bluuebunny/crossref_metadata_2025 huggingface dataset:
Aortic Valve Closure: Relation to Tissue Velocities by Doppler and Speckle Tracking in Patients with Infarction and at High Heart Rates
Authors: Aase Svein A. , Björk‐Ingul Charlotte , Thorstensen Anders , Torp Hans , Støylen Asbjørn
Published: March 2010

Aim: To resolve the event in tissue Doppler (TDI)‐ and speckle tracking‐based velocity/time curves that most accurately represent aortic valve closure (AVC) in infarcted ventricles and at high heart rates. Methods: We studied the timing of AVC in 13 patients with myocardial infarction and in 8 patients at peak dobutamine stress echo. An acquisition setup for recording alternating B‐mode and TDI image frames was used to achieve the same frame rate in both cases (mean 136.7 frames per second [FPS] for infarcted ventricles, mean 136.9 FPS for high heart rates). The reference method was visual assessment of AVC in the high frame rate narrow sector B‐mode images of the aortic valve. Results: The initial negative velocities after ejection in the velocity/time curves occurred before AVC, 44.9 ± 21.0 msec before the reference in the high heart rate material, and 25.2 ± 15.2 msec before the reference in the infarction material. Using this time point as a marker for AVC may cause inaccuracies when estimating end‐systolic strain. A more accurate but still a practical marker for AVC was the time point of zero crossing after the initial negative velocities after ejection, 5.4 ± 15.3 msec before the reference in high heart rates and 8.2 ± 12.9 msec after the reference in the infarction material. Conclusion: The suggested marker of AVC at high heart rate and in infarcted ventricles was the time point of zero crossing after the initial negative velocities after ejection in velocity/time curves. (Echocardiography 2010;27:363‐369)
Memory, Forgetting, and Economic Crisis:
Authors: Epele María E.
Published: March 2010

Closely linked to the increase in psychotropic pill consumption, forgetting and remembering emerged from devastated social scenarios as a new local idiom among poor youth in the late 1990s and the new millennium. Drawing on ethnographic fieldwork carried out during the years of the deepest economic crisis in Argentina (2001–03), I argue that psychotropic pill consumption is associated with not only deteriorating economic conditions but also changes in the quality and price of cocaine, and in the scarcity and subsequent change of status of medications during the economic breakdown. Taking into account developments in the field of memory studies, I examine the relationship among political economy, social memory work, and changing drug‐use practices. Regarding memory as a social practice, I argue that the growth of psychotropic pill consumption in the late 1990s can be understood through the interplay of Paul Ricoeur's notions regarding different kinds and levels of forgetting. By analyzing changing survival strategies, social network dismantlement, changing mortality patterns, and abusive police repression, I discuss how social fragmentation engendered by structural reforms has modified social memory work.
Transformative Ties:
Authors: Parson Nia
Published: March 2010

Although a significant body of scholarship on trauma has emerged in medical anthropology, there has been little examination of how gendered expectations shape the aftermath of extreme human experience, forms of recovery, and subjectivity. Here, I show how domestic and other forms of violence have shaped Luz's suffering in the dictatorial (1973–90) and officially democratic (1990–present) eras in Chile. I then elucidate how Luz's engagement with Safe Space, an NGO connected to UN violence against women frameworks, and other globally connected women's groups, have allowed her to generate transformative ties with other women. These relationships provide support for Luz's self‐defined project of transforming herself and society, largely in relationship to gendered expectations, so that her recovered sense of self will have more of a home in the world, outside the boundaries of narrowly defined gender roles. This analysis is based on ethnographic research in Santiago, Chile, over 19 months in 2000–04 and 2009, including participant‐observation at two domestic violence centers and life history interviews with 18 women who sought help there.
Ultrahigh‐Temperature Semiconductors Made from Polymer‐Derived Ceramics
Authors: Ryu Hee‐Yeon , Wang Qi , Raj Rishi
Published: March 2010

We report the semiconductor behavior of polymer‐derived ceramics at high temperatures extending up to 1300°C, far above that of any known material. The conductivity depends strongly on the N/O molar ratio, reaching its highest value when the ratio is approximately unity. The temperature dependence of the conductivity for these specimens, σ, shows good agreement with the Mott's variable range hopping (VRH) mechanism for three–dimensional conduction in amorphous materials as described by.The comparison yields the following range of values for the density of states,N(E)=4.9 × 1017–5.9 × 1018(eV·cm3)−1, hopping energy,W=0.017–0.047 eV, and hopping distance,R=13.4–21.8 nm. The charge carrier mobilities predicted by the VRH model are in excellent agreement with the values measured in the Hall experiment. The long hopping distances are an unusual feature of this ceramic, suggesting long‐range wave functions that may arise from clusters of SiCNO atoms that can exist in the form of a nanodomain network. Specimens that are either rich in oxygen (at the expense of nitrogen) or rich in nitrogen, have conductivities that are four to eight orders of magnitude lower than the ∼equimolar compositions. One oxygen‐rich specimen shows band‐gap controlled semiconductivity with an activation energy of 1.1 eV. Taken together, these results suggest that the electronic properties of the SiCNO ceramics are controlled by complex interactions between C and other atoms (Si, N, and O). These results are at variance with the simple picture where “free carbon” is assumed to determine the electronic behavior.
Room‐Temperature Solid‐State Reaction Behavior, Hydrothermal Crystallization and Physical Characterization of NaRE(MoO4)2, and Na5Lu(MoO4)4 Compounds
Authors: Wu Jianhua , Yan Bing
Published: March 2010

