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Peripartum replacement of factor VIII and von Willebrand factor is not usually required in type 1 von Willebrand disease, as the levels of endogenous factors tend to increase to within the normal range as a physiological change of pregnancy. However, there is wide heterogeneity of genotypes and phenotypes associated with type 1 von Willebrand disease. Here, we describe the anesthetic management of a parturient with type 1C von Willebrand disease, a subtype characterized by decreased plasma von Willebrand factor survival.

Asthma triggers are exogenous or endogenous factors that could worsen asthma acutely to cause an exacerbation, or perpetuate chronic symptoms and airflow limitation. Because it is well known that recent asthma exacerbations and poor symptom control are strong predictors of future disease activity, it is not surprising that the number of (allergic or nonallergic) asthma triggers in the environment correlates with the disease-related quality of life. There is a need to identify and avoid specific triggers as the centerpiece of disease management, especially in those with heightened sensitivity to certain factors.

The constant interplay between environment (including both exogenous and endogenous factors) and epigenome (defined as the combination of chromatin, its covalent modifications and noncoding RNAs) triggers epigenetic events that, by modulating gene expression, capture information about changes in the environment. In this mini review, we will focus on the neurodevelopmental implications of exposure to adverse prenatal milieu with emphasis on mechanistic and functional aspects. Several neurotoxic insults have been shown to affect epigenetics with negative consequences on the development of the nervous system; among them are methylmercury, lead, arsenic and cadmium, as well as excess of glucocorticoids. Further investigations on the individual susceptibility to epigenetic changes are needed to propose and validate such modifications as possible biomarkers for early identification of neurological/neurodevelopmental disorders and for predicting/monitoring response to treatment.

The number of preclinical studies that use drugs or endogenous factors for various targetable sites aiming to improve islet function and engraftment has recently gained more interest. Several molecules have been proposed to support and augment the functionality of islets. Here, we review five different classes of beta cell protection factors, classified as antioxidants, anti-inflammatory, anti-apoptotic, immunomodulatory, vascularization enhancers, and promoter of beta cell proliferation and function and their effect on islet grafting and function after transplantation in animal models of type 1 diabetes.

We estimate a structural dynamic model of the determinants of obesity. In addition to including many of the well-recognized endogenous factors mentioned in the literature as obesity determinants, we also model the individual’s residential location as a choice variable, which is the main contribution of this paper to the literature. This allows us to control for an individual's self-selection into communities that possess the types of amenities in the built environment, which in turn affect their obesity-related behaviors such as physical activity (PA) and fast food consumption. We specify reduced form equations for a set of endogenous demand decisions, together with an obesity structural equation. The whole system of equations is jointly estimated by a semi-parametric full information log-likelihood method that allows for a general pattern of correlation in the errors across equations. Our model predicts a reduction in adult obesity of 7 percentage points as a result of a continued high level PA from adolescence into adulthood; a reduction of 0.7 (3) percentage points in adult obesity as a result of one standard deviation reduction in weekly fast food consumption for women (men); and a reduction of 0.02 (0.05) in adult obesity as a result of one standard deviation change in several neighborhood amenities for women (men). Another key finding is that controlling for residential self-selection has substantive implications. To our knowledge, this has not been yet documented within a full information maximum likelihood framework.

Rett syndrome (RTT) is a progressive neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene. RTT patients show multisystem disturbances associated with perturbed redox homeostasis and inflammation, which appear as possible key factors in RTT pathogenesis. In this study, using primary dermal fibroblasts from control and RTT subjects, we performed a proteomic analysis that, together with data mining approaches, allowed us to carry out a comprehensive characterization of RTT cellular proteome. Functional and pathway enrichment analyses showed that differentially expressed proteins in RTT were mainly enriched in biological processes related to immune/inflammatory responses. Overall, by using proteomic data mining as supportive approach, our results provide a detailed insight into the molecular pathways involved in RTT immune dysfunction that, causing tissue and organ damage, can increase the vulnerability of affected patients to unknown endogenous factors or infections.

Recent explanations of regional path development tend to neglect public policy interventions into the analysis of new path creation in non-core regions. I argue that the evolutionary approach in economic geography effort in highlighting endogenous theories to explain industrial renewal in the periphery, should be more aware of theories of exogenous inflows from outside in order to explain innovation and growth in regions. I suggest that the concept of local content policies in the global petroleum industry is pivotal in understanding regions ability to break out of trajectories seen as path dependent in theories of regional development. Drawing on a combination of studies of two petroleum projects in the region of Finnmark and one in Nordland in Northern Norway, this paper explores recent local content initiatives, and evaluate their potential benefit for companies and regions. I argue that the role of policy actions should be a pivotal issue in explaining growth and innovation in peripheral areas, and that a combination of endogenous and exogenous factors gives a more balanced picture of the situation rather than leaning on endogenous factors alone.

