bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonation of 3‐pyridinols
Authors: Mutterer F. , Weis C. D.
Published: April 2009

Procedures are described for the high pressure carbonation of substituted 3‐pyridinols, yielding the corresponding pyridine carboxylic acids. Treatment of o‐aminohydroxypyridinecarboxylic acid with cyanogen and with phosgene, respectively, gave access to oxazolo[4,5‐b]pyridine derivatives. The synthesis of 3‐amino‐6‐methyl‐2‐pyridinecarboxylic acid was accomplished by heating 3‐hydroxy‐6‐methyl‐2‐pyridinecarboxylic acid in liquid ammonia.
Transformations of some substituted methylene heterocycles with some nucleophiles
Authors: Drobnič‐Košorok M. , Jernejc‐Pfundner K. , Peternel J. , Stanovnik B. , Tišler M.
Published: April 2009

To the ring nitrogen substituted o‐methylene derivatives of pyridine, pyridazine, quinoline and isoquinoline were transformed into the corresponding pyrazolyl derivatives when treated with hydrazine hydrate. On the other hand, the substituted methylene derivatives of quinoline or isoquinoline were transformed with aqueous sodium hydroxide or with sodium ethylate into 2‐methylquinoline or 1‐methylisoquinoline. This reaction represents a facile introduction of a methyl group in the above mentioned heterocycles.
Partial methylation of quercetin: Direct synthesis of tamarixetin, ombuin and ayanin
Authors: Rao Koppaka V. , Owoyale Jacob A.
Published: April 2009

Methylalion of the penlahydroxy flavone, quercetin, was observed to proceed in distinct stages. From the reaction mixture (methyl sulfale/potassium carbonate/acetone), the isolation of three major intermediates, a mono‐, a di‐ and a trimethyl ether and their identification as the naturally occurring ethers: tamarixelin, ombuin and ayanin is described.
Preparation of fluorescently‐labeled amyloid‐beta peptide assemblies: the effect of fluorophore conjugation on structure and function
Authors: Jungbauer L. M. , Yu C. , Laxton K. J. , LaDu M. J.
Published: April 2009

Recent research has focused on soluble oligomeric assemblies of the 42 amino acid isoform of the amyloid‐beta peptide (Aβ42) as the proximal cause of neuronal injury, synaptic loss, and the eventual dementia associated with Alzheimer's disease (AD). While neurotoxicity, neuroinflammation, and deficits in behavior and memory have all been attributed to oligomeric Aβ42, the specific roles for this assembly in the cellular neuropathology of AD remain poorly understood. In particular, lack of reliable and well‐characterized forms of easily detectable Aβ42 oligomers has hindered study of the cellular trafficking of exogenous Aβ42 by neurons in vitro and in vivo. Therefore, the objective of this study is to fluorescently label soluble oligomeric Aβ42 without altering the structure or function of this assembly. Previous studies have demonstrated the advantages of using tapping mode atomic force microscopy (AFM) to characterize the structural assemblies formed by synthetic Aβ42 under specific solution conditions (e.g., oligomers, protofibrils, and fibrils). Here, we extend these methods to establish a strategy for fluorescent labeling of oligomeric Aβ42 assemblies that are structurally comparable to unlabeled oligomeric Aβ42. To compare function, we demonstrate that the uptake of labeled and unlabeled oligomeric Aβ42 by neurons in vitro is similar. AFM‐characterized fluorophore‐Aβ42 oligomers are an exciting new reagent for use in a variety of studies designed to elucidate critical cellular and molecular mechanisms underlying the functions of this Aβ42 assembly form in AD. Copyright © 2009 John Wiley & Sons, Ltd.
Acidity, nutrient stocks, and organic‐matter content in soils of a temperate deciduous forest with different abundance of European beech (Fagus sylvatica L.)
Authors: Guckland Anja , Jacob Mascha , Flessa Heiner , Thomas Frank M. , Leuschner Christoph
Published: April 2009

The production and composition of leaf litter, soil acidity, exchangeable nutrients, and the amount and distribution of soil organic matter were analyzed in a broad‐leaved mixed forest on loess over limestone in Central Germany. The study aimed at determining the current variability of surface‐soil acidification and nutrient status, and at identifying and evaluating the main factors that contributed to the variability of these soil properties along a gradient of decreasing predominance of European beech (Fagus sylvatica L.) and increasing tree‐species diversity. Analyses were carried out in (1) mature monospecific stands with a predominance of beech (DL 1), (2) mature stands dominated by three deciduous‐tree species (DL 2: beech, ash [Fraxinus excelsior L.], lime [Tilia cordata Mill. and/or T. platyphyllos Scop.]), and (3) mature stands dominated by five deciduous‐tree species (DL 3: beech, ash, lime, hornbeam [Carpinus betulus L.], maple [Acer pseudoplatanus L. and/or A. platanoides L.]).

