Exploring Entrepreneurial Roles and Identity in the United Kingdom and China

This paper examines entrepreneurial identity in both the United Kingdom and China through the lenses of identity theory and social identity theory to develop a deeper and more holistic understanding of the concept of entrepreneurial identity. By examining the entrepreneur as both a role and an identity this paper explores how an entrepreneur views the role of the entrepreneur, the counter-roles to the entrepreneur, the ‘self-as-entrepreneur’ understand how entrepreneurs construct their identity as entrepreneur. By looking at the role identity in different social constructs, a more nuanced view of entrepreneurial identity can be uncovered for entrepreneurs in both the UK and China. The study argues that entrepreneurs in the UK use counter-roles to bridge the disconnect between their understanding of the entrepreneur-as-role and the self-as-entrepreneur whereas entrepreneurs in China have less conflict reconciling the two, and use the counter-role as a way to paint entrepreneurship as a ‘calling’, justifying their abandonment of other identities

Loss of Cannabinoid Receptor CB1 Induces Preterm Birth

Preterm birth accounting approximate 10% of pregnancies in women is a tremendous social, clinical and economic burden. However, its underlying causes remain largely unknown. Emerging evidence suggests that endocannabinoid signaling via cannabinoid receptor CB1 play critical roles in multiple early pregnancy events in both animals and humans. Since our previous studies demonstrated that loss of CB1 defers the normal implantation window in mice, we surmised that CB1 deficiency would influence parturition events.Exploiting mouse models with targeted deletion of Cnr1, Cnr2 and Ptgs1 encoding CB1, CB2 and cyclooxygenase-1, respectively, we examined consequences of CB1 or CB2 silencing on the onset of parturition. We observed that genetic or pharmacological inactivation of CB1, but not CB2, induced preterm labor in mice. Radioimmunoassay analysis of circulating levels of ovarian steroid hormones revealed that premature birth resulting from CB1 inactivation is correlated with altered progesterone/estrogen ratios prior to parturition. More strikingly, the phenotypic defects of prolonged pregnancy length and parturition failure in mice missing Ptgs1 were corrected by introducing CB1 deficiency into Ptgs1 null mice. In addition, loss of CB1 resulted in aberrant secretions of corticotrophin-releasing hormone and corticosterone during late gestation. The pathophysiological significance of this altered corticotrophin-releasing hormone-driven endocrine activity in the absence of CB1 was evident from our subsequent findings that a selective corticotrophin-releasing hormone antagonist was able to restore the normal parturition timing in Cnr1 deficient mice. In contrast, wild-type females receiving excessive levels of corticosterone induced preterm birth.CB1 deficiency altering normal progesterone and estrogen levels induces preterm birth in mice. This defect is independent of prostaglandins produced by cyclooxygenase-1. Moreover, CB1 inactivation resulted in aberrant corticotrophin-releasing hormone and corticosterone activities prior to parturition, suggesting that CB1 regulates labor by interacting with the corticotrophin-releasing hormone-driven endocrine axis

Multi-spacecraft Analysis of the Properties of Magnetohydrodynamic Fluctuations in Sub-Alfvénic Solar Wind Turbulence at 1 AU

We present three-dimensional magnetic power spectra in wavevector space to investigate anisotropy and scalings of sub-Alfv\'enic solar wind turbulence at magnetohydrodynamic (MHD) scale using the Magnetospheric Multiscale spacecraft. The magnetic power distributions are organized in a new coordinate determined by wavevectors (k) and background magnetic field ($b_0$) in Fourier space. This study utilizes two approaches to determine wavevectors: singular value decomposition method and timing analysis. The combination of both methods allows an examination of magnetic field properties in terms of mode compositions without spatiotemporal hypothesis. Observations show that fluctuations ($\delta B_{\perp1}$) in the direction perpendicular to k and $b_0$ prominently cascade perpendicular to $b_0$, and such anisotropy increases with wavenumber. The reduced power spectra of $\delta B_{\perp1}$ follow Goldreich-Sridhar scalings: $P(k_\perp)\sim k_\perp^{-5/3}$ and $P(k_{||}) \sim k_{||}^{-2}$. In contrast, fluctuations within $kb_0$ plane show isotropic behaviors: perpendicular power distributions are approximately the same as parallel distributions. The reduced power spectra of fluctuations within $kb_0$ plane follow the scalings: $P(k_\perp)\sim k_\perp^{-3/2}$ and $P(k_{||})\sim k_{||}^{-3/2}$. Comparing frequency-wavevector spectra with theoretical dispersion relations of MHD modes, we find that $\delta B_{\perp1}$ are probably associated with Alfven modes. For Alfvenic components, the ratio of cascading rate to the wave frequency is found to be around a factor of one, fully consistent with critical balance in the strong turbulence regime. The magnetic field fluctuations within $kb_0$ plane more likely originate from fast modes based on isotropic behaviors. The anisotropy and scalings of different magnetic field components are consistent with predictions of the current compressible MHD theory