This paper presents an integrated modelling study aimed at exploring the possible effects of drivers of change in commercial natural annual grasslands. We consider drivers as factors that affect the rangeland but are not affected by it. Thus, the stocking rate is not treated as a driver, but as an endogenous factor ultimately determined by drivers. This approach, which call for integrated multidisciplinary studies, is rare in the rangeland literature. We try to alleviate this lack by presenting and utilizing a novel multidisciplinary integrated system-dynamics model (108 equations) which represents an area of privately owned extensive farms, its farmers (their numbers and decisions), herds or flocks, herbage production, soil erosion and the linked local markets. By means of a global sensitivity analysis of this model we evaluated the sensitivities of key endogenous factors to the same percentage variation in 70 factors, including economic and climate drivers. The analysis considered the behaviours of 288,000 variants of the modelled system, each under a different 300-year driver scenario. We found that the environmental component of the model was almost exclusively sensitive to biophysical factors, whereas the socio-economic component was almost exclusively sensitive to socio-economic factors, despite the model takes account of key feedbacks connecting both components. Our results suggest that cautiously-managed commercial natural grasslands could socially and economically cope with climate change, especially in a scenario of rising prices of animal products, and also that, even though stocking rates would increase due to an increase in the demand for livestock products, the main threat to the provision of ecosystem services in the studied system would be climate change.

Selective sustained attention is vital for higher order cognition. Although endogenous and exogenous factors influence selective sustained attention, assessment of the degree to which these factors influence performance and learning is often challenging. We report findings from the Track-It task, a paradigm that aims to assess the contribution of endogenous and exogenous factors to selective sustained attention within the same task. Behavioral accuracy and eye-tracking data on the Track-It task were correlated with performance on an explicit learning task. Behavioral accuracy and fixations to distractors during the Track-It task did not predict learning when exogenous factors supported selective sustained attention. In contrast, when endogenous factors supported selective sustained attention, fixations to distractors were negatively correlated with learning. Similarly, when endogenous factors supported selective sustained attention, higher behavioral accuracy was correlated with greater learning. These findings suggest that endogenously and exogenously driven selective sustained attention, as measured through different conditions of the Track-It task, may support different kinds of learning.

In this study we postulate that a firm's external knowledge sourcing decision is determined by factors that are exogenous and endogenous to the firm and that exogenous factors moderate the effect of endogenous factors on a firm's external knowledge sourcing decision. Exogenous factors of the external environment such as market and technology turbulence and competitive intensity are assumed to induce a firm to source knowledge externally for innovation, whereas endogenous factors such as ambiguity avoidance, organizational inertia, and low absorptive capacity may inhibit external knowledge sourcing. In this study, particularly, we examine both the direct effects of exogenous and endogenous factors as well as the moderating effect of the exogenous factors on firm-specific characteristics on a firm's external knowledge sourcing decision. We postulate that on the one hand, environmental factors may prompt firms to source knowledge externally; however, they may also prevent firms from engaging in external knowledge sourcing by moderating specific organizational attributes endogenous to the firm, thus producing a dual effect. We present research findings from a sample of 127 innovative Korean SMEs to support the existence of direct effects of environmental and firm-specific factors as well as the moderating effects of the external environment on firm-specific factors on a firm's external knowledge sourcing decision with customers, suppliers & distributors and other firms. We discuss the findings and provide directions for future research.

Foundation soil properties are influenced by many factors. Endogenous processes are one of these. Foundation soil and building constructions are exposed to a number of factors, which can be influenced to a greater or lesser extent. Endogenous processes are factors that cannot be avoided. Construction works interact with these processes and have to cope with its effects. If we are unable to predict their occurrence, its impact strength and possible consequences, we are not able to confront these phenomena. Tectonic movements that cause subsidence, landslides, erosion, earthquakes, waterlogging, flooding areas and many others belong to endogenous processes. An earthquake is an endogenous process as well. An earthquake causes quakes, destruction of buildings, landslides, soil liquefaction, subsidence and changes in relief. The last phenomenon covered in this publication is volcanic activity. Volcanic activity causes a change in relief, destruction of buildings, earthquakes, landslides and fires. Endogenous processes cannot be separated from exogenous processes. Exogenous and endogenous factors are interconnected and together affect terrain morphology, rock properties, groundwater, and many others. Speech endogenous processes is often much greater, more destructive, but at a significantly smaller area.

An extensive literature documents large and persistent within-industry heterogeneity of firm performance. While some authors explain such evidence in terms of factor misallocation, we provide an alternative framework that is based on the interaction among exogenous and endogenous factors. Exogenous factors, both supply and demand-related, define the opportunity set that is available to firms. Endogenous factors reflect instead firm-specific interpretations of such set, which combined with the available resources and capabilities determine firm’s strategic responses that can be markedly heterogeneous. Whenever the diversity of firm conducts is associated with relatively small profit differentials, firm heterogeneity can persist. Evidence based on the evolution of labour productivity and profit dispersion in the Italian manufacturing sector between the 1990s and early 2000s provides support for our interpretative framework.

Structural equation modelling (SEM) is an estimation method that can handle a large number of exogenous and endogenous factors as well as unobserved (latent) variables that are specified as linear combinations of observed (measurement) factors. This paper presents a SEM procedure with latent variables for estimating the financial and non-financial performance in airline companies. The model includes independent, mediator and dependent latent variables. The sample for this research comprises 214 airline companies. The results indicate that the model is capable of estimating performance with respect to the economic situation and it has also been determined that two types of constructs affect performance. One type is the economic situation acting as an initial construct and the other is the internal operation acting as the mediator in the research model.

Time passing drives all living organismes to cellular decline with age-associated dysfuntion, diseases and death. It appeared now that ageing like any biological process is surceptible to regulation. Environmental factors such as stimuli/stresses as well as endogenous factors, i.e., expression and mutation of some particular genes might act as the main regulators. Psychological factors as a human specific dimension could contribute in delaying the senescence decline.

