bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hochpräzise Fügungen mittels reaktiven Nanometermultischichten
Authors: Dietrich Georg , Rühl Maximilian , Braun Stefan , Leson Andreas 
Published: February 2012

AbstractEtablierte Fügetechniken wie Schweißen oder Löten bewirken im Allgemeinen einen großen Wärmeeintag in die zu fügenden Bauteile. Vor allem bei wärmempfindlichen Bauteilen, wie zum Beispiel MEMS, kann dies zu spannungsinduzierten Verformungen bzw. zur Beschädigung der Bauteile führen. Es wird daher eine Fügemethode benötigt, welche durch einen lokal definierten und kurzzeitigen Wärmeeintrag eine Schädigung der Bauteile vermeidet. Die sogenannten reaktiven Multischichtsysteme (RMS) bieten einen vielversprechenden Ansatz diese Forderung zu erreichen. RMS bestehen aus einigen hundert bis mehreren tausend alternierenden Schichten mit Dicken im Bereich von einigen Nanometern, wobei die Materialien der verschiedenen Schichten exotherm miteinander reagieren können. Wird eine mit einer Lot‐Schicht beschichtete RMS zwischen zwei Oberflächen gebracht, kann diese als kontrollierbare lokale Wärmequelle zum Fügen verwendet werden.Die verschiedenen Anwendungsmöglichkeiten von RMS haben in den letzten Jahren intensive FuE‐Aktivitäten erforderlich gemacht. Aufbauend auf einer früheren Veröffentlichung aus dem Jahr 2009 [1], in der theoretische Untersuchungen und grundlegende Anwendungsmöglichkeiten der RMS diskutiert wurden, werden im folgenden Artikel die neuesten Entwicklungen auf den Gebieten Herstellung, Charakterisierung und Anwendung der RMS zum Fügen präsentiert.
Gastrointestinal Stromal Tumors: Case Series of 29 Patients Defining the Role of Imatinib Prior to Surgery
Authors: Shrikhande Shailesh V. , Marda Sachin S. , Suradkar Kunal , Arya Supreeta , Shetty Guruprasad S. , Bal Munita , Shukla Parul J. , Goel Mahesh , Mohandas K. M. 
Published: February 2012

AbstractBackgroundThe aim of this study was to assess the role of neoadjuvant imatinib in redefining treatment for gastrointestinal stromal tumors (GISTs).MethodsA total of 76 patients were reviewed. Among them, 29 patients who were administered neoadjuvant imatinib for borderline resectable and locally advanced GISTs followed by surgery were analyzed. Adjuvant imatinib was administered based on risk stratification.ResultsThe median age of the neoadjuvant imatinib group was 51 years. The median duration of neoadjuvant imatinib administration was 8.5 months. The response rate with neoadjuvant imatinib was 79.3%. Five patients, initially considered to have locally unresectable lesions, ultimately underwent resection (three R0, two R2). Another three patients, who had M1 disease, underwent R2 resection (due to the presence of metastasis) with complete resection of the primary lesion. In 19 patients, who would have originally required extensive surgery, underwent conservative surgery (R0). In two patients, neoadjuvant imatinib did not influence the final procedure. The postoperative complication rate was 13.8%, and there were no postoperative deaths. There was one locoregional recurrence and two cases of distant metastasis. The 1‐, 2‐, and 3‐year overall survivals were each 100%.ConclusionsNeoadjuvant imatinib for locally advanced GISTs is a safe concept for downsizing, improving resectability, and aiding organ‐preserving surgery. It also improves the chance of long‐term survival. Surgery, however, remains the cornerstone of curative treatment of GISTs even after neoadjuvant imatinib.
The Evolution of Breast Reconstruction: A Historical Perspective
Authors: Champaneria Manish C. , Wong Wendy W. , Hill Michael E. , Gupta Subhas C. 
Published: February 2012

