Water-immiscible dissolved oxygen carriers in combination with Pluronic F 68 in bioreactors

The supply and availability of dissolved oxygen (DO) in aerobic bioprocesses is often a limiting factor for the scaling up, improvement and general performance of these bioprocesses. The use of different DO carriers, particularly the use of perfluorocarbons as oxygen carriers, is discussed in this review. It also highlights interactions of microbial cultures with the surfactant, Pluronic F 68. Although oxygen carriers have been used extensively in the medical field, this review only focuses on their use in microbial bioprocess used for the production of high-value bioproducts. The use of water-immiscible compounds in combination with Pluronic F 68 in bioprocesses is discussed with the intention of analysing their combined effect where bioreactor and biomass performance is affected by DO limitations, nutrient starvation, high concentrations of trace element ions, oxidative stress and cell death from mechanical stress

Acute affective responses to prescribed and self-selected exercise sessions in adolescent girls: an observational study

Background Positive affective responses can lead to improved adherence to exercise. This study sought to examine the affective responses and exercise intensity of self-selected exercise in adolescent girls. Methods An observational study where twenty seven females (Age M?=?14.6?�?0.8 years) completed three 20-minute exercise sessions (2 self-selected and 1 prescribed intensity) and a graded exercise test. The intensity of the prescribed session was matched to the first self-selected session. Intensity, affective responses and ratings of perceived exertion were recorded throughout the sessions and differences examined. Repeated measures ANOVAs were conducted to examine differences. Results There were no significant differences in intensity between the prescribed and self-selected sessions, but affective responses were significantly more positive (p?<?.01) during the self-selected session. Ratings of perceived exertion were significantly lower (p?<?.01) during the self-selected session than the prescribed session. On average participants worked at 72% V?O2 peak; well within the intensity recommended by the American College of Sports Medicine. Conclusion Even though the intensity did not differ between the self-selected and prescribed sessions, there was a significant impact on affective responses, with more positive affective responses being elicited in the self-selected session. This highlights the importance of autonomy and self-paced exercise for affective responses and may have potential long-term implications for adherence

The impacts of corruption on firm performance: some lessons from 40 African countries

The current evidence-base regarding the impacts of corruption on firm performance is based largely on studies of individual countries and contains mixed results. Therefore, the aim of this paper is to achieve a better insight into this relationship by reporting the results of a firm-level analysis of the impacts of corruption on firm performance using World Bank Enterprise Survey (WBES) data across 40 African countries. The clear result is that corruption significantly enhances rather than harms annual sales, employment and productivity growth rates. The outcome is to re-theorize participation in acts of corruption as beneficial for the individual firms engaged in such activity, while recognizing the wider evidence that this is not an optimal strategy at the aggregate country level. The outcome will be to advance knowledge about how corruption needs to be tackled. To eliminate corruption, it is shown here to be necessary for public authorities to recognize that corruption is an efficient strategy at the firm level and to adopt measures to alter the cost/benefit ratio confronting individual enterprises, and at the same time, to address the country-level formal institutional deficiencies that characterize many developing countries and result in the prevalence of corruption

Starting-up unregistered and firm performance in Turkey

© 2016 The Author(s) Recent years have seen a questioning of the negative representation of informal sector entrepreneurship and an emergent view that it may offer significant benefits. This paper advances this rethinking by evaluating the relationship between business registration and future firm performance. Until now, the assumption has been that starting-up unregistered is linked to weaker firm performance. Using World Bank Enterprise Survey data on 2494 formal enterprises in Turkey, and controlling for other determinants of firm performance as well as the endogeneity of the registration decision, the finding is that formal enterprises that started-up unregistered and spent longer unregistered have significantly higher subsequent annual sales and productivity growth rates compared with those registered from the outset. This is argued to be because in such weak institutional environments, the advantages of registering from the outset are outweighed by the benefits of deferring business registration and the low risks of detection and punishment. The resultant implication is that there is a need to shift away from the conventional eradication approach based on the negative depiction of informal entrepreneurship as poorly performing, and towards a more facilitating approach that improves the benefits of business registration and tackles the systemic formal institutional deficiencies that lead entrepreneurs to decide to delay the registration of their ventures

In the face of threat: neural and endocrine correlates of impaired facial emotion recognition in cocaine dependence.