Selective sustained attention (SSA) is crucial for higher-order cognition. Factors promoting SSA are described as exogenous or endogenous. However, there is little research specifying how these factors interact during development – due, largely, to the paucity of developmentally-appropriate paradigms. We report findings from a novel paradigm designed to investigate SSA in preschoolers. The findings indicate that this task (1) has good psychometric and parametric properties, and (2) allows investigation of exogenous and endogenous factors within the same task, making it possible to attribute changes in performance to different mechanisms of attentional control rather than to differences in engagement in different tasks.

Nowadays plant polyphenols attract much attention in the prevention of chronic diseases. Epidemiological and intervention studies strongly suggest that polyphenol intake has beneficial effects on vascular health. It is unlikely that polyphenols act as direct antioxidants, although oxidative stress profoundly contributes to vascular impairment leading to cardiovascular diseases. Polyphenols, in particular, low-molecular weight flavonoids may exert their function by tuning the cellular redox state to an adaptive response or tolerable stress. However, the optimum intake of flavonoids from supplements or diet has not been clarified yet, because a number of exogenous and endogenous factors modulating their bioavailability affect their vascular function. This lecture will focus on the current knowledge of the bioavailability and its consequence on vascular function of an antioxidative flavonoid quercetin. Current intervention studies imply that intake of quercetin-rich onion improves vascular health. Onion may be superior to quercetin supplement from the viewpoint of quercetin bioavailability, probably because the food matrix enhances the intestinal absorption of quercetin. a-Glucosylation increases its bioavailability by elevating the accessibility to the absorptive cells. Prenylaton may enhance bioaccumulation at the target site by increasing the cellular uptake. However, these chemical modifications do not guarantee health benefits to the vascular system. Although dietary quercetin is exclusively present as their conjugated form in the blood stream, its vascular function seems to be mediated by inflammation-dependent deconjugation reaction. Finally, bioavailability of non-absorptive polyphenols to microbiota in the gut should be pointed out, as the colonic microbiota is regarded as a separate organ within the human host.

The cultural approaches and the economic approaches advocated by mainstream neoclassical economists and new institutional economists fail to provide an adequate explanation of the differences between ethnic groups in the rate of business formation. These approaches provide only a partial explanation, much of which is based on static, predetermined exogenous and/or endogenous factors. By comparison the old institutional economists’ framework, when applied to this area, offers a more holistic explanation of differential ethnic business formation by bringing together a range of cultural and economic factors that emphasize the path dependency of activities and the dynamic evolution of behaviour and actions.

The COMET assay is recognized as a rapid and sensitive method in quantifying radiation induced DNA damage. We investigated the distorting influence of endogenous, assay-inherent factors onto base (single cell level) and primary outcome measures (experimental/slide level), such as olive tail moment (OTM) and percentage DNA in the tail (%tail-DNA). From 2003 to 2008, we performed the assay on lymphocytes isolated from the blood samples of 355 lung cancer patients, 170 controls, and 610 relatives, as well as one single reference individual, repeated 170 times. In total, the data from 10,016 single experiments containing around 1,750,000 cells have been included in this study. This is the first time that the endogenous variability of the COMET assay has been validated systematically on such a huge data set over a 5 year period. Assuming that the reference sample reflects assay specific white noise, we estimated a proportion of 7-95% of the variability of the outcome measures due to assay variation (white noise) depending on parameter, exposure level, and study group. The proportion of white noise was largest for the initial radiation damage. The specific endogenous factors considered attribute to 14.8% of the total variability in the primary outcome measurements of the OTM and 6.9% of the %tail-DNA. OTM turns out to be a sensitive parameter to detect variation, but is also more susceptible to disturbance caused by endogenous factors than %tail-DNA. To reduce the experimental variability in COMET assays, we recommend a highly standardized operation protocol as well as inspecting and/or adjusting the primary outcome measures according to endogenous factors before calculating secondary outcome measures, e.g. DNA repair capacity (DRC) or testing statistical inference. A human reference (HR) sample is also useful to inspect homogeneity in the temporal progression of long lasting investigations, but not for calibrating primary outcome measurements.

Summary Background An increasing number of studies confirm that pathogenesis and prevalence of bronchial asthma are age and sex dependent. Detailed physiological mechanisms of the changing sex ratios with age are not fully known, however, the gender (socio-cultural) factors are also imperative. Although multiple factors definitely influence the pathogenesis of asthma, only individual or few combinations of these have been investigated. Methods The terms ‘sex’, ‘gender’ and plausible combinations of both were systematically researched in selected databases (Medline, Scopus) or other sources, including publications from January 2000 to June 2007. Generated articles were categorized, either as endogenous or exogenous factors influencing the pathogenesis of asthma, and divided into the following subgroups: genetic, immunological, hormonal, gynaecological, nutritional, and environmental parameters. Results An increasing number of studies investigate the influence of sex and gender in the aetiology, therapy and prevention of asthma. While their results are still debatable, others regarding its initiation, perpetuation and cessation have been clarified. Recent insights into interactions at biomolecular and immunological levels greatly contribute to clarifying sex-specific influences. Despite occasional oversimplifications, a trend for explanations considering the complex interplay of different factors can be observed. This work is in line with this trend and offers explanation models from our point of view. Conclusions Some disagreements regarding the patho-physiology, diagnosis, treatment and prevention of asthma still prevail. Nevertheless, in order to better appreciate its complexity, openness to and persistent consideration for interdisciplinary as well as sex- and gender-related factors is required of the medical-research community in future investigations.