AbstractPlastic surgeons have been performing operations to improve the aesthetic aspect of the breast for centuries. Throughout ancient times, great controversy produced many theories of how breast cancer occurred and the best treatment. Because of beliefs that closure of mastectomy sites could conceal tumor recurrence, breast reconstruction did not gain wide acceptance until the mid‐1900s. Today, plastic surgeons have a variety of techniques to reconstruct the breast. The first autologous muscle flap for breast reconstruction was the latissimus dorsi myocutaneous flap, described in 1896 by Iginio Tansini. The introduction of Carl Hartrampf’s transverse rectus abdominis myocutaneous flap and Robert J. Allen’s deep inferior epigastric perforator flap have also provided excellent reconstructive options. With regard to augmentation, Vincenz Czerny attempted to enhance a woman’s breast in 1895 with implantation of a lumbar lipoma. Soon after, surgeons used paraffin injections and polyvinylic alcohol sponge implantation, which yielded disastrous results. In 1961, Thomas Cronin and Frank Gerow promoted the first silicone implant, paving the way for today’s silicone and saline prototypes. Although reduction mammaplasty techniques had originated centuries earlier than mastopexy methods, the advancements of both have largely paralleled one another. In 1949, the Wise pattern was introduced to preoperatively plan safer and predictable outcomes in breast reductions. Efforts to minimize scars were achieved with Claude Lassus’ introduction and Madeleine Lejour’s subsequent modification of the vertical scar mammaplasty. In hopes of fostering an understanding of current post‐mastectomy procedures and instilling passion for innovating future techniques, we provide a near‐complete, surgically focused historical account of the primary contributors to breast reconstruction.
A defined growth medium with very low background carbon for culturingClostridium thermocellum
Authors: Holwerda Evert K , Hirst Kyle D , Lynd Lee R 
Published: February 2012

AbstractA growth medium was developed for cultivation of Clostridium thermocellum ATCC 27405 in which “background” carbon present in buffers, reducing agents, chelating agents, and growth factors was a small fraction of the carbon present in the primary growth substrate. Background carbon was 1.6% of primary substrate carbon in the low-carbon (LC) medium, whereas it accounts for at least 40% in previously reported media. Fermentation of cellulose in LC medium was quite similar to Medium for Thermophilic Clostridia (MTC), a commonly used growth medium that contains background carbon at 88% of primary substrate carbon. Of particular note, we found that the organism can readily be cultivated by eliminating some components, lowering the concentrations of others, and employing a tenfold lower concentration of reducing agent. As such, we were able to reduce the amount of background carbon 55-fold compared to MTC medium while reaching the same cell biomass concentration. The final mass ratios of the products acetate:ethanol:formate were 5:3.9:1 for MTC and 4.1:1.5:1 for LC medium. LC medium is expected to facilitate metabolic studies involving identification and quantification of extracellular metabolites. In addition, this medium is expected to be useful in studies of cellulose utilization by anaerobic enrichment cultures obtained from environmental inocula, and in particular to diminish complications arising from metabolism of carbon-containing compounds other than cellulose. Finally, LC medium provides a starting point for industrial growth media development.
Crossing Boundaries: Nativity, Ethnicity, and Mate Selection
Authors: Qian Zhenchao , Glick Jennifer E. , Batson Christie D. 
Published: February 2012

AbstractThe influx of immigrants has increased diversity among ethnic minorities and indicates that they may take multiple integration paths in American society. Previous research on ethnic integration has often focused on panethnic differences, and few have explored ethnic diversity within a racial or panethnic context. Using 2000 U.S. census data for Puerto Rican–, Mexican-, Chinese-, and Filipino-origin individuals, we examine differences in marriage and cohabitation with whites, with other minorities, within a panethnic group, and within an ethnic group by nativity status. Ethnic endogamy is strong and, to a lesser extent, so is panethnic endogamy. Yet, marital or cohabiting unions with whites remain an important path of integration but differ significantly by ethnicity, nativity, age at arrival, and educational attainment. Meanwhile, ethnic differences in marriage and cohabitation with other racial or ethnic minorities are strong. Our analysis supports that unions with whites remain a major path of integration, but other paths of integration also become viable options for all ethnic groups.
Effect of non-parallel mean flow on the Green’s function for predicting the low-frequency sound from turbulent air jets
Authors: Goldstein M. E. , Sescu Adrian , Afsar M. Z. 
Published: February 2012