The production of leaf litter was similar in all stands (3.2 to 3.9 Mg dry matter ha–1 y–1) but the total quantity of Ca and Mg deposited on the soil surface by leaf litter increased with increasing tree‐species diversity and decreasing abundance of beech (47 to 88 kg Ca ha–1 y–1; 3.8 to 7.9 kg Mg ha–1 y–1). The soil pH(H2O) and base saturation (BS) measured at three soil depths down to 30 cm (0–10 cm, 10–20 cm, 20–30 cm) were lower in stands dominated by beech (pH = 4.2 to 4.4, BS = 15% to 20%) than in mixed stands (pH = 5.1 to 6.5, BS = 80% to 100%). The quantities of exchangeable Al and Mn increased with decreasing pH and were highest beneath beech. Total stocks of exchangeable Ca (0–30 cm) were 12 to 15 times larger in mixed stands (6660 to 9650 kg ha–1) than in beech stands (620 kg ha–1). Similar results were found for stocks of exchangeable Mg that were 4 to 13 times larger in mixed stands (270 to 864 kg ha–1) than in beech stands (66 kg ha–1). Subsoil clay content and differences in litter composition were identified as important factors that contributed to the observed variability of soil acidification and stocks of exchangeable Ca and Mg. Organic‐C accumulation in the humus layer was highest in beech stands (0.81 kg m–2) and lowest in stands with the highest level of tree‐species diversity and the lowest abundance of beech (0.27 kg m–2).

The results suggest that redistribution of nutrients via leaf litter has a high potential to increase BS in these loess‐derived surface soils that are underlain by limestone. Species‐related differences of the intensity of soil–tree cation cycling can thus influence the rate of soil acidification and the stocks and distribution of nutrients.
LRRK2 mutations and risk variants in Japanese patients with Parkinson's disease
Authors: Zabetian Cyrus P. , Yamamoto Mitsutoshi , Lopez Alexis N. , Ujike Hiroshi , Mata Ignacio F. , Izumi Yuishin , Kaji Ryuji , Maruyama Hirofumi , Morino Hiroyuki , Oda Masaya , Hutter Carolyn M. , Edwards Karen L. , Schellenberg Gerard D. , Tsuang Debby W. , Yearout Dora , Larson Eric B. , Kawakami Hideshi
Published: April 2009

Mutations in the leucine‐rich repeat kinase 2 (LRRK2) gene are the most common genetic determinant of Parkinson's disease (PD) in European‐derived populations, but far less is known about LRRK2 mutations and susceptibility alleles in Asians. To address this issue, we sequenced the LRRK2 coding region in 36 patients with familial PD, then genotyped variants of interest in an additional 595 PD cases and 1,641 controls who were all of Japanese ancestry. We also performed a meta‐analysis of studies on G2385R, a polymorphism previously reported to associate with PD. One pathogenic (G2019S) and one putative pathogenic (R1067Q) mutation were each observed in two patients with sporadic PD. The overall mutation frequency among patients was 0.6%. G2385R was highly associated with PD under a dominant model in our dataset (adjusted OR, 1.83; 95% CI, 1.31–2.54; P = 3.3 × 10−4) and similar results were seen in the meta‐analysis (summary OR assuming fixed effects, 2.55; 95% CI, 2.10–3.10). G2385R represents the first consistently replicated common PD susceptibility variant in a non‐European population and its effect size is substantially greater than that reported for other well‐validated genetic risk factors for the disease. However, LRRK2 mutations appear to be rare among Japanese patients with PD. © 2009 Movement Disorder Society
Kontrolle über Laborsynthesen
Authors: Groth Urs
Published: April 2009

Bei organischen Synthesen hält das Reaktionssystem Easymax die Temperatur konstant und dokumentiert den Reaktionsverlauf.
Nah an der Lösung: MS in der Koordinationschemie
Authors: Streb Carsten , Wilson Elizabeth F.
Published: April 2009

Strukturelle Informationen über labile Koordinationsverbindungen in Lösung sind nur schwer erhältlich. Massenspektrometrie mit sanften Ionisierungstechniken kann hier weiterhelfen: Sie liefert Informationen über Aufbau und Verhalten von labilen Komplexen in flüssiger Phase.
Identification and characterization of proteins interacting with SIRT1 and SIRT3: implications in the anti‐aging and metabolic effects of sirtuins
Authors: Law Ivy K. M. , Liu Ling , Xu Aimin , Lam Karen S. L. , Vanhoutte Paul M. , Che Chi‐Ming , Leung Priscilla T. Y. , Wang Yu
Published: April 2009

Sirtuins are a family of NAD+‐dependent protein deacetylases that regulate cellular functions through deacetylation of a wide range of protein targets. Overexpression of Sir2, the first gene discovered in this family, is able to extend the life span in various organisms. The anti‐aging effects of human homologues of sirtuins, SIRT1‐7, have also been suggested by animal and human association studies. However, the precise mechanisms whereby sirtuins exert their anti‐aging effects remain elusive. In this study, we aim to identify novel interacting partners of SIRT1 and SIRT3, two human sirtuins ubiquitously expressed in many tissue types. Our results demonstrate that SIRT1 and SIRT3 are localized within different intracellular compartments, mainly nuclei and mitochondria, respectively. Using affinity purification and MALDI‐TOF/TOF‐MS/MS analysis, their potential interacting partners have been identified from the enriched subcellular fractions and specific interactions confirmed by co‐immunoprecipitation and Western blotting experiment. Further analyses suggest that overexpression of SIRT1 or SIRT3 in HEK293 cells could induce hypoacetylation and affect the intracellular localizations and protein stabilities of their interacting partners. Taken together, the present study has identified a number of novel SIRT protein interacting partners, which might be critically involved in the anti‐aging and metabolic regulatory activities of sirtuins.
Interspecies comparison of prostate cancer gene‐expression profiles reveals genes associated with aggressive tumors
Authors: Kela Itai , Harmelin Alon , Waks Tova , Orr‐Urtreger Avi , Domany Eytan , Eshhar Zelig
Published: April 2009

