bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas chromatography/mass spectrometry of polychlorinated biphenyls using atmospheric pressure chemical ionization and atmospheric pressure photoionization microchips
Authors: Luosujärvi Laura , Karikko Mika‐Matti , Haapala Markus , Saarela Ville , Huhtala Sami , Franssila Sami , Kostiainen Risto , Kotiaho Tapio , Kauppila Tiina J.
Published: January 2008

Gas chromatography (GC) and ion trap mass spectrometry (MS) were combined with microchip atmospheric pressure chemical ionization (µAPCI) and microchip atmospheric pressure photoionization (µAPPI) sources. Selected polychlorinated biphenyls (PCBs, IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180) were analyzed by GC/µAPCI‐MS and GC/µAPPI‐MS to demonstrate the applicability of the miniaturized ion sources in negative ion mode analysis. The µAPCI and µAPPI methods were evaluated in respect of detection limit, linearity and repeatability. The detection limits for the PCB congeners were somewhat lower with µAPCI than with µAPPI, whereas µAPPI showed slightly wider linear range and better repeatability. With both methods, the best results were obtained for highly chlorinated or non‐ortho‐chlorinated PCBs, which possess the highest electron affinities. Finally, the suitability of the GC/µAPPI‐MS method for the analysis of PCBs in environmental samples was demonstrated by analyzing soil extracts, and by comparing the results with those obtained by gas chromatography with electron capture detection (GC/ECD). Copyright © 2008 John Wiley & Sons, Ltd.
The application of ITTFA and ARXPS to study the ion beam mixing of metal/Si bilayers
Authors: Palacio C. , Arranz A.
Published: January 2008

Metal/silicon interfaces produced by metal thin film deposition on Si substrates have been ion beam mixed using either Ar+ or reactive N2+ low‐energy ion beams. The ion beam mixing (IBM) has been studied by means of ultraviolet photoelectron spectroscopy (UPS), X‐ray photoelectron spectroscopy (XPS), angle resolved XPS (ARXPS) and iterative target testing transformation factor analysis (ITTFA). The IBM using Ar+ is characterized by the formation of metal silicide. For the IBM interfaces using N2+, a fast nitrogen incorporation in the near surface region, followed by a steady state, is observed. Once the saturation is reached, the Me/Si ratio can be varied in a broad range with a nearly constant nitrogen concentration, as a consequence of sputtering, nitruration and mixing effects taking place simultaneously. The comparison of the experimental results with those obtained from TRIDYN simulations that uses pure ballistic mechanisms, suggests that additional rate‐controlling mechanisms, as radiation‐enhanced diffusion processes or the chemical reaction with nitrogen, have to be considered to explain the IBM of Me/Si interfaces by low‐energy Ar+ and N2+ bombardment. Copyright © 2008 John Wiley & Sons, Ltd.
Relative fatigue life estimation of cylindrical hollow rollers in general pure rolling contact
Authors: Abu Jadayil Wisam M.
Published: January 2008

Solid and hollow cylindrical rollers in pure rolling contact have been modelled. The two rollers are subjected to a combined normal and tangential loading. The tangential loading is one‐third of the normal loading value. The finite element package, ABAQUS, is used to study the stress distribution and the resulting deformations in the bodies of the rollers. Then the Ioannides–Harris fatigue life model for rolling bearings is applied on the ABAQUS numerical results to investigate the fatigue life of the solid and hollow rollers. Using the fatigue life of the solid rollers as the reference fatigue life, the relative fatigue lives of hollow rollers are determined. Four main different hollowness percentages are been studied: 20, 40, 60 and 80%. The hollowness percentage is the ratio of the diameter of the hole to the outer diameter of the cylinder. For each of those hollowness percentages, two cases are studied – when the two rollers in contact are hollow and when one hollow roller is in contact with a solid roller. This study includes two main models: Model 1, where the two cylindrical rollers in contact are of the same size, and Model 2, where the two rollers in contact are not of the same size. The estimated relative fatigue lives of hollow rollers showed a great improvement of the fatigue life compared with solid rollers under the same loading conditions. This was a result of the redistribution of stresses in the contact zone in the case of hollow rollers. Redistribution of stresses over a larger volume of the roller body decreased the peak stress and reduced the volume under risk. Increasing the hollowness percentage from 20 to 60% increased the flexibility of the roller, and better stress distribution was achieved, which resulted in improving the fatigue life. Although 80% of hollowness rollers have more flexibility than 60% of hollowness rollers, the bending stresses (σb) on the inner surface of the rollers tend to decrease the fatigue life. Copyright © 2007 John Wiley & Sons, Ltd.
Nutrient digestibility and fecal characteristics are different among captive exotic felids fed a beef‐based raw diet
Authors: Vester Brittany M. , Burke Sarah L. , Dikeman Cheryl L. , Simmons Lee G. , Swanson Kelly S.
Published: January 2008

