bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Pressures in Anglo-American Diplomacy in Mexico, 1917-1918
Authors: Rosenberg Emily S.
Published: March 2007

During the years 1917-1918 Mexico stood at the crossroads between revolutionary nationalism and foreign control. Nevertheless, much of the diplomacy of this wartime period and the variety of foreign threats to the regime of Venustiano Carranza remain obscure. Only very recently have scholars (Glaser, 1971; Machado and Judge, 1971; Trow, 1971; Tulchin, 1971; Smith, 1972; Meyer, 1968) realized the extent of the American movement for armed intervention in Mexico in 1919. But the more subtle strategy to guide the Mexican government's policy through economic pressure has received little attention. Likewise, the anti-Carrancista policy of the British Foreign Office has been ignored (see Fabela, 1958-1959; López de Roux, 1965; Zorrilla, 1965; Smith, 1969, 1972; Meyer, 1968). If one focuses less on the possibilities of overt military intervention and more on the economic issues of monetary exchange, food, loans, and oil, the years 1917-1918 (usually quickly sandwiched between the Pershing incursion and the 1919 interventionist movement) acquire major significance.
Guatemalan Revolutionaries and Havana's Ideological Offensive of 1966-1968
Authors: Crain David A.
Published: March 2007

A marked improvement has occurred since 1968 in Havana's relations with Moscow and the traditional Communist parties of Latin America. Previously, however, from approximately 1966-1968 Fidel Castro's actions and words came perilously close to precipitating a formal split between his regime and the pro-Soviet parties of the hemisphere. At one time, sporadic criticisms of standard Communist party revolutionary strategy and tactics escalated in frequency and gravity. An ideological offensive advanced as Castro flaunted an independent Marxist line in both domestic and international affairs. Havana proceeded to exacerbate growing tensions in the uneasy alliance between guerrilla movements and Communist parties in several Latin American countries.

Attempts to establish the factors prompting these actions have to date focused on Cuban reactions to developments in the Venezuelan revolutionary movement during 1964-1966.
Colombia, the United States, and Interamerican Aviation Rivalry, 1927-1940
Authors: Randall Stephen James
Published: March 2007

Recent research on U.S. diplomacy in Latin America has indicated the prominent role of the State Department in gaining for American airlines a major share of interamerican aviation in the mid-1920s. The department's campaign to “de-Germanize” commercial aviation in the western hemisphere immediately prior to and during World War II has also drawn the attention of historians (McCann, 1968; Newton, 1965; Conn, 1960; Burden, 1943). Yet little analysis has been directed to U.S. policy in the late 1920s and early 1930s, crucial years for the shift of power away from European-supported commercial airlines in Latin America to Pan American Airways.
Nuevas Corrientes
Authors: McNicoll Robert E.
Published: March 2007

A revolutionary change in the shape of inter-American relations has taken place in the last few years. The most casual observer is aware of this fact but it is difficult to assess the effects of the changes and to determine the prevailing tendency for the future. Fidel Castro's takeover of Cuba in 1959 appeared for a while to be just another Latin American “revolution” but it soon developed into a major threat to United States hegemony, confirmed by the ensuing missile crisis which marked the entry of another great power into the Western Hemisphere, a major zone of United States influence. Nothing in the Americas has been the same since then, although the effects of Castro's regime on other American States continue to be debated with more heat than light. Results tend to reflect previously established positions on the nature both of Castro's government and that of the states influenced by his activities.
Women in Colombia: Attitudes and Future Perspectives in the Political System
Authors: Schmidt Steffen W.
Published: March 2007

[For] women to begin to participate more fully in politics on an equal par with men, the changes that have to take place go far beyond the raising of consciousness of women themselves, as well as of the men. Major changes will also be necessary in the structure of the society, in particular in the relationship between the two institutions—the family and the polity.

In this concluding paragraph of a paper on Brazilian women, Blachman (1972) charts two major areas of significance to those interested in the study of women—the ideological dimension and the institutional reality. At the same time we are reminded that the link between the two, a dialectic of structures and values, may still be the most confounding and frustrating obstacle to an analysis of women in society and, for our interests here, women in politics. (For an excellent overview of the material on women in Latin America, see Pescatello, 1972.)
Recent Work on Latin American Women: A Review Essay
Authors: Susan A. Soeiro
Published: March 2007

The recent literature on women in Latin America as yet forms a minute part of a necessary revision aimed at achieving a balanced and multidimensional view of the Ibero-American reality, past and present. Men, as the traditional transmitters of culture in society, have conveyed what they knew, understood, and judged to be important. Since women's activities differed considerably from those of men, they were regarded as insignificant and unworthy of mention. Scholars have further perpetuated the patriarchal and sexist assumptions of their own societies or those they have studied. As a fesult, more than four and a half centuries of history and all of the important ongoing processes of modernization, urbanization, professionalization, and even propagation seem to have occurred without the participation or even the presence of women. It was simply assumed that what was said of men held equally true for women. Hence the conception of reality perpetrated by social scientists and historians was that perceived by a dominant male group, who represented a partial construct as if it were a more complex whole.
Electoral Aspects of Peronism, 1946-1954
Authors: Little Walter
Published: March 2007