Prostate cancer (PC) is a heterogeneous disease whose aggressive phenotype is the second leading cause of cancer‐related death in men. The identification of key molecules and pathways that play a pivotal role in PC progression towards an aggressive form is crucial. A major effort towards this end has been taken by global analyses of gene expression profiles. However, the large body of data did not provide a definitive idea about the genes which are associated with the aggressive growth of PC. In order to identify such genes, we performed an interspecies comparison between several human data sets and high quality microarray data that we generated from the transgenic adenocarcinoma of mouse prostate (TRAMP) strain. The TRAMP PC mimics the histological and pathological appearance as well as the aggressive phenotype of human PC (huPC). Analysis of the microarray data, derived from microdissected TRAMP specimens removed at different stages of the disease yielded genetic signatures delineating the TRAMP PC development and progression. Comparison of the TRAMP data with a set of genes representing the core expression signature of huPC yielded a limited set genes. Some of these genes are known predictors of poor prognosis in huPC. Interestingly, the modulation of genes responsible for the invasive phenotype of huPC occurs in TRAMP already during the transition to prostate intraepithelial neoplasia (PIN) and onwards to localized tumors. We therefore suggest that critical oncogenic events leading to an aggressive phenotype of huPC can be studied in the PIN stage of TRAMP. Prostate 69:1034–1044, 2009. © 2009 Wiley‐Liss, Inc.
Expression of the gastrin‐releasing peptide receptor, the prostate stem cell antigen and the prostate‐specific membrane antigen in lymph node and bone metastases of prostate cancer
Authors: Ananias Hildo J.K. , van den Heuvel Marius C. , Helfrich Wijnand , de Jong Igle J.
Published: April 2009

OBJECTIVE

Cell membrane antigens like the gastrin‐releasing peptide receptor (GRPR), the prostate stem cell antigen (PSCA), and the prostate‐specific membrane antigen (PSMA), expressed in prostate cancer, are attractive targets for new therapeutic and diagnostic applications. Therefore, we investigated in this study whether these antigens are expressed in metastasized prostate cancer.

METHODS

Formalin‐fixed, paraffin‐embedded specimens of 15 patients with uni‐ or bilateral lymph node metastases of prostate cancer (totaling 21 cases) and 17 patient‐cases of bone metastases were processed for immunohistochemistry with anti‐GRPR, anti‐PSCA, and anti‐PSMA antibodies. A pathologist blinded to clinical and pathological data scored the immunoreactivity for these antibodies on a four‐point scale (0 = no staining; 1+ = weak staining; 2+ = moderate staining; 3+ = strong staining) and documented the distribution pattern.

RESULTS

GRPR staining in lymph node metastases was seen in 85.7% of cases (18 of 21 cases), PSCA in 95.2% (20/21), and PSMA in 100% (21/21). GRPR in bone metastases was seen in 52.9% of cases (9/17), PSCA in 94.1% (16/17), and PSMA in 100% (17/17).

CONCLUSION

We have shown for the first time that GRPR is expressed in the vast majority of lymph node metastases and in 52.9% of bone metastases of prostate cancer. PSCA and PSMA are both highly expressed in lymph node and bone metastases. Although PSCA and PSMA are mostly expressed in prostate cancer metastases, GRPR offers an interesting alternative target as it can be targeted relatively easy with peptide‐based (radio)pharmaceuticals. Prostate 69:1101–1108, 2009. © 2009 Wiley‐Liss, Inc.
Heliumpartialdrucksensor statt Massenspektrometer im Helium‐Leckdetektor
Authors: Wetzig D.
Published: April 2009

Die Dichtheitsprüfung mit Helium als Prüfgas ist in der industriellen Fertigung zur Qualitätssicherung etabliert. Insbesondere bei Applikationen mit hohen Anforderungen zu Genauigkeit und Nachweisgrenze steht kein alternatives Verfahren zur Verfügung.

In den Prüfanlagen erfolgt der Nachweis des Heliums bisher mit massenspektroskopischen Methoden. Hierzu sind Hochvakuumbedingungen notwendig. Die Sicherstellung dieser Bedingung in der Industrieumgebung ist zeitaufwendig und kostenintensiv.

Der neuartige Wise TechnoloyTM Sensor weist Helium unabhängig vom Umgebungsdruck bis hin zum atmosphärischen Druck nach. Die Anforderungen an das Pumpsystem in den Prüfanlagen sind also drastisch geringer, bzw. das Pumpsystem kann komplett entfallen.

Im Sensor wird zum Heliumnachweis mit einer sehr dünnen, beheizten Quarzmembran das Helium von anderen Luftbestandteilen getrennt. In einem gekapselten, evakuierten Volumen hinter der separierenden Membran wird mit hoher Präzision der Totaldruck gemessen. Die gute Selektivität der Quarzmembran für Helium ermöglicht die Gleichsetzung des gemessenen Totaldrucks mit dem Heliumpartialdruck.

