bluuebunny/crossref_metadata_2025 huggingface dataset:
Brief communication "Important role of the mid-tropospheric atmospheric circulation in the recent surface melt increase over the Greenland ice sheet"
Authors: Fettweis X. , Hanna E. , Lang C. , Belleflamme A. , Erpicum M. , Gallée H.
Published: September 2012

Abstract. Since 2007, there has been a succession of surface melt records over the Greenland Ice Sheet (GrIS) in continuity of the trend observed since the end of the 1990s towards increasing melt. But, these last two decades are characterized by an increase of negative phases of the North-Atlantic Oscillation (NAO) favouring warmer and drier summers than normal over GrIS. In this context, we use a circulation type classification based on the daily 500 hPa geopotential height to evaluate the role of the atmospheric dynamics in this surface melt acceleration since 20 yr. Due to the lack of direct observations, the interannual melt variability is gauged here by the summer (June-July-August) mean temperature at 700 hPa over Greenland; analogous atmospheric circulations in the past show that ~70% of the 1992–2011 warming at 700 hPa over Greenland has been driven by changes in the atmospheric flow frequencies. Indeed, the occurrence of anticyclones in surface and at 500 hPa centred over the GrIS has doubled since the end of 1990s which induces southerly warm air advection along the Western Greenland coast and over the neighbouring Canadian islands. These changes in the NAO modes explain also why no significant warming has been observed these last five summers over Svalbard, where northerly atmospheric flows are more frequent than before. Therefore, the recent warmer summers over Greenland, Ellesmere and Baffin Islands can not be considered as a long term climate warming but are more rather a consequence of the NAO variability impacting the atmospheric heat transport. While no global model from the CMIP5 database projects consequent changes in NAO through this century, we can not exclude that these changes in NAO are due to global warming.
Glaucoma Progression Detection: Agreement, Sensitivity, and Specificity of Expert Visual Field Evaluation, Event Analysis, and Trend Analysis
Authors: Antón Alfonso , Pazos Marta , Martín Belén , Navero José Manuel , Ayala Miriam Eleonora , Castany Marta , Martínez Patricia , Bardavío Javier
Published: September 2012

Purpose.

To assess sensitivity, specificity, and agreement among automated event analysis, automated trend analysis, and expert evaluation to detect glaucoma progression.

Methods.

This was a prospective study that included 37 eyes with a follow-up of 36 months. All had glaucomatous disks and fields and performed reliable visual fields every 6 months. Each series of fields was assessed with 3 different methods: subjective assessment by 2 independent teams of glaucoma experts, glaucoma/guided progression analysis (GPA) event analysis, and GPA (visual field index-based) trend analysis. Kappa agreement coefficient between methods and sensitivity and specificity for each method using expert opinion as gold standard were calculated.

Results.

The incidence of glaucoma progression was 16% to 18% in 3 years but only 3 cases showed progression with all 3 methods. Kappa agreement coefficient was high (k=0.82) between subjective expert assessment and GPA event analysis, and only moderate between these two and GPA trend analysis (k=0.57). Sensitivity and specificity for GPA event and GPA trend analysis were 71% and 96%, and 57% and 93%, respectively.

Conclusions.

The 3 methods detected similar numbers of progressing cases. The GPA event analysis and expert subjective assessment showed high agreement between them and moderate agreement with GPA trend analysis. In a period of 3 years, both methods of GPA analysis offered high specificity, event analysis showed 83% sensitivity, and trend analysis had a 66% sensitivity.
Clinical and Epidemiologic Features of Diarrheal Disease due to Aeromonas hydrophila and Plesiomonas shigelloides Infections Compared with Those due to Vibrio cholerae Non-O1 and Vibrio parahaemolyticus in Bangladesh
Authors: Klontz Erik H. , Faruque Abu S. G. , Das Sumon K. , Malek Mohammed A. , Islam Zhahirul , Luby Stephen P. , Klontz Karl C.
Published: September 2012

Using data from the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) from 1996 to 2001, we compared the clinical features of diarrhea in patients with stool specimens yielding only A. hydrophila (189 patients; 1.4% of 13,970 patients screened) or P. shigelloides (253 patients) compared to patients with sole V. cholerae non-O1 infection (99 patients) or V. parahaemolyticus infection (126 patients). Patients exhibited similar frequencies of fever (temperature >37.8°C), stools characterized as watery, and stools containing visible mucus. Dehydration was observed more often among patients with V. parahaemolyticus or V. cholerae non-O1 infection. Compared to patients infected with V. parahaemolyticus, those with A. hydrophila, P. shigelloides, or V. cholerae non-O1 infection were less likely to report visible blood in the stool and, on microscopic examination, less likely to exhibit stool red blood cell and white blood cell counts exceeding 20 cells per high power field. The proportion of patients reporting subjective cure at the time of discharge was significantly smaller for those infected with V. parahaemolyticus. These findings suggest that A. hydrophila and P. shigelloides produce diarrheal disease that is less severe than that resulting from infection with V. cholerae non-O1 or V. parahaemolyticus.
Electrodynamics of Bechgaard Salts: Optical Properties of One-Dimensional Metals
Authors: Dressel Martin
Published: September 2012

The electrodynamic properties of the quasi-one-dimensional organic conductors (TMTSF)2X are discussed, with particular emphasis on important deviations from the simple Drude model, the transition from a Luttinger-liquid to a Fermi-liquid behavior at the dimensional crossover when pressure is applied or temperature reduced, indications of a pseudogap as well as a low-frequency collective mode. Superconductivity and spin-density-wave ground states breaking the symmetry and gaps should occur in the excitation spectra. The previous literature is summarized and the current status of our understanding presented. Novel THz experiments on (TMTSF)2PF6 and (TMTSF)2ClO4 not only shine light into some of the open questions, but also pose new ones.
Conditions Associated with Childhood Asthma in North Texas
Authors: Newcomb Patricia , Cyr Alaina
Published: September 2012

