cssi/SciSciGPT-SciSciNet huggingface dataset:
Race, Gender, and Residency: a Survey of Trainee Experience.

Abstract Background Racial minority and female trainees undergo residency attrition at significantly higher rates than their counterparts. We hypothesize that racial minority, and female trainees will report significantly different training experiences from non-minority and male trainees, respectively. Further, we hypothesize that thoughts of withdrawal and summative description of residency experience will be significantly impacted by access to mentorship and feelings of isolation. Methods A link to a Qualtrics survey was sent to program officials from all residency programs registered with the ACGME to be distributed to their trainees. It was live from June through August of 2019 and collected data about respondent's demographics and posed questions addressing some of the key elements of the residency experience. Results Minority trainees reported lower scores for ease of execution of orders placed compared to non-minority trainees 2.12 vs. 2.28 (p = 0.030). Females reported more frequently being mistaken for staff at lower training levels and more frequently feeling overwhelmed than male trainees, 3.29 vs. 1.64 (p Conclusion Minority status and female gender impact some of the key elements of the residency experience, manifesting as decreased respect afforded to these trainees. Thoughts of withdrawal and overall residency experience are significantly impacted by access to mentorship and feelings of isolation during residency. Attention should be paid to ensuring that high risk trainees have adequate access to mentorship, making deliberate efforts to cultivate a sense of community and camaraderie among residents, and emphasizing the value of diversity and inclusion.
Pseudouridine synthases in the RluA family negatively regulate Drosophila nociception.

Nociceptive neurons of Drosophila larvae are characterized by highly branched dendritic processes whose proper morphogenesis relies on a large number of RNA-binding proteins. Post-transcriptional regulation of RNA in these dendrites has been found to play an important role in their function. Here, we investigate the neuronal functions of two putative RNA modification genes RluA-1, and RluA-2, which are predicted to encode pseudouridine synthases. RluA-1 is specifically expressed in larval sensory neurons while RluA-2 expression is ubiquitous. Nociceptor-specific RNAi knockdown of RluA-1 caused hypersensitive nociception phenotypes, which were recapitulated with genetic null alleles. These were rescued with genomic duplication and nociceptor-specific expression of UAS-RluA-1-cDNA. As with RluA-1, RluA-2 loss of function mutants also displayed hyperalgesia. Interestingly, nociceptor neuron dendrites showed a hyperbranched morphology in the RluA-1 mutants. The latter may be a cause or a consequence of heightened sensitivity in mutant nociception behaviors.
Towards a More Coherent Doctrine of Trademark Genericism and Functionality: Focusing on Fair Competition

The doctrines of trademark genericism and functionality serve similar functions under the Lanham Act and the common law of unfair competition. Genericism, in the context of word marks, and functionality, for trade dress, bar trademark registration under the Lanham Act and, both under the Act and at common law, render a trademark unprotectable and invalid. In the word mark context, genericism stands for the proposition that certain parts of our vocabulary cannot be cordoned off as trademarks; all competitors must be able to use words that consumers understand to identify the goods or services that they are selling. Functionality likewise demands that certain aspects of product design cannot be legally protected as trade dress, as to do so would potentially limit competitors’ ability to make products that work as well, at the same price. The core concern, for both doctrines, is or should be the preservation of free and fair market competition. The types of trademarks typically at issue when making genericism and functionality determinations – word marks that are, at best, descriptive, or product design functioning as trade dress – are correctly described as weak. The genericism and functionality doctrines therefore play a critical role in marking the boundaries of trademark law. To properly draw those lines, decision makers need to correctly define and understand the theory underlying both doctrines. Both genericism and functionality, in their practical interpretation and purpose, should more clearly reflect the core principle of protecting fair competition. In particular, the concept of viable, competitive alternatives – either in the form of words or alternative designs – should play an enhanced role in determining whether an erstwhile trademark is generic or functional. The various tests for genericism and functionality currently employed by the courts often attempt to draw artificial distinctions among categories of words or product features that may confound business owners (and their lawyers) and divert the focus of the courts’ inquiry in such cases away from the core value at the heart of both doctrines: preserving fair competition.
Allocating Access for Information and Contributions

Legislators value both campaign contributions and policy-relevant information that interest groups might offer through lobbying. At the same time, there is some evidence that legislators are price setters to the extent that access to an incumbent legislator is conditional in part on making some level of campaign contribution. In this paper, I consider a legislator's tradeoff between granting access for informational reasons and granting access for contributions. In the model, legislative influence is exclusively through the provision of decision relevant information, and money is used exclusively to seek access. In particular, groups cannot make contributions in exchange for policy decisions. The focus of the analysis is on the implications of the legislator's price-setting on the induced pattern of demand for access and the consequences for the informational quality of subsequent legislative decisions. Moreover, although lobbyists are permitted to choose their informational source strategically, there is no possibility of dissembling when making an argument for one policy decision over another. The analysis yields both empirical predictions on the frequency and character of induced lobbying by different types of agent and provides some qualified support for limiting campaign contributions.
Ultra-high-speed wide-field photoacoustic microscopy

