Different Roles of Mast Cells in Obesity and Diabetes: Lessons from Experimental Animals and Humans

Mast cells (MCs) play an important role in allergic hyperresponsiveness and in defending microorganism infections. Recent studies of experimental animals and humans have suggested that MCs participate in obesity and diabetes. MC distribution and activities in adipose tissues may vary, depending on the locations of different adipose tissues. In addition to releasing inflammatory mediators to affect adipose tissue extracellular matrix remodeling and to promote inflammatory cell recruitment and proliferation, MCs directly and indirectly interact and activate adipose tissue cells, including adipocytes and recruited inflammatory cells. Plasma MC protease levels are significantly higher in obese patients than in lean subjects. Experimental obese animals lose body weight after MC inactivation. MC functions in diabetes are even more complicated, and depend on the type of diabetes and on different diabetic complications. Both plasma MC proteases and MC activation essential immunoglobulin E levels are significant risk factors for human pre-diabetes and diabetes mellitus. MC stabilization prevents diet-induced diabetes and improves pre-established diabetes in experimental animals. MC depletion or inactivation can improve diet-induced type 2 diabetes and some forms of type 1 diabetes, but also can worsen other forms of type 1 diabetes, at least in experimental animals. Observations from animal and human studies have suggested beneficial effects of treating diabetic patients with MC stabilizers. Some diabetic patients may benefit from enhancing MC survival and proliferation – hypotheses that merit detailed basic researches and clinical studies

Superconductivity in Compressed Potassium and Rubidium

Calculations of the electron-phonon interaction in the alkali metals, Potassium and Rubidium, using the results of band theory and BCS theory-based techniques suggest that at high pressures K and Rb would be superconductors with transition temperatures approaching 10 K.Comment: three figure

Bypassing the structural bottleneck in the ultrafast melting of electronic order

The emergent properties of quantum materials, such as symmetry-broken phases and associated spectral gaps, can be effectively manipulated by ultrashort photon pulses. Impulsive optical excitation generally results in a complex non-equilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, we directly monitor the photo-induced collapse of the spectral gap in a canonical charge-density-wave material, blue bronze Rb0.3MoO3. We find that ultra-fast (about 60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (about 315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photo-induced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system

Women on Top: Diversity in Gender and Education Profiles of Top Management and Board of Directors of Philippine Publicly Traded Firms

Women have been making headway when it comes to occupying corporate board and senior management positions in companies all over the world, particularly in the Philippines. Stylized facts released by international reports point to the surprising prevalence of women holding leadership positions among Philippine firms. Hence, this descriptive study bridges a gap in the Philippine corporate governance literature by using data on around 250 PSE-listed firms to examine gender diversity composition and trends among CEOs, boards, and top management teams in Philippine publicly traded firms on a five-year interval (i.e. 2003, 2008, 2013) and for the most recent year (i.e. 2014). Additionally, we provide information on the educational profile of CEOs of PSE-listed firms. Our study confirms the existence of a gender gap among governing and managing bodies of Philippine public firms, but observes a gradual improvement in the representation of women in key leadership positions. We also find that most CEOs of PSE-listed firms share a common educational background in terms of undergraduate and graduate degrees received and tertiary schools attended

Gender Diversity in Boards and Performance of Philippine Publicly Traded Firms: Do Women Matter?

The issue of gender diversity in corporate boards has been attracting research interest in various countries because of the many socioeconomic contributions women directors are purported to confer to the firm, some of which involve improved board monitoring quality and a more ethical and democratic form of leadership. This rationale forms part of the “economic case” for women’s participation in boards, apart from the usual grounds of social or equality considerations. We examine this board-level gender diversity issue for the case of the firms traded in the Philippine Stock Exchange during the period 2003 to 2014. Using an unbalanced panel of 2,645 firm-years, we find that greater gender diversity in boards, which in the case of our sample firms also indicates the presence of more female directors in the board, does not significantly affect short-term firm performance as alternatively measured by ROA and ROE, but seems to drive down long-term firm value as measured by Tobin’s Q. Our results are robust with respect to board-level gender diversity measures and are based on estimates that take into account the effects of unobserved individual effects and potential endogeneity of gender diversity. Our findings are consistent with the investor bias theory, which argues that investors collectively drive down the market value of firms with more gender-diverse boards because they have a perceptual bias against women as capable firm leaders and directors. Our results put to question the economic rationale of imposing any minimum gender quota on boards of, at least, Philippine publicly listed firms, similar to the practice in most European countries. We suggest that policy makers must be cautious in proposing quotas that seek to promote gender parity in boards of directors of publicly traded firms based on a claim that it will significantly improve firm performance and shareholder value. Instead, enforcing board-level gender quotas may have to be justified in terms of social equality, business reputation, and purely ethical grounds