פרסומים

Many cell-cell adhesive events are mediated by the dimerization of cadherin proteins presented on apposing cell surfaces. Cadherin-mediated processes play a central role in the sorting of cells into separate tissues in vivo, but in vitro assays aimed at mimicking this behavior have yielded inconclusive results. In some cases, cells that express different cadherins exhibit homotypic cell sorting, forming separate cell aggregates, whereas in other cases, intermixed aggregates are formed. A third pattern is observed for mixtures of cells expressing either N- or E-cadherin, which form distinct homotypic aggregates that adhere to one another through a heterotypic interface. The molecular basis of cadherin-mediated cell patterning phenomena is poorly understood, in part because the relationship between cellular adhesive specificity and intermolecular binding free energies has not been established. To clarify this issue, we have measured the dimerization affinities of N-cadherin and E-cadherin. These proteins are similar in sequence and structure, yet are able to mediate homotypic cell patterning behavior in a variety of tissues. N-cadherin is found to form homodimers with higher affinity than does E-cadherin and, unexpectedly, the N/E-cadherin heterophilic binding affinity is intermediate in strength between the 2 homophilic affinities. We can account for observed cell aggregation behaviors by using a theoretical framework that establishes a connection between molecular affinities and cell-cell adhesive specificity. Our results illustrate how graded differences between different homophilic and heterophilic cadherin dimerizaton affinities can result in homotypic cell patterning and, more generally, show how proteins that are closely related can, nevertheless, be responsible for highly specific cellular adhesive behavior.

The book based on this PhD thesis titled "The Golden Age of the Lithuanian Yeshivas" is published in 2022 by Indiana University Press. 

We present a qualitative study of battered women, which examined their experiences while staying at shelters. In-depth, semi-structured interviews were conducted with 18 battered women staying at shelters. The interviews elicited four main themes: the women's perceptions of the shelter; the woman's perceptions of herself and her life experiences; the woman's perceptions of her relations with other battered women at the shelter; and the woman's perceptions of her relations with the staff of the shelter. The paper concludes with a discussion of the limitations of the study, implications for future research, implications for theory development, and implications for therapy and intervention with the problem of wife battering.

Two salient features of modern economic growth are the rise in aggregate savings rates and the steady increase in life expectancy. This paper links these processes, showing that under certain conditions economic theory supports the hypothesis that increased longevity leads to higher aggregate savings in steady state. The analysis is based on a lifecycle model with uncertain longevity in which individuals choose an optimum consumption path and a retirement age. Conditions on the age-specific pattern of improvements in survival probabilities are shown to ensure that individual savings rise with longevity and that aggregation preserves this result. Population theory (Coale (1972)) is used to link the steady-state age density function and the population's growth rate to individuals' survival probabilities. The importance of a competitive annuity market in avoiding unintended bequests is underscored.

We investigated the effects of low power laser irradiation on the proliferation of retinal pigment epithelial (RPE) cells. Adult human RPE cells were artificially pigmented by preincubation with sepia melanin, and exposed to a single sublethal laser pulse (590 nm, 1 μs, <200 mJ/cm2). DNA synthesis, cell number, and growth factor activity in irradiated RPE cells were subsequently monitored. The effect of sublethal laser irradiation on the "wound" healing response of an RPE monolayer in an in vitro scratch assay was also investigated. Single pulsed laser irradiation increased DNA synthesis in pigmented RPE cells measured 6 h post-treatment. In the scratch assay, laser irradiation increased the rates of cell proliferation and wound closure. Conditioned medium, collected 48 h following laser treatment, increased cell proliferation of unirradiated cells. Irradiation increased RPE cell secretion of platelet-derived growth factor (PDGF)-B chain, and increased mRNA levels of several growth factors and their receptors, including PDGF, transforming growth factor-β1, basic fibroblast growth factor, epidermal growth factor, insulin-like growth factor, as well as heat shock proteins. This demonstrates, for the first time, that low power single pulsed laser irradiation stimulates the proliferation of RPE cells, and upregulates growth factors that are mitogenic for RPE cells. © 2008 Biomedical Engineering Society.

Lysyl oxidase-like enzymes (LOXL) are expressed in various cancers. We analyzed the expression of LOXL2, LOXL3, and LOXL4 in cancers involving the serosal cavities-breast carcinoma, ovarian carcinoma, and malignant mesothelioma using reverse-transcriptase polymerase chain reaction. We discovered two new alternative splice variants of LOXL4. The spliced segments were exon 9 (splice variant 1) or both exons 8 and 9 (splice variant 2). In ovarian carcinoma, splice variant 1 was significantly elevated in effusions compared to solid lesions (p < 0.001). Splice variant 2 appeared only in effusions. In breast carcinoma, LOXL4 was expressed only in the effusion samples. In malignant mesothelioma, LOXL4 and its splice variants were expressed at all sites. Breast carcinoma effusions showed significantly higher LOXL2 (p = 0.003) and lower LOXL3 (p < 0.001) expression compared to primary carcinomas. Our data show differences in LOXL messenger RNA expression as a function of anatomic site and tumor type in cancers affecting the serosal cavities.

Managerial reasoning about performance targets and subsequent actions can be influenced by whether they focus their attention on expectations of future events or internal efforts to meet organizational goals. This study explores how managers think about expectations and aspirations by examining the semantic similarities and differences between these concepts for practicing managers and economists, the results suggesting subtle differences in how economists and managers reason about aspirations and expectations. For economists, the concept of expectations played a major role and influenced their subsequent thinking about goals and actions while managers conceptually separated factors that were controllable and uncontrollable, the concept of expectation not playing the central role for them. Implications for descriptive and prescriptive models of decision- making are discussed.

We present a detailed study on the possibility of manipulating quantum information encoded in the 'radial' modes of arrays of trapped ions (i.e. in the ions' oscillations orthogonal to the trap's main axis). In such systems, because of the tightness of transverse confinement, the radial modes pertaining to different ions can be addressed individually. In the first part of the paper we show that, if local control of the radial trapping frequencies is available, any linear optical and squeezing operation on the locally defined modes—on single as well as on many modes—can be reproduced by manipulating the frequencies. Then, we proceed to describe schemes apt to generate unprecedented degrees of bipartite and multipartite continuous variable (CV) entanglement under realistic noisy working conditions and even restricting only to a global control of the trapping frequencies. Furthermore, we consider the transmission of the quantum information encoded in the radial modes along the array of ions, and show it to be possible to a remarkable degree of accuracy, for both finite-dimensional and CV quantum states. Finally, as an application, we show that the states which can be generated in this setting allow for the violation of multipartite non-locality tests, by feasible displaced parity measurements. Such a demonstration would be a first test of quantum non-locality for 'massive' degrees of freedom (i.e. for degrees of freedom describing the motion of massive particles).