The Problems and Challenges of Working in International Settings: A Special Topic Issue of the Cornell Quarterly

[Excerpt] While international issues have always been part of the content published in the Cornell Hotel and Restaurant Administration Quarterly, this is the first issue devoted exclusively to multinational content. In part, this issue is a signal of the importance of and need for international research in the hospitality domain. The breadth of topics and approaches also highlights the diversity of the content necessary to contribute to practice. This issue begins a periodic series that examines some of the challenges and opportunities that face hoteliers and restaurateurs as the travel business becomes increasingly internationally focused. Greater understanding of the critical elements that must be considered by executives accepting assignments in other lands can help to ensure success and avoid critical errors that can ruin promising careers and hurt the parent companies. Some of the most essential considerations are outlined below; other thoughts will arise from readers and can be the subject of articles in future issues of the Cornell Quarterly

An Emerging Pulmonary Haemorrhagic Syndrome in Dogs: Similar to the Human Leptospiral Pulmonary Haemorrhagic Syndrome?

Severe pulmonary haemorrhage is a rare necropsy finding in dogs but the leptospiral pulmonary haemorrhagic syndrome (LPHS) is a well recognized disease in humans. Here we report a pulmonary haemorrhagic syndrome in dogs that closely resembles the human disease. All 15 dogs had massive, pulmonary haemorrhage affecting all lung lobes while haemorrhage in other organs was minimal. Histologically, pulmonary lesions were characterized by acute, alveolar haemorrhage without identifiable vascular lesions. Seven dogs had mild alveolar wall necrosis with hyaline membranes and minimal intraalveolar fibrin. In addition, eight dogs had acute renal tubular necrosis. Six dogs had a clinical diagnosis of leptospirosis based on renal and hepatic failure, positive microscopic agglutination test (MAT) and/or positive blood/urine Leptospira-specific PCR. Leptospira could not be cultured post mortem from the lungs or kidneys. However, Leptospira-specific PCR was positive in lung, liver or kidneys of three dogs. In summary, a novel pulmonary haemorrhagic syndrome was identified in dogs but the mechanism of the massive pulmonary erythrocyte extravasation remains elusive. The lack of a consistent post mortem identification of Leptospira spp. in dogs with pulmonary haemorrhage raise questions as to whether additional factors besides Leptospira may cause this as yet unrecognized entity in dogs

How Dilute are Dilute Solutions in Extensional Flows?

Submitted to J. Rheol.We investigate the concentration-dependence of the characteristic relaxation time of dilute polymer solutions in transient uniaxial elongational flow. A series of monodisperse polystyrene solutions of five different molecular weights (1.8×10^6 ≤ M ≤ 8.3×10^6 g/mol) with concentrations spanning five orders of magnitude were dissolved in two solvents of differing solvent quality (diethyl phthalate and oligomeric styrene). Optical measurements of the rate of filament thinning and the time to break-up in each fluid are used to determine the characteristic relaxation time. A lower sensitivity limit for the measurements was determined experimentally and confirmed by comparison to numerical calculations. Above this sensitivity limit we show that the effective relaxation time of moderately dilute solutions (0.01 ≤ c/c* ≤ 1) in transient extensional flow rises substantially above the fitted value of the relaxation time extracted from small amplitude oscillatory shear flow and above the Zimm relaxation time computed from kinetic theory and intrinsic viscosity measurements. This effective relaxation time exhibits a power-law scaling with the reduced concentration (c/c*) and the magnitude of the exponent varies with the thermodynamic quality of the solvent. This scaling appears to be roughly consistent to that predicted when the dynamics of the partially elongated and overlapping polymer chains are described within the framework of blob theories for semi-dilute solutions.NASA Microgravity Fluid Dynamic