Nutrient digestibility has not been well characterized in exotic felids. The objective of this experiment was to evaluate differences in nutrient digestibility and fecal characteristics in five large exotic captive felid species, including bobcats, jaguars, cheetahs, Indochinese tigers, and Siberian tigers. All animals were individually housed and adapted to a beef‐based raw diet (Nebraska Brand® Special Beef Feline, North Platte, NE) for 16 d. Total fecal collections were conducted from days 17 to 20. Fecal samples were weighed and scored on collection. Diet and fecal samples were evaluated for dry matter, organic matter, protein, fat, and energy to determine total tract digestibility. Fresh fecal samples were collected to determine fecal pH, ammonia, phenol, indole, short‐chain fatty acid, and branched‐chain fatty acid concentrations. Fecal scores were greater (P<0.01) in Indochinese tigers when compared with all other species, and cheetahs had greater (P<0.01) fecal scores than jaguars and bobcats. Fat digestibility was greater (P<0.01) in Siberian tigers, Indochinese tigers, and bobcats (96%) compared with cheetahs and jaguars (94%). Digestible energy was greater (P<0.05) in bobcats and Indochinese tigers at 93.5 and 92.9%, respectively, compared with cheetahs and jaguars, 91.6%. Fecal pH was greater (P<0.01) in bobcats compared with all other species evaluated. Indole concentrations were greater (P<0.05) in cheetahs and jaguars compared with bobcats and Indochinese tigers. Fecal ammonia concentrations were increased (P<0.05) in cheetahs compared with all other species. The beef‐based raw diet was highly digestible; however, differences in fat and digestible energy suggest that species should be considered when determining caloric needs of exotic felids. Zoo Biol 27:126–136, 2008. © 2008 Wiley‐Liss, Inc.
Alpha‐1 antitrypsin deficiency: A conformational disease associated with lung and liver manifestations
Authors: Greene C. M. , Miller S. D. W. , Carroll T. , McLean C. , O'Mahony M. , Lawless M. W. , O'Neill S. J. , Taggart C. C. , McElvaney N. G.
Published: January 2008

Alpha‐1 antitrypsin (A1AT) is a serine anti‐protease produced chiefly by the liver. A1AT deficiency is a genetic disorder characterized by serum levels of less than 11 μmol/L and is associated with liver and lung manifestations. The liver disease, which occurs in up to 15% of A1AT‐deficient individuals, is a result of toxic gain‐of‐function mutations in the A1AT gene, which cause the A1AT protein to fold aberrantly and accumulate in the endoplasmic reticulum of hepatocytes. The lung disease is associated with loss‐of‐function, specifically decreased anti‐protease protection on the airway epithelial surface. The so‐called ‘Z’ mutation in A1AT deficiency encodes a glutamic acid‐to‐lysine substitution at position 342 in A1AT and is the most common A1AT allele associated with disease. Here we review the current understanding of the molecular pathogenesis of A1AT deficiency and the best clinical management protocols.
Male parentage and queen mating frequency in the bumblebee Bombus ignitus (Hymenoptera: bombinae)
Authors: Takahashi Jun‐ichi , Itoh Mitsuru , Shimizu Isamu , Ono Masato
Published: January 2008

Kin selection theory predicts conflict between queens and workers in the social insect colony with respect to male production. This conflict arises from the haplodiploid system of sex determination in Hymenoptera that creates relatedness asymmetries in which workers are more closely related to the sons of other workers than to those of the queen. In annual hymenopteran societies that are headed by a single queen, the mating frequency of the queen is the only factor that affects the colony kin structure. Therefore, we examined the mating structure of queens and the parentage of males in a monogynous bumblebee, Bombus ignitus, using DNA microsatellites. In the seven colonies that were studied, B. ignitus queens mated once, thereby leading to the prediction of conflict between the queen and workers regarding male production. In each of the five queen‐right colonies, the majority of the males (95%) were produced by the colony's queen. In contrast, workers produced approximately 47% of all the males in two queenless colonies. These results suggest that male production in B. ignitus is a conflict between queen and workers.
A perennialist perspective on religion and conflict
Authors: Cutsinger James S. , El-Ansary Waleed
Published: January 2008

Whereas Huntington and other like-minded scholars argue that a clash of civilisations is inevitable, this essay presents the opposite view that religion itself is not at the root of conflicts. The authors describe the theological foundations for the Christian understanding of Christ and the Muslim understanding of jihād, and examine how both these traditions have been misunderstood and misinterpreted in order to justify violence.
Mesenchymal stem cells from human bone marrow or adipose tissue differently modulate mitogen‐stimulated B‐cell immunoglobulin production in vitro
Authors: Bochev Ivan , Elmadjian Gabriel , Kyurkchiev Dobroslav , Tzvetanov Liubomir , Altankova Iskra , Tivchev Peter , Kyurkchiev Stanimir
Published: January 2008

Mesenchymal stem cells (MSC) have been characterized as multipotent cells which are able to differentiate into several mesodermal and nonmesodermal lineage cells and this feature along with their extensive growth and comprehensive immunomodulatory properties establish them as a promising tool for therapeutic applications, including cell‐based tissue engineering and treatment of immune‐mediated disorders. Although bone marrow (BM) is the most common MSC source, cells with similar characteristics have been shown to be present in several other adult tissues. Adipose tissue (AT), large quantities of which can be easily obtained, represents an attractive alternative to BM in isolating adipose tissue‐derived MSC (AT‐MSC). BM‐MSCs and AT‐MSCs share some immunomodulatory properties as they are both not inherently immunogenic and suppress the proliferation of alloantigen‐ or mitogen‐stimulated T‐cells. Our purpose was to comparatively examine under appropriate in vitro conditions, phenotypes, morphology and some functional properties of BM‐MSCs and AT‐MSCs, such as differentiation potential and especially the ability to suppress the immunoglobulin production by mitogen‐stimulated B‐cells. While the morphological, immunophenotypical, colony‐forming and adipogenic characteristics of both types of cells were almost identical, AT‐MSCs showed less potential for osteogenic differentiation than BM‐MSCs. We found that AT‐MSCs not only inhibited the Ig‐production but also suppressed this B‐cell function to a much greater extent compared to BM‐MSC. This finding supports the potential role of AT‐MSCs as an alternative to BM‐MSCs for clinical purposes.
Chemical detection of the proteins and lipids in the fat body cells from workers of Attini ants (Hymenoptera: Formicidae)
Authors: Roma Gislaine Cristina , Bueno Odair Corrêa , Camargo‐Mathias Maria Izabel
Published: January 2008