Optical-resolution photoacoustic microscopy (OR-PAM) has become a popular tool in small-animal studies. However, previous OR-PAM techniques variously lacked a high imaging speed, a high spatial resolution, and/or a large field of view. Here we report a high-speed OR-PAM system using an innovative water-immersible polygon-mirror scanner, which has achieved a cross-sectional frame rate of as high as 2400 Hz over a 12-mm scanning range. Using this polygon-scanner-based OR-PAM system, we have performed various studies on mouse models with stroke and cardiac arrests. We expect that the new OR-PAM system will become a powerful tool for imaging hemodynamics and neuronal functions.
Survey of Electromagnetic Field and Wave Interaction With "Surfaces" [Book/Software Reviews]

This book presents a timely set of topics in surface electromagnetics (SEMs). With contributions from prominent and pioneering scientists and engineers in this field, this book covers a wide range of subject matter related to EM field and wave interactions with a variety of structures categorized as “surfaces.” The editors, Prof. Yang and Prof. Rahmat-Samii, two of the most outstanding and innovative pioneers in EMs, have compiled and assembled a comprehensive set of topics, ranging from the fundamental aspects of wave– surface interactions, such as the modeling, analysis, and synthesis of SEMs; to guided waves, leaky waves, and the plane wave features of such surfaces in various applied areas, e.g., cloaking and transparency; to orbital angular momentum, microwave, terahertz (THz), and optical applications.
Holocaust and the Meaning of the Srebrenica Genocide: A Reflection on a Controversy

Over the past year, a series of controversies have erupted regarding the role of Holocaust scholars in determining whether other, more recent mass atrocities (in China, Myanmar, Syria, and elsewher...
Orientalizing Vietnam: The American Cold War, its “Problems” with Refugee Handicraft Artisans, and their Relationship to Barthes’s Mythology

This paper examines discourses of orientalism narrating the political and cultural significance of representations of Vietnamese handicraft that the U.S. State Department’s International Cooperation Administration’s handicraft production and export program in Southeast Asia published in American craft, design and art journals and used in trade and department store exhibitions from 1955 to 1961. The American program to bring economic stability to the region developed in response to anxiety about the spread of communism in Southeast Asia, which intensified following the end of the first Indochina War, the French departing Vietnam in 1954 and Vietnam dividing at the 17th Parallel a year later. At issue are the ways those who implemented the program narrated the Vietnamese handicraft artisans as problems by treating both their plight as political refugees fleeing from communist forces in the north and the vulnerability of their fledgling nation in the south to communism, as a Cold War American Orientalist tale of the U.S. salvaging Vietnam from political uncertainty including the destruction of its potential democracy and capitalism. To this point, the Orientalizing saturates Russel Wright’s article, “Gold Mine in Southeast Asia,” which overlays relationships of Western power and civilization as well as anthropological notions of salvage over references to the ways an ostensibly timeless albeit primitive culture of a non-western society (Vietnam) could maintain its essential identity by serving the needs of an overly industrialized one. Of particular interest are thematic correspondences between the Orientalist thrust of the American cultural diplomacy as evidenced in Wright’s article, and Roland Barthes’ early work, especially “Myth Today”.
Effect of Tungsten and Vanadium on the in Vitro Assembly of Assimilatory Nitrate Reductase Utilizing Neurospora Mutant nit-1

Abstract Tungsten or vanadium in a nutrient medium containing nitrate, but not ammonia, as the sole nitrogen source inhibited the formation of assimilatory NADPH-nitrate reductase (but not nitrate-inducible NADPH-cytochrome c reductase) and growth of wild type Neurospora crassa. Inhibition was prevented by high levels of molybdate in the nutrient medium but was not reversed by adding molybdate to subsequently prepared cell-free enzyme preparations. Neither tungsten nor vanadium was inhibitory when added to partially purified wild type Neurospora NADPH-nitrate reductase. Cell-free preparations of uninduced wild type grown in increasing concentrations of tungsten or vanadium showed progressive inhibition of ability to assemble nitrate reductase in vitro (with extracts of nitrate-induced Neurospora mutant nit-1) which was partially or entirely restored by subsequent addition of molybdate to the extracts of the tunsgten- or vanadium-grown uninduced wild type. Tungsten or vanadium added to acid-treated bovine milk xanthine oxidase or to extracts of uninduced wild type also inhibited in vitro enzyme assembly, with added molybdate partially preventing inhibition. The tungsten or vanadium analogue of nitrate reductase formed in vivo or by in vitro assembly is considerably more labile than its molybdenum counterpart as indicated by the complete loss of 185W or 48V from the enzyme as a result of trichloroacetic acid precipitation or heat treatment. Sucrose density gradient profiles of the Neurospora NADPH-nitrate reductase formed in vitro with 185W- or 48V-grown uninduced wild type or induced nit-1 showed, as in the case of 99Mo, that uninduced wild type and not nit-1 can be the source of tungsten or vanadium in the in vitro assembly of the enzyme. Exogenous 185W added to cell-free extracts of uninduced wild type or acid treated bovine milk xanthine oxidase prior to in vitro assembly of nitrate reductase using nit-1 failed to appear in the subsequently formed enzyme, whereas 48V experienced a small but consistent incorporation only with acid-treated xanthine oxidase. There was no in vitro exchange or incorporation of 185W or 48V into the already formed wild type enzyme. The data implicate tungsten and vanadium as competitive inhibitors of molybdenum in nitrate reductase structure and function.
Efficient delivery of transgenes to human hair follicle progenitor cells using topical lipoplex