Multispacecraft Analysis of the Properties of Magnetohydrodynamic Fluctuations in Sub-Alfvénic Solar Wind Turbulence at 1 au

We present three-dimensional magnetic power spectra in wavevector space to investigate anisotropy and scalings of sub-Alfv\'enic solar wind turbulence at magnetohydrodynamic (MHD) scale using the Magnetospheric Multiscale spacecraft. The magnetic power distributions are organized in a new coordinate determined by wavevectors (k) and background magnetic field ($b_0$) in Fourier space. This study utilizes two approaches to determine wavevectors: singular value decomposition method and timing analysis. The combination of both methods allows an examination of magnetic field properties in terms of mode compositions without spatiotemporal hypothesis. Observations show that fluctuations ($\delta B_{\perp1}$) in the direction perpendicular to k and $b_0$ prominently cascade perpendicular to $b_0$, and such anisotropy increases with wavenumber. The reduced power spectra of $\delta B_{\perp1}$ follow Goldreich-Sridhar scalings: $P(k_\perp)\sim k_\perp^{-5/3}$ and $P(k_{||}) \sim k_{||}^{-2}$. In contrast, fluctuations within $kb_0$ plane show isotropic behaviors: perpendicular power distributions are approximately the same as parallel distributions. The reduced power spectra of fluctuations within $kb_0$ plane follow the scalings: $P(k_\perp)\sim k_\perp^{-3/2}$ and $P(k_{||})\sim k_{||}^{-3/2}$. Comparing frequency-wavevector spectra with theoretical dispersion relations of MHD modes, we find that $\delta B_{\perp1}$ are probably associated with Alfven modes. For Alfvenic components, the ratio of cascading rate to the wave frequency is found to be around a factor of one, fully consistent with critical balance in the strong turbulence regime. The magnetic field fluctuations within $kb_0$ plane more likely originate from fast modes based on isotropic behaviors. The anisotropy and scalings of different magnetic field components are consistent with predictions of the current compressible MHD theory

Multispacecraft Analysis of the Properties of Magnetohydrodynamic Fluctuations in Sub-Alfvénic Solar Wind Turbulence at 1 au

International audienceWe present observations of three-dimensional magnetic power spectra in wavevector space to investigate the anisotropy and scalings of sub-Alfvénic solar wind turbulence at magnetohydrodynamic (MHD) scale using the Magnetospheric Multiscale spacecraft. The magnetic power distributions are organized in a new coordinate determined by wavevectors ( $\hat{{\boldsymbol{\kappa }}}$ ) and background magnetic field ( ${\widehat{{\boldsymbol{b}}}}_{0}$ ) in Fourier space. This study utilizes two approaches to determine wavevectors: the singular value decomposition method and multispacecraft timing analysis. The combination of the two methods allows an examination of the properties of magnetic field fluctuations in terms of mode compositions without any spatiotemporal hypothesis. Observations show that fluctuations (δ B ⊥1) in the direction perpendicular to $\hat{{\boldsymbol{\kappa }}}$ and ${\widehat{{\boldsymbol{b}}}}_{0}$ prominently cascade perpendicular to ${\widehat{{\boldsymbol{b}}}}_{0}$ , and such anisotropy increases with wavenumbers. The reduced power spectra of δ B ⊥1 follow Goldreich-Sridhar scalings: $\hat{P}({k}_{\perp })\propto {k}_{\perp }^{-5/3}$ and $\hat{P}({k}_{\parallel })\propto {k}_{\parallel }^{-2}$ . In contrast, fluctuations within the $\hat{k}{\hat{b}}_{0}$ plane show isotropic behaviors: perpendicular power distributions are approximately the same as parallel distributions. The reduced power spectra of fluctuations within the $\hat{k}{\hat{b}}_{0}$ plane follow the scalings $\hat{P}({k}_{\perp })\propto {k}_{\perp }^{-3/2}$ and $\hat{P}({k}_{\parallel })\propto {k}_{\parallel }^{-3/2}$ . Comparing frequency-wavevector spectra with theoretical dispersion relations of MHD modes, we find that δ B ⊥1 are probably associated with Alfvén modes. On the other hand, magnetic field fluctuations within the $\hat{k}{\hat{b}}_{0}$ plane more likely originate from fast modes based on their isotropic behaviors. The observations of anisotropy and scalings of different magnetic field components are consistent with the predictions of current compressible MHD theory. Moreover, for the Alfvénic component, the ratio of cascading time to the wave period is found to be a factor of a few, consistent with critical balance in the strong turbulence regime. These results are valuable for further studies of energy compositions of plasma turbulence and their effects on energetic particle transport