AbstractIt is now well-known that there is an exact formula relating the far-field jet noise spectrum to the convolution product of a propagator (that accounts for the mean flow interactions) and a generalized Reynolds stress autocovariance tensor (that accounts for the turbulence fluctuations). The propagator depends only on the mean flow and an adjoint vector Green’s function for a particular form of the linearized Euler equations. Recent numerical calculations of Karabasov, Bogey & Hynes (AIAA Paper 2011-2929) for a Mach 0.9 jet show use of the true non-parallel flow Green’s function rather than the more conventional locally parallel flow result leads to a significant increase in the predicted low-frequency sound radiation at observation angles close to the downstream jet axis. But the non-parallel flow appears to have little effect on the sound radiated at $9{0}^{\ensuremath{\circ} } $ to the downstream axis. The present paper is concerned with the effects of non-parallel mean flows on the adjoint vector Green’s function. We obtain a low-frequency asymptotic solution for that function by solving a very simple second-order hyperbolic equation for a composite dependent variable (which is directly proportional to a pressure-like component of this Green’s function and roughly corresponds to the strength of a monopole source within the jet). Our numerical calculations show that this quantity remains fairly close to the corresponding parallel flow result at low Mach numbers and that, as expected, it converges to that result when an appropriately scaled frequency parameter is increased. But the convergence occurs at progressively higher frequencies as the Mach number increases and the supersonic solution never actually converges to the parallel flow result in the vicinity of a critical- layer singularity that occurs in that solution. The dominant contribution to the propagator comes from the radial derivative of a certain component of the adjoint vector Green’s function. The non-parallel flow has a large effect on this quantity, causing it (and, therefore, the radiated sound) to increase at subsonic speeds and decrease at supersonic speeds. The effects of acoustic source location can be visualized by plotting the magnitude of this quantity, as function of position. These ‘altitude plots’ (which represent the intensity of the radiated sound as a function of source location) show that while the parallel flow solutions exhibit a single peak at subsonic speeds (when the source point is centred on the initial shear layer), the non-parallel solutions exhibit a double peak structure, with the second peak occurring about two potential core lengths downstream of the nozzle. These results are qualitatively consistent with the numerical calculations reported in Karabasov et al. (2011).
Turbulence dynamics near a turbulent/non-turbulent interface
Authors: Teixeira M. A. C. , da Silva C. B. 
Published: February 2012

AbstractThe characteristics of the boundary layer separating a turbulence region from an irrotational (or non-turbulent) flow region are investigated using rapid distortion theory (RDT). The turbulence region is approximated as homogeneous and isotropic far away from the bounding turbulent/non-turbulent (T/NT) interface, which is assumed to remain approximately flat. Inviscid effects resulting from the continuity of the normal velocity and pressure at the interface, in addition to viscous effects resulting from the continuity of the tangential velocity and shear stress, are taken into account by considering a sudden insertion of the T/NT interface, in the absence of mean shear. Profiles of the velocity variances, turbulent kinetic energy (TKE), viscous dissipation rate ($\varepsilon $), turbulence length scales, and pressure statistics are derived, showing an excellent agreement with results from direct numerical simulations (DNS). Interestingly, the normalized inviscid flow statistics at the T/NT interface do not depend on the form of the assumed TKE spectrum. Outside the turbulent region, where the flow is irrotational (except inside a thin viscous boundary layer),$\varepsilon $decays as${z}^{\ensuremath{-} 6} $, where$z$is the distance from the T/NT interface. The mean pressure distribution is calculated using RDT, and exhibits a decrease towards the turbulence region due to the associated velocity fluctuations, consistent with the generation of a mean entrainment velocity. The vorticity variance and$\varepsilon $display large maxima at the T/NT interface due to the inviscid discontinuities of the tangential velocity variances existing there, and these maxima are quantitatively related to the thickness$\delta $of the viscous boundary layer (VBL). For an equilibrium VBL, the RDT analysis suggests that$\delta \ensuremath{\sim} \eta $(where$\eta $is the Kolmogorov microscale), which is consistent with the scaling law identified in a very recent DNS study for shear-free T/NT interfaces.
Is Discussion of the “United States of Africa” Premature? Analysis of ECOWAS and SADC Integration Efforts
Authors: Forere Malebakeng 
Published: February 2012