Introduction. The purpose of this study was to identify significant associations between asthma diagnosis, comorbid conditions, and social problems in children. Method. This study explored data collected in a unique, regional survey of children’s health in north Texas originally administered in 2009 to a random sample of 21,530 households with children from 0 to 14 years of age. Descriptive statistics were compiled for the subsample of children with asthma, associations of interest were identified, and strengths of relevant associations were calculated. Results. The prevalence of asthma in school-aged children in the target area is 19–25%, which exceeds both national and state values. Statistically significant associations were found between asthma and allergies, sleep problems, and tonsillectomy. Significant associations were identified between asthma and school absences, academic problems, and behavior problems in school. There was a significantly greater prevalence of obesity/overweight among children with asthma than without asthma.
Discussion. Children with asthma are at high risk for impairment in multiple dimensions. Thorough assessment, including comprehensive medical, social, and environmental histories, is critical in management of pediatric asthma.
Mules and Men and Messiahs: Continuity in Yoruba Divination Verses and African American Folktales
Authors: Washington Teresa N.
Published: September 2012

Zora Neale Hurston’s Mules and Men reveals that African Americans were able to revise, restructure, and reformulate African orature to fit their social, political, and spiritual needs. This study examines the transformation of Yoruba ese Ifá (Ifá divination verses) into folktales and analyzes the similarities and divergences in the content and characters of the orature. This essay highlights the subtle ways that African Americans politicized and revolutionized the ese Ifá to protect the verses’ wisdom and facilitate their proliferation. The revised ese Ifá, disguised as innocuous folktales, were central to the formation of the African American worldview because they reminded dislocated Africans that divinity was not restricted to an invisible entity or controlled by a select few but was both an inheritance and an imperative essential for liberation and self-actualization.
Establishing Igbo Community Tradition in the United States: Lessons from Folkloristics
Authors: Njoku J. Akuma-Kalu
Published: September 2012

Since 2000, the goal of my teaching of Igbo cultural heritage in the United States has been to resuscitate suppressed Igbo community traditions and neglected traditional knowledge among educated parents so that they can pass their Igbo culture on to their American-born children. It is for this reason that I have chosen to be called, and have come to be known in Igbo American communities as TICHA, which stands for the Teaching of Igbo Cultural Heritage in America. This article shows how I have been using lessons from my over thirty years’ study of Igbo folklore to reacquaint Igbo people in America with Igbo cultural heritage, thereby shaping their preparedness to resuscitate and establish their ethnic community tradition in the United States.
“Sisebutas” en Buenos Aires. Family strips de los años veinte
Authors: Gené Marcela
Published: September 2012

O artigo trata de uma das tiras familiares de maior sucesso que circulou na imprensa de Buenos Aires nos anos 20: Pequenas delícias da vida conjugal, (Bringin'up father) criada por George Macmanus em 1912 para o empório jornalístico de W.R. Hearst. A trama aponta para as vicissitudes cotidianas de um casamento formado por uma esposa "autoritária" e um marido "dominado", um topos humorístico de longa tradição na cultura ocidental. Nosso propósito é analisar, sob a ótica da história cultural e dos estudos warburguianos, sua trajetória histórica em produções de diversos gêneros artísticos, bem como investigar as projeções desse topos nas histórias em quadrinhos contemporâneas e em outras esferas artísticas, como a literatura. , teatro e cinema.
El viejo problema del analfabetismo sigue en pie: el escenario educativo en la provincia de Buenos Aires durante la década del ’40
Authors: Petitti Eva Mara
Published: September 2012

Neste trabalho pretendemos investigar o problema do analfabetismo na província de Buenos Aires durante a década de 1940, enfocando especialmente as vésperas do governo de Domingo Mercante (1946-1952) e nos primeiros anos de sua gestão. Para isso, tomamos dois eixos. A primeira tem a ver com o nível de percepções, ou seja, com os diagnósticos feitos pelos políticos antes e depois da ascensão de Domingo Mercante como governador. A segunda está relacionada à heterogeneidade do cenário educacional na província de Buenos Aires durante essa década. Enquadrando-nos nos trabalhos que analisam o peronismo a partir de uma perspectiva regional, escolhemos o caso da província de Buenos Aires, não só por sua gravitação na vida política argentina, mas também por ser a província com maior população em idade escolar e interna imigração.
Historicismo: notas sobre um paradigma
Authors: Barros José D’Assunção
Published: September 2012

Este artigo tem por objetivo desenvolver algumas considerações sobre o Historicismo e sua possibilidade de ser examinado como um dos paradigmas que concorrem para o estabelecimento de uma história científica no século XIX. O primeiro ponto tratado é relativo às origens do paradigma historicista na transição do século XVIII para o século XIX. Na sequência, aproximamo-nos da apropriação conservadora do paradigma historicista no novo contexto no qual a burguesia européia está assentada no Poder, combinando-se com a consolidação dos modernos estados-nações. A especificação das características deste paradigma constituem o principal ponto de análise.
Os rumos da centralização agrícola e industrial no Brasil: a agricultura nacional segundo André Rebouças
Authors: Meira Roberta Barros
Published: September 2012

