Abstract During the past fifty years, academics have tried to understand the factors that influence the tendency of people to engage in entrepreneurial activity. Recently, researchers have examined whether there is a genetic predisposition to entrepreneurship. By dint of our genetic makeup, are some of us more likely than others to come up with new business ideas, start companies, and engage in the other activities that entrepreneurs undertake? This chapter provides a framework to explain how human biology affects the tendency of people to become entrepreneurs. It discusses how researchers have learned about genetic effects on entrepreneurial activity and how they have identified physiological pathways through which biological factors influence business behavior. It discusses the two primary ways in which researchers seek to identify genetic effects on entrepreneurial activity: quantitative and molecular genetics studies. It also examines how researchers use cognitive neuroscience and studies of hormones to investigate the physiological mechanisms through which biological factors operate. Finally, it discusses the implications of a biological perspective for entrepreneurship research.
PURPOSE: To compare the pretreatment characteristics and outcome of postmenopausal women with stage I-II breast cancer treated with conservative surgery and radiation who had a history of hormone replacement therapy (HRT) with those who had never received HRT. MATERIALS AND METHODS: From 1979 to 1993, 485 postmenopausal women underwent excisional biopsy, axillary dissection, and radiation for stage I-II breast cancer. The median follow-up was 5.9 years. One hundred forty-one patients reported a history of HRT. The median length of use was 5 years. Three hundred forty-four patients reported no history of HRT. RESULTS: Statistically significant differences between the two groups were observed for median age (HRT 60 years v no HRT 64 years; P = .0009), median weight (HRT 142 lbs v no HRT 152 lbs; P = .004), clinical tumor size ≤ 2 cm (HRT 77% v no HRT 66%; P = .02), and the use of re-excision (HRT 62% v no HRT 49%; P = .01). The method of detection by mammogram only (HRT 52% v no HRT 42%; P = .06) was of borderline statistical significance. The HRT patients had a statistically significant increased cumulative incidence of ipsilateral breast tumor recurrence (8% v 2%; P = .02), a statistically significant decreased cumulative incidence of distant metastases (HRT 6% v no HRT 17%; P = .01), and a borderline statistically significant improvement in cause-specific survival at 10 years (HRT 92% v no HRT 86%; P = .07). Postmenopausal women with a history of HRT did not have an increased risk of contralateral breast cancer or second non–breast cancer malignancy. CONCLUSION: This study failed to identify an adverse effect of HRT on breast cancer mortality in patients with stage I-II disease treated with conservative surgery and radiation.
Tertius iungens brokering that brings together people who might not otherwise meet is crucial for organizational effectiveness. But we know little about whether and why women and men differ in their propensity to engage in this brokering. Our paper focuses on the origins and mitigation of gender differences in the propensity to bring people together. In study 1, we showed that the Totterdell et al. (2008) propensity-to-join-others scale that we used in study 2 and the Obstfeld (2005) tertius iungens scale overlapped not only conceptually, but also empirically, and that these measures of tertius iungens were distinct from mediation- and separation-brokering propensities (Grosser et al. 2019). In study 2, we used a natural experiment to examine the tertius iungens brokering propensities of 876 identical and 625 fraternal same-sex twins. We found that brokering propensity was lower for women than for men, although the propensity toward sociability in terms of making friends and acquaintances was lower for men. We also found that for women, relative to men, tertius iungens brokering propensity was largely affected by environmental influences, such as the experience of stereotyping and discrimination, rather than representing an inherited disposition. Moreover, the differences between men and women with respect to brokering were mitigated for empowered samples, such as well-educated or entrepreneurial individuals. Our research asks new questions about how environmental pressures and empowerment affect social networking. Gender differences in brokering may be amenable to mitigation through empowering practices that include education and entrepreneurial experience.
The results of radiation on the local control of triple receptor-negative breast cancer (negative estrogen [ER], progesterone [PR], and HER-2/neu receptors) was studied.Conservative surgery and radiation were used in 753 patients with T1-T2 breast cancer. Three groups were defined by receptor status: Group 1: ER or PR (+); Group 2: ER and PR (-) but HER-2 (+); and Group 3: triple-negative (TN). Factors analyzed were age, menopausal status, race, stage, tumor size, lymph node status, presentation, grade, extensive in situ disease, margins, and systemic therapy. The primary endpoint was 5-year locoregional recurrence (LRR) isolated or total with distant metastases.ER- and PR-negative patients were statistically significantly more likely to be black, have T2 disease, have tumors detectable on both mammography and physical examination, have grade 3 tumors, and receive chemotherapy. There were no significant differences noted with regard to ER- and PR- patients by HER-2 status. There was a significant difference noted in rates of first distant metastases (3%, 12%, and 7% for Groups 1, 2, and 3, respectively; P = .009). However, the isolated 5-year LRR was not significantly different (2.3%, 4.6%, and 3.2%, respectively; P = .36) between the 3 groups.Patients with TN breast cancer do not appear to be at a significantly increased risk for isolated LRR at 5 years and therefore remain appropriate candidates for breast conservation.
Concentrations of homovanillic acid (HVA), 5‐hydroxyindoleacetic acid (5‐HIAA) and 3‐methoxy‐4‐hydroxyphenylglycol (MHPG) were measured in lumbar CSF from 33 patients with affective illnes and from 23 neurological controls. The group of patients with affective illness comprised 29 depressed and four manic patients. During illness, the concentration of HVA was higher in the depressed patients (P >0.001) than in the controls. Both unipolar and bipolar depressed patients had increased HVA levels (P >0.001 and P >0.05, respectively). The concentration of MHPG was greater than control values in the unipolar (P < 0.001) and bipolar (P < 0.002) subgroups but did not differ from control values in the depressed group as a whole. The concentration of 5‐HIAA in the depressed patients as a whole and in the unipolar and bipolar subgroups did not differ from control concentrations. During illness the manic patients had increased levels of HVA (P >0.01) and normal levels of 5‐HIAA and MHPG. Sixteen of the 29 depressed patients had a second lumbar puncture after they had recovered. Compared with the pre‐recovery values, the concentration of HVA was reduced in the unipolar depressives (P < 0.01) and the concentration of 5‐HIAA lowered in the depressed group as a whole (P >0.02). The present findings suggest involvement of catecholamines in affective disorders.
We critically examine the potential that neuroscience holds for the future of entrepreneurship research and provide a framework for entrepreneurship researchers interested in pursuing this line of inquiry. Specifically, we propose four complementary mechanisms through which neuroscience can inform entrepreneurship theory and research. We conclude with a discussion of the limitations and ethical implications of a neuroscientific approach to entrepreneurship.
Nine patients who sustained high-velocity missile injuries to the thorax are reported. Two types of injury were seen: a 'through-and-through' injury (6 patients), and a 'tangential' injury (3 patients). Six patients underwent thoracotomy: 3 had pulmonary resections and 2 had closure of bronchopleural fistulas, while 1 had repair of the diaphragm and liver, which were lacerated, and a pleural toilet. A further patient had a rib resection for empyema at a later stage. All patients had intercostal drains inserted as initial treatment. There were no deaths, and those patients who underwent pulmonary resection recovered fully and rapidly after operation. Extensive pulmonary damage and lobar infarction occurred with 'tangential' high-velocity missile injuries to the thorax.