Resolution of inflammation and induction of immune tolerance are essential to stabilize immune homeostasis and to limit the occurrence of exacerbated inflammatory and autoimmune conditions. Multiple mechanisms act together to ensure the re-establishment of immune homeostasis and maintenance of tolerance. The identification of endogenous factors that regulate these processes is crucial for the development of new therapies for inflammatory/autoimmune conditions. Neuropeptides produced during an ongoing inflammatory response emerged as endogenous anti-inflammatory agents that participate in processes leading to the resolution of inflammation and maintenance of tolerance. Anti-inflammatory neuropeptides and hormones such as vasoactive intestinal peptide, urocortin, adrenomedullin, melanocyte stimulating hormone, ghrelin, and cortistatin have beneficial effects in a variety of experimental inflammatory and autoimmune models. Their therapeutic effect has been attributed to their capacity to downregulate innate immunity, to inhibit antigen-specific T(H)1-driven responses, and to generate regulatory T cells. Finally, some of these neuropeptides have been identified as mediators of innate defense acting as natural antimicrobial peptides. Here we present the research findings in the neuropeptide immunoregulatory field, and examine possible therapies based on anti-inflammatory neuropeptides and hormones as a new pharmacologic platform.

Sudden infant death syndrome (SIDS) still accounts for considerable numbers of unexpected infant deaths in many countries. While numerous theories have been advanced to explain these events, it is increasingly clear that this group of infant deaths results from the complex interaction of a variety of heritable and idiosyncratic endogenous factors interacting with exogenous factors. This has been elegantly summarised in the "three hit" or "triple risk" model. Contradictions and lack of consistencies in the literature have arisen from diverse autopsy approaches, variable applications of diagnostic criteria and inconsistent use of definitions. An approach to sudden infant death is outlined with discussion of appropriate tissue sampling, ancillary investigations and the use of controls in research projects. Standardisation of infant death investigations with the application of uniform definitions and protocols will ensure optimal investigation of individual cases and enable international comparisons of trends.

Relapse is an important outcome measure in patients with Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome. Although relapses are common in these diseases, it remains unclear why these occur and whether they are influenced by exogenous or endogenous factors. A key to minimizing the consequences of relapse is early recognition through monitoring. This is particularly essential to detect glomerulonephritis that is often asymptomatic and can be rapidly progressive. While the presence of relapse is currently based on objective evidence of active disease, investigations seek to identify factors that may distinguish patients at risk of relapse or markers that reliably predict the occurrence of relapse prior to organ injury. With the ability to successfully induce remission and the toxicities of available therapies, the relapse rate has become a critical issue in assessing the efficacy of new treatments. Recent clinical trials have sought to investigate safer therapeutic options that decrease disease relapse.

Patients with alien hand (AH) syndrome from medial frontal lesions exhibit involuntary but seemingly purposeful contralesional upper limb movements. Two observations about AH patients have received little, if any, experimental confirmation. The first is that AH is triggered opportunistically by nearby objects. The second is that AH behaviors are increased in conditions of fatigue or anxiety, i.e. under reduced attentional control. A prominent account explains AH as reduced intention-driven (endogenous) executive control. This account predicts that erroneous AH behaviors should be driven by environmental (i.e. exogenous) factors, such as distractor proximity to the hand. AH errors should be less influenced by the intention or action plan (i.e. endogenous factors), such as the semantic relatedness of distractors to targets. Moreover, due to capacity limitations of the endogenous controller, AH behaviors should increase under conditions of secondary task load. We tested these predictions with an AH patient in two experiments using a naturalistic coffee-making task. Experiment 1 demonstrated that the affected hand was highly perseverative and strongly influenced by exogenous but not endogenous factors. The non-alien hand made fewer errors. Experiment 2 showed that there was a disproportionate increase in perseverations and exogenous errors of the affected hand under secondary task load. The non-alien hand was significantly less disrupted by dual task conditions. These data provide experimental support for previous anecdotal observations about AH behavior in naturalistic settings, and are consistent with a unilateral defect in endogenous control.

Immunosuppressed patients retain transplants but become more susceptible to opportunistic infections, which is a major complication in organ transplantation. Life-long immunosuppression for such patients could be reduced by creating immune tolerance, although this might be associated with an increased risk for infections and malignancies. An alternative therapeutic concept could consist of boosting the innate immune response against infections while continuing to suppress the adaptive immune response to prevent graft rejection. We propose granulocyte-macrophage colony-stimulating factor (GM-CSF) as a novel candidate to achieve this goal, based on recent studies in which beneficial effects were demonstrated in immunosuppressed mice with skin allografts and in dexamethasone-suppressed blood from healthy volunteers and blood from liver transplant recipients undergoing immunosuppressive therapy. Such data suggest that GM-CSF or other endogenous factors with similar properties should be examined in clinical trials.