Ao pensarmos na produção açucareira do final no XIX, deparamo-nos com um setor em crise que precisava de capitais para implementar o moderno maquinismo adotado já há algum tempo pelos países concorrentes. O presente trabalho indaga-se sobre a importância das idéias de André Rebouças em relação às demandas da indústria sacarina no seu trabalho intitulado “Agricultura nacional e estudos econômicos”. Assim, o objetivo deste estudo é relacionar os temas abordados por Rebouças, arguto observador de seu tempo, principalmente no que tange a problemática enfrentada pela indústria sacarina e as idéias correntes neste período sobre a viabilidade da adoção da centralização agrícola e industrial no Brasil.
Modernización capitalista y pobreza en Mendoza, Argentina. Desarrollo agroindustrial y condiciones de vida de los sectores populares, 1890-1918
Authors: Richard-Jorba Rodolfo
Published: September 2012

Entre a última década do século XIX e as duas primeiras do século XX, a província argentina de Mendoza experimentou mudanças substanciais em seu território, economia e sociedade causadas pelo avanço do capitalismo, que formou uma das primeiras economias regionais do país: a viticultura industrial. O desenvolvimento capitalista gerou uma expansão econômica até então desconhecida, com a qual se multiplicaram todos os indicadores: ampliação do cultivo vitícola, instalação de vinícolas, aumento da capacidade vitivinícola, tecnificação. No social, parcelamento da terra, surgimento de uma classe empresarial e expansão dos grupos médios da sociedade. No entanto, os setores majoritariamente populares, incessantemente aumentados pela imigração ultramarina, sofriam condições de vida caracterizadas por baixos rendimentos, que se mantiveram em valores nominais durante o período estudado; e problemas habitacionais e de saúde, que levaram à disseminação de doenças infectocontagiosas graves e altas taxas de mortalidade infantil. O artigo mostra o contraste entre um vigoroso desenvolvimento das forças produtivas e as condições miseráveis em que vivia a maioria da população.
A burguesia enquadrada: Mafalda e sua turma criticam elementos da sociedade burguesa (a naturalização das diferenças, a desumanização e a competição) na aula de História
Authors: Oliveira Carlos Eduardo Rebuá
Published: September 2012

Este trabalho objetiva, a partir de uma perspectiva marxista, refletir sobre a possibilidade de, em se criticando a sociedade burguesa na aula de História, se construir coletivamente, no limite, leituras contrahegemônicas da realidade. Alicerçados no conceito gramsciano de hegemonia e na noção de contrahegemonia, analisamos as histórias em quadrinhos não no intuito de instrumentalizar esta linguagem cada vez mais presente na sala de aula, mas no esforço de compreendê-la como um elemento que pode contribuir bastante para a crítica do real, para a explicitação do momento histórico em que foi produzida, para um ensino de História mais lúdico e crítico ao mesmo tempo. Em termos metodológicos, foram selecionadas três tiras de Mafalda (intituladas “A naturalização das diferenças”, “A desumanização” e “A competição”), presentes na obra Toda Mafalda (2002), no intuito de subsidiar as reflexões aqui esboçadas. Este trabalho representa um recorte da dissertação de mestrado defendida no Programa de Pós-Graduação em Educação da UERJ (ProPEd), em março de 2011, sob o título: Mafalda na aula de História: a crítica aos elementos característicos da sociedade burguesa e a construção coletiva de sentidos contra-hegemônicos.
Um modelo para imitar: a Disney no projeto empresarial de Ezeiza e Dante Quiinterno
Authors: Vazquez Laura
Published: September 2012

Este artigo pertence ao campo dos estudos culturais transnacionais e busca contrastar o filme “Saludos Amigos” dos Estúdios Disney e o curta-metragem “Upa en apuros” realizado nos estúdios de Dante Quiinterno, ambos realizados no ano de 1941/1942. Como veremos, enquanto os filmes produzidos pela Disney são um "trabalho de aluguel", a produção de Quiinterno dá conta do interesse do editor em seguir os passos de seu professor, mas, sobretudo, mostra a vontade de progredir de Quiterno. A maneira como um dos empregadores mais conservadores e tradicionais conduz esse plano tem suas próprias contradições. Parto de um conjunto de problemas decorrentes das poucas fontes disponíveis na visita de Walt Disney à Argentina, com o objetivo final de evitar o reducionismo que sugere um fenômeno linear de 'americanização' da oferta de entretenimento em nosso país.
Extraocular sebaceous carcinoma: a series of three cases with varied presentation
Authors: Panjwani Poonam K. , Tirumalae Rajalakshmi , Castra Julian , Manjunath Suraj , Rout Pritilata
Published: September 2012

Background: Extraocular sebaceous carcinomas are rare cutaneous malignancies that account for only about 25% of all sebaceous carcinomas. The most common site of occurrence is the head/neck region. They are aggressive neoplasms that possess metastatic potential to regional or distant sites. Wide local excision of the lesion with removal of regional lymph nodes is the usual mode of therapy.

Methods: We present a series of three cases of sebaceous carcinomas occurring in extraocular sites outside the head and neck areas, like the axilla, chest wall, arm and thigh. One of these cases had an associated colonic carcinoma and constituted Muir-Torre syndrome (MTS). Another case presented with a skin nodule and regional nodal metastasis. The third case had a history of recurrent similar lesions at the same site.