The ultrastructural cytochemistry study and the chemical analysis carried out to examine the fat body of workers of the basal Attini Cyphomyrmex rimosus and Mycetarotes parallelus and the derived Acromyrmex disciger and Atta laevigata revealed very electrondense protein granules of varied sizes and shapes distributed throughout the cytoplasm of parietal and perivisceral trophocytes and oenocytes. Lipids were present in the cytoplasm of trophocytes as very electrondense granules. In M. parallelus, A. disciger, and A. laevigata, lipids were present as droplets. In parietal as well as perivisceral oenocytes, lipid granules were very electrondense. In A. laevigata, lipids were present as droplets. The chemical analysis using gas chromatography showed that the main lipid compounds present in trophocytes and oenocytes were saturated (myristic, palmitic, and stearic) and unsaturated fatty acids (oleic and linoleic). Also, in basal species, lipid compounds consisted of mainly saturated fatty acids, while in derived species saturated as well as unsaturated fatty acids were observed.
Effect of small interfering RNAs of cytochrome P450 17α‐hydroxylase/17,20‐lyase (CYP17) on androgen biosynthesis in theca cells
Authors: Du Jing , Liang Xiaoyan , Zeng Haitao , Shu Yimin , Yao Shuzhong , Zhu Bo , Zhuang Guanglun
Published: January 2008

Polycystic ovary syndrome (PCOS) is associated with a variety of endocrinologic and metabolic abnormalities, with clinical features of hyperandrogenism and hyperandrogenemia. Cytochrome P450 17α‐hydroxylase/17,20‐lyase (CYP17) is critical in androgen biosynthesis, and CYP17 mRNA expression was proven augmented in PCOS theca cells. To demonstrate whether RNA interference (RNAi) could lower the androgen concentration in theca cells, small interfering RNA (siRNA) targeting the CYP17 gene was co‐cultured with exogenous CYP17 in HeLa cells and endogenous CYP17 of theca cells. CYP17 gene expression was measured by fluorescent microscopy, flow cytometry and real‐time reverse transcription‐polymerase chain reaction analysis. Androstenedione and progesterone concentrations were measured by ELISA. RNAi effectively reduced the expression of exogenous CYP17 in HeLa cells by up to 50%. The CYP17 mRNA and androstenedione production of theca cells were slightly, but not significantly, reduced when compared with non‐specific siRNA.
Reduced thermal hyperalgesia and enhanced peripheral nerve injury after hind paw inflammation in mice lacking the serotonin‐transporter
Authors: Palm Florian , Mössner Rainald , Chen Yong , He Lan , Gerlach Manfred , Bischofs Stefan , Riederer Peter , Lesch Klaus‐Peter , Sommer Claudia
Published: January 2008

Mice lacking the serotonin‐transporter (5‐HTT‐/‐ mice) develop reduced thermal hyperalgesia after nerve injury, concomitant with reduced serotonin (5‐HT) levels in nervous tissue. Here we investigated pain behaviour in 5‐HTT‐/‐ mice compared to their wild type littermates after hind paw inflammation induced by complete Freund's adjuvant (CFA). We used standard tests for pain behaviour, high performance liquid chromatography for measurement of 5‐HT, and immunohistochemistry of hind paw skin tissue and L5 dorsal root ganglia (DRG) to measure local inflammation and nerve injury. After intraplantar CFA injection, hyperalgesia to heat was attenuated in 5‐HTT‐/‐ mice compared to wild type mice. Their 5‐HT levels in nervous and adrenal tissue were reduced. An intraplantar injection of 5‐HT four days after CFA transiently brought withdrawal latencies of 5‐HTT‐/‐ mice down to the level of wild type mice, thus rescuing the phenotype and supporting the role of 5‐HT in the development of CFA‐induced thermal hyperalgesia. The density of intraepidermal nerve fibres in plantar skin after CFA injection was reduced to a higher degree in 5‐HTT‐/‐ mice than in wild type mice, suggesting greater peripheral nerve injury in the knock‐out mice during hind paw inflammation. Accordingly, a higher number of injured DRG neurons was identified by activating transcription factor 3 (ATF3) staining in 5‐HTT‐/‐ mice after CFA. We conclude that the phenotype of 5‐HTT‐/‐ mice leads to reduced inflammatory pain due to reduced tissue 5‐HT levels and to greater peripheral nerve injury after inflammation. Human variants of the 5‐HTT genotypes might be part of the factors determining the extent of nerve injury and hyperalgesia in inflammation.
Becoming Turk the Rajput Way: Conversion and Identity in an Indian Warrior Narrative
Authors: TALBOT CYNTHIA
Published: January 2008