Although it is of importance for any understanding of the Peronist regime as a whole, little is known in detail about the social character of the popular support upon which the regime was based. This state of affairs is not as paradoxical as it might at first seem. In part it is a reflection of the fact that the continued political importance of the Peronist movement has meant that until recently the debate over Peronism has been polemical in nature and that opportunities for dispassionate analysis have been correspondingly restricted. For example, to apologists for Peronism, the popular support that it enjoyed is evidence merely that it represented a profound revolution in social and economic priorities which was fully understood and appreciated by the people themselves. To its detractors it is evidence of little more than the manipulation of the ignorant, corruption of the venal, and coercion of the educated. To both groups it has been a premise for further argument rather than an object worthy of study in its own right.
Modernization for Emigration
Authors: Portes Alejandro , Ross Adreain A.
Published: March 2007

The problem of the brain drain—movement of highly skilled personnel across national borders—has been an object of increasing concern during the last two decades. International agencies, especially those linked with the United Nations, have seized the subject as one of the clearest manifestations of international imbalances in favor of the developed’ countries (United Nations, 1971; Kidd, 1967).

It is clear, despite variations across countries, that loss of professionals represents a significant cost for many nations, especially less developed ones. Recent data from three widely different countries may be used to illustrate such costs: from 1955 to 1968 Colombia lost 20,506 professionals to the United States; at an estimated cost of U.S. $8,000 for the training of each individual, Colombia made a contribution to the “development” of the United States of $164,048,000 during the period.
Campesino Movements and Class Conflict in Latin America: The Functions of Exchange and Power
Authors: Singelmann Peter
Published: March 2007

This paper will attempt to evaluate the utility of exchange theory for analyzing and interpreting the currently available evidence about emergingcampesinomovements in Latin America. The focus will be on the transactions and exchanges campesinos engage in both horizontally (with their peers) and vertically (with the landlord and other patrons). My principal thesis is that in the past the gains campesinos could accrue from vertical exchanges have outweighed the actual and potential gains derived from horizontal solidarities within their own community; furthermore, the vertical solidarities between campesinos and landholders served to undermine the precarious horizontal relationships in the campesino community which did exist. As a result, the development of campesino movements, organized or spontaneous, has been directly related to changes in the relative outcomes campesinos obtain in exchanges with one another, with their landlord, or with alternative patrons.
Obstacles to Change in the Church: Lessons from Four Brazilian Dioceses
Authors: Bruneau Thomas C.
Published: March 2007

A review of the popular and even scholarly literature dealing with the Catholic Church in Latin America during the last decade will leave the reader confused. The books, articles, and media coverage in comparison with each other are ambiguous and at times contradictory. If on the one hand the Church is described as the fastest-changing institution on the continent, there is on the other hand ample proof put forth that the institution is stagnant and in many cases apparently bankrupt. While some students point to the emergence of militant clergy groups such as the Golconda movement in Colombia or Priests of the Third World in Argentina, others as easily argue that these movements are beyond the institution and without significance in the larger society. And for every time the Church is shown siding with the poor and oppressed, two instances are held up in which words are not followed by action.
Housing in Chile: The Economics of Stimulus-Response
Authors: Frankenhoff Charles A.
Published: March 2007

Chile has a housing problem but not in the traditional sense of something to be solved. Like any other country in the throes of modernization, Chile is producing an inadequate flow of housing services for low income families. Each family participates to some extent in the available housing services, but an estimated 600,000 families are not receiving an adequate supply. This analysis is concerned with the economics of the government response to this situation from 1965 to 1969.

The focus is on the economics of housing because the basic question that the housing policy decisions taken by the government must face is the more efficient administration of the scarce resources available for the production of improved housing services. Housing is a basic social need to which limited resources must be assigned by both the public and private sectors.
Cuban Population Estimates, 1953-1970
Authors: Nelson Lowry
Published: March 2007

There has been no official population census of Cuba since the decennial count of 1953. The Castro government, which came to power in January 1959, has not seen fit to continue census-taking on decennial basis, which would have regularly called for an enumeration in 1963. Until 1958 Cuban government agencies, including the National Bank and the National Economic Council, published annual estimates, intending presumably to adjust them in accordance with what would have been a census in 1963. The revolutionary government has continued annual estimates, but until recently, made no official announcement of them. In 1967, for the first time, the year-by-year estimates became available in official statistical publications.

Much interest has been associated with the population trends by students of Cuba because of a number of factors which presumably would affect them, notably the extraordinary emigration from the island. There have been attempts to arrive at estimates independently.
Messianism and Protestantism in Brazil's Sertão
Authors: Curry Donald Edward
Published: March 2007

A “messiah,” as the term is used here, is taken to mean a person believing himself to be divinely called, as a result of a dream or a series of visions, to lead a group of people from some catastrophic set of conditions into a more perfect state of affairs. “Messianism” is a term used in a variety of ways but usually to characterize a religious movement led by a messiah.Sertãois a Portuguese word meaning simply “hinterland” or interior and is usually taken to refer to a region in Brazil known as thepolígona das sêcas(drought polygon) which extends over an area of the states of Maranhão, Piauí, Ceará, Pernambuco, Rio Grande do Norte, Sergipe, Alagoas, and Bahia subject to periodic and unpredictable droughts.
Progesterone, but not luteal estrogen, is required for the establishment of pregnancy in the new world monkey Cebus apella
Authors: Ortiz M.E. , Ortiz R.E. , Garfield R. , Zepeda A.J. , Croxatto H.B.
Published: March 2007