Conclusion: Although rare, extraocular sebaceous carcinomas are seen at varied sites and frequently pose problems in diagnosis. A longterm follow-up of these cases is warranted due to their aggressive behaviour, risks of recurrence, metastasis and the possibility of development of visceral malignancies.
Human papillomavirus induced periungual pigmented Bowen’s disease
Authors: Ramirez-Fort Marigdalia K.
Published: September 2012

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Extensive regression in pigmented skin lesions: a dangerous confounding feature
Authors: Lallas Aimilios , Apalla Zoe , Moscarella Elvira , Zalaudek Iris , Tzellos Thrasivoulos , Lefaki Ioanna , Cota Carlo , Argenziano Giuseppe
Published: September 2012

Spontaneous regression in melanomas is not an uncommon phenomenon, as it has been described in 10-35% of primary cutaneous lesions [1]. Regression does not appear to predict a more favorable course, since even fully regressed melanomas may progress into metastatic disease [2]. Several dermoscopic features have been correlated with the regression process, including white scar-like depigmented areas and gray-blue, pepper-like granules, which correspond to dermal scarring, pigment incontinence and presence of melanophages [3,4]. Regression may occur not only in melanomas, but also in melanocytic nevi, which similarly may exhibit white areas and gray-blue granules or areas under dermoscopy [5]. Overall, white areas have been proposed to be associated with the fibrosis type of regression and gray-blue areas to the melanosis type of regression of melanocytic tumors [3]. Lichen planus like keratosis (LPLK) is considered to represent a regressed solar lentigo or seborrheic keratosis. Dermoscopy of LPLK at the late stage of the regression process reveals a diffuse gray-blue granular pattern, similar to that observed in regressed melanocytic lesions [6].

In this context, when evaluating skin lesions that exhibit high degree of regression, interpretation of dermoscopic findings may be problematic, especially when no other dermoscopic clues can be recognized.
Aggressive basal cell carcinoma: dermatoscopy vascular features as clues to the diagnosis
Authors: Pyne John , Sapkota Devendra , Wong Jian Cheng
Published: September 2012

Background: Basal cell carcinoma (BCC) can present with indolent or aggressive subtypes. These subtypes usually display vascular features, which are often readily identified using dermatoscopy.

Objective: Dermatoscopy vascular features of aggressive BCC were compared to superficial, superficial and nodular, and nodular BCC for diagnostic discrimination.

Method: Dermatoscopy vascular features were recorded live direct from the patient for 1,098 consecutive BCC. Cases with potential confounding influences were excluded. These tumor vascular features included branching (arborizing), serpentine, dot, coil (glomerular), loop (hairpin) and linear vessels. The proportion of pink within the tumor, central versus peripheral tumor vessel distribution and the presence of large vessels within the tumor boundary were also recorded.

Results: Different subtypes of BCC have distinctive vascular features. Aggressive BCC (n=213) displays a tumor area with no pink (12.2%) or less than half the area pink (27.2%) and absent vessels in the central tumor area (22.1%, CI 17.0%-28.1%, P<0.001) compared to other subtypes. Superficial BCC (n=284) have more than half the tumor area pink (84.9%) and absent large vessels (92.6%), CI 89.0% – 95.1%. Nodular BCC (n=230) is characterized by larger vessels (45.7%, CI 39.3%-52.1%, P<0.001) as compared to other subtypes, as well as less dot, coil and loop vessels. Kappa values for all recorded features ranged from 0.48 to 1.0.

Limitations: Aggressive BCCs within the combined aggressive group were not assessed separately.

Conclusions: Diagnostic discrimination between different subtypes of BCC is facilitated by vascular feature assessment. Compared to other subtypes, aggressive BCC displays less or no pink and less or absent central tumor vessels.
Strategies for early recognition of cutaneous melanoma—present and future
Authors: Brehmer Franziska , Ulrich Marina , Haenssle Holger A.
Published: September 2012

Cutaneous melanoma is a highly aggressive malignant tumor of skin melanocytes with an increasing incidence in most countries of the world, especially in the fair-skinned populations. Despite all preventive and therapeutic efforts, malignant melanoma is still the most lethal skin cancer. A delayed diagnosis results in an advanced stage and worsened prognosis. Once distant metastases are present, the five-year survival rate is less than 10 percent. At the same time, patients may be cured by an early diagnosis of cutaneous melanoma followed by a wide excision. Therefore, the early detection of melanoma at curable stages is crucial for the patients’ survival. Besides the investigation of pigmented lesions with the unaided eye, a wide range of examination techniques for improved diagnostic accuracy have been developed and validated in clinical trials. However, none of these techniques are able to provide a definite and final diagnosis or to replace an excisional biopsy of suspicious lesions followed by histological analysis. This review provides a concise overview of general principles as well as current and future strategies for an improved early diagnosis of cutaneous melanoma.
Pigmented poroma with unsusual locatin and dermatoscopic features
Authors: Kassuga Luiza E.B.P. , Jeunon Thiago , Jeunon Sousa Maria Auxiliadora , Campos-do-Carmo Gabriella
Published: September 2012

Poroma is a benign adnexal neoplasm with “poroid”/ductal differentiation that mimics benign and malignant skin tumors. Histopathology shows circumscribed proliferation of poroid cells intermingled with a variable number of cuticular cells. We report a case of pigmented poroma located on the face that simulated clinically and dermatoscopically a pigmented basal cell carcinoma. The features of pigmented and non-pigmented poromas were revisited in order to assist in the diagnosis.
Neuroimaging and Neurocognitive Correlates of Aggression and Violence in Schizophrenia
Authors: Weiss Elisabeth M.
Published: September 2012

