Impact of contraception and IVF hormones on metabolic, endocrine, and inflammatory status

Assisted reproductive technologies (ART) represent commonly utilized management strategies for infertility with multifactorial causes (including genetically predisposed diseases). Amongst ART, in vitro fertilization (IVF) is the most popular. IVF treatment may predispose the mother to increased risks and complications during pregnancy, and there may be adverse fetal outcomes. Hormonal therapies, including oral contraceptives, may impair glucose and lipid metabolism, and promote insulin resistance and inflammation. IVF treatment involves administration of reproductive hormones, similar in composition but in much higher doses than those used for oral contraception. The provision of IVF reproductive hormones to mice associates with glucose intolerance. In addition, the physiological and hormonal changes of pregnancy can trigger an inflammatory response, and metabolic and endocrine changes. There is controversy regarding the potential effects of IVF hormonal therapies in the promotion of diabetogenic and inflammatory states, additional to those that occur during pregnancy, and which may therefore predispose women with IVF-conceived pregnancies to adverse obstetric outcomes compared with women with spontaneously conceived pregnancies. This review summarizes the limited published evidence regarding the effect of IVF-based fertility therapies on glucose homeostasis, insulin resistance, cardio-metabolic profile, and markers of inflammation

The Community Structure of R&D Cooperation in Europe. Evidence from a social network perspective

The focus of this paper is on pre-competitive R&D cooperation across Europe, as captured by R&D joint ventures funded by the European Commission in the time period 1998-2002, within the 5th Framework Program. The cooperations in this Framework Program give rise to a bipartite network with 72,745 network edges between 25,839 actors (representing organizations that include firms, universities, research organizations and public agencies) and 9,490 R&D projects. With this construction, participating actors are linked only through joint projects. In this paper we describe the community identification problem based on the concept of modularity, and use the recently introduced label-propagation algorithm to identify communities in the network, and differentiate the identified communities by developing community-specific profiles using social network analysis and geographic visualization techniques. We expect the results to enrich our picture of the European Research Area by providing new insights into the global and local structures of R&D cooperation across Europe

Slow dynamics at the smeared phase transition of randomly layered magnets

We investigate a model for randomly layered magnets, viz. a three-dimensional Ising model with planar defects. The magnetic phase transition in this system is smeared because static long-range order can develop on isolated rare spatial regions. Here, we report large-scale kinetic Monte Carlo simulations of the dynamical behavior close to the smeared phase transition which we characterize by the spin (time) autocorrelation function. In the paramagnetic phase, its behavior is dominated by Griffiths effects similar to those in magnets with point defects. In the tail region of the smeared transition the dynamics is even slower: the autocorrelation function decays like a stretched exponential at intermediate times before approaching the exponentially small asymptotic value following a power law at late times. Our Monte-Carlo results are in good agreement with recent theoretical predictions based on optimal fluctuation theory.Comment: 7 pages, 6 eps figures, final version as publishe

Impact and Cost-Effectiveness of Point-Of-Care CD4 Testing on the HIV Epidemic in South Africa.

Rapid diagnostic tools have been shown to improve linkage of patients to care. In the context of infectious diseases, assessing the impact and cost-effectiveness of such tools at the population level, accounting for both direct and indirect effects, is key to informing adoption of these tools. Point-of-care (POC) CD4 testing has been shown to be highly effective in increasing the proportion of HIV positive patients who initiate ART. We assess the impact and cost-effectiveness of introducing POC CD4 testing at the population level in South Africa in a range of care contexts, using a dynamic compartmental model of HIV transmission, calibrated to the South African HIV epidemic. We performed a meta-analysis to quantify the differences between POC and laboratory CD4 testing on the proportion linking to care following CD4 testing. Cumulative infections averted and incremental cost-effectiveness ratios (ICERs) were estimated over one and three years. We estimated that POC CD4 testing introduced in the current South African care context can prevent 1.7% (95% CI: 0.4% - 4.3%) of new HIV infections over 1 year. In that context, POC CD4 testing was cost-effective 99.8% of the time after 1 year with a median estimated ICER of US$4,468/DALY averted. In healthcare contexts with expanded HIV testing and improved retention in care, POC CD4 testing only became cost-effective after 3 years. The results were similar when, in addition, ART was offered irrespective of CD4 count, and CD4 testing was used for clinical assessment. Our findings suggest that even if ART is expanded to all HIV positive individuals and HIV testing efforts are increased in the near future, POC CD4 testing is a cost-effective tool, even within a short time horizon. Our study also illustrates the importance of evaluating the potential impact of such diagnostic technologies at the population level, so that indirect benefits and costs can be incorporated into estimations of cost-effectiveness

Composition-tuned smeared phase transitions

Phase transitions in random systems are smeared if individual spatial regions can order independently of the bulk system. In this paper, we study such smeared phase transitions (both classical and quantum) in substitutional alloys A$_{1-x}$B$_x$ that can be tuned from an ordered phase at composition $x=0$ to a disordered phase at $x=1$. We show that the ordered phase develops a pronounced tail that extends over all compositions $x<1$. Using optimal fluctuation theory, we derive the composition dependence of the order parameter and other quantities in the tail of the smeared phase transition. We also compare our results to computer simulations of a toy model, and we discuss experiments.Comment: 6 pages, 4 eps figures included, final version as publishe

The Community Structure of R&D Cooperation in Europe. Evidence from a social networks perspective