The aim of this study was to examine the requirement of luteal progesterone or luteal estrogen for the establishment of pregnancy in the Cebus monkey and to test in a primate species the synergism between RU 486 and letrozole (LTZ) found in rodents for inhibiting implantation. Exposure of target tissues to either hormone was suppressed during the mid‐luteal phase of mating cycles by subcutaneous administration of the antiprogestin (RU 486), the aromatase inhibitor LTZ or the antiestrogen (ICI 182780) on days 4–7 of the luteal phase. Administration of 0.1 or 0.5 mg/kg of LTZ on days 5–7 of the luteal phase caused a profound drop in the levels of E2 in all animals, whereas administration of ICI 182780 0.2 mg/kg on days 4–6 of the luteal phase had the opposite effect. The pregnancy rate in vehicle treated cycles of the same females was (58.3%). Treatment with RU 486, 0.8 mg/kg/day on days 5–7 of the luteal phase‐induced endometrial bleeding in 3/5 mated females none of which became pregnant, whereas pregnancy was confirmed in one of the two animals that did not bled. Treatment with RU 486, 0.4 mg/kg/day alone or with LTZ on days 5–7 or ICI 182780 alone, on days 4–6 of the luteal phase failed to induce bleeding, allowing the establishment of pregnancy in 50.0–66.6% of the animals in these groups. We conclude that in Cebus monkeys, progesterone but not luteal estradiol is required for the establishment of pregnancy and that RU 486 and LTZ do not exhibit in this species the synergism found in rodents. Am. J. Primatol. 69:1131–1140, 2007. © 2007 Wiley‐Liss, Inc.
Dopamine inhibits trigeminovascular transmission in the rat
Authors: Bergerot Astrid , Storer Robin J. , Goadsby Peter J.
Published: March 2007

Objective

Clinical evidence, such as premonitory or postdromal symptoms, indicate involvement of dopamine in the pathophysiology of migraine.

Methods

To study the influence of dopamine on nociceptive trigeminovascular neurotransmission, we first determined using immunohistofluorescence that dopamine receptors were present in the rat trigeminocervical complex; then using extracellular recording techniques, we examined whether dopamine modulates cell firing in the trigeminocervical complex.

Results

We identified a discrete population of D1 receptors (median, 11; interquartile range, 7–30 neurons/hemisection) predominantly located in the deep laminae and a more abundant population of D2 receptors (median,75; interquartile range, 30–99 neurons/hemisection) that were evenly distributed in the trigeminocervical complex. Intravenous dopamine had no effect on trigeminovascular neurons, whereas when dopamine was applied microiontophoretically, a potent reversible inhibition of L‐glutamate–evoked firing was observed. The effect of microiontophoretically applied dopamine was dose dependent. Dopamine also strongly inhibited activation of trigeminocervical neurons in response to middle meningeal artery stimulation in vivo with a maximum effect obtained within 10 minutes after the application and return to baseline within 30 minutes.

Interpretation

We conclude that central dopamine‐containing neurons may play a role in modulating trigeminovascular nociception; these neurons offer an important target that will expand our understanding of migraine and may offer new directions for therapy. Ann Neurol 2007;61:251–262
The pathogenesis of ACTA1‐related congenital fiber type disproportion
Authors: Clarke Nigel F. , Ilkovski Biljana , Cooper Sandra , Valova Valentina A. , Robinson Phillip J. , Nonaka Ikuya , Feng Juan‐Juan , Marston Steven , North Kathryn
Published: March 2007

Objective

Mutations in ACTA1 have been associated with a variety of changes in muscle histology that likely result from fundamental differences in the way that ACTA1 mutations disrupt muscle function. Recently, we reported three patients with congenital fiber type disproportion (CFTD) caused by novel heterozygous missense mutations in ACTA1 (D292V, L221P, P332S) with marked type 1 fiber hypotrophy as the only pathological finding on muscle biopsy. We have investigated the basis for the histological differences between these CFTD patients and patients with ACTA1 nemaline myopathy (NM).

Methods and Results

Mass spectrometry and two‐dimensional gel electrophoresis demonstrate that mutant actin accounts for 25 and 50% of α‐skeletal actin in the skeletal muscle of patients with the P332S and D292V mutations, respectively, consistent with a dominant‐negative disease mechanism. In vitro motility studies indicate that abnormal interactions between actin and tropomyosin are the likely principal cause of muscle weakness for D292V, with tropomyosin stabilized in the “switched off” position. Both the D292V and P322S CFTD mutations are associated with normal sarcomeric structure on electron microscopy, which is atypical for severe NM. In contrast, we found no clear difference between ACTA1 mutations associated with NM and CFTD in tendency to polymerize or aggregate in C2C12 expression models.