Im Artikel wird das Prinzip und die Eigenschaft des neuartigen Sensors beschrieben. Die Stärken dieses Nachweises werden anhand von Applikationsbeispielen aufgezeigt.
Fabry disease in a patient with Turner syndrome
Authors: Brouns R. , Eyskens F. , De Boeck K. , Ceuterick‐de Groote C. , Van den Broeck M. , Van Broeckhoven C. , De Deyn P. P.
Published: April 2009

We report a unique case with co‐occurrence of Turner syndrome and Fabry disease (OMIM #301500). The latter is a rare X‐linked lysosomal storage disease that is characterized by partial or complete deficiency of α‐galactosidase A (GLA; EC 3.2.1.22) following mutations in the gene (GLA) localized at Xq22.1. Accumulation of metabolic intermediates can occur in many tissues and leads to severe morbidity, especially due to renal failure, cardiac involvement and stroke. It is well established that hemizygous male mutation carriers with Fabry disease are generally more severely affected than heterozygous female mutation carriers, but disabling clinical features and disease progression often occur in female Fabry patients as well. The majority of this patient's cells are of the 45,X type, making her a hemizygous GLA mutation carrier displaying a very severe Fabry disease phenotype.
Association analysis of TNFRSF1B polymorphisms with type 2 diabetes and its related traits in North India
Authors: Tabassum Rubina , Chavali Sreenivas , Mahajan Anubha , Ghosh Saurabh , Madhu S. V. , Tandon Nikhil , Bharadwaj Dwaipayan
Published: April 2009

Inflammation plays a crucial role in the pathogenesis of type 2 diabetes and various lines of evidences suggest an important contribution of type 2 receptor for TNFα (TNFR2), a mediator of inflammatory responses. Though genetic association of TNFRSF1B (encoding TNFR2) polymorphisms have been investigated in various studies, their involvement is not clear because of inconsistent findings. Because of high susceptibility of Indian population to type 2 diabetes and its complications, we evaluated the association of TNFRSF1B polymorphisms-rs1061622 (M196R; exon6) and rs3397 (3′UTR) and (CA)
n
repeat (intron 4) in 1,852 subjects including 1,040 cases and 812 controls with type 2 diabetes and its associated peripheral neuropathy and hypertension in North Indians of Indo-European ethnicity. The allelic and genotypic distributions of these polymorphisms were comparable among healthy control vs. type 2 diabetes, peripheral neuropathy vs. non-neuropathy and hypertensive vs. normotensive groups. (CA)
n
polymorphism has been shown to be associated with diabetic neuropathy in Caucasians, however, this could not be replicated in our study (P = 0.27). None of the polymorphisms were found to influence the 14 anthropometric and biochemical traits related to type 2 diabetes studied here. Thus, we conclude that TNFRSF1B is not a major contributing factor to the genetic risk of type 2 diabetes, its associated peripheral neuropathy and hypertension and related metabolic traits in North Indians.
Availability of free fruits and vegetables at canteen lunch improves lunch and daily nutritional profiles: a randomised controlled trial
Authors: Lachat Carl K. , Verstraeten Roosmarijn , De Meulenaer Bruno , Menten Joris , Huybregts Lieven F. , Van Camp John , Roberfroid Dominique , Kolsteren Patrick W.
Published: April 2009

Canteens are known to be promising settings for activities to promote intake of fruits and vegetables, but it remains unclear to what extent distributing free fruits and vegetables can influence dietary patterns of customers. The present study evaluated the effect of providing fruits and vegetables for free in a university canteen on the daily diet of university canteen customers. Canteen customers (n 209) were randomly allocated to a fruit and vegetable group (FVG) and a control group (CG). FVG participants were given two portions of fruits and one portion of vegetables for free at lunchtime. Food and beverage intake was measured using a dietary record for 3 d and dietary quality was appraised using a comprehensive scoring system. The FVG participants ate 80 g more fruits (P < 0·01) and 108 g more vegetables (P < 0·001) on a daily basis compared with the CG participants. No differences were found for energy density, total energy, Na and energy from fat between the groups per day. A higher intake of fruits and vegetables was observed at lunch and of vegetables during the dinner and evening snacks. The FVG participants were more likely to comply with dietary recommendations for fruits and vegetables and had a better dietary profile on the study days and for the lunch consumed on those days. The results of the present study demonstrate how modifications of a canteen lunch can be instrumental to enhance the nutritional quality of lunch as well as the overall quality of the diet of the customers.
Photosynthetic responses to the temperature of size-fractionated phytoplankton in the wintertime north-western Pacific
Authors: Shiomoto Akihiro
Published: April 2009

This study shows that the smaller phytoplankton are better able to acclimate to rapid fluctuations in temperature in the open ocean. In contrast, phytoplankton of all sizes have possibly the same ability along the coast.
What is the Order Among the Varieties of Goodness? A Question Posed by von Wright; and a Conjecture Made by Aristotle
Authors: Wiggins David
Published: April 2009

The great variousness and plurality of goodness has given comfort to general scepticism about values and a multitude of metaethical attitudes or predilections. But is this variousness and plurality really the hotch-potch it has appeared? The paper recapitulates and expands von Wright's typology of the varieties of goodness and looks to explain the order or system that underlies the phenomena by developing and extending a conjecture of Aristotle's, the so-called ‘focal hypothesis’, and combining therewith a suggestion of von Wright's, to the effect that the central case of something good is the faring well of a being. By means of focal hypothesis, one may account fairly well for medical, technical, instrumental, beneficial and utilitarian goodness. Other varieties such as hedonic and ethical goodness complicate the picture, as also do all cases where it seems that an antecedent kind of goodness impinges upon a being. These complications mirror in part the finding that the human scale of values is not a scale exclusively of human values.
Alliances in a Unipolar World
Authors: Walt Stephen M.
Published: April 2009