The Kyamkhanis were a small Indian Muslim community who flourished in northern Rajasthan from c. 1450 to 1730. This article examines memories of the Kyamkhani past recorded in a seventeenth-century history of the ruling lineage, as a case study of both the process of Islamic expansionism in South Asia and the self-identity of rural Muslim gentry. While celebrating the ancestor who had converted to Islam generations earlier, the Kyamkhanis also represented themselves as local warriors of the Rajput class, an affiliation that is considered exclusively Hindu in India today. Their history was written in a local literary language, Braj Bhasa, rather than in the more cosmopolitan Persian that was widely used by Muslim elites at the time. The Kyamkhanis of the early modern era thus negotiated multiple social and cultural spheres, simultaneously participating in the local/vernacular as well as global/cosmopolitan arenas.
In defence of a realist interpretation of theology
Authors: MACDONALD PAUL A.
Published: January 2008

In this essay, I defend theology against a recent argument made by Peter Byrne. According to Byrne, any discipline of thought that can be interpreted realistically shows the accumulation of reliable or widespread belief about the reality it investigates. I challenge this claim, first, by showing how theology, so construed as an exercise of ‘faith seeking understanding’, can and should be interpreted realistically, even if it does not show the accumulation of reliable or widespread belief about divine reality. Second, I give a plausible account of why theology is beset by internal disagreement and division, even if the goal of theological enquiry is to overcome such disagreement and division.
Pierre Bourdieu, the ‘cultural turn’ and the practice of international history
Authors: JACKSON PETER
Published: January 2008

The rise of the ‘cultural turn’ has breathed new life into the practice of international history over the past few decades. Cultural approaches have both broadened and deepened interpretations of the history of international relations. This article focuses on the use of culture as an explanatory methodology in the study of international history. It outlines the two central criticisms often made of this approach. The first is that it suffers from a lack of analytical rigour in both defining what culture is and understanding how it shapes individual and collective policy decisions. The second is that it too often leads to a tendency to exaggerate the importance of the cultural predispositions of individual or collective actors at the expense of the wider structures within which policymaking takes place. The article provides a brief outline of the social theory of Pierre Bourdieu – which focuses on the interaction between the cultural orientations of social actors and the structural environment that conditions their strategies and decisions. It then argues that Bourdieu’s conceptual framework can provide the basis for a more systematic approach to understanding the cultural roots of policymaking and that international historians would benefit from engagement with his approach.
Antecedents of Islamic Political Radicalism Among Muslim
Communities in Europe
Authors: Awan Akil N.
Published: January 2008

Recent years have witnessed a rapid proliferation of radical Islamist
activity in western Europe, from MI5's claim in 2006 of 30 incipient
“terror plots” and 1,600 individuals under surveillance, to actual
terrorist atrocities in European cities, the most infamous and
deadly of which included the transport network bombings in Madrid in
2003 and in London in 2005. Concomitantly, both the media and the
wider social discourse have been rife with self-appointed punditry
and a plethora of commentators pontificating on European radical
Islam's putative causal factors and remedies. This paper will
attempt to address the complex issues by providing a fuller, more
nuanced understanding of some of the causes and antecedents of
Islamic political radicalism among western European Muslims.
Radical Atmosphere: Explaining Jihadist Radicalization in
the UK
Authors: O'Duffy Brendan
Published: January 2008

In the months following the July 7, 2005, attack that killed 52
people and injured hundreds more, the British government was at
pains to deny allegations that Britain was targeted by homegrown,
al-Qaeda-affiliated terrorists because of its Middle East foreign
policy. Yet the government was privately aware by May 2004 that a
“particularly strong cause of disillusionment amongst Muslims … is a
perceived ‘double standard’ in the foreign policy of western
governments (and often those of Muslim governments), in particular
Britain and the U.S” (FCO/HO 2005).
Specific causes cited were bias towards Israel vis-à-vis
Palestinians; non-action on Kashmir and Chechnya; and “active
oppression” in Iraq, Afghanistan, and the wider “war on terror.”
Other alleged causes included social and economic deprivation,
Islamophobia (particularly following 9/11), and intergenerational
clashes between first, second, and third generation Muslims. But
little attempt was made either before or after July 7, 2005, to
examine the interaction between these domestic and foreign sources
of radicalization. This paper attempts to do so by examining the
rhetoric and actions of a range of young British Muslims including:
examples of 48 persons convicted of, charged for, or killed by
violent jihad—evidence of young Muslim opinion on extremism and
causes of violent jihadi terror in Britain. The evidence from this
preliminary study, though not large enough to draw reliable
statistical inferences, does suggest that not only is British
foreign policy a significant source of alienation among young
British Muslims, but that attitudes towards British foreign policy
interact with and often reinforce domestic social, cultural, and
economic sources of discontent. As explained in the literature
review below, examining the links between perceptions of foreign
policy towards the wider Muslim Ummah and sources of domestic
discontent offers a more satisfying account of British Muslim
radicalization than those offered by the dominant structural (social
network theories) and “aggrieved actor” interpretations. I would like to thank Jonathan
Githens-Mazer for organizing the PSA panel at the 2007 APSA
Annual Meeting where I presented this paper. I would also like
to thank Shah Miah for allowing me to cite evidence from his BA
research project (Queen Mary, University of London); Emily
Mclean Inglis and Anthony de Silva for research assistance; and
Zamila Bunglawala for advice and data on British Muslims and the
labor market.
Leadership Choice and Party Performance: The Democratic
Takeover of the 110th Congress—Editor's
Introduction
Authors: Harris Douglas B.
Published: January 2008