Interpretation

These data suggest that ACTA1 CFTD mutations cause weakness by disrupting sarcomere function rather than structure. We raise the possibility that the presence or absence of structural disorganization when mutant actin incorporates into sarcomeres may be an important determinant of whether the histological patterns of CFTD or NM develop in ACTA1 myopathy. Ann Neurol 2007
An analysis of two approaches in information retrieval: From frameworks to study designs
Authors: Järvelin Kalervo
Published: March 2007

There is a well‐known gap between systems‐oriented information retrieval (IR) and user‐oriented IR, which cognitive IR seeks to bridge. It is therefore interesting to analyze approaches at the level of frameworks, models, and study designs. This article is an exercise in such an analysis, focusing on two significant approaches to IR: the lab IR approach and P. Ingwersen's (1996) cognitive IR approach. The article focuses on their research frameworks, models, hypotheses, laws and theories, study designs, and possible contributions. The two approaches are quite different, which becomes apparent in the use of independent, controlled, and dependent variables in the study designs of each approach. Thus, each approach is capable of contributing very differently to understanding and developing information access. The article also discusses integrating the approaches at the study‐design level.
Tissue engineering with electric fields: Immobilization of mammalian cells in multilayer aggregates using dielectrophoresis
Authors: Sebastian Anil , Buckle Anne‐Marie , Markx Gerard H.
Published: March 2007

Positive dielectrophoresis can be used to create aggregates of animal cells with 3D architectures. It is shown that the cells, when pulled together into an aggregate by positive dielectrophoresis in a low‐conductivity iso‐osmotic solution, adhere to each other. The adherence of the cells to each other is non‐specific and increases in time, and after 10–15 min becomes strong enough to immobilize the cells in the aggregate, enabling the ac electric field to be released, and the iso‐osmotic buffer to be replaced by growth or other media. Cell viability is maintained. The new method of immobilization significantly simplifies the construction of aggregates of animal cells by dielectrophoresis, and increases the utility of dielectrophoresis in tissue engineering and related areas. Biotechnol. Bioeng. 2007;98: 694–700. © 2007 Wiley Periodicals, Inc.
Effluent recirculation to improve perchlorate reduction in a fixed biofilm reactor
Authors: Choi Hyeoksun , Silverstein JoAnn
Published: March 2007

The effect of effluent recirculation on perchlorate reduction in a nominally plug‐flow fixed biofilm reactor was studied in two cases: influent concentrations of 10 and 400 µg/L at low hydraulic loading rates (1.9 and 37.5 m3/m2/day without and with recirculation, respectively) and after a step increase in perchlorate concentration to 1,000 µg/L at the higher hydraulic loading rate (5 and 100 m3/m2/day without and with recirculation, respectively). Complete perchlorate reduction was sustained for influent concentrations of 400 and 10 µg/L in both flow regimes at the lower hydraulic loading rates. Reactor tracer profiles showed that biofilm diffusion had a more significant effect on mass transfer in the plug flow reactor compared with recirculation. The recirculation bioreactor acclimated more rapidly to increased hydraulic and perchlorate mass loading rates with significantly lower effluent perchlorate compared to the plug flow reactor: 16 µg/L versus 46 µg/L, respectively, although complete perchlorate removal was not achieved in either flow regime after 21 days acclimation to the higher loading. Total biofilm mass was more uniformly distributed in the recirculation reactor which may have contributed to better performance under increased perchlorate loading. Biotechnol. Bioeng. 2007; 98: 132–140. © 2007 Wiley Periodicals, Inc.
Descriptive analysis of estrogen receptor (ER)‐negative, progesterone receptor (PR)‐negative, and HER2‐negative invasive breast cancer, the so‐called triple‐negative phenotype
Authors: Bauer Katrina R. , Brown Monica , Cress Rosemary D. , Parise Carol A. , Caggiano Vincent
Published: March 2007

BACKGROUND.

Tumor markers are becoming increasingly important in breast cancer research because of their impact on prognosis, treatment, and survival, and because of their relation to breast cancer subtypes. The triple‐negative phenotype is important because of its relation to the basal‐like subtype of breast cancer.

METHODS.

Using the population‐based California Cancer Registry data, we identified women diagnosed with triple‐negative breast cancer between 1999 and 2003. We examined differences between triple‐negative breast cancers compared with other breast cancers in relation to age, race/ethnicity, socioeconomic status (SES), stage at diagnosis, tumor grade, and relative survival.

RESULTS.

A total of 6370 women were identified as having triple‐negative breast cancer and were compared with the 44,704 women with other breast cancers. Women with triple‐negative breast cancers were significantly more likely to be under age 40 (odds ratio [OR], 1.53), and non‐Hispanic black (OR, 1.77) or Hispanic (OR, 1.23). Regardless of stage at diagnosis, women with triple‐negative breast cancers had poorer survival than those with other breast cancers, and non‐Hispanic black women with late‐stage triple‐negative cancer had the poorest survival, with a 5‐year relative survival of only 14%.

CONCLUSIONS.