Analysis of Magnetohydrodynamic Perturbations in Radial-field Solar Wind from Parker Solar Probe Observations

We report analysis of sub-Alfv\'enic magnetohydrodynamic (MHD) perturbations in the low-\b{eta} radial-field solar wind using the Parker Solar Probe spacecraft data from 31 October to 12 November 2018. We calculate wave vectors using the singular value decomposition method and separate the MHD perturbations into three types of linear eigenmodes (Alfv\'en, fast, and slow modes) to explore the properties of the sub-Alfv\'enic perturbations and the role of compressible perturbations in solar wind heating. The MHD perturbations there show a high degree of Alfv\'enicity in the radial-field solar wind, with the energy fraction of Alfv\'en modes dominating (~45%-83%) over those of fast modes (~16%-43%) and slow modes (~1%-19%). We present a detailed analysis of a representative event on 10 November 2018. Observations show that fast modes dominate magnetic compressibility, whereas slow modes dominate density compressibility. The energy damping rate of compressible modes is comparable to the heating rate, suggesting the collisionless damping of compressible modes could be significant for solar wind heating. These results are valuable for further studies of the imbalanced turbulence near the Sun and possible heating effects of compressible modes at MHD scales in low-\b{eta} plasma.Comment: 17 pages, 8 figures, accepted for publication in Ap

Observations of an Electron‐Cold Ion Component Reconnection at the Edge of an Ion‐Scale Antiparallel Reconnection at the Dayside Magnetopause

Solar wind parameters play a dominant role in reconnection rate, which controls the solar wind-magnetosphere coupling efficiency at Earth's magnetopause. Besides, low-energy ions from the ionosphere, frequently detected on the magnetospheric side of the magnetopause, also affect magnetic reconnection. However, the specific role of low-energy ions in reconnection is still an open question under active discussion. In the present work, we report in situ observations of a multiscale, multi-type magnetopause reconnection in the presence of low-energy ions using NASA's Magnetospheric Multiscale data on September 11, 2015. This study divides ions into cold (10–500 eV) and hot (500–30,000 eV) populations. The observations can be interpreted as a secondary reconnection dominated by electrons and cold ions (mainly in $XY_{GSE}$ plane) located at the edge of an ion-scale reconnection (mainly in $XY_{GSE}$ plane). This analysis demonstrates a dominant role of cold ions in the secondary reconnection without hot ions' response. Cold ions and electrons are accelerated and heated by the secondary process. The case study provides observational evidence for the simultaneous operation of antiparallel and component reconnection. Our results imply that the pre-accelerated and heated cold ions and electrons in the secondary reconnection may participate in the primary ion-scale reconnection affecting the solar wind-magnetopause coupling and the complicated magnetic field topology could affect the reconnection rate

Observations of an Electron-Cold Ion Component Reconnection at the Edge of an Ion-Scale Antiparallel Reconnection at the Dayside Magnetopause

International audienceSolar wind parameters play a dominant role in reconnection rate, which controls the solar wind-magnetosphere coupling efficiency at Earth's magnetopause. Besides, low-energy ions from the ionosphere, frequently detected on the magnetospheric side of the magnetopause, also affect magnetic reconnection. However, the specific role of low-energy ions in reconnection is still an open question under active discussion. In the present work, we report in situ observations of a multiscale, multi-type magnetopause reconnection in the presence of low-energy ions using NASA's Magnetospheric Multiscale data on September 11, 2015. This study divides ions into cold (10-500 eV) and hot (500-30,000 eV) populations. The observations can be interpreted as a secondary reconnection dominated by electrons and cold ions (mainly in XYGSE plane) located at the edge of an ion-scale reconnection (mainly in XZGSE plane). This analysis demonstrates a dominant role of cold ions in the secondary reconnection without hot ions' response. Cold ions and electrons are accelerated and heated by the secondary process. The case study provides observational evidence for the simultaneous operation of antiparallel and component reconnection. Our results imply that the pre-accelerated and heated cold ions and electrons in the secondary reconnection may participate in the primary ion-scale reconnection affecting the solar wind-magnetopause coupling and the complicated magnetic field topology could affect the reconnection rate