We have read the article titled “Association between Socioeconomic Factors and Depression among Cardiovascular Patients Living in Rich Resourced Middle Eastern Country” written by Tam Truong Donnelly with great interest [1]. This article highlights the impact of heterogeneous socioeconomic factors on cardiovascular patients with depression as well as the importance of collaborative management to improve both mental and physical conditions in this population. The author reported that some socioeconomic and demographic factors like unemployment, being full-time homemaker, female sex, and lowmonthly incomewere associatedwith depression in cardiovascular patients. Depression is among the most debilitating disorders worldwide while it is associated with significant disability and low quality of life by its own apart from comorbidities. Although association between socioeconomic factors and depression has been demonstrated, endogenous factors also play a role in the pathophysiology of the disease. According to some authors, endogenous depression is classified as a subtype of depression. Recent studies showed that depression has been associated with neuroendocrinological and neuroinflammatory factors such as immune system dysregulation with increased activity of proinflammatory cytokines, hypothalamic-pituitary–adrenal axis activation resulting in hypercortisolemia, and autonomic system

The development of asthmatic inflammation involves a complex array of cytokines that promote the recruitment and activation of a number of different immune cells. While factors involved in initiating and establishing inflammation are well characterized, the process by which this pro-inflammatory cascade is regulated is less well understood. The identification and characterization of immunomodulatory cytokines in asthma has been a difficult proposition. Many of the putative regulatory factors have pleiotropic bioactivities and have been characterized as pro-inflammatory in association with certain pathologic conditions. This chapter addresses the potential role of several endogenous factors which appear to attenuate asthmatic inflammation. Understanding the integration of these factors into the regulation of the inflammatory process will likely result in novel therapeutic approaches.

Contains fulltext : 62152.pdf (Publisher’s version ) (Closed access) Examples from experimental epilepsy in animals are used to illustrate the view that a crucial role of the transfer of mechanisms from compensatory into pathogenic (e.g. lethal ones in the course of a disease), is played by the power of pathologic stimuli. In the genesis of epilepsy it is suggested that a critical increase of endogenous factors may underlie the conversion of the absence form of epilepsy into a generalized self-supporting form. The ability to precipitate endogenous self-augmenting mechanisms of diseases may have increased in the course of evolution. The lethal result of a serious pathogenic process leads to the suggestion that organisms cope with the disease by dying. This prevents spreading of the putative infectious disease within the population. The mechanisms of disease aggravation could pay a role in the survival of the species and in further evolutionary progress. This may explain why certain species may have survived in evolution and supports the theory of synthetic evolution.

Experimental, clinical and epidemiological evidence indicates that exposure to environmental agents may contribute to the pathogenesis of Parkinson's disease (PD). The development of animal models of toxicant-induced nigrostriatal injury has furthered our understanding of mechanisms of neurodegeneration and will help us to identify compounds or classes of compounds as potential PD risk factors. Examples are rodent models utilizing the pesticides paraquat or rotenone. Important implications for PD are also likely to arise from knowledge of synergistic environmental interactions (e.g. the paraquat/maneb model), as well as relationships between exogenous and endogenous factors. In particular, the endogenous protein α-synuclein, recently linked to PD pathophysiology, could play an important role in the neurodegenerative process triggered by toxicant exposure.

We characterized β-synuclein, the non-amyloidogenic homolog of α-synuclein, as an inhibitor of aggregation of α-synuclein, a molecule implicated in Parkinson's disease. For this, doubly transgenic mice expressing human (h) α- and β-synuclein were generated. In doubly transgenic mice, β-synuclein ameliorated motor deficits, neurodegenerative alterations, and neuronal α-synuclein accumulation seen in hα-synuclein transgenic mice. Similarly, cell lines transfected with β-synuclein were resistant to α-synuclein accumulation. hα-synuclein was coimmunoprecipitated with hβ-synuclein in the brains of doubly transgenic mice and in the double-transfected cell lines. Our results raise the possibility that β-synuclein might be a natural negative regulator of α-synuclein aggregation and that a similar class of endogenous factors might regulate the aggregation state of other molecules involved in neurodegeneration. Such an anti-amyloidogenic property of β-synuclein might also provide a novel strategy for the treatment of neurodegenerative disorders.

A number of theories have proposed the involvement of different brain structures and neurotransmitters in order to explain the regulation of the sleep wake cycle. However, there is no clear consensus as to the mechanisms through which the brain structures and their various neurotransmitters interact to produce theses phases. Perhaps the problem is related to the fact sleep is a very fragile state, easily modified or influenced by a variety of substances or experimental manipulations. In this paper, we describe the evidence of two different groups of factors that induce important changes on the sleep wake cycle. The endogenous factors: neurotransmitters; hormone; peptides; and some substances of lipidic nature and exogenous factors: stress, food intake, learning, sleep deprivation, sensorial stimulation, exercise and temperature on the regulation the sleep-wake cycle. Likewise, we propose a hypothesis which attempts to reconcile the fact that endogenous and exogenous factors have similar effects.

An important goal in protein engineering is to control associations between designed proteins. This is most often done by fusing known, naturally occurring oligomerization modules, such as leucine zippers [1] [2] [3], to the proteins of interest [4] [5] [6]. It is of considerable interest to design or discover new oligomerization domains that have novel binding specificities [7] [8] [9] [10] [11] in order to expand the 'toolbox' of the protein engineer and also to eliminate associations of the designed proteins with endogenous factors. We report here a simple genetic selection scheme through which to search libraries for peptides that are able to mediate homodimerization or higher-order self-oligomerization of a protein in vivo. We found several peptides that support oligomerization of the lambda repressor DNA-binding domain in Escherichia coli cells, some of them as efficiently as the endogenous dimerization domain or the GCN4 leucine zipper. Many are very small, comprising as few as six residues. This study strongly supports the notion that peptide sequence space is rich in small peptides, which might be useful in protein engineering and other applications.