The topical delivery of transgenes to hair follicles has potential for treating disorders of the skin and hair. Here we show that the topical administration of liposome-DNA mixtures (lipoplex) to mouse skin and to human skin xenografts resulted in efficient in vivo transfection of hair follicle cells. Transfection depended on liposome composition, and occurred only at the onset of a new growing stage of the hair cycle. Manipulating the hair follicle cycle with depilation and retinoic acid treatment resulted in nearly 50% transfection efficiency-defined as the proportion of transfected, newly growing follicles within the xenograft. Transgenes administered in this fashion are selectively expressed in hair progenitor cells and therefore have the potential to affect the characteristics of the follicle. These findings form a foundation for the future use of topical lipoplex applications to alter hair follicle phenotype and treat diseases of the hair and skin.
Christianity and Business Ethics

The moral language and operating norms of business find their roots in Judaism, Catholicism and Protestantism. Judaism gives business ethics a set of operative norms, upon which Christianity builds to identify principles, that reflect the complexity and diversity of business activity outside the ancient Jewish world. Early Christian traditions influenced heavily by the work of St. Ambrose, Augustine, and Thomas, plus the contemporary contributions of Catholic social thought articulated by Popes Leo XIII, John Paul II, Benedict XVI, and others, contribute to concepts of justice, virtue and specific acts in business and management. Luther, Weber, and others writing in the wake of the Protestant Reformation introduce in the language and norms of business ethics concepts like the vocation or “calling” to business as a type of ministry, the work ethic, and the spirit of economic activity. Keywords: Judaism and work; Max Weber; Pope Leo XIII; Rerum Novarum; Centesiumus Annus; Caritas in Veritate; protestant work ethic; reformation; servant strength; business ethics; business history; Catholic social teaching; faith and work
Speaking Conflict: Ideological Barriers to Bilingual Policy Implementation in Civil War Sri Lanka

This article presents a holistic view of ideological barriers to bilingual policy implementation in Sri Lanka, a conflict-ridden postcolonial nation-state. I examine Sinhalese youth and adults' Tamil as a second language (TSL) learning and speaking practices across three contexts: a multilingual school, a program for government servants, and an NGO. Though limited interactional spaces emerge where Sinhalese students speak Tamil, bilingual policies continue to reinforce inequalities between the Sinhalese Buddhist majority and Tamil-speaking minority groups.
Update on breast cancer detection using comb-push ultrasound shear elastography

In this work, tissue stiffness estimates are used to differentiate between benign and malignant breast masses in a group of pre-biopsy patients. The rationale is that breast masses are often stiffer than healthy tissue; furthermore, malignant masses are stiffer than benign masses. The comb-push ultrasound shear elastography (CUSE) method is used to noninvasively assess a tissue’s mechanical properties. CUSE utilizes a sequence of simultaneous multiple laterally spaced acoustic radiation force (ARF) excitations and detection to reconstruct the region of interest (ROI) shear wave speed map, from which a tissue stiffness property can be quantified. In this study, the tissue stiffnesses of 73 breast masses were interrogated. The mean shear wave speeds for benign masses (3.42 ± 1.32 m/s) were lower than malignant breast masses (6.04 ± 1.25 m/s). These speed values correspond to higher stiffness in malignant breast masses (114.9 ± 40.6 kPa) than benign masses (39.4 ± 28.1 kPa and p 83 kPa is established as a cut-off value for differentiating between malignant and benign suspicious breast masses, with a receiver operating characteristic curve (ROC) of 89.19% sensitivity, 88.69% specificity, and 0.911 for the area under the curve (AUC).
Evaluation of TK1 targeting carboranyl thymidine analogs as potential delivery agents for neutron capture therapy of brain tumors

In this report we describe studies with N5-2OH, a carboranyl thymidine analog (CTA), which is a substrate for thymidine kinase 1 (TK1), using the F98 rat glioma model. In vivo BNCT studies have demonstrated that intracerebral (i.c.) osmotic pump infusion of N5-2OH yielded survival data equivalent to those obtained with i.v. administration of boronophenylalanine (BPA). The combination of N5-2OH and BPA resulted in a modest increase in MST of F98 glioma bearing rats compared to a statistically significant increase with the RG2 glioma model, as has been previously reported by us (Barth et al., 2008). This had lead us to synthesize a second generation of CTAs that have improved in vitro enzyme kinetics and in vivo tumor uptake (Agarwal et al., 2015).
Encoding Apparent Motion in Animated Mimic Displays

