4,022 research outputs found
TRADE AND FOREIGN DIRECT INVESTMENT MANAGEMENT STRATEGIES FOR U.S. PROCESSED FOOD FIRMS IN CHINA
This research examines the relationship between U.S. foreign direct investment (FDI) and exports of processed foods to China and identifies management strategies to enhance U.S. competitiveness. Two-stage least-squares empirical econometric results from a simultaneous equation system indicate that there exists a strong complementary relationship between U.S exports and FDI into China. Therefore, the appropriate managerial strategy to access Chinese processed foods markets is to increase overall business activity, both FDI and exports into China.Agribusiness, International Relations/Trade,
Oral history interview with Kenneth S. Greenberg (SOH-049)
Kenneth Greenberg, distinguished professor of history and former dean of Suffolk University’s College of Arts & Sciences, discusses his life from childhood in the 1950s to college and graduate work in the 1960s and 1970s. He describes his first teaching opportunity at the Harriett Beecher-Stowe Middle School in New York City and how it influenced his teaching style. Greenberg also goes into detail about his scholarship, service, and leadership activities within New York, Wisconsin, and Boston. He explains the background and motivations behind his books, essays, and documentary film surrounding the stories of Nat Turner. Related to Suffolk University, he reflects on the school’s history, his tenure as dean of the College of Arts & Sciences, and as chair of the history department. The interview ends with brief a discussion of his recent return to the faculty and his ongoing scholarly research and writing.https://dc.suffolk.edu/soh/1044/thumbnail.jp
Calcium Influx: Beyond ‘Current’ Biology
A novel, cell-surface protein essential for Ca2+ release-activated Ca2+ (CRAC) channel function has been identified through independent genome-wide screens. This huge advance will enable molecular dissection of the CRAC channel complex, moving the field beyond Icrac signature to structure
IP3 Receptor Activity Is Differentially Regulated in Endoplasmic Reticulum Subdomains during Oocyte Maturation
SummaryFertilization competency results from hormone-induced remodeling of oocytes into eggs. The signaling pathways that effect this change exemplify bistability, where brief hormone exposure irrevocably switches cell fate. In Xenopus, changes in Ca2+ signaling epitomize such remodeling: The reversible Ca2+ signaling phenotype of oocytes rapidly adapts to support irreversible propagation of the fertilization Ca2+ wave. Here, we simultaneously resolved IP3 receptor (IP3R) activity with endoplasmic reticulum (ER) structure to optically dissect the functional architecture of the Ca2+ release apparatus underpinning this reorganization. We show that changes in Ca2+ signaling correlate with IP3R redistribution from specialized ER substructures called annulate lamellae (AL), where Ca2+ release activity is attenuated, into IP3R-replete patches in the cortical ER of eggs that support the fertilization Ca2+ wave. These data show: first, that IP3R sensitivity is regulated with high spatial acuity even between contiguous ER regions; and second, that drastic reorganization of Ca2+ signaling dynamics can be driven by subcellular redistribution in the absence of changes in channel number or molecular or familial Ca2+ channel diversity. Finally, these results define a novel role for AL in Ca2+ signaling. Because AL are prevalent in other scenarios of rapid cell division, further studies of their impact on Ca2+ signaling are warranted
Timing in Cellular Ca2+ Signaling
SummaryCalcium (Ca2+) signals are generated across a broad time range. Kinetic considerations impact how information is processed to encode and decode Ca2+ signals, the choreography of responses that ensure specific and efficient signaling and the overall temporal amplification such that ephemeral Ca2+ signals have lasting physiological value. The reciprocal importance of timing for Ca2+ signaling, and Ca2+ signaling for timing is exemplified by the altered kinetic profiles of Ca2+ signals in certain diseases and the likely role of basal Ca2+ fluctuations in the perception of time itself
Cooperative activation of IP3 receptors by sequential binding of IP3 and Ca2+ safeguards against spontaneous activity
AbstractBackground: Ca2+ waves allow effective delivery of intracellular Ca2+ signals to cytosolic targets. Propagation of these regenerative Ca2+ signals probably results from the activation of intracellular Ca2+ channels by the increase in cytosolic [Ca2+] that follows the opening of these channels. Such positive feedback is potentially explosive. Mechanisms that limit the spontaneous opening of intracellular Ca2+ channels are therefore likely to have evolved in parallel with the mechanism of Ca2+-induced Ca2+ release.Results: Maximal rates of 45Ca2+ efflux from permeabilised hepatocytes superfused with medium in which the [Ca2+] was clamped were cooperatively stimulated by inositol 1,4,5-trisphosphate (IP3). A minimal interval of ∼400 msec between IP3 addition and the peak rate of Ca2+ mobilisation indicate that channel opening does not immediately follow binding of IP3. Although the absolute latency of Ca2+ release was unaffected by further increasing the IP3 concentration, it was reduced by increased [Ca2+].Conclusions: We propose that the closed conformation of the IP3 receptor is very stable and therefore minimally susceptible to spontaneous activation; at least three (probably four) IP3 molecules may be required to provide enough binding energy to drive the receptor into a stable open conformation. We suggest that a further defence from noise is provided by an extreme form of coincidence detection. Binding of IP3 to each of its four receptor subunits unmasks a site to which Ca2+ must bind before the channel can open. As IP3 binding may also initiate receptor inactivation, there may be only a narrow temporal window during which each receptor subunit must bind both of its agonists if the channel is to open rather than inactivate
Planning a Family:priorities and concerns in rural Tanzanmia
A fertility survey using qualitative and quantitative techniques described a high fertility setting (TFR 5.8) in southern Tanzania where family planning use was 16%. Current use was influenced by rising parity, educational level, age of last born child, breastfeeding status, a\ud
preference for longer than the mean birth interval (32 months), not being related to the household head, and living in a house with a tin roof. Three principal concerns amongst women were outlined from the findings. First, that there is a large unmet need for family planning services in the area particularly among teenagers for whom it is associated with induced abortion. Second, that family planning is being used predominantly for spacing but fears\ud
associated with it often curtail effective use. Third, that service provision is perceived to be lacking in two main areas — regularity of supply, and addressing rumours and fears associated with family planning. Reproductive health interventions in the area should ultimately be more\ud
widespread and, in particular, abortion is highlighted as an urgent issue for further research.\ud
The potential for a fast and positive impact is high, given the simplicity of the perceived needs of\ud
women from this study. (Afr J Reprod Health 2004; 8[2]:111-123)\u
Free surface cusp formation as a failure mechanism for hard disk drives with fluid dynamic bearings
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