The C. elegans genome encodes a single lamin protein (Ce-lamin), three LEM domain proteins (Ce-emerin, Ce-MAN1 and LEM-3) and a single BAF protein (Ce-BAF). Down-regulation of Ce-lamin causes embryonic lethality. Abnormalities include rapid changes in nuclear morphology during interphase, inability of cells to complete mitosis, abnormal condensation of chromatin, clustering of nuclear pore complexes (NPCs), and missing or abnormal germ cells. Ce-emerin and Ce-MAN1 are both embedded in the inner nuclear membrane, and both bind Ce-lamin and Ce-BAF; in addition, both require Ce-lamin for their localization. Mutations in human emerin cause X-linked recessive Emery-Dreifuss muscular dystrophy. In C. elegans, loss of Ce-emerin alone has no detectable phenotype, while loss of 90% Ce-MAN1 causes approximately 15% embryonic lethality. However in worms that lack Ce-emerin, a approximately 90% reduction of Ce-MAN1 is lethal to all embryos by the 100-cell stage, with a phenotype involving chromatin condensation and repeated cycles of anaphase chromosome bridging and cytokinesis. The anaphase-bridged chromatin retained a mitosis-specific phosphohistone H3 epitope, and failed to recruit detectable Ce-lamin or Ce-BAF. Down-regulation of Ce-BAF showed similar phenotypes. These findings suggest that lamin, LEM-domain proteins and BAF are part of a lamina network essential for chromatin organization and cell division, and that Ce-emerin and Ce-MAN1 share at least one and possibly multiple overlapping functions, which may be relevant to Emery-Dreifuss muscular dystrophy.
Why do political parties and politicians turn to litigation instead of using political channels in their efforts to affect public policies? Over the past 20 years, there has been a noticeable trend in which Israeli parties and politicians have turned to the courts for intervention in national and internal party affairs, government policies, and even parliamentary procedures. The authors argue that this phenomenon is tied to the growth of open competition within political parties on one hand and reforms in the legal doctrines controlling access to litigation on the other. This study indicates that politicians seek litigation even when their chances of winning in court are marginal. According to the findings, politicians exhibit a lower propensity to seek out-of-court settlements than other kinds of litigants. The results suggest that politicians resort to litigation to challenge majoritarian policies and also because they gain considerable media exposure (regardless of the actual outcome of litigation), enhancing their political stature. Keywords: judicial review; constitutional politics; legislative behavior: litigation
Reactive oxidants are associated with the pathogenesis of pulmonary diseases and affect various cell functions, from proliferation to apoptosis. We have shown that oxidants exert growth control on airway epithelial cells by modulating upstream receptor function. Additionally, hydrogen peroxide-mediated oxidative stress modulates ceramide levels to induce apoptosis in lung epithelium. Depletion of glutathione in lung epithelial cells results in ceramide accumulation, suggesting that ceramide elevation, coupled to oxidative stress, initiates apoptosis. While it is desirable to prevent cell death and tissue injury induced by oxidants in diseases such as asthma or acute respiratory distress syndrome, the opposite is sought in cancer. But oxidants may also activate growth factor receptors, enhancing cell proliferation and facilitating tumor promotion. Under oxidative stress, phosphorylation of the epidermal growth factor receptor (EGFR) is abrogated at tyrosine 1,045, the docking site for the ubiquitin ligase c-Cbl, rendering EGFR unable to recruit c-Cbl and be ubiquitylated and degraded. We thus proposed that this deficiency, which confers prolonged receptor signaling at the plasma membrane, links oxidative stress, EGFR, and tumorigenesis. Decoding the molecular interactions between oxidative stress and ceramide pathways and characterizing ubiquitylation control of receptor desensitization should provide new strategies for intervention in diverse pulmonary diseases and in diagnosing and eradicating cancer.
We demonstrate the physical principles for the construction of a nanometer-sized magnetoresistance device based on the Aharonov-Bohm effect [Phys. Rev. 115, 485 (1959)]. The proposed device is made of a short single-walled carbon nanotube (SWCNT) placed on a substrate and coupled to a tip/contacts. We consider conductance due to the motion of electrons along the circumference of the tube (as opposed to the motion parallel to its axis). We find that the circumference conductance is sensitive to magnetic fields threading the SWCNT due to the Aharonov-Bohm effect, and show that by retracting the tip/contacts, so that the coupling to the SWCNT is reduced, very high sensitivity to the threading magnetic field develops. This is due to the formation of a narrow resonance through which the tunneling current flows. Using a bias potential the resonance can be shifted to low magnetic fields, allowing the control of conductance with magnetic fields of the order of 1 T.
Efrat Farber, Avner Vengosh, Ittai Gavrieli, Amer Marie, Thomas D Bullen, Bernhard Mayer, Ran Holtzman, Michal Segal, and Uri Shavit. 2005. “Management scenarios for the Jordan River salinity crisis.” Applied geochemistry, 20, Pp. 2138–2153. URL
Betty Rojtman. 2005. “The Metaphor of Talion.” Partial Answers, Journal of Literature and the History of Ideas, The Hebrew University of Jerusalem, 3, 1, Pp. 1-18.