Individuals diagnosed with major mental disorders such as schizophrenia are more likely to have engaged in violent behavior than mentally healthy members of the same communities. Although aggressive acts can have numerous causes, research about the underlying neurobiology of violence and aggression in schizophrenia can lead to a better understanding of the heterogeneous nature of that behavior and can assist in developing new treatment strategies. The purpose of this paper is to review the recent literature and discuss some of the neurobiological correlates of aggression and violence. The focus will be on schizophrenia, and the results of neuroimaging and neuropsychological studies that have directly investigated brain functioning and/or structure in aggressive and violent samples will be discussed as well as other domains that might predispose to aggression and violence such as deficits in responding to the emotional expressions of others, impulsivity, and psychopathological symptoms. Finally gender differences regarding aggression and violence are discussed. In this context several methodological and conceptional issues that limited the comparison of these studies will be addressed.
Microwave Tubes
Authors: Granatstein Victor L. , Parker (deceased) Robert K.
Published: September 2012

The sections in this article are

Principles of Operation

Types of Microwave Tubes

Future Directions
Lip and Oral Cavity
Authors: Sobin L. H. , Gospodarowicz M.K. , Wittekind Ch.
Published: September 2012

The TNM system is used to describe and classify cancer stages and progression based on the assessment of three components:

T

The extent of the primary tumour

N

The absence or presence and extent of regional lymph node metastasis

M

The absence or presence of distant metastasis.

TNM classification for the above site is described under the following headings:

Rules for classification with the procedures for assessing T, N, and M categories; additional methods may be used when they enhance the accuracy of appraisal before treatment

Anatomical sites and subsites where appropriate

Definition of the regional lymph nodes

TNM Clinical classification

pTNM Pathological classification

G Histopathological grading

Stage grouping

Summary
Retinoblastoma
Authors: Sobin L. H. , Gospodarowicz M.K. , Wittekind Ch.
Published: September 2012

The TNM system is used to describe and classify cancer stages and progression based on the assessment of three components:

T

The extent of the primary tumour

N

The absence or presence and extent of regional lymph node metastasis

M

The absence or presence of distant metastasis.

TNM classification for the above site is described under the following headings:

Rules for classification with the procedures for assessing T, N, and M categories; additional methods may be used when they enhance the accuracy of appraisal before treatment

Anatomical sites and subsites where appropriate

Definition of the regional lymph nodes

TNM Clinical classification

pTNM Pathological classification

G Histopathological grading

Stage grouping

Summary
Changes in the properties of normal human red blood cells during in vivo aging
Authors: Franco Robert S. , Puchulu‐Campanella M. Estela , Barber Latorya A. , Palascak Mary B. , Joiner Clinton H. , Low Philip S. , Cohen Robert M.
Published: September 2012

The changes in red blood cells (RBC) as they age and the mechanisms for their eventual removal have been of interest for many years. Proposed age‐related changes include dehydration with increased density and decreased size, increased membrane IgG, loss of membrane phospholipid asymmetry, and decreased activity of KCl cotransport. The biotin RBC label allows unambiguous identification of older cells and exploration of their properties as they age. Autologous normal human RBC were labeled ex vivo and, after reinfusion, compared with unlabeled RBC throughout their lifespan. RBC density increased with age, with most of the change in the first weeks. Near the end of their lifespan, RBC had increased surface IgG. However, there was no evidence for elevated external phosphatidylserine (PS) even though older RBC had significantly lower activity of aminophospholipid translocase (APLT). KCl cotransport activity persisted well past the reticulocyte stage, but eventually decreased as the RBC became older. These studies place limitations on the use of density fractionation for the study of older human RBC, and do not support loss of phospholipid asymmetry as a mechanism for human RBC senescence. However, increased levels of IgG were associated with older RBC, and may contribute to their removal from the circulation. Am. J. Hematol. 2013. © 2012 Wiley Periodicals, Inc.
Reproductive effects on skeletal health in Shuar women of Amazonian Ecuador: A life history perspective
Authors: Madimenos Felicia C. , Snodgrass J. Josh , Liebert Melissa A. , Cepon Tara J. , Sugiyama Lawrence S.
Published: September 2012

Objective:

Clinical and epidemiological research suggest that bone mineral density (BMD) in women is shaped by various reproductive factors such as parity and lactation patterns. However, the extent of these effects on BMD remains unclear because of contradictory findings and a focus on industrialized populations. Because fertility patterns in these groups are vastly different than those of women from non‐Western, subsistence populations, our current understanding of the reproductive effects on skeletal health is incomplete. Using a life history perspective, this study examines the relationship between reproductive factors and bone density among women from the Indigenous Shuar population, an Amazonian Ecuadorian forager‐horticulturalist group.

Methods:

This preliminary, cross‐sectional study included 130 premenopausal and postmenopausal women (14–86 years old) from the Morona‐Santiago region of Ecuador. Anthropometrics were recorded, as was estimated BMD using a calcaneal ultrasonometer. A reproductive history questionnaire was administered that included questions regarding menarche, parity, lactation patterns, and menopause.

Results:

Among postmenopausal women, early menarche and greater stature were significantly associated with higher bone density values. Among premenopausal women, few significant relationships between bone values and reproductive variables were documented; effects of lactation appeared to be transient and restored following weaning.