Animated mimic displays represent system components, the physical connections between components, and the analogical flow of information or resources. These displays have the potential to improve the effectiveness of both training and real-time performance. One animation technique that is particularly efficient (from a computational perspective) is color table animation, which produces a subjective impression of movement through apparent motion. Display variables likely to influence the effectiveness of apparent motion were investigated in two experiments. The primary experimental manipulations were the levels of chromatic and luminance contrast in the displays (temporal frequency and direction of apparent motion were also varied). The results suggest that both types of contrast can be used to encode apparent motion but that luminance contrast is more effective. Several additional variables likely to influence the effectiveness of animation were held constant and are discussed briefly. Language: en
A comparison of language processing techniques for a constrained speech translation system

A system designed to allow Post Office counter clerks to communicate with deaf customers by translating speech into sign language is described. The system uses approximately 370 pre-stored phrases which may be signed to the customer using a specially designed avatar. The clerk is unable to memorise this number of phrases and therefore the system attempts to map from their input speech to the semantically equivalent pre-stored phrase. We describe a number of language processing techniques developed to perform the mapping, and give results obtained using alternative formulations of the phrases from a number of speakers. We then give results for recognised speech input and show how misrecognitions effect the mapping system. Best performance is obtained using a mapping system based on an entropy weighted, vector based distance measure between the test phrase and each of the signed phrases.
8.1 nJ/b 2.4 GHz Short-Range Communication Receiver in 65 nm CMOS

An 8.1 nJ/bit 2.4 GHz receiver with integrated digital baseband supporting O-QPSK DSSS modulation compliant with the IEEE 802.15.4 standard is presented that targets short-range, Internet of Things applications (IoTs). The sensitivity of a wireless communication receiver in general trades with power consumption. This receiver exploits this tradeoff to achieve a total power consumption of 2.02 mW including ADCs and digital baseband processing, at a sensitivity of $-$ 52.5 dBm at 250 Kbps. The energy-efficiency of the radio frequency (RF) front-end alone is nearly 2x better than the prior art. The receiver was fabricated in 65 nm CMOS with an area of 0.86 ${\rm mm}^{2}$ .
Influence of exercise intensity and duration on biochemical adaptations in skeletal muscle

The influence of intensity and daily duration of exercise on cytochrome c concentration in the three muscle fiber types was assessed in rats that were treadmill trained for 8 wk (5 days/wk) by 1 of 19 protocols. The importance of exercise duration was determined at six running intensities (10, 20, 30, 40, 50, and 60 m/min). Daily run times resulted in a maximal adaptive change for each running intensity. The general pattern of cytochrome c change, caused by increasing daily run times, followed a first-order manner in all fiber types. The final time-independent asymptotic values were dependent on the intensity of running. In addition, as running intensity was increased, the length of daily run time required to achieve the peak adaptive response was shortened. The intensity influence was very different between fiber types. In the fast-twitch red fiber, the maximal time-independent response at each work intensity was altered by exercise intensity at only submaximal work loads (i.e., the adaptation from 19 to 29 nmol/g was not further increased at 50 and 60 m/min). In contrast, the adaptive response in the fast-twitch white fiber began at 30 m/min (approx 80% VO2max) and increased exponentially as intensity was increased (200% increase at 60 m/min). Whether this different adaptive response between fiber types is due solely to the ordered recruitment of motor units remains to be determined.
Stratigraphic evidence for late Quaternary dune activity near Hudson on the Piedmont of northern Colorado

Stabilized dune fields are common features near Hudson, on the Piedmont of northern Colorado. Exposures in dune and interdune sites expose a sequence of eolian sediments and paleosols that record a complex history of eolian activity during the late Quaternary. Radiocarbon and thermoluminescence age estimates on A horizons buried by eolian sand indicate that dunes were reactivated sometime between 7 and 9 ka. On the basis of morphology of surface soils, the dunes were most recently stabilized <3 ka. At present there are no data to indicate if there were multiple periods of dune movement and stabilization during the Holocene. The penultimate pre-Holocene dune-forming episode probably terminated ca. 13 ka and may be coincident with the Pinedale glaciation. The stratigraphy at interdune sites shows at least two eolian depositional events prior to the penultimate event; they were separated by periods of pedogenesis, one of which may have exceeded 40 ka. This analysis indicates that dunes in northern Colorado were active during both cold-arid and warm-arid periods in the late Quaternary.
Paraganglioma (pheochromocytoma) of the posterior mediastinum: a case report and review of the literature

Pheochromocytoma is an uncommon tumor in the pediatric population. Paraganglioma, or extra-adrenal pheochromocytoma, accounts for only a small fraction of pediatric pheochromocytomas, with most of these tumors presenting within the abdominal cavity. Herein the authors report the extremely rare case of a biochemically active paraganglioma presenting as a posterior mediastinal mass in an 8-year-old boy.
Finitistic dimensions of ring extensions

(1982). Finitistic dimensions of ring extensions. Communications in Algebra: Vol. 10, No. 9, pp. 993-1001.
A TRIAC dimmable driver design for high dimmer compatibility in low power LED lighting