The present invention provides an in vitro system for compartmentalization of mol. or cellular libraries and provides methods for selection and isolation of desired mols. or cells from the libraries. The library includes a plurality of distinct mols. or cells encapsulated within a water-in-oil-in-water (w/o/w) emulsion. The emulation includes a continuous external aq. phase and a discontinuous dispersion of water-in-oil droplets. The internal aq. phase of a plurality of such droplets comprises a specific mol. or cell that is within the plurality of distinct mols. or cells of the library. According to a first aspect the present invention provides a gene library comprising a plurality of re-emulsified water-in-oil droplets, each droplet comprises an external water phase surrounding a central water-in-oil droplet, the internal water phase within each droplet comprises a genetic element, in vitro transcription-translation reaction system. To ensure that the genetic elements and gene products may not diffuse between primary water-in-oil droplets or between re-emulsified water-in-oil droplets, the-contents of each droplet must be isolated from the contents of the surrounding droplets, so that there is no or little exchange of gene products between the droplets over the timescale of the expt. The method of the present invention requires that there are only a limited no. of genetic elements per droplet. This ensures that the gene product of an individual genetic element will be isolated from other genetic elements. Finally, the formation and the compn. of the droplets must not interrupt with the function of the expression machinery of the genetic elements and the activity of the gene products. Prepn. and sorting of w/o/w emulsions by FACS (fluorescence-activated cell sorting) were demonstrated using lacZ reporter selection from a pool of lacZ gene mutants. Compartmentalization and detection of PON1 (serum paraoxonase) gene variants in single Escherichia coli cells were also demonstrated. [on SciFinder(R)]
We demonstrate the use of molecular recognition to control the spatial distribution of guest molecules within block copolymer films. Block copolymers bearing recognition units were combined with complementary and noncomplementary molecules, and the extent of segregation of these molecules into the different domain types within microphase-separated thin films was quantitatively analyzed using dynamic secondary ion mass spectrometry (SIMS). Complementarity between the guest molecules and the polymer functionalities proved to be a key factor and an efficient tool for directing the segregation preference of the molecules to the different domain types. The effect of segregation preference on the glass transition temperature was studied using differential scanning calorimetry (DSC), and the results corroborate the SIMS findings. In a complementary study, guests with tunable sizes (via dendron substituents) were used to control block copolymer morphology. Morphological characterization using transmission electron microscopy (TEM) and X-ray diffraction reveal that selectivity differences can be directly translated into the ability to obtain different morphologies from recognition unit-functionalized block copolymer scaffolds.
The interaction between the Eurasian pastoral nomads - most famously the Mongols and Turks - and the surrounding sedentary societies is a major theme in world history. Nomads were not only raiders and conquerors, but also transmitted commodities, ideas, technologies and other cultural items. At the same time, their sedentary neighbours affected the nomads, in such aspects as religion, technology, and political culture. The essays in this volume use a broad comparative approach that highlights the multifarious nature of nomadic society and its changing relations with the sedentary world in the vicinity of China, Russia and the Middle East, from antiquity into the contemporary world.
Hebrew words are composed of two interwoven morphemes: a three-consonantal root and a word-pattern (a nominal or a verbal pattern). Previous research has revealed that a parafoveal preview of a word derived from the same root morpheme as the foveal target word facilitated first-pass reading (as indexed by first fixation duration and gaze duration). In the current study we extended our research on parafoveal preview effects to other derivational morphemes in Hebrew and also examined whether context has an influence on these early morphological effects. We found that a parafoveal preview which had a common verbal pattern with a target word facilitated processing, but a preview with a common nominal pattern did not. These results are similar to previous results obtained using the masked priming paradigm with single words, and suggest that masked priming and parafoveal preview tap similar cognitive processes in word recognition. Furthermore, a preview of a verbal form (that was syntactica
OBJECT: The authors hypothesized that spinal fusion can be achieved and monitored by using cell-mediated gene therapy. Mesenchymal stem cells (MSCs) genetically engineered to express recombinant human bone morphogenetic protein-2 (rhBMP-2) conditionally, were implanted into the paraspinal muscles of mice to establish spinal fusion. The goal was to demonstrate an MSC-based gene therapy platform in which controlled gene expression is used to obtain spinal fusion in a murine model. METHODS: Mesenchymal stem cells expressing the rhBMP-2 gene were injected into the paravertebral muscle in mice. Bone formation in the paraspinal region was longitudinally followed by performing micro-computerized tomography scanning, histological studies, and an analysis of osteocalcin expression to demonstrate the presence of engrafted engineered MSCs. The minimal period of rhBMP-2 expression by the engineered MSCs required to induce fusion was determined. The results of this study demonstrate that genetically engineered MSCs induce bone formation in areas adjacent to and touching the posterior elements of the spine. This newly formed bone fuses the spine, as demonstrated by radiological and histological studies. The authors demonstrate that injected cells induce active osteogenesis at the site of implantation for up to 4 weeks postinjection. They found that a 7-day induction of rhBMP-2 expression in genetically engineered MSCs was sufficient to form new bone tissue, although the quantity of this bone increased as longer expression periods were implemented. CONCLUSIONS: After their injection genetically engineered MSCs can efficiently form new bone in the paraspinal muscle of the mouse to obtain spinal fusion. The extent and quantity of this newly formed bone can be monitored by controlling the duration of rhBMP-2 gene expression.
2005. “Nabokov's Worldview.” In The Cambridge Companion to Nabokov, Pp. 232-47. Ed. Julian Connolly. Cambridge: Cambridge University Press.
