controls for the economic vulnerability and human capital of developing countries. Econometric analysis of cross-section and panel data is presented that supports this contention. The paper also contends that performance and exogenous economic shocks are likely to be pro-cyclical. This implies a double punishment when aid is allocated according to performance. Evidence of such punishment is also provided. The paper concludes by arguing that economic vulnerability and human capital variables should augment performance measures in aid allocation decision-making.

N-acetylcysteine modulates glutamatergic dysfunction and depressive behavior in Huntington's disease

Glutamatergic dysfunction has been implicated in the pathogenesis of depressive disorders and Huntington's disease (HD), in which depression is the most common psychiatric symptom. Synaptic glutamate homeostasis is regulated by cystine-dependent glutamate transporters, including GLT-1 and system xc (-) In HD, the enzyme regulating cysteine (and subsequently cystine) production, cystathionine-γ-lygase, has recently been shown to be lowered. The aim of the present study was to establish whether cysteine supplementation, using N-acetylcysteine (NAC) could ameliorate glutamate pathology through the cystine-dependent transporters, system xc (-) and GLT-1. We demonstrate that the R6/1 transgenic mouse model of HD has lower basal levels of cystine, and showed depressive-like behaviors in the forced-swim test. Administration of NAC reversed these behaviors. This effect was blocked by co-administration of the system xc (-) and GLT-1 inhibitors CPG and DHK, showing that glutamate transporter activity was required for the antidepressant effects of NAC. NAC was also able to specifically increase glutamate in HD mice, in a glutamate transporter-dependent manner. These in vivo changes reflect changes in glutamate transporter protein in HD mice and human HD post-mortem tissue. Furthermore, NAC was able to rescue changes in key glutamate receptor proteins related to excitotoxicity in HD, including NMDAR2B. Thus, we have shown that baseline reductions in cysteine underlie glutamatergic dysfunction and depressive-like behavior in HD and these changes can be rescued by treatment with NAC. These findings have implications for the development of new therapeutic approaches for depressive disorders.