LED lighting driver design in TRIAC dimming application has been faced with the difficulties of dimmer compatibility due to low LED power. The LED current dimming is basically controlled by primary side regulation with feedback modulation in the proposed TRIAC dimmable driver. With system compactness and better dimmable compatibility, passive bleeder is designed to stabilize TRIAC turn-on and turn-off operation. Filter discharger is also introduced to keep uniformity of dimmer output voltage to remove visible flicker. The proposed TRIAC dimmable LED driver has been experimentally verified in 3W LED lamp system.
A simple scheme of molecular electronic devices with multiwalled carbon nanotubes as the top electrodes

A simple fabrication scheme for molecular electronic junctions is presented with multiwalled carbon nanotubes (MWCNTs) as the top electrodes. Results indicate that our approach retains the molecular character of the chosen molecules [a self-assembled monolayer of octadecanethiol on gold bottom electrodes] and opens the door for studying a wide variety of organothiol candidates for molecular electronics. The fabrication scheme is designed in a way that it can be modified into all-carbon devices in the future by using graphitic carbon bottom electrodes functionalized with nitrozoabenzene, for example, and MWCNTs or graphene as the top electrodes. Alternatively, the scheme is applicable for all-gold devices with gold bottom electrodes and gold nanowire top electrodes.
CELL-SURFACE EXPRESSION OF AN AMINO-TERMINAL FRAGMENT OF APOLIPOPROTEIN B INCREASES LIPOPROTEIN LIPASE BINDING TO CELLS

Abstract Previous studies (Sivaram, P., Choi, S. Y., Curtiss, L. K., and Goldberg, I. J. (1994) J. Biol. Chem. 269, 9409-9412) from this laboratory showed that the NH2-terminal region of apoB (NTAB) has binding domains for lipoprotein lipase (LPL). LPL binding to endothelial cells, we hypothesize, involves interaction both with heparan sulfate proteoglycans and with a protein that has homology to NTAB. To test whether cell-surface NTAB would increase the amount and affinity of LPL binding to cells, we produced stable Chinese hamster ovary cell lines that have NTAB anchored to the cell surface. A cDNA encoding the amino-terminal 17% of apoB (apoB17) was fused to a cDNA coding for the last 37 amino acids of decay-accelerating factor (DAF), which contains the signal for glycosylphosphatidylinositol anchor attachment. The fused construct was sequence-verified and cloned into expression vector pCMV5. The pCMV5-apoB17-DAF plasmid was cotransfected with a neomycin resistance gene into wild-type (WT) cells and mutant heparan sulfate proteoglycan-deficient Chinese hamster ovary cells (745 cells), and stable cell lines were established. Expression of apoB17 on the cell surface was confirmed by the release of apoB17 by phosphatidylinositol-specific phospholipase C. LPL binding to WT and apoB17-DAF-transfected cells was determined. Using 0.8-6 μg of LPL, 1.3-2.2-fold more LPL associated with apoB17-DAF WT cells compared with WT cells; apoB17-DAF also increased LPL binding to 745 cells. After heparinase treatment, LPL binding to apoB17-DAF cells was still greater than to treated WT cells. This increased binding to apoB17-DAF cells was almost abolished by treatment of cells with phosphatidylinositol-specific phospholipase C or anti-apoB monoclonal antibody. LPL dissociated from WT cells with k−1 = 2.55 × 10−2 min−1, whereas LPL dissociated more slowly from apoB17-DAF-containing cells with k−1 = 1.08 × 10−2 min−1. Furthermore, almost 95% of the LPL on WT cells was dissociated by 1 M NaCl, while only 65% of the LPL dissociated from apoB17-DAF cells at the same high salt concentration. Similarly, in high salt, more LPL remained associated with apoB17-DAF cells than with nontransfected 745 cells. These data show that NTAB on cell surfaces can function as a LPL-binding protein. Moreover, they demonstrate that LPL association with cells can be increased by simultaneously binding to both proteoglycan and non-proteoglycan binding sites.
Impact of anode evaporation on the anode region of a high-intensity argon arc

Experimental studies of a free-burning, high-intensity argon arc operated at 800 Torr with a solid, molten, or resolidified copper anode demonstrate that the cathode region is not affected by Cu vapor from the anode. Also Cu vapor concentrations in the arc core (beyond 1 mm from the anode surface) are negligible. In contrast, there is a strong effect of the Cu vapor on the anode region of the arc. The arc fringes become electrically conducting due to the presence of Cu vapor, resulting in a flattening of the current density distribution and a corresponding drop of the temperature in the arc core. At the same time, the overall arc voltage shows a slight drop (<1 V). In the case of the resolidified anode, the overall arc voltage increases, which seems to be associated with the distribution of the stagnation flow in front of the anode due to a dip in the center of the anode.
Urban Circulation and the Everyday Politics of African Urban Youth: The Case of Douala, Cameroon

