Laser Doppler velocimetry with polarization-bistable VCSELs

We present a rate equation model of a single mode vertical-cavity surface-emitting laser (VCSEL) with two states of linear polarization, subject to Doppler-shifted optical feedback. Recent experimental work has shown that the polarization bistability often observed in VCSELs can be exploited to enhance the responsivity of these semiconductor lasers in speed-sensing applications. We review these experimental results briefly and use the rate equation model to explain the increased signal-to-noise ratio.     

Making the ‘MOST’ out of RFID technology: a research agenda for the study of the adoption,usage and impact of RFID

Radio frequency identification (RFID) technology dramatically increases the ability of the organization to acquire a vast array of data about the location and properties of any entity that can be physically tagged and wirelessly scanned within certain technical limitations. RFID can be applied to a variety of tasks, structures, work systems and contexts along the value chain, including business-to-business logistics, internal operations, business-to-consumer marketing, and after-sales service applications. As industry adoption of RFID increases there is an emerging interest by academic researchers to engage in scholarly investigation to understand how RFID relates to mobility, organizational and systems technologies (MOST). In this paper, we explore RFID and propose a research agenda to address a series of broad research questions related to how RFID technology: (1) is developed, adopted, and implemented by organizations; (2) is used, supported, and evolved within organizations and alliances; and (3) impacts individuals, business processes, organizations, and markets. As with many technological innovations, as the technical problems associated with implementing and using RFID are addressed and resolved, the managerial and organizational issues will emerge as critical areas for IS research.

Crystalloids vs. colloids in fluid resuscitation: a systematic review

OBJECTIVE: To systematically review the effects of isotonic crystalloids compared with colloids in fluid resuscitation. DATA SOURCES: Computerized bibliographic search of published research and citation review of relevant articles. STUDY SELECTION: All randomized clinical trials of adult patients requiring fluid resuscitation comparing isotonic crystalloids vs. colloids were included. Pulmonary edema, mortality, and length of stay were evaluated. Independent review of 105 articles identified 17 relevant primary studies of 814 patients. Weighted c about article inclusion was high (0.76). DATA EXTRACTION: Data on population, interventions, outcomes, and methodologic quality of the studies were obtained by duplicate independent review with differences resolved by consensus. Weighted ic on the validity assessment was moderate (0.54). DATA SYNTHESIS: No difference was observed overall between crystalloid and colloid resuscitation with respect to mortality and pulmonary edema; however, the power of the aggregated data was insufficient to detect small but potentially clinically important differences. Subgroup analysis suggested a statistically significant difference in mortality in trauma in favor of crystalloid resuscitation (relative risk 0.39, 95% confidence intervals: 0.17 to 0.89). Several methodologic issues are noteworthy regarding the primary studies, including lack of blinding (except in three studies). The type, dose, and duration of fluid administration and outcomes measured were different across these trials. CONCLUSIONS: Overall, there is no apparent difference in pulmonary edema, mortality, or length of stay between isotonic crystalloid and colloid resuscitation. Crystalloid resuscitation is associated with a lower mortality in trauma patients. Methodologic limitations preclude any evidence-based clinical recommendations. Larger well-designed randomized trials are needed to achieve sufficient power to detect potentially small differences in treatment effects if they truly exist.     

Molecular Dynamics Simulations of Interfacial Sliding in Carbon-Nanotube/Diamond Nanocomposites

Molecular dynamics simulations are reported for the pullout force and interfacial friction of single- and multiwall carbon nanotubes (CNT) with interwall sp ³ bonds embedded in a diamond matrix. The van der Waals interaction and sp ³ bonding are shown to have a strong influence on friction at the nano-scale interface. Multiwall CNTs (MWCNTs) with interwall sp ³ bonding have friction stresses two times larger than either single-wall CNTs (SWCNTs) or double-wall CNTs with no sp ³ bonding for the same nominal conditions. The friction stress follows the form τ=τ_o+μ p , where μ is a friction coefficient and p the radial pressure. The measured p compares reasonably well to estimates based on the van der Waals interaction, and we find that the MWCNTs with interwall bonding have a larger friction coefficient μ. The origin of the higher friction is postulated to arise from increased interface roughness associated with the interwall bonding. Because higher interface friction is beneficial to composite strength and toughness, nanoceramic composites composed of MWCNTs could have improved properties as compared with SWCNTs for the same fundamental interface chemistry and composite structure.     

Intra-renal and subcellular distribution of the human chloride channel, CLC-5, reveals a pathophysiological basis for Dent's disease

Dent's disease, which is a renal tubular disorder characterized by low molecular weight proteinuria, hypercalciuria and nephrolithiasis, is associated with inactivating mutations of the X-linked chloride channel, CLC-5. However, the manner in which a functional loss of CLC-5 leads to such diverse renal abnormalities remains to be defined. In order to elucidate this, we performed studies to determine the segmental expression of CLC-5 in the human kidney and to define its intracellular distribution. We raised and characterized antisera against human CLC-5, and identified by immunoblotting an 83 kDa band corresponding to CLC-5 in human kidney cortex and medulla. Immunohistochemistry revealed CLC-5 expression in the epithelial cells lining the proximal tubules and the thick ascending limbs of Henle's loop, and in intercalated cells of the collecting ducts. Studies of subcellular human kidney fractions established that CLC-5 distribution was associated best with that of Rab4, which is a marker of recycling early endosomes. In addition, confocal microscopy studies using the proximal tubular cell model of opossum kidney cells, which endogenously expressed CLC-5, revealed that CLC-5 co-localized with the albumin-containing endocytic vesicles that form part of the receptor-mediated endocytic pathway. Thus, CLC-5 is expressed at multiple sites in the human nephron and is likely to have a role in the receptor-mediated endocytic pathway. Furthermore, the functional loss of CLC-5 in the proximal tubules and the thick ascending limbs provides an explanation for the occurrences of low molecular weight proteinuria and hypercalciuria, respectively. These results help to elucidate further the patho-physiological basis of the renal tubular defects of Dent's disease.     

Feminine desire in the age of satellite television

Television texts around the world increasingly feature female characters who resist or reformulate conventional gender roles. This trend seems to defy expectations that the concentration of media ownership leads to a conservative, homogeneous flow of popular imagery. Such an apparent contradiction can be explained by close analysis of the strategies, operations, and discourse of culture industries in the neo-network era of satellite and cable media. This era is paradoxically characterized by corporate conglomeration and by strategies of flexibility and decentralization. Consequently, media firms actually benefit for the transnational circulation of multiple and alternative representations of feminine desire. Although this does not necessarily democratize media, in most societies it significantly expands the range of feminine imagery available in popular culture.     

KinMutBase, a database of human disease-causing protein kinase mutations

KinMutBase (http://www.uta.fi/laitokset/imt/KinMut Base.html) is a registry of mutations in human protein kinases related to disorders. Kinases are essential cellular signalling molecules, in which mutations can lead into diseases including, e.g., immunodeficiencies, cancers and endocrine disorders. The first release of KinMutBase contains information for nine protein tyrosine kinases. There are altogether 170 entries representing 273 families and 403 patients. Mutations appear both in conserved hallmark residues of the kinases as well as in non-homologous sites. The KinMutBase WWW pages provide plenty of information, namely mutation statistics and display, clickable sequences with mutations, restriction enzyme patterns and online submission.