AbstractFor integration to succeed, the intending bloc of nations must begin with integration efforts that are based on gradual, continuous and concrete achievements, to create de facto solidarity among community members. This is the theoretical premise on which this article is based. This perspective is also drawn from the normative framework of both the Constitutive Act of the African Union (AU) and the Treaty Establishing the African Economic Community. According to its objectives, the AU aims to form a union government, to be preceded by successful economic integration through regional economic communities (RECs). While there are several RECs in Africa, this article examines those in west and southern Africa, being among the more developed. The article discusses whether the RECs have achieved their objectives to the extent that would warrant discussion of, and efforts towards, the imminent formation of the “United States of Africa”.
Female Genital Mutilation in Uganda: A Glimpse at the Abolition Process
Authors: Mujuzi Jamil Ddamulira 
Published: February 2012

AbstractThis article looks at three legal steps that have been taken in Uganda to abolish the practice of female genital mutilation: (1) a process during the drafting of the constitution that resulted in the enactment of different constitutional provisions that implicitly rendered female genital mutilation unconstitutional; (2) the declaration by the Constitutional Court in the case of Law and Advocacy for Women in Uganda v Attorney General in July 2010 that the practice is unconstitutional; and (3) the enactment in April 2010 of the Prohibition of Female Genital Mutilation Act. This article highlights some of the challenges that are likely to be encountered in enforcing both the Constitutional Court decision and the Prohibition of Female Genital Mutilation Act.
The Performance of Investment Bank-Affiliated Mutual Funds: Conflicts of Interest or Informational Advantage?
Authors: Hao (Grace) Qing , Yan Xuemin (Sterling) 
Published: February 2012

AbstractUsing a comprehensive sample of U.S. mutual funds from 1992 to 2004, we find strong evidence that investment bank-affiliated funds underperform unaffiliated funds. Consistent with the conflict of interest hypothesis, we find that affiliated funds hold disproportionately large amounts of stocks of their initial public offering and seasoned equity offering clients. Moreover, worse-performing clients are more likely to be held by affiliated funds. Our results are robust to alternative risk adjustments, portfolio weighting schemes, and regression methodologies. Overall, our findings are consistent with the idea that investment banks use affiliated funds to support underwriting business at the expense of fund shareholders.
‘Land for Those Who Work It’: A Visual Analysis of Agrarian Reform Posters in Velasco's Peru
Authors: CANT ANNA 
Published: February 2012

AbstractLatin American military dictatorships of the twentieth century were often right-wing, elitist and violent. A marked exception was the left-wing Peruvian military government of Juan Velasco Alvarado. More exceptional still was the government's use of visual media. Between 1968 and 1970 it produced approximately 20 posters, printed in editions of 50,000 to 200,000, to promote the radical Agrarian Reform Law. These posters provide vibrant representations of the agrarian reform's ideological aspects, which have been under-studied. A detailed exploration of visual communication shows that the government deployed aesthetically sophisticated propaganda and symbols to encourage social participation in the reform.
From Insurgent to Transgressive Citizenship: Housing, Social Movements and the Politics of Rights in São Paulo
Authors: EARLE LUCY 
Published: February 2012

AbstractThis article examines the rhetoric and practice of a large social movement organised around low-income housing in the city of São Paulo, Brazil. Making explicit the relationship between housing and citizenship, the União de Movimentos de Moradia (Alliance of Housing Movements) articulates a ‘politics of rights’ with which it calls on the state to uphold the constitutional right to housing, and legitimates its high-profile occupations of abandoned buildings in the centre of the city. The article engages with James Holston's historical examination of homeowners’ struggles on the peripheries of São Paulo to assert themselves as rights-holders and to mobilise against threats of eviction. While Holston names these groups of residents ‘insurgent’ citizens for the way they have unsettled entrenched social inequalities, this article presents the concept of ‘transgressive’ citizenship to reflect the challenge the housing movement makes to the state as it uses text-based law to justify building occupations.
Visual servoing applied to real-time stabilization of a multi-rotor UAV
Authors: Romero Hugo , Salazar Sergio , Lozano Rogelio 
Published: February 2012