Unipolarity is a novel condition in world politics, and its effects on international alliances have yet to receive sustained theoretical attention. Tracing its impact requires a careful distinction between the purely structural features common to any unipolar system and the unique characteristics of the current unipole (the United States) or the policies undertaken by particular U.S. leaders (such as George W. Bush). In general, the unipole will enjoy greater freedom of action and be less dependent on allied support, enabling it to rely more readily on ad hoc “coalitions of the willing.” Lesser powers will be concerned about the concentration of power held by the unipole, but they will also face larger barriers to concerted action to contain it. Hard balancing against the unipole will be unlikely—unless the unipole begins a major effort to expand—but lesser powers will engage in soft balancing to contain the latter's influence. Medium powers may pursue alliances with others in order to reduce dependence on the unipole, but weaker states are likely to ally with the unipole in order to use its power against local security challenges. Bandwagoning will remain rare even under unipolarity, but disputes over burden sharing and alliance leadership will continue. Weaker states will prefer multilateral arrangements that enhance their own influence, while the unipole will prefer bilateral or ad hoc coalitions of the willing that it can more readily dominate.
System Maker and Privilege Taker
Authors: Mastanduno Michael
Published: April 2009

There is striking consistency in the international economic behavior of the United States across the bipolar and unipolar eras. The United States has been simultaneously a system maker and privilege taker, and its ability to play that dual role has required the willing collaboration of foreign partners. U.S. influence over those partners, however, has changed in important ways. During the cold war the United States dominated international economic adjustment struggles. Its ability to prevail in those struggles after the cold war has been significantly compromised. The United States, notwithstanding its preponderant power, no longer enjoys the same type of security leverage it once possessed, and the very success of the U.S.-centered world economy has opened a greater range of international and domestic economic options for America's supporters. In the unipolar era the United States may continue to act its own way, but it can no longer count on getting its own way.
Picturing Political Science
Authors: Cooper Christopher A. , Collins Todd A. , Knotts H. Gibbs
Published: April 2009

What do political scientists study? As part of a larger project, we
coded every article in 25 leading journals between 2000 and 2007. We
then created a word cloud of the 6,005 titles using http://www.wordle.net. The 150 most-used words appear in
the word cloud. The size of each word is proportional to the number
of times the word is mentioned. Draw your own conclusions.
Strategic Voting in Plurality Elections: A Simulation of
Duverger's Law
Authors: Endersby James W. , Shaw Kelly B.
Published: April 2009

Experiments designed as an election simulation involve participants
in an investigation of strategic voting. Participants assigned
political preferences and informed of candidate/party positions on
an ideological dimension respond to and learn the results of two
public opinion polls before voting. When given two alternatives, the
participants vote sincerely. Confronted with three or more
alternatives, participants make tactical decisions to narrow the
field. Strategic behavior quickly reduces the number of alternatives
to two. Consistent with Duverger's law, candidate/party viability
encourages strategic voting and the development of a two-party
system. The election simulation serves as a useful tool to teach
about electoral behavior and to explore topics such as strategic
voting.
Being True and Being You: Race, Gender, Class, and the
Fieldwork Experience
Authors: Townsend-Bell Erica
Published: April 2009

Fieldwork advice has increased and improved over the years. Yet, the
bulk of political science fieldwork advice is general; it assumes
that the subject to whom advice is given is simply a political
scientist—in training, perhaps—with no other salient identities that
might intercede (but see Mazzei and O'Brien 2005 and the PS 2006
fieldwork symposium, The Methodologies of Field Research in the
Middle East, for recent exceptions). Of course in reality it is not
just the fieldwork setting that varies; the relationship of the
researcher to the field matters a great deal—and that may be much
more dependent on our specific identities than we have previously
credited. It is not simply the subjects that we study, but us as
well who have to negotiate sometimes sticky issues of race, class,
gender, nationality, and so forth.
Embodied Researchers: Gendered Bodies, Research Activity, and Pregnancy in the Field
Authors: Ortbals Candice D. , Rincker Meg E.
Published: April 2009

Kathleen B. Jones, in her now famous essay about women-friendly polities, explains that that citizenship must be redefined to include a body that does not “easily fit military-corporate uniforms” (1990, 794). Jones calls theorists to recognize women's “embodied lives,” and in doing so, considers how “women's bodies are problematic” and “sex/gendered identity affects … life” (786). We argue here that recognizing women's embodied lives is similarly important to a discussion of gender and fieldwork. As researchers in the field, we have been defined by our social position as women, thus putting us at distinct disadvantages and advantages (Sundberg 2003).
Unwilling Participant Observation among Russian
Siloviki and the Good-Enough Field
Researcher
Authors: Johnson Janet Elise
Published: April 2009

In 1999, on a trip to Russia to study gender violence, I was sitting
in on a special training at a Moscow police academy. In between
jokes about the impossibility of prostitutes getting raped, the
cops-in-training could not stop focusing on me, the one American and
one of three women in a rowdy room. For example, one man loudly
asked me whether all Americans had cars and followed up with a
comment that, of course we did, because this is where “you” (meaning
me) would have sex. The training on rape and sexual harassment that
I had come to observe had come to a halt because the new police were
so intent on making sexual jokes. These comments felt even more
threatening than they might otherwise because, a few days before, I
had been picked up by the Russian police, shoved into a police car
with several drunken officers, and driven around Moscow until I
offered a bribe.
WILLIAM W. KAUFMANN
Authors: Kaplan Fred
Published: April 2009