Triple‐negative breast cancers affect younger, non‐Hispanic black and Hispanic women in areas of low SES. The tumors were diagnosed at later stage and were more aggressive, and these women had poorer survival regardless of stage. In addition, non‐Hispanic black women with late‐stage triple‐negative breast cancer had the poorest survival of any comparable group. Cancer 2007. © 2007 American Cancer Society.
In‐plane free‐field response of actual sites
Authors: Wolf John P. , Obernhuber Pius
Published: March 2007

To study the characteristic features of the in‐plane free‐field response, two actual sites of nuclear power plants, a soft and a rock site, are analysed, by varying the location of the control point and the nature of the wave pattern. Harmonic and transient seismic excitations are examined. The conclusions reached in the vast parametric study of Reference 6 are confirmed for the actual sites. These apply to the range of possible apparent velocities and the associated motions, the spatial variations with depth and in the horizontal direction.

If only one component of the control motion, e.g. the horizontal, is matched, then it can be associated either with a body wave or with a surface wave. In the latter case, a specific mode is used up to the frequency at which the next higher mode starts, since for a given frequency, the higher modes attenuate less. The other component of the motion follows. If both components are prescribed, the motion can be interpreted as arising from a combination of a P‐ and an SV‐wave (with a common apparent velocity). Surface waves alone cannot be used to match both components. A body wave has to be included, at least up to the frequency at which the second mode starts.

For the soft site, the surface waves decay significantly, especially in the range of higher frequencies, where the apparent velocity is considerably smaller than the shear‐wave velocity of the rock. For this site, it seems sufficient to examine only (extremely shallow) body waves. For a rock site, however, Rayleigh‐waves exist which attenuate little, leading to smaller apparent velocities than extremely shallow body waves.
Diversity of viruses associated with acute gastroenteritis in children hospitalized with diarrhea in Ho Chi Minh City, Vietnam
Authors: Nguyen Tuan Anh , Yagyu Fumihiro , Okame Michio , Phan Tung Gia , Trinh Quang Duy , Yan Hainian , Hoang Kim Trong , Cao Anh Thi Huynh , Le Hoang Phuc , Okitsu Shoko , Ushijima Hiroshi
Published: March 2007

A molecular epidemiological study on common diarrheal viruses was conducted in Ho Chi Minh City, Vietnam between October 2002 and September 2003. Fecal samples were collected from 1,010 hospitalized children with acute gastroenteritis. Those samples were screened for groups A, B, and C rotavirus, adenovirus, genogroups I and II norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) by RT‐multiplex PCR, and the positive specimens were characterized further by ELISA, nested PCR, or sequencing. Among the diarrheal viruses detected, group A rotavirus was the most common, with a proportion of 67.4%, whereas NoV GII, adenovirus, SaV, and HAstV were also found in 5.5, 3.2, 0.8, and 0.6%, respectively. It is noteworthy that the group C rotavirus was first reported in Vietnam, with a proportion of 0.5% in this study. Fifty‐six of 1,010 (5.5%) samples were found positive with more than one viral agent, in which 25 samples contained both group A rotavirus and NoV GII. Group A rotavirus could be identified throughout year with the peaks in both the dry and rainy season, whereas other viruses prevailed mainly in the rainy season. G‐typing for the group A rotavirus showed that genotype 1 was still the most prevailing (33.0%), but interestingly, serotype 9 was emergent and became the third most common rotavirus G‐type in these samples (13.7%). The four most common G–P combinations globally, G1P[8], G2P[4], G3P[8], and G4P[8] were found in 46.8% of rotavirus‐positive samples, and it is of interest that one unusual rotavirus G9P[19] strain was first detected in Vietnam. The majority of NoV strains belonged to GII/4, and SaV strains mainly clustered with the Manchester strain (GI/1). Twenty‐seven out of 32 adenovirus strains were identified as serotype 41. All HAstVs belonged to genotype 1. The results indicated clearly the impact of viral agents causing gastroenteritis and the importance of vaccination against diarrhea in Vietnam. J. Med. Virol. 79:582–590, 2007. © 2007 Wiley‐Liss, Inc.
Differential regulation of BACE1 promoter activity by nuclear factor‐κB in neurons and glia upon exposure to β‐amyloid peptides
Authors: Bourne Krystyn Z. , Ferrari Diana C. , Lange‐Dohna Christine , Roßner Steffen , Wood Thomas G. , Perez‐Polo J. Regino
Published: March 2007

The brains of Alzheimer's disease (AD) patients display cerebrovascular and parenchymal deposits of β‐amyloid (Aβ) peptides, which are derived by proteolytic processing by the β‐site APP‐cleaving enzyme 1 (BACE1) of the amyloid precursor protein (APP). The rat BACE1 promoter has a nuclear factor‐κB (NF‐κB) binding site. Deletion studies with a BACE1 promoter/luciferase reporter suggest that the NF‐κB binding DNA consensus sequence plays a suppressor role, when occupied by NF‐κB, in the regulation of neuronal brain BACE1 expression. Here we characterize a signal transduction pathway that may be responsible for the increases in Aβ associated with AD. We propose that the transcription factor NF‐κB acts as a repressor in neurons but as an activator of BACE1 transcription in activated astrocytes present in the CNS under chronic stress, a feature present in the AD brain. The activated astrocytic stimulation of BACE1 may in part account for increased BACE1 transcription and subsequent processing of Aβ in a cell‐specific manner in the aged and AD brain. As measured by reporter gene promoter constructs and endogenous BACE1 protein expression, a functional NF‐κB site was stimulatory in activated astrocytes and Aβ‐exposed neuronal cells and repressive in neuronal and nonactivated astrocytic cells. Given the evidence for increased levels of activated astrocytes in the aged brain, the age‐ and AD‐associated increases in NF‐κB in brain may be significant contributors to increases in Aβ, acting as a positive feedback loop of chronic inflammation, astrocyte activation, increased p65/p50 activation of BACE1 transcription, and further inflammation. © 2007 Wiley‐Liss, Inc.
Late Weichselian fluvio‐aeolian sands and coversands of the type locality Grubbenvorst (southern Netherlands): sedimentary environments, climate record and age
Authors: Kasse C. , Vandenberghe D. , De Corte F. , Van Den Haute P.
Published: March 2007