Institutions across many cities in Africa lack sufficient authority to instil any overarching matrix of definitions and spatial framework capable of holding residents in stable articulations with infrastructure, territory and urban resources of all kinds. The resultant dispersion of ways of operating in cities does not necessarily mean that regularities are impossible to attain. Rather, an increasingly generalized practice of converting bodies, infrastructure and urban objects into mutltiplex and unstable uses can give rise to particular forms of sociality which in turn cultivate a certain flexibility in how highly volatile urban situations are appropriated and lived. By examining various modalities of circulation — through disparate spatial and symbolic economies — engaged in by youth in various situations and quarters in Douala, Cameroon, this article attempts to explore the elaboration of specific urban political practices. These practices are aimed at countering marginalization and reappropriating the city as a platform for more diverse engagements with a larger world. Dans de nombreuses grandes villes d’Afrique, les institutions manquent de l’autorite suffisante pour faire naitre une enveloppe de definitions et un cadre spatial capables d’assurer aux habitants des articulations stables avec une infrastructure, un territoire et des ressources urbaines de toutes sortes. Il en resulte une dispersion des modes operatoires dans les villes, ce qui n’interdit pas forcement toute forme de regularite. Au contraire, la conversion generalisee d’organismes, infrastructures et objets urbains en usages composites et instables fait naitre des formes specifiques de socialite qui elles-memes nourrissent une certaine flexibilite dans la maniere dont les habitants s’approprient et vivent des situations urbaines tres volatiles. En etudiant plusieurs modalites de circulation-via des economies symboliques et spatiales disparates — adoptees par les jeunes dans des situations et des quartiers varies de Douala (Cameroun), cet article tente d’explorer l’elaboration de pratiques politiques urbaines specifiques. Ces dernieres visent a combattre la marginalisation et a se reapproprier la ville en tant que scene d’engagements plus diversifies avec un monde plus vaste.
Neurointermediate pituitary lobe cells synthesize and release interleukin-6 in vitro: effects of lipopolysaccharide and interleukin-1 beta

The cytokine interleukin-6 (IL-6) is produced by a variety of cells, including macrophages, T-cells, and B-cells. Recent studies have confirmed a neuroendocrine role for IL-6 in the regulation of anterior pituitary (AP) hormone release. Because the neurointermediate pituitary lobe (NIL) may modulate AP hormone release, we investigated the production of IL-6 by NIL cells in vitro. NIL tissue removed from pituitary glands of male Long-Evans rats was enzymatically and mechanically dispersed, and the cells were subsequently cultured in 96-well tissue culture plates for 4-6 days in 10% serum-containing RPMI-1640. Test incubations were performed in serum-free RPMI-1640, and IL-6 concentrations were determined using the 7TD1 cell bioassay. Preliminary studies revealed a cell-dependent release of IL-6: increasing the number of NIL cells per well from 6.25 to 50 x 10(3) revealed detectable basal release of IL-6 between 25-50 x 10(3) cells/well. The endotoxin lipopolysaccharide (LPS; 100 ng/ml) and IL-1 beta (100 ng/ml) stimulated IL-6 release at 25 and 50 x 10(3) cells/well. Subsequent studies used a cell density of 50 x 10(3) cells/well and demonstrated time-dependent 3- to 6-fold inductions of IL-6 release by 100 ng/ml IL-1 beta and LPS. Concentration-response studies revealed maximal stimulation of IL-6 release by 1 ng/ml and a minimally effective concentration of 1 pg/ml for both IL-1 beta and LPS. Treatment of NIL cells with 1-10 mM (Bu)2cAMP increased IL-6 release by 7- to 14-fold. Endotoxin and IL-1 beta also enhanced the accumulation of IL-6 messenger RNA in these cells. Vasopressin and oxytocin (1 microM) inhibited LPS and IL-1 beta stimulation of IL-6 release from NIL cells, but did not inhibit IL-6 release from AP cells. Immunofluorescent dual labeling of NIL cells for flow cytometry revealed that greater than 95% of the cells did not stain for CD11b/c (common epitope found on monocytes, granulocytes, and macrophages) or CD45 (leukocyte common antigen). These results demonstrate for the first time the synthesis and release of IL-6 from cultured NIL cells. Agents that enhance IL-6 release [LPS, IL-1 beta, and (Bu)2cAMP] from other cell types also increase IL-6 release from NIL cells. Vasopressin and oxytocin inhibition of IL-6 release suggests a role for these neuropeptides in feedback inhibition in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)
Ecosystem as circuits: diagrams and the limits of physical analogies

Diagrams refer to the phenomena overtly represented, to analogous phenomena, and to previous pictures and their graphic conventions. The diagrams of ecologists Clarke, Hutchinson, and H.T. Odum reveal their search for physical analogies, building on the success of World War II science and the promise of cybernetics. H.T. Odum's energy circuit diagrams reveal also his aspirations for a universal and natural means of reducing complexity to guide the management of diverse ecological and social systems. Graphic conventions concerning framing and translation of ecological processes onto the flat printed page facilitate Odum's ability to act as if ecological relations were decomposable into systems and could be managed by analysts external to the system.
Noneffect of electronegative gases on pulsed laser-induced optical surface damage thresholds.