William W. Kaufmann died on December 14, 2008, in his sleep, at the
age of 90. During the cold war, he was a key figure among the
“defense intellectuals”—less famous but more influential than
most—who moved freely from think tanks to the Pentagon to academia
and back again, crafting the theories of nuclear deterrence and
translating them to policy. Yet by the '80s, in the final, rococo
phase of the standoff, he'd come to reject much of his old thinking
and emerged, quite publicly, as one of the defense establishment's
most accredited critics.
JOHN STANGA
Authors: Kahn Melvin
Published: April 2009

John Stanga, our highly esteemed Wichita State University colleague,
died on December 30, 2008, at the age of 69. He is survived by his
three sons—Tomas, Joseph, and John Peter. As colleagues, we
respected him as a unique scholar, teacher, and friend. In an era
often characterized by narrow specialization, he was a true
Renaissance man—not only publishing and teaching in several fields
of our discipline, but also demonstrating a deep mastery of
literature and music, particularly jazz.
Badro, Brodsky, and Pataki Receive 2008 James B. Macelwane Medals
Authors: Ryerson F. J. , Badro James , Lay Thorne , Brodsky Emily E. , Ehleringer James , Pataki Diane E.
Published: April 2009

James Badro, Emily E. Brodsky, and Diane E. Pataki were awarded the 2008 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held 17 December 2008 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by a young scientist of outstanding ability.”
Moonlet discovered in Saturn's G ring
Authors: Showstack Randy
Published: April 2009

A half‐ kilometer‐wide moonlet that NASA's Cassini spacecraft has found embedded within Saturn's G ring—one of the planet's outer, diffuse rings—could be a main source of that ring and its single ring arc, according to Cassini imaging scientists. “Before Cassini, the G ring was the only dusty ring that was not clearly associated with a known moon, which made it odd. The discovery of this moonlet, together with other Cassini data, should help us make sense of this previously mysterious ring,” said Matthew Hedman, a Cassini imaging team associate at Cornell University, in Ithaca, N.Y.
Role of Science, Policy, and Society in Adaptive Watershed Management: Planning for an Uncertain Future: Monitoring, Integration, and Adaptation; Estes Park, Colorado, 8–11 September 2008
Authors: Webb Richard M. T.
Published: April 2009

Water managers around the world are being tasked to include potential effects of climate change in their future operations scenarios. One important water manager, the federal government, owns and manages 30% of all land in the United States, the vast majority of which is in western states and Alaska. On 9 March 2007, the Secretary of the Interior signed Order 3270, which states that adaptive management should be considered when (1) there are consequential decisions to be made; (2) there is an opportunity to apply learning; (3) the objectives of management are clear; (4) the value of reducing uncertainty is high; (5) uncertainty can be expressed as a set of competing, testable models; and (6) an experimental design and monitoring system can be put in place with a reasonable expectation of reducing uncertainty.
Competition favours reduced cost of plasmids to host bacteria
Authors: Haft Rembrandt J F , Mittler John E , Traxler Beth
Published: April 2009

Conjugative plasmids of Gram-negative bacteria have both vertical and horizontal modes of transmission: they are segregated to daughter cells during division, and transferred between hosts by plasmid-encoded conjugative machinery. Despite maintaining horizontal mobility, many plasmids carry fertility inhibition (fin) systems that repress their own conjugative transfer. To assess the ecological basis of self-transfer repression, we compared the invasion of bacterial populations by fin+ and fin− variants of the plasmid R1 using a computational model and co-culture competitions. We observed that the fin+ variant had a modest cost to the host (measured by reduction in growth rate), while the fin− variant incurred a larger cost. In simulations and empirical competitions the fin− plasmid invaded cultures quickly, but was subsequently displaced by the fin+ plasmid. This indicated a competitive advantage to reducing horizontal transmission and allowing increased host replication. Computational simulations predicted that the advantage associated with reduced cost to the host would be maintained over a wide range of environmental conditions and plasmid costs. We infer that vertical transmission in concert with competitive exclusion favour decreased horizontal mobility of plasmids. Similar dynamics may exert evolutionary pressure on parasites, such as temperate bacteriophages and vertically transmitted animal viruses, to limit their rates of horizontal transfer.
The SHED‐IT Randomized Controlled Trial: Evaluation of an Internet‐based Weight‐loss Program for Men
Authors: Morgan Philip J. , Lubans David R. , Collins Clare E. , Warren Janet M. , Callister Robin
Published: April 2009