Conclusions:

Although preliminary and not based on longitudinal data, these findings suggest that the effects of reproduction are transient as the system of calcium homeostasis in premenopausal women efficiently restores the bone loss that results from metabolically active reproductive states. Further, this research suggests that the timing of early life history events may canalize bone density phenotype. Am. J. Hum. Biol., 2012. © 2012 Wiley Periodicals, Inc.
Strukturen alkalimetallorganischer und verwandter Verbindungen
Authors: Weiss Erwin
Published: September 2012

Die Erforschung der Reaktivität und Struktur alkalimetallorganischer Verbindungen hat in den letzten Jahrzehnten eine geradezu stürmische Entwicklung durchlaufen. Zu diesen Verbindungen gehören einige für das Verständnis der chemischen Bindung besonders wichtige und auch einfache wie die Methylverbindungen der Alkalimetalle, deren Strukturen nun vollständig aufgeklärt sind. Ganz allgemein erwiesen sich die organischen Verbindungen der Alkalimetalle und auch des Magnesiums als Ionenaggregate, deren Eigenschaften sich durch Solvatisierung, z.B. durch Ether und Amine, stark verändern lassen. Auf diesen Erkenntnissen beruhen auch wichtige Fortschritte bei der Synthese vor allem von Verbindungen der schwereren Alkalimetalle. Lange galten die Alkalimetalle als wenig koordinationsfreundlich, und ihre Komplexchemie bot kaum Überraschungen. Dieses Bild hat sich völlig gewandelt. Kristallstrukturuntersuchungen erbrachten eine Fülle von oft überraschenden Strukturtypen (Ringe, Heterocubane, Ketten, Stapel etc.), nicht nur bei ihren organischen Verbindungen, sondern auch bei ihren Amiden, Imiden, Alkoxiden, Phenoxiden, Enolaten und sogar Halogeniden. Ein Vergleich läßt interessante Gemeinsamkeiten der scheinbar so verschiedenen Verbindungen erkennen und führt zu einer allgemeineren Klassifizierung derartiger Strukturtypen mit C‐, N‐, O‐ und Halogeno‐Liganden.
Wasserlösliche Liganden, Metallkomplexe und Komplexkatalysatoren: Synergismen aus Homogen‐ und Heterogenkatalyse
Authors: Herrmann Wolfgang A. , Kohlpaintner Christian W.
Published: September 2012

Rasche Fortschritte auf dem Gebiet der Katalyse führen zu einem zunehmenden Bedarf an maßgeschneiderten Katalysatoren. Wasserlösliche Komplexkatalysatoren, neuerdings intensiv erforscht, vereinigen Vorteile der Homogen‐ und Heterogenkatalyse: einfache und vollständige Produkt‐Katalysator‐Trennung, hohe Aktivitäten und hohe Selektivitäten. Aus dem großen Repertoire an wasserlöslichen Liganden lassen sich für viele Reaktionen maßgeschneiderte Katalysatoren entwickeln. Industrielle Anwendungen auf den Gebieten der Hydrierung und Hydroformylierung zeigen schon heute die breiten Einsatzmöglichkeiten dieser Katalysatorklasse. Die Jahresproduktion von 300 000 Tonnen Butyraldehyd auf der Basis wasserlöslicher Rhodiumkomplexe im Ruhrchemie/Rhône‐Poulenc‐Verfahren überzeugt schon jetzt von der technischen Anwendbarkeit des Konzepts der komplexkatalysierten Reaktionen in Zweiphasensystemen. Die effiziente Gestaltung katalytischer Prozesse erfordert zunehmend die verlustfreie Rückführung des Edelmetallkontaktes, was mit Zweiphasensystemen einfach und ökonomisch realisierbar ist. Spezialanwendungen bei biochemischen Problemen eröffnen wasserlöslichen übergangsmetallkomplexen Entwicklungsfelder, die weit über die angestammte Homogenkatalyse hinausweisen. In naher Zukunft wird die Erforschung und Anwendung von Metallkomplexkatalysatoren, die im physiologisch unbedenklichen, billigen und umweltfreundlichen Lösemittel Wasser ihre Wirkung entfalten, zu einem Schwerpunkt der Katalysatorforschung werden.
Hydrophobe Effekte – Ansichten und Tatsachen
Authors: Blokzijl Wilfried , Engberts Jan B. F. N.
Published: September 2012

Das Bestreben relativ unpolarer Verbindungen, sich in wäßriger Lösung aneinander zu lagern, wird mit dem Begriff hydrophobe Wechselwirkungen beschrieben. Diese Wechselwirkungen sind in vielen Gebieten der Chemie, einschließlich der Chemie in vivo, von entscheidender Bedeutung. Enzym‐Substrat‐Wechselwirkungen, die Anordnung von Lipiden in biologischen Membranen, die Aggregation oberflächenaktiver Stoffe und kinetische Solvenseffekte in wasserreichen Lösungsmittelsystemen – sie alle werden in erster Linie durch hydrophobe Wechselwirkungen bestimmt. Trotz enormer Anstrengungen weiß man noch wenig über die Hydratation unpolarer Moleküle und über die nichtkovalenten Wechselwirkungen zwischen diesen Molekülen in Wasser. Wenn man sich nun die Frage stellt, was denn die treibende Kraft hinter hydrophoben Wechselwirkungen ist, so führt dies zu der Forderung, die herausragenden Eigenschaften flüssigen Wassers genau zu verstehen. Diese übersicht beschreibt einige neue Erkenntnisse auf diesem Gebiet aus den letzten zehn Jahren. Schwerpunkte sind sowohl die hydrophobe Hydratation als auch hydrophobe Wechselwirkungen, denn beide Phänomene hängen ganz eng zusammen. Es hat sich gezeigt, daß viele der bisherigen Sichtweisen zutiefst unbefriedigend sind, und man hat mutige Versuche unternommen, die treibende Kraft für hydrophobe Wechselwirkungen zwischen zwei oder vielen Molekülen zu verstehen. Hier wird eine zugegebenerweise persönliche Auswahl experimenteller und theoretischer Entwicklungen der letzten Zeit vorgestellt und, wenn nötig, durch Hinweise auf relevante frühere Studien ergänzt.
Einfluß der Symbolik und des Formalismus auf die Entwicklung des mathematischen Denkens
Authors: Knobloch Eberhard
Published: September 2012

The object of this article is the study of possibilities and tendencies arising from the use of symbolic language including signs, characters, and symbols in mathematics. Five aspects are discussed: compactness and simultaneity, problem‐solving and generalizations, heuristics and progress, mechanisms and calculations, formalism. This is done primarily by looking at three disciplines, which at the same time are of fundamental importance to theoretical physics: classical algebra, calculus, and vector analysis.