Having been out of power in the House since 1994 and in the Senate
for 10 of those 12 years as well, congressional Democrats' takeover
of Congress in the 2006 midterm elections was an important moment in
American political history. Having won the House and, somewhat more
unexpectedly, the Senate by a bare majority, the Democrats
recaptured control of an entire branch of the federal government for
the first time since Bill Clinton left the White House. Controlling
the levers of power in the House and the Senate—the legislative
schedule, committees and subcommittees, and, to the extent that
party bonds hold, the majority of votes in committee and on the
floor—Democrats were poised to influence, but of course not
unilaterally control, policymaking in the 110th Congress
and the conduct of the last two years of the Bush administration
through key congressional resources including funding and
administrative oversight. I would like
to thank all of the authors in the symposium for their
willingness to participate and their excellent contributions. A
special note of thanks also goes to Sean Kelly for his
encouragement and advice on this project from first conception
to final completion. Thanks also to Stephen Yoder and Rebecca
Fowler at PS for their patience and guidance
throughout.
Congressional Leadership on the Front Lines: Committee Chairs, Electoral Security, and Ideology
Authors: Becker Lawrence A. , Moscardelli Vincent G.
Published: January 2008

During the 2006 campaign, many on the political right expressed anxiety about the slate of Democratic representatives and senators poised to become committee chairs in the event of a Democratic victory. After the election, despite post-election promises of “unity” and “bipartisanship” among congressional Democrats, the question remained: How well would this progressive group of “old bulls” work with the new majority, the existence of which was due in part to the 61 Democrats representing House districts that President George W. Bush won in 2004? (Greenblatt 2007, 524) In this paper, we investigate the claim that Democratic committee leaders in the 110thCongress are out of step with their party caucus by comparing the ideological leadership profiles of chairs in the 110thCongress with those of their Republican predecessors in the 109th, as well as those of Democratic chairs from the “Textbook,” “Reform,” and early “Post-reform” eras. We show that Democratic chairs in the 110thCongress are primarily drawn from the most liberal ranks of the Democratic Caucus, particularly in the House. The authors wish to thank Sara Callow for her excellent and timely research assistance.
Leading the New Majorities
Authors: Sinclair Barbara
Published: January 2008

When a political party wrests control of either house of Congress
from the other, expectations for change are usually high and that
was certainly the case in January 2007 when Democrats took
majorities in both chambers for the first time in 12 years. What did
the new majorities—and specifically their leaders—promise? To what
extent have they delivered? And how do the experiences of the new
majorities during their first nine months conform with or raise
questions about our theories of Congress? This is perforce an
interim report but, even so, it can perhaps shed some light on our
theories as well as provide a first assessment of the new majorities
and their leaders. In addition to the
references cited here, this paper is based on interviews,
observation and news accounts.
The “Myth” of Moral Values Voting in the 2004
Presidential Election
Authors: Mulligan Kenneth
Published: January 2008

“Which ONE issue mattered most in deciding how you voted for
president?” This survey question, which appeared on the 2004
National Election Pool (NEP) exit poll, attracted as much
controversy as any in recent years. More respondents chose “moral
values” than any other issue. Among this 22% of respondents, 80%
voted for President Bush. Initially, news reporters and pundits
interpreted this finding as indicating that moral values played a
decisive role in Bush's victory. The morning after the election,
Chris Matthews, host of the MSNBC program Hardball,
suggested the election was “a referendum on values” (“Chris Matthews
Gives his Assessment”). Tim Russert, host of NBC's Meet the
Press, said that “People had an agenda. They put their
moral values ahead of some of their economic interests”
(“Analysis”). A reporter for the CBS Morning News
concluded that “in the end, the number-one voter motivator [was]
morality” (“Morality Proves Number One”).
Assessing Assessment: Examining the Assessment Plans at
50 Political Science Departments
Authors: Ishiyama John , Breuning Marijke
Published: January 2008

This paper represents a broad survey study of assessment models used
in political science programs at 50 universities and colleges across
the country. We examine the most frequently used assessment
activities and then investigate whether differences between
institutions is a function of institutional characteristics. What
are the techniques currently employed by departments across the
country?
Teaching the Iraq War
Authors: Burgos Russell A.
Published: January 2008

The last time members of the graduating class of 2008 lived in a
nation at peace, they were in the first month of their high school
sophomore year. Because they are not subject to conscription;
because the wars in Afghanistan and Iraq are being fought by a
professional army that has separated itself in many respects from
civil society; and because the government has asked little of
society in the way of sacrifice for the wars, today's undergraduates
have little direct experience of conflict, the armed forces, or
those people most affected by it. What do we teach students about
the war? Political scientists are often reluctant to teach current
events—aside from the fact emotions can run high and classroom
discussion can be hijacked by unproductive ideological debates, in
real-time we lack the kinds of patterned data that lend themselves
to systematic analysis and prediction.
Political Science Methodology: Opening Windows Across
Europe … and the Atlantic
Authors: Rihoux Benoît , Kittel Bernhard , Moses Jonathon W.
Published: January 2008