The pulsed laser-induced damage threshold of several optical surfaces has been measured as a function of the pressure and type of ambient gas. Measurements were made in vacuum and various pressures of nitrogen, Freon 14, (CF4), and SF6 in an attempt to decrease the growth rate of the avalanche which accompanies pulsed laser-induced damage. Test samples included conventional dielectric coatings of ZrO2, diamond-turned copper, bare surfaces of fused silica and ARG-2 glass, and porous surface layers of both leached ARG-2 glass and some solgel coatings. From this preliminary study, it is apparent that the ambient gas has no observable effect on 1-on-1 surface damage thresholds (although some improvement in N-on-1 damage levels had been reported). The present finding is in agreement with previous observations that damage sites appear to be initiated on or just below the surface of optical elements. For uncoated surfaces, both conventional and porous initiation sites seem to be isolated impurities embedded near the surface resulting in the formation of pits. In either case, such damage initiation levels are unmodified by the presence of electronegative gases, and no change in threshold is observed.
An increase in glutathione peroxidase activity induced by high supplementation of vitamin C in rats

Abstract Weanling rats were maintained on purified diets containing marginal levels of vitamin E; they were divided into three groups with six rats each, and received vitamin C at 0, 2.0, or 4.0 g/kg diet for 16 weeks. The determination of antioxidant status of the animals showed that the high supplementation of vitamin C significantly lowered plasma level of vitamin E and erythrocyte (RBC) level of reduced glutathione. The activity of glutathione peroxidase increased significantly in RBC and plasma; but not in the liver, kidney, spleen, muscle, heart, and testis of the vitamin C supplemented groups. The activities of superoxide dismutase, catalase, glutathione reductase and glucose-6-phosphate dehydrogenase in RBC and liver were not affected by the vitamin C supplementation. The increase in glutathione peroxidase activity in RBC of high vitamin C supplemented groups may be due to the development of cellular defense mechanisms induced by peroxidative stress of vitamin C.
Competition between species: theoretical models and experimental tests.

Experimental determinations of Drosophila population dynamics cannot be explained by the Lotka-Volterra model of interspecific competition. This paper presents other possible mathematical models of competition between species, and gives the results of experiments designed to test the validity of such models. Eight of the ten new models presented contain the Lotka-Volterra model as a special case. The experiments made to test the models are of two kinds. Type 1 experiments are continuous one- or two-species populations, which permit the estimation of the carrying capacity of each species and the numbers of the two species at the point of stable equilibrium. Type 2 experiments measure the change in numbers over a short time interval in populations started with many different initial densities of the two species. Type 2 experiments give information on the dynamics of the two-species system in the phase plane whose coordinates are the number of individuals of each species. The models accounting best for the results are models five and seven (Table II). Each of these two models contains one parameter more than the Lotka-Volterra model. Model five adds a nonlinear term of self-interaction (−βiN2i). Model seven has the form, dNi/dt = riN/Kθii(Kθii − Nθi i − αijNj1−θi i). The exponential parameter θ removes the restriction of the logistic theory of population growth, that each individual added to the population decrease the rate of growth of the population by a constant amount. With model seven the rate of growth of a population of a single species need not have its maximum at K2, that is when the number of individuals is half the carrying capacity of the environment.
Relationship of protein level, age and ambient temperature to laying hen performance.

Abstract THE requirement of laying hens for protein has been the subject of numerous investigations, and a wide range of protein levels has been found to support reasonable rates of production. Reports have indicated the protein needs of the laying hen to be from 11 to 18% (Heywang et al., 1955; Miller et al., 1956; Frank and Waibel, 1959; Griminger and Fisher, 1959; Thornton et al., 1957; Quisenberry and Williams, 1952; Milton and Ingram, 1957; Creek and Combs, 1958). Based on these reports, a number of factors would seem to be involved in an evaluation of the total protein needs of the laying hen. Factors which might be responsible for the variations in protein requirements among different reports are egg production rate, hen size, age, dietary energy, ambient temperature, stress and breed differences. The question of amino acid balance in changing the dietary protein content has been dealt with in several…
Optimization of low-thrust interplanetary trajectories using collocation and nonlinear programming

The method of collocation with nonlinear programming is applied to the determination of minimum-time, low-thrust interplanetary transfer trajectories. Since the vehicle motor operates continuously, the minimum-time trajectories are also propellant minimizing. The numerical solution method requires that the transfer be divided into three phases: escape from the departure planet, heliocentric flight, and arrival at the destination planet. Two-body gravitational models are used in each phase and the transformation from planetocentric coordinates to heliocentric coordinates and vice-versa is incorporated as a set of nonlinear constraints on the problem variables. No a priori assumptions on the optimal control time history are required. An Earth-to-Mars transfer with a very low thrust acceleration of 0.0001 g is used as an example.
Growth of a Au-Ni-Sn intermetallic compound on the solder-substrate interface after aging