The Weichselian Late Pleniglacial and Lateglacial aeolian stratigraphy (Older Coversand I, Beuningen Gravel Bed, Older Coversand II, Younger Coversand I, Usselo Soil, Younger Coversand II) in the southern Netherlands has been reinvestigated in its type locality (Grubbenvorst). Sedimentary environments have been reconstructed and related to their climatic evolution based on periglacial structures. In addition, 22 optically stimulated luminescence (OSL) ages have been determined that provide an absolute chronology for the climatic evolution and environmental changes of the coversand area.

From this work it appears that, prior to 25 ka fluvial deposition by the Maas dominated. After 25 ka fluvial activity reduced and deposition occurred in a fluvio‐aeolian environment with continuous permafrost (Older Coversand I). This depositional phase was dated between 25.2 ± 2.0 and 17.2 ± 1.2 ka. The upward increase of aeolian activity and cryogenic structures in this unit is related to an increase of climatic aridity and a decrease in sedimentation rate during the Last Glacial Maximum (LGM). The Beuningen Gravel Bed, that results from deflation with polar desert conditions and that represents a stratigraphic marker in northwestern Europe, was bracketed between 17.2 ± 1.2 and 15.3 ± 1.0 ka. Based on this age result a correlation with Heinrich event H1 is suggested. Permafrost degradation occurred at the end of this period. Optical ages for the Older Coversand II unit directly overlying the Beuningen Gravel Bed range from 15.3 ± 1.0 ka at the base to 12.7 ± 0.9 ka at the top. Thus this regionally important Older Coversand II unit started at the end of the Late Pleniglacial and continued throughout the early Lateglacial. Its formation after the Late Pleniglacial (LP) maximum cold and its preservation are related to rapid climatic warming around 14.7 ka cal. BP. The Allerød age of the Usselo Soil was confirmed by the optical ages. Copyright © 2007 John Wiley & Sons, Ltd.
Design and fabrication of 3D‐plotted polymeric scaffolds in functional tissue engineering
Authors: Yousefi Azizeh‐Mitra , Gauvin Chantal , Sun Louise , DiRaddo Robert W. , Fernandes Julio
Published: March 2007

Regenerating the load‐bearing tissues requires 3D scaffolds that balance the temporary mechanical function with the biological requirements. In functional tissue engineering, designing scaffolds with biomimetic mechanical properties could promote tissue ingrowth since the cells are sensitive to their local mechanical environment. This work aims to design scaffolds that mimic the mechanical response of the biological tissues under physiological loading conditions. Poly(L‐lactide) (PLLA) scaffolds with varying porosities and pore sizes were made by the 3D‐plotting technique. The scaffolds were tested under unconfined ramp compression to compare their stress profile under load with that of bovine cartilage. A comparison between the material parameters estimated for the scaffolds and for the bovine cartilage based on the biphasic theory enabled the definition of an optimum window for the porosity and pore size of these constructs. Moreover, the finite element prediction for the stress distribution inside the scaffolds, surrounded by the host cartilaginous tissue, demonstrated a negligible perturbation of the stress field at the site of implantation. The finite element modeling tools in combination with the developed methodology for optimal porosity/pore size determination can be used to improve the design of biomimetic scaffolds. POLYM. ENG. SCI., 47:608–618, 2007. © 2007 Society of Plastics Engineers.
Influence of hemicelluloses on the structure and properties of Lyocell fibers
Authors: Zhang Huiru , Tong Mingwei
Published: March 2007

In the present paper the difference in the structure and properties of Lyocell fibers with different hemicelluloses content was investigated. The supermolecular structure and the morphological characterization were compared. The fibril aggregation size was estimated by the cross‐polarization magic‐angle spinning carbon‐13 nuclear magnetic resonance (CP/MAS13C‐NMR) spectroscopy. Meanwhile, the difference in the mechanical, the fibrillation resistance and the dyeing properties of Lyocell fiber with different hemicelluloses content was also analyzed. POLYM. ENG. SCI., 47:702–706, 2007. © 2007 Society of Plastics Engineers.
Thermal properties of poly(alkylene dicarboxylate)s derived from 1,12‐dodecanedioic acid and even aliphatic diols
Authors: Celli Annamaria , Barbiroli Giancarlo , Berti Corrado , Francesco Di Credico , Lorenzetti Cesare , Marchese Paola , Marianucci Elisabetta
Published: March 2007