Peptic ulcer disease - a chronic relapsing poly etiologic disease is widespread throughout the world. Among the patients who are hospitalized with gastrointestinal diseases, peptic ulcer disease is diagnosed in 35.8% of cases. Implementation of peptic ulcer disease is carried out by the interaction of exogenous and endogenous factors: genetic predisposition, such as the nervous and endocrine systems, psycho-emotional characteristics, the characteristics of metabolic, biochemical reactions. In modern conditions, there is a noticeable increase in the incidence of peptic ulcer caused by stressful situations, bad habits, use of drugs, resulting in impaired balance between “aggressive” factors and “protective” factors of gastroduodenal zone. Aim of research Investigating of extracellular nucleic acid contamination changing and histone like proteins in blood of patients with complications of peptic ulcer disease. Material and methods The object of the study was the blood of patients with ulcer complications, which were determined precursors of nucleic acids and histone like proteins. Results of study A significant increase in the fraction 1.9 times H1, H2A, and H3, H4 fraction in 3.5 times in comparison with the control values and a significant decrease H2B fraction 1.5. The quantity of ASF in the blood of patients with peptic ulcer disease significantly increased by 1.2 times compared with the control, with corresponding reduction of circulating extracellular nucleic acids. Conclusion Changing the content of histone like proteins extracellular nucleic acids, in patients with a complication of gastric ulcer, can be explained by “breakdown” compensatory mechanisms adapted by the action of unfavorable factors that lead to oxidative degradation of histone proteins and metabolic disorders predecessors nucleic acids.

The use of biomarkers such as cytochrome P4501A (CYP1A) or metallothionein (MT) for pollution monitoring is based on the assumption that an increased activity or concentration is primarily caused by exposure to contaminants. Previous studies have shown that the response of biomarkers may be affected by factors such as season, temperature, gender, nutritional status or size. The objective of the present study was to identify natural factors that affect the hepatic activity of CYP1A and hepatic concentration of MT in flounder ( Platichthys flesus L.). Thirty flounder were sampled at each of two sites in the Hvaler archipelago, southern Norway, monthly through one year. A set of variables were recorded for each sampling and individual including water temperature, salinity, external and internal lesions, intestinal content, sex, size and organ weights. Hepatic CYP1A activity (EROD), MT and metal concentrations were determined for each individual flounder. The influence of environmental and endogenous factors on the response of these two biomarkers was assessed in multiple regression models. For both biomarkers, 50–60% of the total variability could be explained from factors directly related to season, gender and maturation. Season contributed significantly in the model for EROD, as did external lesions. Size, condition and diet did not contribute greatly when the above factors were included. The results confirm previous findings that season, gender and maturation must be taken into account in biomarker monitoring, but also indicate that other factors such as external lesions should be considered.

Genomic instability is a commonly observed feature of tumors. Most investigations addressing the mechanism of tumor progression have focused on the genetic factors that may play a role. Growing evidence now suggests that, in addition to these endogenous factors, the exogenous environment within solid tumors may by itself be mutagenic and constitute a significant source of genetic instability. The tumor microenvironment is characterized by regions of fluctuating hypoxia, low pH, and nutrient deprivation. Each of these microenvironmental factors has been shown to cause severe disturbance in cell metabolism and physiology. Both in vivo and in vitro data demonstrate that exposure of tumor cells to adverse conditions can directly cause mutations, contributing to genetic instability. In this review, we will reexamine the current body of evidence on the role of the tumor microenvironment in inducing mutagenesis and consequent tumor progression.

Recent evidence demonstrates that members of the CXC chemokine family can act as either angiogenic or angiostatic factors, depending on the presence of the ELR (Glu-Leu-Arg) motif in their NH(2) terminus. As such, these molecules have been shown to regulate tumor growth and metastasis in an animal model of human non-small cell lung cancer. ELR-positive members (for example, IL-8) are tumor-derived proteins that promote tumor growth and metastasis. Conversely, ELR-negative members (for example, IP-10 and MIG) are endogenous factors that inhibit tumor growth and metastasis. The levels of these factors in human tumor specimens may have predictive value for determining which patients are at risk for developing metastasis, and alteration of these CXC chemokine levels may provide a therapeutic intervention.

The discovery of heterogeneous populations of retinal precursors with sequentially modified fates may help solve the conundrum of conserved histogenesis in the absence of determination either by birthdate or lineage. Combined with a wealth of new data on the exogenous and endogenous factors that influence cellular fate in the retina, models of how complexity is generated are beginning to emerge.