‘Gobbling drops’: the jetting–dripping transition in flows of polymer solutions

This paper discusses the breakup of capillary jets of dilute polymer solutions and the dynamics associated with the transition from dripping to jetting. High-speed digital video imaging reveals a new scenario of transition and breakup via periodic growth and detachment of large terminal drops. The underlying mechanism is discussed and a basic theory for the mechanism of breakup is also presented. The dynamics of the terminal drop growth and trajectory prove to be governed primarily by mass and momentum balances involving capillary, gravity and inertial forces, whilst the drop detachment event is controlled by the kinetics of the thinning process in the viscoelastic ligaments that connect the drops. This thinning process of the ligaments that are subjected to a constant axial force is driven by surface tension and resisted by the viscoelasticity of the dissolved polymeric molecules. Analysis of this transition provides a new experimental method to probe the rheological properties of solutions when minute concentrations of macromolecules have been added.Schlumberger FoundationMIT Class of 1951 Fellowship Fun

Concept Maps as Tools for Assessing Students\u27 Epistemologies of Science

The use of concept maps as instruments for assessing preservice teachers’ epistemologies of science (their ideas of the nature of scientific knowledge) was evaluated in this study. Twenty-three preservice elementary teachers’ responses to the Views of the Nature Of Science (VNOS) questionnaire were compared to concept maps created in response to the general probe, “What is science?” While VNOS responses allowed a richer analysis of the content and quality of the participants’ epistemologies, the concept maps provided information about structural changes of participants’ epistemologies as well as how those epistemologies relate to their overall conceptions of science as a field of study. Both instruments also revealed important connections between NOS tenets, which were more numerous on the concept maps but more informative on the VNOS, and between NOS tenets and pedagogical issues. Implications for assessment of students’ epistemologies of science in classrooms are discussed

Cross-species oncogenomics offers insight into human muscle-invasive bladder cancer

Background In humans, muscle-invasive bladder cancer (MIBC) is highly aggressive and associated with a poor prognosis. With a high mutation load and large number of altered genes, strategies to delineate key driver events are necessary. Dogs and cats develop urothelial carcinoma (UC) with histological and clinical similarities to human MIBC. Cattle that graze on bracken fern also develop UC, associated with exposure to the carcinogen ptaquiloside. These species may represent relevant animal models of spontaneous and carcinogen-induced UC that can provide insight into human MIBC. Results Whole-exome sequencing of domestic canine (n = 87) and feline (n = 23) UC, and comparative analysis with human MIBC reveals a lower mutation rate in animal cases and the absence of APOBEC mutational signatures. A convergence of driver genes (ARID1A, KDM6A, TP53, FAT1, and NRAS) is discovered, along with common focally amplified and deleted genes involved in regulation of the cell cycle and chromatin remodelling. We identify mismatch repair deficiency in a subset of canine and feline UCs with biallelic inactivation of MSH2. Bovine UC (n = 8) is distinctly different; we identify novel mutational signatures which are recapitulated in vitro in human urinary bladder UC cells treated with bracken fern extracts or purified ptaquiloside. Conclusion Canine and feline urinary bladder UC represent relevant models of MIBC in humans, and cross-species analysis can identify evolutionarily conserved driver genes. We characterize mutational signatures in bovine UC associated with bracken fern and ptaquiloside exposure, a human-linked cancer exposure. Our work demonstrates the relevance of cross-species comparative analysis in understanding both human and animal UC

Ubiquitous LEA29Y Expression Blocks T Cell Co-Stimulation but Permits Sexual Reproduction in Genetically Modified Pigs

We have successfully established and characterized a genetically modified pig line with ubiquitous expression of LEA29Y, a human CTLA4-Ig derivate. LEA29Y binds human B7.1/CD80 and B7.2/CD86 with high affinity and is thus a potent inhibitor of T cell co-stimulation via this pathway. We have characterized the expression pattern and the biological function of the transgene as well as its impact on the porcine immune system and have evaluated the potential of these transgenic pigs to propagate via assisted breeding methods. The analysis of LEA29Y expression in serum and multiple organs of CAG-LEA transgenic pigs revealed that these animals produce a biologically active transgenic product at a considerable level. They present with an immune system affected by transgene expression, but can be maintained until sexual maturity and propagated by assisted reproduction techniques. Based on previous experience with pancreatic islets expressing LEA29Y, tissues from CAG-LEA29Y transgenic pigs should be protected against rejection by human T cells. Furthermore, their immune-compromised phenotype makes CAG-LEA29Y transgenic pigs an interesting large animal model for testing human cell therapies and will provide an important tool for further clarifying the LEA29Y mode of action