A series of new aliphatic polyesters derived from 1,12‐dodecanedioic acid and different diols with an even number of methylene units have been studied to assess the effect of the chemical structure on the final thermal properties of the materials. The polyesters have high thermal stability and are fast crystallizing polymers, with crystallization rate similar to that of polyethylene (PE). This behavior is connected to the fact that long aliphatic chains assume conformational characteristics very similar to that of PE. However, the polyester prepared from ethanediol shows a peculiar behavior (for example, double melting peak, melting and crystallization temperatures, which do not fit the trend of those of the other samples and ringed spherulites) owing to a probable different conformation, deviating from the all‐trans planar typical of PE. In the isothermal crystallization studies, a bell‐shape trend has been found for the crystallization rate as a function of the number of (CH2) units in the diol. The high crystallization rate of the sample with long (CH2) sequences has been attributed to the high chain flexibility and, thus, high mobility in the molten state and ease of chain folding. By reducing the aliphatic sequence length, instead, implications of the structural characteristics of the samples are probably involved. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1053–1067, 2007
Mechanical properties and morphology of homoblends of a poly(ethyl acrylate) ionomer having one ion pair per ionic repeat unit and a poly(ethyl acrylate) ionomer having two ion pairs
Authors: Song Ju‐Myung , Luqman Mohammad , Kim Joon‐Seop , Shin Kwanwoo
Published: March 2007

The mechanical properties and morphology of homoblends of poly(ethyl acrylate‐co‐acrylate) (PEAA) having one ion pair per ionic monomer repeat unit and poly(ethyl acrylate‐co‐itaconate) (PEAITA) having two ion pairs were investigated. It was found that the compositional variation in the ionomer homoblends did not affect the matrix or cluster glass transition temperatures of the two ionomers of the homoblends. It was also observed that the ionomer homoblends showed two ionic plateaus and that the changes in the two ionic moduli were directly related to the relative amounts of the two ionomers. The ionic moduli calculated with the model for filler‐dispersed materials were found to fit the experimental data to a great extent. Therefore, it was suggested that the PEAITA/PEAA ionomer homoblends were filler‐containing composite materials rather than miscible blends. In the X‐ray scattering study, it was observed that the morphology of the ionomer homoblends was not affected by mixing. The results obtained in this work might be useful for the modification of the storage moduli of copolymers in a certain temperature range without the alteration of their processing temperatures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1045–1052, 2007.
Probe‐dependent and nonexponential relaxation kinetics: Unreliable signatures of downhill protein folding
Authors: Hagen Stephen J.
Published: March 2007

The theoretical suggestion that some proteins may encounter no significant free energy barriers during their folding raises an important question: What experimental signature does this downhill folding produce? Several authors have argued that nonexponential (and especially stretched exponential) or probe‐dependent kinetics represent useful experimental signatures of a downhill free energy surface. Here we examine more closely the connection between unusual kinetics and downhill energy surfaces. Simulation of diffusive relaxation dynamics on a variety of generically downhill, two‐dimensional free energy surfaces shows that these surfaces do not necessarily produce either probe‐dependent or significantly nonexponential kinetics. Conversely, we find that two‐dimensional surfaces with significant (>3kB T) energy barriers can readily give rise to nonexponential and probe‐dependent kinetics. These results show that downhill folding does not constitute a necessary or sufficient condition for nonexponential and/or probe‐dependent folding kinetics. One cannot easily prove or disprove that a protein folds downhill simply by studying its relaxation kinetics. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Two years of Visual Odometry on the Mars Exploration Rovers
Authors: Maimone Mark , Cheng Yang , Matthies Larry
Published: March 2007

NASA's two Mars Exploration Rovers (MER) have successfully demonstrated a robotic Visual Odometry capability on another world for the first time. This provides each rover with accurate knowledge of its position, allowing it to autonomously detect and compensate for any unforeseen slip encountered during a drive. It has enabled the rovers to drive safely and more effectively in highly sloped and sandy terrains and has resulted in increased mission science return by reducing the number of days required to drive into interesting areas. The MER Visual Odometry system comprises onboard software for comparing stereo pairs taken by the pointable mast‐mounted 45 deg FOV Navigation cameras (NAVCAMs). The system computes an update to the 6 degree of freedom rover pose (x,y,z, roll, pitch, yaw) by tracking the motion of autonomously selected terrain features between two pairs of256×256stereo images. It has demonstrated good performance with high rates of successful convergence (97% on Spirit, 95% on Opportunity), successfully detected slip ratios as high as 125%, and measured changes as small as 2 mm, even while driving on slopes as high as 31 deg. Visual Odometry was used over 14% of the first 10.7 km driven by both rovers. During the first 2 years of operations, Visual Odometry evolved from an “extra credit” capability into a critical vehicle safety system. In this paper we describe our Visual Odometry algorithm, discuss several driving strategies that rely on it (including Slip Checks, Keep‐out Zones, and Wheel Dragging), and summarize its results from the first 2 years of operations on Mars. © 2006 Wiley Periodicals, Inc.
Differential effects of apolipoprotein E3 and E4 on markers of oxidative status in macrophages
Authors: Jofre-Monseny Laia , de Pascual-Teresa Sonia , Plonka Eva , Huebbe Patricia , Boesch-Saadatmandi Christine , Minihane Anne-Marie , Rimbach Gerald
Published: March 2007