Mathematical achievements and statements by eminent mathematicians from antiquity to the present (Archimedes, Leibniz, Newton, Euler, Gauß, Hilbert) show the importance of adequate symbolism for the development of mathematics. The corresponding philosophical discussions (Hobbes, Condillac, Degérando, Apelt, Cassirer, among others) are controversial.
Erschließung neuer Wahrnehmungsebenen durch die Kinematographie: Ästhetik‐Überlegungen zum wissenschaftlichen Film
Authors: Reimers Karl Friedrich
Published: September 2012

By some recent meanings of psychological research in structures of perception cinematographical research and education ist compelled to take the fluctuation between emotions/sensations and cognitions into a more systematic consideration. ‚Born’︁ as well on the market‐place as by experimental research documentations film as a medium can offer essential connecting links for this aspect. Certainly there is to begin with recovering an especially understanding of esthetics: more different relations between various standards of qualitative and quantitative analysis must be rendered possible. This is substantial, first of all, for an experimentally working anthropology, research in cultures/civilizations, and sociological sciences. In these fields of research and education, if using research film, we especially need inter‐disciplinary cooperations for critical investigation and for making didactical use of cinematographic sources.
Strukturen der wissenschaftlichen Betätigung und das zeitlich exponentielle Wachstum der neuzeitlichen Naturwissenschaft
Authors: Stuhlhofer Franz
Published: September 2012

Structures of scientific activity and the exponential growth (as a function of time) of modern science. Scientific research may have an additive, multiplicative or exponential character. ‚Additive’︁ signifies that single facts are gathered; ‚multiplicative’︁ signifies that out of several facts, a regularity or formula is recognized: single facts are thereby multiplied into many. ‚Exponential’︁ signifies that every finding serves as a springboard for further findings, which in turn serve as springboards for others as well. This exponential character, however, does not necessarily have as a consequence an exponential growth of knowledge as a function of time.

The slogan of the doubling of knowledge every 15 years is not universally valid: since the 16th century knowledge of plant species has doubled every 60 years; for animal species during the two centuries before ca. 1930, the doubling period is 21–22 years. For comets, the doubling periods are considerably longer and for chemical elements, the increase is only linear (one new element every 2 1/2 years). Science as a whole is composed of many such smaller fields. The specification of the speed (or better the acceleration) of its growth depends on which ‚degree of importance’︁ of knowledge is measured. If one takes only very important (e.g. University Textbook) knowledge as a standard, the doubling period is just short of a century. Of course, this does not alter the correctness of the observation that modern science has grown exponentially. If, however, one wishes to speak of a ‚law’︁, it is necessary to formulate one.
Die Bedeutung des physico‐theologischen Gottesbeweises für die nachcartesianische Physiologie im 18. Jahrhundert
Authors: Toellner Richard
Published: September 2012

The importance of the physico‐theological literature is underlined as its influence expands with Ray and Derham, flooding continental Europe in the first half of the 18th century. Until now the history of science, philosophy, and theology have either ignored or tended to underplay the influence of the concept of nature presented in the physico‐theological writings. The development of this concept, however, was a major historical precondition for the empirical investigations of nature which followed in the early Enlightment. Physico‐theology is characterized by the combination of belief in God's creation of the world, a rationalistic model of nature, an epistemology grounded in sensual perception and the primacy of observational science. It popularized a mechanical model of nature and reconciled this new model with the religious needs of the age by interpreting nature as the perfect order of a perfect Maker and by shifting emphasis from the construction of the machine to its functions by means of its search for and description of the wonderful utility of nature. The example of Albrecht von Haller helps clarify these claims.
Coassembly of Metal and Titanium Dioxide Nanocrystals Directed by Monolayered Block Copolymer Inverse Micelles for Enhanced Photocatalytic Performance
Authors: Acharya Himadri , Sung Jinwoo , Bae Insung , Kim TaeHee , Kim Dong Ha , Park Cheolmin
Published: September 2012

Functional nanostructures of self‐assembled block copolymers (BCPs) incorporated with various inorganic nanomaterials have received considerable attention on account of their many potential applications. Here we demonstrate the two‐dimensional self‐assembly of anisotropic titanium dioxide (TiO2) nanocrystals (NCs) and metal nanoparticles (NPs) directed by monolayered poly(styrene)‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) copolymer inverse micelles. The independent position‐selective assembly of TiO2 NCs and silver nanoparticles (AgNPs) preferentially in the intermicelle corona regions and the core of micelles, respectively, for instance, was accomplished by spin‐coating a mixture solution of PS‐b‐P4VP and ex situ synthesized TiO2 NCs, followed by the reduction of Ag salts coordinated in the cores of micelles into AgNPs. Hydrophobic TiO2 NCs with a diameter and length of approximately 3 nm and 20–30 nm, respectively, were preferentially sequestered in the intermicelle nonpolar PS corona regions energetically favorable with the minimum entropic packing penalty. Subsequent high‐temperature annealing at 550 °C not only effectively removed the block copolymer but also transformed the TiO2 NCs into connected nanoparticles, thus leading to a two‐dimensionally ordered TiO2 network in which AgNPs were also self‐organized. The enhanced photocatalytic activity of the AgNP‐decorated TiO2 networks by approximately 27 and 44 % over that of Ag‐free TiO2 networks and randomly deposited TiO2 nanoparticles, respectively, was confirmed by the UV degradation property of methylene blue.
First Perphenylated carbo‐Oligoacetylenes: An Extension of the Polytriacetylene Family
Authors: Rives Arnaud , Maraval Valérie , Saffon‐Merceron Nathalie , Chauvin Remi
Published: September 2012