The aim of this study was to evaluate the efficacy of an Internet‐based weight‐loss program for men in an assessor blinded randomized controlled trial. In total, 65 overweight/obese male staff and students at the University of Newcastle (mean (s.d.) age = 35.9 (11.1) years; BMI = 30.6 (2.8)) were randomly assigned to either (i) Internet group (n = 34) or (ii) control group (information only) (n = 31). Both groups received one face‐to‐face information session and a program booklet. Internet group participants used the study website to self‐monitor diet and activity with feedback provided based on participants' online entries on seven occasions over 3 months. Participants were assessed at baseline, 3‐, and 6‐month follow‐up for weight, waist circumference, BMI, blood pressure, resting heart rate, objectively measured physical activity, and self‐reported total daily kilojoules. Intention‐to‐treat analysis revealed significant weight loss of 5.3 kg (95% confidence interval (CI): −7.3, −3.3) at 6 months for the Internet group and 3.5 kg (95% CI: −5.5, −1.4) for the control group. A significant time effect was found for all outcomes but no between‐group differences. Per‐protocol analysis revealed a significant group‐by‐time interaction (P < 0.001), with compliers losing more weight at 6 months (−9.1 kg; 95% CI −11.8, −6.5) than noncompliers (−2.7 kg; 95% CI −5.3, −0.01) and the control group (−4.2 kg; 95% CI −6.2, −2.2). Simple weight‐loss interventions can be effective in achieving statistically and clinically significant weight loss in men. The Internet is a feasible and effective medium for weight loss in men but strategies need to be explored to improve engagement in online programs.
Optimal rotor design for reducing the partial demagnetization effect and cogging torque in spoke type PM motor
Authors: Hwang Kyu-yun , Yang Byoung-yull , Rhyu Se-hyun , Kim Byung-taek , Kim Dae-kyong , Rhee Sang-bong , Kwon Byung-il
Published: April 2009

This paper proposes an optimized rotor pole shape that can effectively reduce the partial demagnetization effect and cogging torque. First, for reducing the peak amplitude of the external field that directly affects the partial demagnetization on the permanent magnets in spoke-type permanent magnet motor, we conduct a variation of core shape and insertion of a barrier. Second, with the rotor shape obtained by the first processes for reducing the partial demagnetization effect, another part of the rotor pole is varied to make better sinusoidal distributed air gap flux density to reduce the cogging torque. In the process of designing the rotor pole shape, a steepest descent method and a response surface method are applied for improving convergence. By using the finite element method, we show that the optimized rotor pole shape drastically reduces the effect of the partial demagnetization and cogging torque.
DNA nanomechanics: How proteins deform the double helix
Authors: Becker Nils B. , Everaers Ralf
Published: April 2009

It is a standard exercise in mechanical engineering to infer the external forces and torques on a body from a given static shape and known elastic properties. Here we apply this kind of analysis to distorted double-helical DNA in complexes with proteins: We extract the local mean forces and torques acting on each base pair of bound DNA from high-resolution complex structures. Our analysis relies on known elastic potentials and a careful choice of coordinates for the well-established rigid base-pair model of DNA. The results are robust with respect to parameter and conformation uncertainty. They reveal the complex nanomechanical patterns of interaction between proteins and DNA. Being nontrivially and nonlocally related to observed DNA conformations, base-pair forces and torques provide a new view on DNA-protein binding that complements structural analysis.
The drain velocity overshoot in an 80 nm metal-oxide-semiconductor field-effect transistor
Authors: Tan Michael L. P. , Arora Vijay K. , Saad Ismail , Taghi Ahmadi Mohammad , Ismail Razali
Published: April 2009

The current at the onset of saturation in a metal-oxide-semiconductor field-effect transistor (MOSFET) is shown to be limited by the drain velocity that increases toward its saturation value with the increase in the drain voltage. The saturation of velocity crops up as randomly oriented velocity vectors in equilibrium realign themselves to become unidirectional in the presence of an extremely high electric field. The intrinsic velocity, the ultimate saturation velocity, is the function of carrier concentration and temperature, consistent with the predictions of the ballistic transport. The presence of a quantum emission either by emission of a phonon or photon lowers the saturation velocity below its intrinsic value. Channel conduction beyond the quasisaturation point enhances due to the drain velocity overshoot as a result of enhanced drain electric field as drain voltage is increased. The excellent agreement with experimental data on an 80 nm channel, without using any artificial parameters, confirms the value of ballistic transport in a high electric field.
Void generation during the annealing process of very narrow copper wires
Authors: Sasajima Yasushi , Akabane Tomoaki , Nagai Takeshiro , Chonan Yasunori , Onuki Jin
Published: April 2009

We carried out experiments on stress-induced void formation in ultrathin Cu wires while varying heat-treatment temperature, wire dimensions, and overlayer thickness. We also did molecular dynamics simulations of void formation in a buried wire of nanometer scale and compared these results with experimental results to clarify details of the void formation mechanism. The experimental and simulation results showed good accordance in explaining the effects of wire width, overlayer thickness, and cooling rate on void formation. (1) The narrower the wire width, the easier the void formation. (2) The thicker the overlayer, the easier the void formation. (3) The larger the cooling rate, the greater the suppression of void formation. From the obtained results, we constructed a void formation model for a buried wire. The basic concept of the model describes how local strain at four trench corners is relaxed in the buried wire in the annealing process. There are two ways to relax the local strain: (1) structural relaxation to strengthen adhesion between the wire and substrate and (2) reduction of the surface area to minimize surface energy. The way preferred is dependent on how parameters such as system temperature and wire dimensions are combined. Based on the void formation model, we interpreted the effects of wire strain, wire dimensions, and overlayer thickness.
Temperature dependence of solvation forces as measured in atomic force microscopy
Authors: Lim L. T. W , Wee A. T. S. , O’Shea S. J.
Published: April 2009