ApoE is secreted by macrophages at the lesion site of the atherosclerotic plaque, where it is thought to play a protective role against atherosclerosis independently of its effects on lipid metabolism. Of the three common isoforms for apoE, apoE4 is associated with higher risk of cardiovascular disease (CVD).In vitrostudies have shown that recombinant apoE may act as an antioxidant in an isoform-dependent manner (E2>E3>E4). The oxidative status of the macrophages plays a key role in the process of atherosclerosis. In the present study the possible differential actions of apoE3 and apoE4 on several parameters of oxidative status were determined in stably transfected murine macrophages (RAW 264·7-apoE3 and -apoE4). No differences between genotypes were observed after peroxide challenge in either protection against cytotoxicity or in cell membrane oxidation, and modest differences were observed in the non-enzymatic antioxidants (glutathione and α-tocopherol) in apoE3v.apoE4 macrophages. Importantly, cells secreting apoE4 showed increased membrane oxidation under basal conditions, and produced more NO and superoxide anion radicals than the apoE3 macrophages after stimulation. The present data suggest that apoE genotype influences the oxidative status of macrophages, and this could partly contribute to the higher CVD risk observed in apoE4 carriers.
A multiplicity result including a sign-changing solution for an inhomogeneous Neumann problem with critical exponent
Authors: Hirano Norimichi , Shioji Naoki
Published: March 2007

We study the existence of multiple solutions for the problem

and we show that at least one of them is sign changing. Here Ω is a bounded domain in ℝN with N ⩾ 5 whose boundary is of class C2, ∂/∂ν is the outward normal derivative, and f ∈ LN/2(Ω) whose L2N/(N+2)(Ω) norm is sufficiently small.
On leaf magnetic homogeneity in particulate matter biomonitoring studies
Authors: Szönyi Michael , Sagnotti Leonardo , Hirt Ann M.
Published: March 2007

Biomonitoring of magnetic properties of tree leaves has been postulated to be a good approach to measure particulate matter (PM) pollution levels. We studied the variation of magnetic hysteresis parameters on leaves of Quercus ilex, an evergreen oak previously used for magnetic biomonitoring of air pollution in Rome (Italy). The hysteresis parameters (MRS, MS, BCR and BC) measured on specimens collected at a close spacing on the surface of two single leaves show variances that are smaller than those observed on a collection of Q. ilex leaves sampled from several trees distributed along high‐traffic roads. The variability is higher for magnetizations than for coercivities. This suggests a uniform source for the magnetic particles, such that variations are due mainly to changes in concentration. The normalized hysteresis cycles are remarkably similar for all the specimens. Normalization of magnetic moments by mass appears however more efficient than normalization by volume.
A five‐year analysis of MODIS NDVI and NDWI for grassland drought assessment over the central Great Plains of the United States
Authors: Gu Yingxin , Brown Jesslyn F. , Verdin James P. , Wardlow Brian
Published: March 2007

A five‐year (2001–2005) history of moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) data was analyzed for grassland drought assessment within the central United States, specifically for the Flint Hills of Kansas and Oklahoma. Initial results show strong relationships among NDVI, NDWI, and drought conditions. During the summer over the Tallgrass Prairie National Preserve, the average NDVI and NDWI were consistently lower (NDVI < 0.5 and NDWI < 0.3) under drought conditions than under non‐drought conditions (NDVI>0.6 and NDWI>0.4). NDWI values exhibited a quicker response to drought conditions than NDVI. Analysis revealed that combining information from visible, near infrared, and short wave infrared channels improved sensitivity to drought severity. The proposed normalized difference drought index (NDDI) had a stronger response to summer drought conditions than a simple difference between NDVI and NDWI, and is therefore a more sensitive indicator of drought in grasslands than NDVI alone.
Tidal currents in the northwestern Adriatic: High‐frequency radio observations and numerical model predictions
Authors: Chavanne C. , Janeković I. , Flament P. , Poulain P.‐M. , Kuzmić M. , Gurgel K.‐W.
Published: March 2007

A 2‐year deployment of high‐frequency radio current meters along the Italian coast of the northwestern Adriatic is used to characterize the surface tidal currents. In the middle of the basin, the M2 and K1 currents oscillate along the basin axis, but become more circular toward the Italian coast. Comparisons with a 3‐D finite‐element nonlinear numerical model of the tides show a good agreement for phases in the middle of the basin, although modeled currents amplitudes are overestimated. However, modeled phases lag observed phases by up to 50° (1.7 hours) for M2 and 100° (6.7 hours) for K1, and modeled amplitudes are underestimated, in a 10–20 km wide strip along the Italian coast. This shallow (< 30 m deep) region is stratified by low‐salinity surface water from the Po, and laterally sheared by the Western Adriatic Current, both absent from the model but possibly affecting tidal propagation. The model may also incompletely parameterize the combined effects of bottom friction and vertical mixing of momentum.