The ability to recognize facial expressions of emotion in others is a cornerstone of human interaction. Selective impairments in the recognition of facial expressions of fear have frequently been reported in chronic cocaine users, but the nature of these impairments remains poorly understood. We used the multivariate method of partial least squares and structural magnetic resonance imaging to identify gray matter brain networks that underlie facial affect processing in both cocaine-dependent (n = 29) and healthy male volunteers (n = 29). We hypothesized that disruptions in neuroendocrine function in cocaine-dependent individuals would explain their impairments in fear recognition by modulating the relationship with the underlying gray matter networks. We found that cocaine-dependent individuals not only exhibited significant impairments in the recognition of fear, but also for facial expressions of anger. Although recognition accuracy of threatening expressions co-varied in all participants with distinctive gray matter networks implicated in fear and anger processing, in cocaine users it was less well predicted by these networks than in controls. The weaker brain-behavior relationships for threat processing were also mediated by distinctly different factors. Fear recognition impairments were influenced by variations in intelligence levels, whereas anger recognition impairments were associated with comorbid opiate dependence and related reduction in testosterone levels. We also observed an inverse relationship between testosterone levels and the duration of crack and opiate use. Our data provide novel insight into the neurobiological basis of abnormal threat processing in cocaine dependence, which may shed light on new opportunities facilitating the psychosocial integration of these patients.This work was funded by a research grant from the Medical Research Council (G0701497) and supported by the infrastructure of the Behavioural and Clinical Neuroscience Institute (which is supported by a joint award from the Medical Research Council and the Wellcome Trust). This study was jointly sponsored by the Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge. KD Ersche, CC Hagan, and PS Jones are supported by the Medical Research Council, and DG Smith by the Cambridge Overseas Trust.This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/tp.2015.5

Cool habitats support darker and bigger butterflies in Australian tropical forests

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Epithelial cell shedding and barrier function: a matter of life and death at the small intestinal villus tip

The intestinal epithelium is a critical component of the gut barrier. Composed of a single layer of intestinal epithelial cells (IECs) held together by tight junctions, this delicate structure prevents the transfer of harmful microorganisms, antigens, and toxins from the gut lumen into the circulation. The equilibrium between the rate of apoptosis and shedding of senescent epithelial cells at the villus tip, and the generation of new cells in the crypt, is key to maintaining tissue homeostasis. However, in both localized and systemic inflammation, this balance may be disturbed as a result of pathological IEC shedding. Shedding of IECs from the epithelial monolayer may cause transient gaps or microerosions in the epithelial barrier, resulting in increased intestinal permeability. Although pathological IEC shedding has been observed in mouse models of inflammation and human intestinal conditions such as inflammatory bowel disease, understanding of the underlying mechanisms remains limited. This process may also be an important contributor to systemic and intestinal inflammatory diseases and gut barrier dysfunction in domestic animal species. This review aims to summarize current knowledge about intestinal epithelial cell shedding, its significance in gut barrier dysfunction and host-microbial interactions, and where research in this field is directed

An institutional theory of informal entrepreneurship: some lessons from FYR Macedonia

In recent years, a new institutionalist theory has emerged to explain the prevalence of informal sector entrepreneurship. This argues that formal institutional failures lead to the emergence of an asymmetry between the formal rules (laws and regulations) and the norms, values and beliefs of entrepreneurs regarding the acceptability of participating in the informal sector, which in turn leads to the prevalence of informal entrepreneurship. The aim of this paper is to evaluate this social actor approach by reporting evidence from 453 face-to-face interviews with a nationally representative sample of entrepreneurs in FYR Macedonia. This reveals not only a significant association between participation in the informal economy and the non-alignment of entrepreneurs' views with the formal rules, but specific formal institutional failings that are significantly associated with the acceptability of informal entrepreneurship, namely poor quality public services, a lack of tax fairness, corruption and instability in the formal institutions. The theoretical and policy implications are then discussed