The first examples of a novel family of sp‐carbon‐rich n‐π‐conjugated oligomers/polymers, namely carbo‐mers of polyacetylene, also referred to as “1,4‐PTA” isomers of the classical polytriacetylenes (1,2‐PTAs), are described in the perphenylated series. The two first representatives proved to be stable in solution, and exhibit a zig‐zag arrangement in the crystal state. The third member of the family, isolated in SnCl2 matrix, proved to be stable in the solid state and was characterized by MALDI‐TOF MS, 1H NMR, CPMAS 13C NMR, and absorption spectroscopy. An explanation for its reactivity in solution is proposed. The chromophoric properties in the visible region are shown to vary significantly and consistently along the series.
Fast Synthesis of PbS Nanocrystals in Aqueous Solution with Shape Evolution from Cubic to Octahedral Structures and Their Assembled Structures
Authors: Wu Jian‐Kuan , Lyu Lian‐Ming , Liao Ching‐Wen , Wang Yu‐Ning , Huang Michael H.
Published: September 2012

In this study, we have developed for the first time a fast and energy‐efficient method for the synthesis of PbS nanocrystals with systematic shape evolution from cubic to truncated cubic, cuboctahedral, truncated octahedral, and octahedral structures. The method involves the addition of a small volume of preheated lead acetate and thioacetamide (TAA) mixture to an aqueous growth solution of lead acetate, thioacetamide, cetyltrimethylammonium bromide, and nitric acid. By varying the amount of thioacetamide added to the growth solution, PbS nanocrystals with different morphologies were generated in 2 h at 90 °C. Slight experimental modifications were adopted to generate truncated octahedra. The nanocrystals have very uniform dimensions with average sizes of 32–47 nm. Their structures have been extensively examined by electron microscopy. Nanocube sizes can also be tuned within a range. UV/Vis absorption spectra of PbS cubes, cuboctahedra, and octahedra all show decreasing but continuous absorption from 300 nm to beyond 1000 nm. By monitoring the speed of darkening of solution color, particle growth rate was found to be fastest for nanocubes, followed by truncated cubes, cuboctahedra, and octahedra. These monodisperse nanocrystals can readily form self‐assembled structures. Truncated cubes and octahedra that form monolayer and multilayer packing arrangements have also been studied. This green approach to the synthesis of PbS nanocrystals with fine size and shape control should allow for investigations of their facet‐dependent properties and the fabrication of novel heterostructures.
Indole Synthesis by Conjugate Addition of Anilines to Activated Acetylenes and an Unusual Ligand‐Free Copper(II)‐Mediated Intramolecular Cross‐Coupling
Authors: Gao Detian , Back Thomas G.
Published: September 2012

A versatile new synthesis of indoles was achieved by the conjugate addition ofN‐formyl‐2‐haloanilines to acetylenic sulfones, ketones, and esters followed by a copper‐catalyzed intramolecular C‐arylation. The conjugate addition step was conducted under exceptionally mild conditions at room temperature in basic, aqueous DMF. Surprisingly, the C‐arylation was performed most effectively by employing copper(II) acetate as the catalyst in the absence of external ligands, without the need for protection from air or water. An unusual feature of this process, for the case of acetylenic ketones, is the ability of the initial conjugate‐addition product to serve as a ligand for the catalyst, which enables it to participate in the catalysis of its further transformation to the final indole product. Mechanistic studies, including EPR experiments, indicated that copper(II) is reduced to the active copper(I) species by the formate ion that is produced by the base‐catalyzed hydrolysis of DMF. This process also served to recycle any copper(II) that was produced by the adventitious oxidation of copper(I), thereby preventing deactivation of the catalyst. Several examples of reactions involving acetylenic sulfones attached to a modified Merrifield resin demonstrated the feasibility of solid‐phase synthesis of indoles by using this protocol, and tricyclic products were obtained in one pot by employing acetylenic sulfones that contain chloroalkyl substituents.
Oligo(borolyl)benzenes—Synthesis and Properties
Authors: Braunschweig Holger , Chiu Ching‐Wen , Damme Alexander , Engels Bernd , Gamon Daniela , Hörl Christian , Kupfer Thomas , Krummenacher Ivo , Radacki Krzysztof , Walter Christof
Published: September 2012

Herein, we report the synthesis of boroles that are linked by a conjugated phenylene spacer. The characterization of these compounds was completed by NMR and UV/Vis spectroscopy, as well as X‐ray crystal diffraction. Furthermore, the coordination behavior of these oligoboroles towards five electronically and sterically disparate pyridine derivatives was studied and revealed fundamental differences in the properties of the resulting adducts. The experimental results were supported by density functional theory (DFT) calculations that showed a charge‐transfer effect upon formation of the pyridine‐4‐carbonitrile adduct. By chemical reduction of a tris(borolyl)‐substituted benzene derivative, a hexaanion was isolated as a result of a two‐electron reduction of each borolyl moiety. The interaction of the borolyl units through the aryl spacer, and the possible increase of the Lewis acidity due to the conjugation of the borolyl moieties, were investigated by base transfer reactions.