An atomic force microscope (AFM) has been used to study the effect of temperature on solvation forces in the liquids octamethylcyclotetrasiloxane, n-hexadecane, and n-dodecanol confined between the AFM tip and a graphite surface. Discrete solvation layers can be observed for all three liquids at all the temperatures measured (298–348K). However, with increasing temperature there is a significant decrease in the magnitude of the measured solvation forces and a reduction in the number of solvation oscillations which can be observed. Solvation forces per se are only weakly temperature dependent and the most plausible explanation is that we are measuring how the layers are squeezed from the tip-sample gap. The squeeze out process is a thermally activated phenomenon and gives rise to the large change in the magnitude of the force oscillations with temperature. A simple analysis is provided based on transition rate theory. The large change in solvation force with temperature has implications for the measurement of localized forces using AFM, particularly in interpreting biological interactions and single asperity friction.
Silicon and silicon oxide core-shell nanoparticles: Structural and photoluminescence characteristics
Authors: Ray Mallar , Sarkar Samata , Bandyopadhyay Nil Ratan , Hossain Syed Minhaz , Pramanick Ashit Kumar
Published: April 2009

We report the synthesis of spherical core-shell structures of silicon and silicon oxide by a novel route of forced external oxidation of ball milled silicon. Structural investigations reveal the formation of a crystalline silicon core surrounded by an amorphous oxide shell, with core and shell dimensions varying approximately between 4–10 and 55–170 nm, respectively. The observations suggest partial amorphization of crystalline silicon, invasive oxygen induced passivation of dangling bonds, and formation of different types of defects in the nanocrystalline silicon/silicon oxide core-shell structure, particularly at the interfaces. No detectable photoluminescence (PL) is obtained from the as-milled silicon, but the oxidized core-shell structures exhibit strong room temperature PL, detectable with unaided eye. The peak energy of the PL spectra blueshifts with an increase in excitation energy, with the peak positions varying from 2.24 to 2.48 eV under external excitation ranging from 2.41 to 3.5 eV. The observed PL characteristics are explained in terms of dominant electronic transitions between the localized defect states and quantum confinement induced widened band states.
Molecular dynamics simulation of nanocolloidal amorphous silica particles: Part III
Authors: Jenkins S. , Kirk S. R. , Persson M. , Carlen J. , Abbas Z.
Published: April 2009

Explicit-solvent molecular dynamics simulations were applied to four pairs of amorphous silica nanoparticles, two pairs having a diameter of 2.0 nm and two pairs with diameter 3.2 nm. The silica nanoparticles were immersed in a background electrolyte consisting of Ca2+ and Cl− ions and water and mean forces acting between the pair of silica nanoparticles were extracted at four different background electrolyte concentrations. The pH was indirectly accounted for via the ratio of silicon to sodium used in the simulations. Dependence of the interparticle potential of mean force on the center-of-mass separation and the silicon to sodium ratio (5:1 and 20:1) is demonstrated. A Si:Na+ ratio of 5:1 gave more repulsive interparticle potentials and lower numbers of internanoparticle or “bridging” hydrogen bonds. Conversely a Si:Na+ ratio of 20:1 yielded more attractive potentials and higher numbers of bridging hydrogen bonds. The nature of the interaction of the counterions with charged silica surface sites (deprotonated silanols) was also investigated. The effect of the sodium double layer on water ordering was observed. The number of water molecules trapped inside the nanoparticles was investigated, and at the highest background ionic concentrations were found to consistently behave in accordance with there being an osmotic pressure. This study highlights the effect of divalent (Ca2+) background ions on the interparticle potentials compared with previous work using monovalent (Na+) background ions. Mechanisms of coagulation and the stability of silica nanocolloids found from this work appear to be in agreement with findings from experiments described in the literature.
Carrier mobility as a function of carrier density in type-II InAs/GaSb superlattices
Authors: Szmulowicz F. , Elhamri S. , Haugan H. J. , Brown G. J. , Mitchel W. C.
Published: April 2009

We report on a study of the in-plane carrier mobility in InAs/GaSb superlattices as a function of carrier density. Instead of using a number of differently doped samples, we use the persistent-photoconductivity effect to vary the carrier density over a wide range from n- to p-type in single samples and perform Hall effect measurements. Hence, our data are not obscured by sample to sample nonuniformities. We demonstrate that low-temperature in-plane mobilities are limited by screened interface roughness scattering (IRS), although present models of two-dimensional carrier screening of IRS lead to a limited agreement with our data.
Self-induced magnetic focusing of proton beams by Weibel-like instability in the laser foil-plasma interactions
Authors: Yan X. Q. , Chen M. , Sheng Z. M. , Chen J. E.
Published: April 2009

In the laser foil-plasma interaction the effects of Weibel-like instability have been explored. The self-induced magnetic fields result in the merging of filaments formed at the earlier stage of the instability and subsequent formation of a plasma clump close to the laser propagation axis. A photon cavity is formed in the laser plasma interactions, which can accelerate and focus the proton bunch efficiently, as identified by multidimensional particle-in-cell simulations. These processes are helpful to realize the stable acceleration of hundreds of MeV proton beams with a very low energy spread with circularly polarized intense laser pulses.
Invariant manifolds for dissipative systems
Authors: Ramm A. G.
Published: April 2009

A method is given for a study of a nonlinear evolution equation for finding “slow” invariant manifolds. The method is studied for the evolution problem u̇=−Au+[(Au,u)/(u,u)]u, u(0)=u0, where A is a linear, self-adjoint, possibly unbounded operator in a Hilbert space. Global existence and uniqueness of the solution to this problem are proven. Asymptotic behavior of the solution as t→∞ is studied. Analytic solution of the above nonlinear evolution problem is found. Conditions are given on the spectrum of A and on the initial data u0 for the trajectory u(t) not to have a strong limit in H as t→∞ and not to stay in any finite-dimensional space. In this sense the motion is chaotic.