The focus of this paper is on pre-competitive R&D cooperation across Europe, as captured by R&D joint ventures funded by the European Commission in the time period 2002-2006, within the 5th Framework Program. The cooperations in this Framework Program give rise to a collaborative network, with network nodes representing actors (i.e. organizations including firms, universities, research organizations and public agencies) and network edges representing R&D projects. With this construction, participating actors are linked only through joint projects. We formally describe and analyze the network from a social networks perspective that shifts attention to the detection and analysis of the community structure within the network. Distinct communities within networks may be loosely defined as groups of actors such that there is a higher density of relations within groups than between them. In this study, we attempt to detect communities of actors solely on the basis of the relational structure within the network, and to characterize and differentiate the identified network communities by means of information-theoretic methods, community-specific profiles and the location of their major actors. We expect the results to enrich our picture of the European research area by providing new insights into the global and local structures of R&D cooperation across Europe

Effects of IVF therapies on metabolic, endocrine and inflammatory status in IVF-conceived pregnancy

Rationale In vitro fertilization (IVF) is a common treatment for infertility. In mice, IVF is associated with development of glucose intolerance. However, human data are limited regarding the metabolic, endocrine and inflammatory effects of IVF therapy in IVF‐conceived pregnancies. Objective To explore effects of IVF therapies on metabolic, endocrine and inflammatory parameters in IVF‐conceived pregnancy. Methodology Twelve‐week prospective observational study of adult normoglycaemic women, BMI 18.5‐38 kg/m2 and ≤ 39 years awaiting IVF therapy. Fasting blood samples were collected at baseline and 12 weeks, and serum analysed for reproductive hormones, glucose, lipids, insulin sensitivity, thyroid status, adiponectin inflammatory marker and lipopolysaccharide‐binding protein (LBP). Results Two hundred and seventy‐five women were analysed: 158 IVF‐conceived pregnant women and 117 with failed IVF. Compared with baseline, nonpregnant women had significant (P < .001) increases in 12‐week glucose (86.04‐87.62 mg/dL), insulin (8.72‐9.37 µIU/mL), HOMA‐IR (1.9‐2.1), T‐Chol (169.5‐174.9 mg/dL), TG (71.0‐83.7 mg/dL) and HDL‐C (52.0‐54.11 mg/dL) levels. At 12 weeks, pregnant women also had (P < .001) increases in T‐Chol (177.5‐199.5 mg/dL), TG (73.5‐126.78 mg/dL) and HDL‐C (55.3‐65.1 mg/dL), while a significant reduction in glucose (86.15‐82.19 mg/dL), HbA1c (5.3‐5.08%) and TSH (1.71‐1.36 µIU/mL) levels from baseline. Adiponectin and LBP levels remained the same in either group. Conclusion In vitro fertilization hormonal therapy impairs glucose and insulin levels; these effects are masked in early pregnancy. Changes in lipid profile occur following IVF therapies regardless of pregnancy outcome. Neither adiponectin nor LBP is affected by IVF therapies and during early IVF‐conceived pregnancy

Obesity : novel and unusual predisposing factors

To tackle the complexity of the global obesity epidemic, it is important to consider the many predisposing factors that underlie progressive and sustained weight gain. Some of the biological drivers for weight gain following initial weight loss include persistent changes in appetite hormones [including ghrelin and postprandial plasma peptide YY (PYY)], and ‘persistent metabolic adaptation’. However, many factors within our busy, stressful modern-day environment seem to conspire towards promotion of weight gain. These include the effects of sleep deprivation on appetite regulation, and the effects of modern-day technology on ‘attention competition’. These factors, combined with cultural and societal factors can result in a ‘mindless’ attitude regarding eating-related behaviour that is likely to predispose to weight gain. In addition to the external environment, our internal environment within the gut has also changed radically within the last few decades, resulting from changes in fibre intake, and increased ingestion of highly refined, sterilised and processed foods. Although contentious, these dietary changes have implications for our gut microbiota, and possible downstream effects on control of appetite and metabolism. In this brief review, we consider some of the novel predisposing factors for weight gain within our modern-day 21st century environments (both external and internal), and explore how legal terminology can help to conceptualise the numerous factors that contribute towards weight gain, and, ultimately the global obesity epidemic

Why are women with polycystic ovary syndrome obese?

Introduction Polycystic ovary syndrome (PCOS) is a common condition characterized by reproductive, hyperandrogenic and dysmetabolic features, and often becomes clinically manifest during adolescence, particularly with weight-gain. Sources of data Pubmed search. Areas of agreement PCOS is heritable and closely associates with obesity (based on data from both epidemiological and genetic studies). Furthermore, insulin resistance forms a central cornerstone of the pathogenesis of PCOS and mediates a close association between obesity and the severity of the phenotypic features of PCOS. Areas of controversy Our understanding of the pathogenesis of PCOS remains incomplete, especially regarding its missing heritability (with only a small fraction having been identified from the genome-wide association studies reported to date), and its developmental origins. Growing points A challenge for the future is to explore a role for epigenetic modifications in the development of PCOS, and implications for the in utero environment and novel therapeutic opportunities

Pair Interactions in Red-Faced Warblers

Forty pairs of breeding Red-faced Warblers (Cardellina rubrifrons) were observed in 1992 and 1993 on the Mogollon Rim, Arizona. Intrusions by extra-pair males, interactions between pair members, and other pair interaction behaviors were recorded. The majority of intrusions occurred during the building stage of the nesting cycle. Males responded to intrusions during nest building by decreasing intra-pair distance. Males maintained shorter intra-pair distances by following the female when she initiated movements and by not initiating pair movements themselves. Intra-pair distances were as short or shorter during the incubation period as during nest building, and were shorter during incubation than during egg laying. Males continued to follow females beyond the expected fertile period. Possible explanations for continued mate following include: males guard their mates against predators, males guard their paternity for future nesting attempts, and males respond to extra-pair male intrusions, which continue during incubation