In the following essay, Benoît Rihoux, Bernhard Kittel and Jonathon
W. Moses outline the recent developments in European political
methodology and highlight their own work in developing a number of
projects with the European Consortium for Political Research (ECPR)
that include establishing a Standing Group in Political Methodology,
the ECPR Summer School in Methods and Techniques and the forthcoming
ECPR/Palgrave Macmillan Research Methods Book Series.
A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps
Authors: Anderson Rebecca K. , Miller Gifford H. , Briner Jason P. , Lifton Nathaniel A. , DeVogel Stephen B.
Published: January 2008

Observational records show that the area of ice caps on northern Baffin Island, Arctic Canada has diminished by more than 50% since 1958. Fifty 14C dates on dead vegetation emerging beneath receding ice margins document the persistence of some of these ice caps since at least 350 AD. In situ cosmogenic 14C in rock surfaces, and 14C in plant macrofossils from lake‐sediment cores demonstrate that the plateau remained ice‐free through the middle Holocene, but has supported ice caps for more than 2000 of the past 2800 years. The rapid disappearance of these ice caps over the past century, despite decreasing summer insolation, further demonstrates the unusual character of 20th Century warmth. Widespread ice‐cap expansion ∼1280 AD early in the Little Ice Age, and intensified expansion ∼1450 AD, coincide with peak stratospheric volcanic aerosol loading and reduced solar luminosity, suggesting that these mechanisms may have initiated ice‐cap growth, subsequently maintained by strong positive feedbacks.
Archaeal protoglobin structure indicates new ligand diffusion paths and modulation of haem‐reactivity
Authors: Nardini Marco , Pesce Alessandra , Thijs Liesbet , Saito Jennifer A , Dewilde Sylvia , Alam Maqsudul , Ascenzi Paolo , Coletta Massimiliano , Ciaccio Chiara , Moens Luc , Bolognesi Martino
Published: January 2008

The structural adaptability of the globin fold has been highlighted by the recent discovery of the 2‐on‐2 haemoglobins, of neuroglobin and cytoglobin. Protoglobin from Methanosarcina acetivorans C2A—a strictly anaerobic methanogenic Archaea—is, to the best of our knowledge, the latest entry adding new variability and functional complexity to the haemoglobin (Hb) superfamily. Here, we report the 1.3 Å crystal structure of oxygenated M. acetivorans protoglobin, together with the first insight into its ligand‐binding properties. We show that, contrary to all known globins, protoglobin‐specific loops and an amino‐terminal extension completely bury the haem within the protein matrix. Access of O2, CO and NO to the haem is granted by the protoglobin‐specific apolar tunnels reaching the haem distal site from locations at the B/G and B/E helix interfaces. Functionally, M. acetivorans dimeric protoglobin shows a selectivity ratio for O2/CO binding to the haem that favours O2 ligation and anticooperativity in ligand binding. Both properties are exceptional within the Hb superfamily.
A structural basis for the allosteric regulation of non‐hydrolysing UDP‐GlcNAc 2‐epimerases
Authors: Velloso Lucas M , Bhaskaran Shyam S , Schuch Raymond , Fischetti Vincent A , Stebbins C Erec
Published: January 2008

The non‐hydrolysing bacterial UDP‐N‐acetylglucosamine 2‐epimerase (UDP‐GlcNAc 2‐epimerase) catalyses the conversion of UDP‐GlcNAc into UDP‐N‐acetylmannosamine, an intermediate in the biosynthesis of several cell‐surface polysaccharides. This enzyme is allosterically regulated by its substrate UDP‐GlcNAc. The structure of the ternary complex between the Bacillus anthracis UDP‐GlcNAc 2‐epimerase, its substrate UDP‐GlcNAc and the reaction intermediate UDP, showed direct interactions between UDP and its substrate, and between the complex and highly conserved enzyme residues, identifying the allosteric site of the enzyme. The binding of UDP‐GlcNAc is associated with conformational changes in the active site of the enzyme. Kinetic data and mutagenesis of the highly conserved UDP‐GlcNAc‐interacting residues confirm their importance in the substrate binding and catalysis of the enzyme. This constitutes the first example to our knowledge, of an enzymatic allosteric activation by direct interaction between the substrate and the allosteric activator.
Molecular mechanisms for myocardial mitochondrial dysfunction in the metabolic syndrome
Authors: Bugger Heiko , Dale Abel E.
Published: January 2008

The metabolic syndrome represents a cluster of abnormalities, including obesity, insulin resistance, dyslipidaemia and Type 2 diabetes, that increases the risk of developing cardiovascular diseases, such as coronary artery disease and heart failure. The heart failure risk is increased even after adjusting for coronary artery disease and hypertension, and evidence is emerging that changes in cardiac energy metabolism might contribute to the development of contractile dysfunction. Recent findings suggest that myocardial mitochondrial dysfunction may play an important role in the pathogenesis of cardiac contractile dysfunction in obesity, insulin resistance and Type 2 diabetes. This review will discuss potential molecular mechanisms for these mitochondrial abnormalities.
Many Nations Build the Latest in Synchrotron Light Sources
Authors: Levi Barbara Goss
Published: January 2008

