Electron and Hole Dynamics of InAs∕GaAsInAs∕GaAs Quantum Dot Semiconductor Optical Amplifiers

Single-color and two-color pump-probe measurements are used to analyze carrier dynamics in InAs∕GaAs quantum dot amplifiers. The study reveals that hole recovery and intradot electron relaxation occur on a picosecond time scale, while the electron capture time is on the order of 10ps. A longer time scale of hundreds of picoseconds is associated with carrier recovery in the wetting layer, similar to that observed in quantum well semiconductor amplifiers

Raman Spectroscopy Predicts the Link between Claw Keratin and Bone Collagen Structure in a Rodent Model of Oestrogen Deficiency

Osteoporosis is a common disease characterized by reduced bone mass and an increased risk of fragility fractures. Low bone mineral density is known to significantly increase the risk of osteoporotic fractures; however, the majority of non-traumatic fractures occur in individuals with a bone mineral density too high to be classified as osteoporotic. Therefore, there is an urgent need to investigate aspects of bone health, other than bone mass, that can predict the risk of fracture. Here, we successfully predicted association between bone collagen and nail keratin in relation to bone loss due to oestrogen deficiency using Raman spectroscopy. Raman signal signature successfully discriminated between ovariectomised rats and their sham controls with a high degree of accuracy for the bone (sensitivity 89%, specificity 91%) and claw tissue (sensitivity 89%, specificity 82%). When tested in an independent set of claw samples the classifier gave 92% sensitivity and 85% specificity. Comparison of the spectral changes occurring in the bone tissue with the changes occurring in the keratin showed a number of common features that could be attributed to common changes in the structure of bone collagen and claw keratin. This study established that systemic oestrogen deficiency mediates parallel structural changes in both the claw (primarily keratin) and bone proteins (primarily collagen). This strengthens the hypothesis that nail keratin can act as a surrogate marker of bone protein status where systemic processes induce changes

Raman Spectroscopy as a Predictive Tool for Monitoring Osteoporosis Therapy in a Rat Model of Postmenopausal Osteoporosis

Pharmacological therapy of osteoporosis reduces bone loss and risk of fracture in patients. Modulation of bone mineral density cannot explain all effects. Other aspects of bone quality affecting fragility and ways to monitor them need to be better understood. Keratinous tissue acts as surrogate marker for bone protein deterioration caused by oestrogen deficiency in rats. Ovariectomised rats were treated with alendronate (ALN), parathyroid hormone (PTH) or estrogen (E2). MicroCT assessed macro structural changes. Raman spectroscopy assessed biochemical changes. Micro CT confirmed that all treatments prevented ovariectomy-induced macro structural bone loss in rats. PTH induced macro structural changes unrelated to ovariectomy. Raman analysis revealed ALN and PTH partially protect against molecular level changes to bone collagen (80% protection) and mineral (50% protection) phases. E2 failed to prevent biochemical change. The treatments induced alterations unassociated with the ovariectomy; increased beta sheet with E2, globular alpha helices with PTH and fibrous alpha helices with both ALN and PTH. ALN is closest to maintaining physiological status of the animals, while PTH (comparable protective effect) induces side effects. E2 is unable to prevent molecular level changes associated with ovariectomy. Raman spectroscopy can act as predictive tool for monitoring pharmacological therapy of osteoporosis in rodents. Keratinous tissue is a useful surrogate marker for the protein related impact of these therapies. The results demonstrate utility of surrogates where a clear systemic causation connects the surrogate to the target tissue. It demonstrates the need to assess broader biomolecular impact of interventions to examine side effects. [Figure not available: see full text.]

A Cross-National Comparative Study of Work/Family Demands and Resources

This article presents phase 2 of the Collaborative International Study of Managerial Stress (CISMS2) with the objective of studying cross culturally/cross-nationally potential causes and consequences of work-family conflict. This collaborative international study contributes to the existing literature on work and family by adding a different theoretical perspective (interaction between demands and resources, and resource loss), following the thinking of Grandey and Cropanzano, focusing on a specific collective (managers), and testing both universalistic and cross cultural hypotheses in a large sample taken from 25 countries in different continents, representing different socio-cultural contexts. It will explore cross cultural/cross-national issues in a comparative sense, looking at how family and societal differences relate to work-family conflict. More specifically we expect that individualism/collectivism and the presence of family-supportive government policies will moderate relationships between demands, resources and work-family conflict

Family-Responsive Interventions, Perceived Organizational and Supervisor Support, Work-Family Conflict and Psychological Strain

This study examined organizational family-responsive policies, perceptions of the organization as family supportive, and supervisor support as issues that may be salient to the experience of conflict between paid employment (work) and family roles. Data were collected from 355 managerial personnel in New Zealand. Although work-family conflict and psychological strain were strongly linked, the availability of organizational policies had no significant association with levels of conflict or strain, whereas policy usage was related only to work-to-family interference and not to family-to-work interference. On the other hand, perceptions of the organization as family supportive and supervisor support for work-family balance displayed significant relationships with key variables, highlighting the importance of these variables for interventions designed to ameliorate the negative impact of work-family conflict on managerial well-being. Implications for the effective implementation of family-responsive interventions are discussed

Work Resources, Work-to-Family Conflict, and its Consequences: A Taiwanese-British Cross-Cultural Comparison

The aim of this research was to explore relations between work resources (supervisory support and organizational family supportive values), work-to-family conflict (WFC), and work- and nonwork-related outcomes in a cross-cultural comparative context involving Taiwanese and British employees. The authors surveyed 264 Taiwanese employees and 137 British employees using structured questionnaires. For both Taiwanese and British employees, work resources were found to be negatively related to WFC but positively related to work satisfaction. WFC was negatively related to work and/or family satisfaction. More important, the authors found that nation moderated the relationship between supervisory support and WFC: Supervisory support had a stronger protective effect for Taiwanese than British employees. It is thus recommended that, in addition to introducing various family-friendly policies, companies should be more active in cultivating a family-supportive organizational culture and mobilizing managers to act as supporters of family life, especially in societies sanctioning collectivistic values and large power distance. (PsycINFO Database Record (c) 2016 APA, all rights reserved