Ni/Au metallization layers are used with increasing frequency to protect Cu substrates in ball grid array microelectronic packaging. The external Au layer provides oxidation and corrosion resistance during storage prior to assembly, while the intermediate Ni layer acts as a diffusion barrier that inhibits the formation of a thick Cu-Sn intermetallic layer during aging. During soldering with eutectic Pb-Sn, the Au dissolves into the molten solder and forms fine, needle-shaped AuSn{sub 4} intermetallic precipitates that are retained in a dense distribution in the bulk of the solder joint after it has solidified. However, recent research by Mei et al. has revealed a new and potentially problematic phenomenon that seems to be peculiar to the Ni/au metallization. They found that after extensive aging (150 C for 2 weeks in their case), the Au-Sn intermetallic redeposited onto the solder-substrate interface. The reconstituted interface was significantly weakened and failed by brittle fracture along the surface between the redeposited Au-Sn and the Ni{sub 3}Sn{sub 4} layer that formed during reflow. While the interfacial redeposition of Au-Sn intermetallics has been observed previously, the mechanism remains unknown. The present work was undertaken to identify the mechanism of this phenomenon and explore methods for controlling it.
Bullous morphea: Clinical, pathologic, and immunopathologic evaluation of thirteen cases

Background: Bullous morphea is a rare disease. Its pathogenesis is unknown. Objective: We evaluated bullous morphea clinically, pathologically, and immunopathologi-cally and investigated the role of spirochetes and eosinophils in its pathogenesis. Methods: The clinical and pathologic findings from 13 patients with bullous morphea were reviewed. Tissue sections were studied with the Elias-Bosma stain for spirochetes and indirect immunofluorescence for eosinophil granule major basic protein. Results: Bullae were found in all forms of morphea; the lower extremities were the most common sites of involvement. Lymphatic dilatation was found in 77% of the patients. Deposition of major basic protein was found in 60% of cases studied. There was no evidence of spirochetes in any of the specimens examined with the Elias-Bosma stain. Conclusion: Our results suggest that the pathogenesis of bullous morphea is related to lymphatic dilatation as well as release of major basic protein from eosinophils in some patients. We found no association between spirochetes and bullous morphea.
Convergence results for the EM approach to mixtures of experts architectures

The Expectation-Maximization (EM) algorithm is an iterative approach to maximum likelihood parameter estimation. Jordan and Jacobs (1993) recently proposed an EM algorithm for the mixture of experts architecture of Jacobs, Jordan, Nowlan and Hinton (1991) and the hierarchical mixture of experts architecture of Jordan and Jacobs (1992). They showed empirically that the EM algorithm for these architectures yields significantly faster convergence than gradient ascent. In the current paper we provide a theoretical analysis of this algorithm. We show that the algorithm can be regarded as a variable metric algorithm with its searching direction having a positive projection on the gradient of the log likelihood. We also analyze the convergence of the algorithm and provide an explicit expression for the convergence rate. In addition, we describe an acceleration technique that yields a significant speedup in simulation experiments.
Cerium dioxide nanoparticles induce apoptosis and autophagy in human peripheral blood monocytes.

Cerium dioxide nanoparticles (CeO2 NPs) have diversified industrial uses, and novel therapeutic applications are actively being pursued. There is a lack of mechanistic data concerning the effects of CeO2 NPs on primary human cells. We aimed at characterizing the cytotoxic effects of CeO2 NPs in human peripheral blood monocytes. CeO2 NPs and their suspensions were thoroughly characterized, including using transmission electron microscopy (TEM), dynamic light scattering, and zeta potential analysis. Blood from healthy human volunteers was drawn through phlebotomy, and CD14+ cells were isolated. Cells were exposed to CeO2 NPs (0.5–10 μg/mL) for 20 or 40 h, and mechanisms of cell injury were studied. TEM revealed that CeO2 NPs are internalized by monocytes and are found either in vesicles or free in the cytoplasm. CeO2 NP exposure leads to decrease in cell viability, and treated cells exhibit characteristic hallmarks of apoptosis (activation of Bax, loss of mitochondrial membrane potential, DNA fragmentation)...
Developmental expression of a voltage-dependent potassium channel (Kv3.1) in auditory neurons without cochlear input.

Kv3.1, a voltage-dependent potassium channel, has two forms, -a and -b, which differ in expression during development and at the onset of function in the auditory system. To determine whether cochlear nerve input could affect the expression of these two forms, cultures of the developing cochlear nucleus were explanted in the absence of the cochlear nerve at the beginning of cell migration (Hamburger-Hamilton stage 28–30), while neuroblasts continued to migrate onto the culture substrate. After 8, 15, and 22 days in vitro (three survival groups), cultures were immunostained with antibodies recognizing either both forms of Kv3.1 or only the -b form. Only young and newly migrated nerve cells were sampled. In the three survival groups, all nerve cells expressed Kv3.1, among which only 50% or less expressed the -b form. Some of the more differentiated multipolar cells expressed the -b form, but most were labeled with the antibody that recognizes both forms. Thus, in the absence of peripheral input, both forms of Kv3.1 appear at stages very early in development, although not all cells necessarily coexpress both forms. These results agree with other observations in the chick embryo in situ. They are consistent with previous work implicating Kv3.1 in cell migration during early development. J. Neurosci. Res. 65:121–128, 2001. © 2001 Wiley-Liss, Inc.