At a number of construction sites around the world, crews are laboring in and around large circular tracks to install the accelerators and storage rings that will form the basis of new synchrotron radiation facilities. Most of the budding facilities are designed to produce synchrotron radiation, in the soft- or hard-x-ray regions, that is far brighter than available sources can provide. They are sometimes described as the “third generation.” According to this rough categorization, the first generation consists of circular accelerators originally intended for other purposes: They provide synchrotron radiation to parasitic experiments or, in some cases, they have become partially dedicated to such uses. The second generation comprises facilities specifically designed to support synchrotron radiation experiments, with the radiation produced primarily as electrons or positrons curved in the field of the machines’ bending magnets. The third-generation machines, by contrast, are designed to optimize the radiation that is produced as the electrons or positrons traverse devices known as wigglers and undulators. The new machines will complement existing facilities, and they will provide more opportunities for the growing user community.
Light Travels More Slowly Through Strongly Scattering Materials
Authors: Levi Barbara Goss
Published: January 2008

We expect light to travel through a medium at a rate given by the speed of light in a vacuum divided by the average index of refraction of the material. But a recent experiment performed in the Netherlands indicates that in some strongly scattering materials it may actually take light five to ten times longer to traverse a sample than one would expect from this simple formula for the phase velocity. It appears that the light resonates for a while with the dielectric microspheres of which the material is made so the light takes longer to travel through the sample. This result challenges some assumptions made in the analysis of data from light scattering experiments, especially searches for localized light.
Cold Neutron Research Facility Begins Operating at NIST
Authors: Zeman Ellen J.
Published: January 2008

Materials scientists, condensed matter physicists, analytical chemists and biologists are only part of a large and growing community of researchers who need access to subthermal, or “cold,” neutrons and the various instruments that use these very-lowenergy particles. For the past two decades, many US researchers have had to travel to Western Europe for that access, but now, with the opening of the new, $30-million Cold Neutron Research Facility at the National Institute of Standards and Technology in Gaithersburg, Maryland, intense beams of long-wavelength neutrons are available closer to home.
De Gennes Wins Nobel Physics Prize for Work on Complex Systems
Authors: Levi Barbara Goss
Published: January 2008

In 1977 Pierre-Gilles de Gennes of the Collège de France wrote an article for La Recherche about the Nobel Prize in Physics that had been awarded that year to John Van Vleck, Philip Anderson and Nevill Mott. In his article, de Gennes categorized each of the three Nobelists according to a scheme suggested to him by the wife of an English colleague: She classified physicists either as golf players, who patiently tap a single ball from hole to hole until the end of the game, or as tennis players, who bound around the court to hit the ball from all directions. By this definition de Gennes is a tennis player. In his career he has studied condensed matter in many forms: ferromagnets, superconductors, liquid crystals, polymers and, most recently, interfacial phenomena. Now this Frenchman has won the Nobel Prize, having been cited more for his overall style of play than for any unique stroke. In announcing the prize, the Royal Swedish Academy of Sciences recognized de Gennes for “discovering that methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers.” De Gennes received his prize, worth $1 million, on 10 December.
Nobel Chemistry Prize Recognizes the Importance of Ernst's nmr Work
Authors: Collins Graham P.
Published: January 2008

Richard R. Ernst of the Swiss Federal Institute of Technology (ETH) in Zurich was reviewing research proposals on a flight from Moscow to New York, on his way to collect Columbia University's 1991 Louisa Gross Horwitz Prize, when the captain informed him he had won the 1991 Nobel Prize in Chemistry. While the news was not important enough to interrupt screening of the in-flight movie, Ernst did go forward to the cockpit to receive the radioed congratulations of the Royal Swedish Academy of Sciences, the president of Switzerland and participants in a party organized on his behalf in Zurich.
Nobel Chemists Shed Light on Key Structure in Photosynthesis
Authors: Levi Barbara Goss
Published: January 2008

In December the 1988 Nobel Prize in Chemistry was presented to three scientists who delineated the physical structure of a protein-pigment complex that resides in a cell membrane and plays a critical role in photosynthesis. The three are Johann Deisenhofer of the Howard Hughes Medical Institute Laboratories at the University of Texas Southwestern Medical Center in Dallas, Texas; Robert Huber of the Max Planck Institute for Biochemistry in Martinsried, West Germany; and Hartmut Michel of the Max Planck Institute for Biophysics in Frankfurt, West Germany. Before their work, many had felt that crystallizing and subsequently resolving the structure of a membrane-bound protein would not be possible. The prize not only honors the researchers for this feat but also indirectly recognizes the key role played by this protein in nature's process for converting sunlight into energy.
Ion Sits Still for Sharp ‘Picture’ of Its Optical Transition
Authors: Levi Barbara Goss
Published: January 2008

A single atom, isolated and motionless, should be an excellent clock. It can radiate signals that are free of Doppler shifts and distortions introduced by its interactions with the environment. Just such thinking has motivated much work on ion traps, and that research is now bearing fruit: A group working at the National Institute of Standards and Technology in Boulder has measured the frequency of an ultraviolet transition in a single mercury atom with a linewidth under 180 Hz. The work was reported by James Bergquist, Frank Dietrich (now at Gsänger Optoelectronik, FRG), Wayne Itano and David Wineland at the Ninth International Conference on Laser Spectroscopy, held in Bretton Woods, New Hampshire, last June. Before this recent feat, the narrowest width measured for an optical frequency had been on the order of a few kilohertz.
Short-Wavelength Distortions Seen in the Cosmic Background Radiation
Authors: Andersen Per H.
Published: January 2008