The production of mice with specific deletion of targeted genes (knockouts) has provided a useful tool in understanding the mechanisms underlying behavior. There are many opportunities with this new tool for behavioral neuroendocrinology, specifically, and behavioral biology, generally. Although this genetic technique offers new opportunities to study the mechanisms of behavior, as with all behavioral techniques there are some potential limitations. For example, the products of many genes are essential to normal function, and inactivating the gene may prove lethal or induce gross morphological or physiological abnormalities that can complicate interpretation of discrete behavioral effects. Unexpected compensatory or redundancy mechanisms might be activated when a gene is missing and cloud interpretation of the normal contribution of the gene to behavior. Behavioral tests study the effects of the missing gene (and gene product), not the effects of the gene directly. This conceptual shortcoming can be overcome in the same way that it is overcome in other types of ablation studies, by collecting converging evidence using a variety of pharmacological, lesion, and genetic manipulations. Finally, because mammalian genome mapping is currently focused on mice (Mus musculus), standardized behavioral testing of mice should be adopted. Against those disadvantages are several important advantages to using knockout mice in behavioral research: (1) disabling a gene is often a very precise and "clean" ablation, (2) the effects of the gene product can be abolished without the side-effects of drugs, and (3) genetic manipulations may be the only way to determine the precise role of many endogenous factors on behavior. The use of new inducible knockouts, in which the timing and placement of the targeted gene disruption can be controlled, will be an extremely important tool in behavioral endocrinology research.

Summary One third of referrals for specialist opionion have no identifiable organic disease. The symptomatology is protean, involving all major bodily systems, and may mimic disease of vital organs or systems. These have attracted many attributions, some merely descriptive, some imputing dubious and unproven pathology, e.g. myalgic encephalomyelitis. Hyperventilation, which causes metabolic alkalosis, is a physiological mechanism which underlies all the symptoms and dysfunctions embraced in these syndromes. Elimination of hyperventilation results in cure in 90% of cases. The paper discusses endogenous factors which predispose to, and environmental factors which may be involved in, triggering this reaction. Treatment principles are briefly touched on.

We investigate the trading behavior of a large set of single investors trading the highly liquid Nokia stock over the period 2003-2008 with the aim of determining the relative role of endogenous and exogenous factors that may affect their behavior. As endogenous factors we consider returns and volatility, whereas the exogenous factors we use are the total daily number of news and a semantic variable based on a sentiment analysis of news. Linear regression and partial correlation analysis of data show that different categories of investors are differently correlated to these factors. Governmental and non profit organizations are weakly sensitive to news and returns or volatility, and, typically, they are more correlated with the former than with the latter. Households and companies, on the contrary, are very sensitive to both endogenous and exogenous factors, and volatility and returns are, on average, much more relevant than the number of news and sentiment, respectively. Finally, financial institutions and foreign organizations are intermediate between these two cases, in terms of both the total explanatory power of these factors and their relative importance.

Determinants of default risk of banks in emerging economies have so far received inadequate attention in the literature. Using panel data techniques, this paper seeks to examine the impact of macroeconomic and endogenous factors on non-performing assets during 1997-2009. The findings reveal some interesting inferences contrary to the perception of few opinion makers. Lending rates have been found to be not so significant in affecting the non-performing loans, which is contrary to the general perception. Such assets have a negative and significant influence, indicating that large banks may have better risk management procedures and technology which definitely allows them to finish up with lower levels of non-performing assets compared to smaller banks. Further, this study suggests that private banks and foreign banks have advantages in terms of their efficiencies in better credit management that contains non-performing assets. That indicates that bank privatization can lead to better management of default risk.

We examine the popularity distribution of given names prior, during, and after Mao Zedong’s rule over the People’s Republic of China to clarify how exogenous and endogenous factors act together in shaping cultural change. Whereas recent work in the sociology of culture emphasizes the importance of endogenous processes in explaining fashion (Kaufman 2004), our analysis demonstrates two ways that Mao’s regime impacted cultural expression, even in a domain that was largely untouched by its radical cultural policies: (a) by promoting forms of expression reflecting legitimate political ideologies; and (b) by creating a general feeling of insecurity, whereby citizens fear that any public expression of difference could signal political disloyalty. As argued by Lieberson (2000; Lieberson and Lynn 2003) and developed further in this paper, the latter condition is important because endogenous fashion cycles require a critical mass of individuals who seek to differentiate themselves from common practice. Our analysis suggests how exogenous and endogenous mechanisms interact, with the former setting the conditions for the operation of the latter; our analysis also sheds light on the nature of conformity under authoritarian regimes as well as the social conditions supporting individual expression.

Growth of rainbow trout, at first analysis, appears to be easily understood and simple to measure. However, closer examination reveals that it is a highly complex phenomenon, not easily quantified, and confused by the indeterminant and flexible nature of trout growth. This review summarizes what is known about environmental, genetic, and endogenous factors influencing growth, with particular attention to physiological processes. There are many different factors that can affect growth of rainbow trout. There is a reasonable amount of information available on environmental factors, including nutrition, but there is limited understanding of the endogenous control of growth and the multitude of interactions between the various environmental, genetic and endogenous factors.

Eighty-eight healthy post-menopausal women were divided into two groups, one of 35 subjects who had undergone menopause up to 9 years previously and the second of 53 subjects who were 10 or more years post-menopausal. In each individual we related the bone mineral content (BMC), measured by single photon absorptiometry in the distal forearm, to anthropometric variables and urinary oestrogen excretion. There was a positive association between BMC and both urinary oestrogen excretion and anthropometric variables, but this was statistically significant only in the older women. As expected, BMC in the distal forearm decreased with advancing age, the fall being greatest in the first 9 years after the menopause. We concluded that although a single measurement of urinary oestrogen and anthropometric variables does not provide enough information to predict an individual's BMC, the values obtained may prove of use, along with a single BMC determination, in helping to predict the rate of bone loss.