SUMMARYIn this paper we address the problem of stabilization and local positioning of a four-rotor rotorcraft using computer vision. Our approaches to estimate the orientation and position of the rotorcraft combine the measurements from an Inertial Measurement Unit (IMU) and a vision system composed of a single camera. In the first stage, the vision system is used to estimate the position and yaw angle of the rotorcraft, while in the second stage the vision system is used to estimate the translational velocity of the flying robot. In both cases the IMU gives the pitch and roll angles at a higher rate. The technique used to estimate the position of the rotorcraft in the first stage combines the homogeneous transformation approach for the camera calibration process with the plane-based pose method for estimating the position. In the second stage, a navigation system using the optical flow is also developed to estimate the translational velocity of the aircraft. We present real-time experiments of stabilization and location of a four-rotor rotorcraft.
Importance of shade trees (Grevillea robusta) in the dispersal of forest tree species in managed tea plantations of southern Western Ghats, India
Authors: Chetana H. C. , Ganesh T. 
Published: February 2012

Abstract:Abandoned plantations of coffee, tea and other commercial crops offer opportunities for understanding ecological processes in modified forest ecosystems. Unlike tree plantations tea is maintained as a shrub with a continuous dense short canopy that precludes large-frugivore activity thereby limiting dispersal of forest species to such areas. In this study we determine how location and density ofGrevillea robustaa shade tree in tea plantations and proximity of plantations to forests influences seed arrival from forests into the plantations. We also estimate the importance of dispersal modes in the colonization processes. We laid 10 × 10-m plots at three distance intervals from the forest edge in three different plantation types with varying shade tree densities. Within the plots we laid four 1× 1-m subplots at the corners of the plot. We estimated species richness, abundance and categorized the seeds into dispersal modes in these plots.Grevillea robustaincreased species richness of seeds by three times and abundance of seeds by 3–30 times compared with plantations without them. Higher density ofG. robustaincreased seed input changed species composition and altered species dominance in the plantations. Distance to forests influenced seed arrival in plantations withoutG. robustatrees and plots 95 m from the forest did not have any seeds in them. No such effect was seen in plantations withG. robustatrees. Seeds dispersed by birds or a combination of birds and mammals contribute 30% of the seeds reaching the plantations withG. robustaand this was not influenced by distance from the forest. In plantations withoutG. robustabird dispersal is restricted to 25 m from the forest edge. In general density of shade trees has a strong influence on seed arrival which can negate the forest proximity effect and enhance natural forest colonization.
Salinity constrains size inequality and allometry in two contrasting mangrove habitats in the Gulf of Mexico
Authors: Méndez-Alonzo Rodrigo , Hernández-Trejo Humberto , López-Portillo Jorge 
Published: February 2012

Abstract:The competition for resources increases size inequality in trees, particularly under low abiotic stress. Because mangrove communities are subject to site-specific salinity (and therefore abiotic stress) gradients, these habitats should differ in height–diameter allometry and size inequality. The size inequality (by the Gini Coefficient, G) and maximum potential height (Hmax from a height–diameter asymptotic model) were determined within the mangrove forest of a coastal lagoon in Veracruz, Mexico in 20 0.25-ha plots, 10 in interdistributary basins (IBs, lower salinity) having Avicennia germinans, Laguncularia racemosa and Rhizophora mangle and 10 in mudflats (MFs, higher salinity) dominated by A. germinans. Size inequality was significantly higher in IBs (G = 0.59 ± 0.02 vs. 0.39 ± 0.03). Due to their significant intercorrelation G, total basal area and density were synthesized in one PCA axis accounting for 67% of total variance and inversely correlated with salinity (R = −0.65, P = 0.003). The height–diameter scaling model reached a stable asymptote (Hmax range: 16–21 m; coefficient of variation CV: 7.7) in IBs, suggesting that trees can still increase their diameter after achieving maximum height. In MFs, no stable asymptote was reached (Hmax range: 11–26 m; CV: 32.5), suggesting a lower growth rate of diameter in the MF trees when compared with IB trees.