Recent high-sensitivity measurements of the cosmic background radiation at submillimeter wavelengths indicate significant deviations from a blackbody spectrum. This far-infrared excess radiation may have arisen from physical processes during the “dark ages” in the universe, between the formation of neutral atoms and the formation of galaxies.
Positron Microscopes Offer A New View of Things
Authors: Levi Barbara Goss
Published: January 2008

A positron microscope may soon open a new window to the realm of the very small. While the view through this device would not be as finely resolved as that through its antimatter cousin, the electron microscope, it could reveal a qualitatively different landscape. Hopes for a positron microscope were boosted recently when independent groups successfully operated two such instruments, one with an especially high resolution. Both the devices are based on the reemission of positrons from a surface. James Van House and Arthur Rich of the University of Michigan, who last year also built a transmission positron microscope, have operated their reemission microscope with a resolution of 2000 nm. George Brandes and Karl Canter of Brandeis University, together with Allen Mills of AT&T Bell Labs, have constructed a reemission positron microscope of slightly different design that has a resolution of 300 nm—the limit for optical microscopes—and a magnification factor of 1150. Both groups feel that further enhancements could give the positron microscope a resolution of 1 nm. At such a resolution, the microscope could facilitate studies of crystal defects and of biological molecules.
Exchange frequency in replica exchange molecular dynamics
Authors: Sindhikara Daniel , Meng Yilin , Roitberg Adrian E.
Published: January 2008

The effect of the exchange-attempt frequency on sampling efficiency is studied in replica exchange molecular dynamics (REMD). We show that sampling efficiency increases with increasing exchange-attempt frequency. This conclusion is contrary to a commonly expressed view in REMD. Five peptides (1–21 residues long) are studied with a spectrum of exchange-attempt rates. Convergence rates are gauged by comparing ensemble properties between fixed length test REMD simulations and longer reference simulations. To show the fundamental correlation between exchange frequency and convergence time, a simple model is designed and studied, displaying the same basic behavior of much more complex systems.
Quadratic response functions in the relativistic four-component Kohn-Sham approximation
Authors: Henriksson Johan , Saue Trond , Norman Patrick
Published: January 2008

A formulation and implementation of the quadratic response function in the adiabatic four-component Kohn-Sham approximation is presented. The noninteracting reference state is time-reversal symmetric and formed from Kramers pair spinors, and the energy density is gradient corrected. Example calculations are presented for the optical properties of disubstituted halobenzenes in their meta and ortho conformations. It is demonstrated that correlation and relativistic effects are not additive, and it is shown that relativity alone reduces the μβ¯-response signal by 62% and 75% for meta- and ortho-bromobenzene, respectively, and enhances the same response by 17% and 21% for meta- and ortho-iodobenzene, respectively. Of the employed functionals, CAM-B3LYP shows the best performance and gives hyperpolarizabilities β distinctly different from B3LYP.
Spectral tuning by switching C–H⋯O hydrogen bonds: Rotation-induced spectral shifts of 7-hydroxyquinoline∙HCOOH isomers
Authors: Thut Markus , Manca Carine , Tanner Christian , Leutwyler Samuel
Published: January 2008

Spectral tuning effects on visible chromophores by hydrogen bonds are central to the chemistry of vision and of photosynthesis. A model for large spectral tuning effects by hydrogen bond switching is provided by the 7-hydroxyquinoline∙HCOOH complex, which forms two isomers, CTN1 and CTN2, both with an HCOOH⋯N hydrogen bond but with different (quinoline)C–H⋯OC hydrogen bonds. A 180° rotation of the HCOOH moiety around the O–H⋯N hydrogen bond exchanges the C–H⋯O hydrogen bonds, rotates the dipole moment of HCOOH, and leads to an ∼850cm−1 shift of the electronic spectrum. Mass-selected S1←S0 resonant two-photon ionization, UV-UV holeburning, S1→S0 fluorescence spectra, and photoionization efficiency curves of the two 7-hydroxyquinoline∙HCOOH isomers were measured in supersonic expansions. Comparison to ab initio calculations allow us to determine the H-bond connectivity and structure of the two isomers and to assign their inter- and intramolecular vibrations. The Franck-Condon factors of the intermolecular shear vibration χ in the S1←S0 spectra indicate that the weak C–H⋯O hydrogen bond contracts markedly in the CTN1 isomer but expands in the CTN2 isomer. These changes of H-bond lengths agree with the spectral shifts. In contrast, the strong O–H⋯N hydrogen bond undergoes little change upon S1←S0 excitation.
Relativistic electronic structure of the Sr2 molecule
Authors: Kotochigova Svetlana
Published: January 2008

Diatomic Sr2 has been proposed as a good candidate for precision measurement of possible time variation of fundamental constants. Precise knowledge of its vibrational structure and Stark shift of its levels in an optical lattice is required for realization of this proposal. Motivated by these ideas we have performed a numerical calculation of interatomic potentials and transition dipole moments of the Sr2 molecule using an ab initio relativistic configuration interaction valence bond self-consistent-field method.