The last two decades were marked by a high increase in economic growth research, namely related to three important issues as stated in Klenow et al. [1997]: world growth, country growth and dispersion in income levels. The Charles Jones’ [2002] technique to solve endogenous growth models relies on the two-step approach, which is in fact a clever way to study the dynamic behaviour of the usual two production factors of this type of models, technology and capital. However, he does that sequentially, therefore reducing the general scope of the model, as it is a special case of a broader version developed by David Romer [2001]. Romer’s general case analyse the dynamic behaviour more closely and, more importantly, allowing for a simultaneous analysis of the dynamics of the endogenous factors, which provide additional insights. The aim of this paper is to tackle the differences between the two endogenous models as an exercise to see expost exogenous shocks’ implications to the variables of interest. More specifically, in addition to the strictly theoretical analysis of some dynamic properties of the model, by programming difference equations in discrete time, one is also able to simulate and examine how the model will respond to shocks that one administer to it, on an ad-hoc basis – deterministic simulation.

Aim To identify the range of factors that may artefactually accelerate decomposition and therefore potentially confound time of death estimations. Methods Case files at Forensic Science SA, Adelaide, South Australia, were retrospectively reviewed for cases where decomposition appeared greater than would have been expected for the time interval since death. Exogenous and endogenous reasons for this were evaluated. Results Exogenous factors included: elevated environmental temperatures (outdoors and indoors) involving exposure to hot water, saunas, central heating, electric blankets and car interiors. Endogenous factors included: obesity, fever, infections, use of illicit and prescription drugs and insulin-dependent diabetes mellitus. Discussion Determination of the time since death is often a difficult process beset with many inaccuracies. A supportive feature at autopsy has been the presence/extent of decomposition. If these factors or conditions are identified at autopsy, less significance should be attached to changes of decomposition as markers of the postmortem interval. These factors involve elevation or maintenance of body temperature, increased ante-mortem bacterial loading and increased bacterial nutrient availability. In addition to confusing estimates of the time of death, they may also cause doubt to be expressed concerning the veracity of witness statements.

Technological innovation is a key factor for achieving a better environmental performance of firms and the economy as a whole, to the extent that it helps to increase the material/energy efficiency of production processes and to reduce emission/effluents associated to outputs. Environmental innovation may spur from exogenous driving forces, like policy intervention, and/or from endogenous factors associated to firm market and management strategies. Despite the crucial importance of research in this field, empirical evidence at firm microeconomic level, for various reasons, is still scarce. Microeconomic-based analysis is needed in order to assess what forces are lying behind environmental innovation at the level of the firm, where innovative practices emerge and are adopted. The paper exploits information deriving from two surveys conducted on a sample of manufacturing firms in Emilia Romagna region -Northern Italy- in 2002 and 2004, located in a district-intense local production system. New evidence is provided by testing a set of hypotheses, concerning the influence of: (i) firm structural variables; (ii) environmental R&D; (iii) environmental policy pressure and regulatory costs; (iv) past firm performances; (v) networking activities, (vi) other non-environmental techno-organizational innovations and (vii) quality/nature of industrial relations. We estimate input and output-based environmental innovation reduced form specifications in order to test the set of hypotheses. The applied investigation shows that environmental innovation drivers, both at input and output level, are found within exogenous factors and endogenous elements concerning the firm and its activities/strategies within and outside its natural boundaries. In the present case study, the usual structural characteristics of the firm and performances appear to matter less than R&D, induced costs, networking, organisational flatness and innovative oriented industrial relations. Environmental Policies and environmental voluntary auditing schemes exert some relevant direct and indirect effects on innovation, although evidence is mixed and further research is particularly needed. Although this new empirical evidence is focussing on a specific industrial territory, we provide food for discussion on firm environmental innovation strategies, and research suggestions for further empirical work.

The paper tests whether the increasing current account deficit has negative impact on American economy and society. Using data for American economy in years 1967-2005, it will be shown that perceived welfare effects, as measured by levels of Consumer Confidence, asymmetrically reflect volatility in exports and imports. The provided VAR analysis allowed to filter out potential output and cyclical movements in endogenous factors and to describe the remaining error in terms of external trade volatility. Keeping information on exports and imports as external factors allowed to estimate a structure of the model, where the responsiveness of perceived welfare in respect to simulated changes in current account was studied. The provided analysis shows that opening the economy enhanced observed volatility of the Consumer Confidence, while presence of the current account deficit allowed to obtain superior welfare.

Eag1 display oncogenic properties, and are proposed as markers and therapeutic cancer targets (1− 5). Nevertheless, Eag1 regulation by endogenous factors is poorly understood. Because of the restricted distribution of Eag1 in normal tissues, we wondered whether serum regulates Eag1 expression. We also looked for ERK/MAPK activation and studied the effect of TGF-alpha (which activates ERK/MAPK) on Eag1 gene expression.

Achieving sufficient transgene expression poses a critical challenge for many gene therapies, particularly those designed to produce secreted factors for systemic or remote effects. Although expression may be boosted via increased transgene delivery, this approach is ultimately limited by vector cost or toxicity, often at expression levels which are still therapeutically insufficient. Expression may also be increased via the development of specially designed hybrid or synthetic promoters bearing target sites for potent natural transcriptional activators. Given the reliance of such approaches on the availability of appropriate endogenous factors, however, the resultant constructs often represent cell type-specific solutions to enhancing expression. Moreover, such promoters may also introduce the risk of deranging natural cellular regulatory pathways by squelching the expression of other endogenous genes.