In the context, a novel composite synthesis technology is engaged in the preparation of NaRE(MoO4)2 (RE=Y, La, Nd, Eu, Gd, Tb, Er, and Yb) and Na5Lu(MoO4)4 compounds, which involves a room‐temperature solid‐state reaction and hydrothermal crystallization process. The synthesis mechanism is predicted, indicating that higher temperature and moisture can speed up the reaction process and especially the existence of crystalline water molecules in the precursor is necessary for the solid‐state reaction at room temperature. It is found that different rare‐earth nitrate precursors present different reactivity to sodium molybdate at room temperature. The crystallization degree of the products after the room‐temperature solid‐state reaction depends on the melting point of rare‐earth nitrate precursors. The hydrothermal treatment is beneficial for the good crystallization of NaRE(MoO4)2 (RE=Y, La, Nd, Eu, Gd, Tb, Er, and Yb) and Na5Lu(MoO4)4. Finally, the photoluminescent spectra for these NaRE(MoO4)2:Eu3+ (La, Gd, and Y) are studied, which depend on the species of rare‐earth ions.
Biochemical Characterization of Soluble Acid and Alkaline Invertases from Shoots of Etiolated Pea Seedlings
Authors: Kim Donggiun , Park So Yun , Chung Youngjae , Park Jongbum , Lee Sukchan , Lee Taek‐Kyun
Published: March 2010

Soluble invertase was purified from pea (Pisum sativum L.) by sequential procedures entailing ammonium sulfate precipitation, DEAE‐Sepharose column, Con‐A‐ and Green 19‐Sepharose affinity columns, hydroxyapatite column, ultra‐filtration, and Sephacryl 300 gel filtration. The purified soluble acid (SAC) and alkaline (SALK) invertases had a pH optimum of 5.3 and 7.3, respectively. The temperature optimum of two invertases was 37 °C. The effects of various concentrations of Tris‐HCl, HgCl2, and CuSO4 on the activities of the two purified enzymes were examined. Tris‐HCl and HgCl2 did not affect SAC activity, whereas 10 mM Tris‐HCl and 0.05 mM HgCl2 inhibited SALK activity by about 50%. SAC and SALK were inhibited by 4.8 mM and 0.6 mM CuSO4 by 50%, respectively. The enzymes display typical hyperbolic saturation kinetics for sucrose hydrolysis. The Kms of SAC and SALK were determined to be 1.8 and 38.6 mM, respectively. The molecular masses of SAC shown by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and immunoblotting were 22 kDa and 45 kDa. The molecular mass of SALK was 30 kDa. Iso‐electric points of the SAC and SALK were estimated to be about pH 7.0 and pH 5.7, respectively.
Classification Consistency and Accuracy for Complex Assessments Using Item Response Theory
Authors: Lee Won‐Chan
Published: March 2010

In this article, procedures are described for estimating single‐administration classification consistency and accuracy indices for complex assessments using item response theory (IRT). This IRT approach was applied to real test data comprising dichotomous and polytomous items. Several different IRT model combinations were considered. Comparisons were also made between the IRT approach and two non‐IRT approaches including the Livingston‐Lewis and compound multinomial procedures. Results for various IRT model combinations were not substantially different. The estimated classification consistency and accuracy indices for the non‐IRT procedures were almost always lower than those for the IRT procedures.
A Note on the Invariance of the DINA Model Parameters
Authors: De La Torre Jimmy , Lee Young‐Sun
Published: March 2010

Cognitive diagnosis models (CDMs), as alternative approaches to unidimensional item response models, have received increasing attention in recent years. CDMs are developed for the purpose of identifying the mastery or nonmastery of multiple fine‐grained attributes or skills required for solving problems in a domain. For CDMs to receive wider use, researchers and practitioners need to understand the basic properties of these models. The article focuses on one CDM, the deterministic inputs, noisy “and” gate (DINA) model, and the invariance property of its parameters. Using simulated data involving different attribute distributions, the article demonstrates that the DINA model parameters are absolutely invariant when the model perfectly fits the data. An additional example involving different ability groups illustrates how noise in real data can contribute to the lack of invariance in these parameters. Some practical implications of these findings are discussed.
The mammalian KIR2.x inward rectifier ion channel family: expression pattern and pathophysiology
Authors: De Boer T. P. , Houtman M. J. C. , Compier M. , Van Der Heyden M. A. G.
Published: March 2010

Inward rectifier currents based on KIR2.x subunits are regarded as essential components for establishing a stable and negative resting membrane potential in many excitable cell types. Pharmacological inhibition, null mutation in mice and dominant positive and negative mutations in patients reveal some of the important functions of these channels in their native tissues. Here we review the complex mammalian expression pattern of KIR2.x subunits and relate these to the outcomes of functional inhibition of the resultant channels. Correlations between expression and function in muscle and bone tissue are observed, while we recognize a discrepancy between neuronal expression and function.
European consumers' acceptance of functional foods
Authors: Grunert Klaus G.
Published: March 2010

Consumer acceptance of functional foods is analyzed from the perspective of consumer quality perception of food products. Four major dimensions of food quality are identified: taste and other sensory characteristics, healthiness, convenience, and naturalness. Functional foods provide, from the consumer perspective, synergies between healthiness and convenience, but may, in the consumer mind, lead to trade‐offs between healthiness on the one side and taste and naturalness on the other side. This may explain the reluctance of European consumers to accept functional food products.
The importance of dietary modulation of cAMP and insulin signaling in adipose tissue and the development of obesity
Authors: Madsen Lise , Kristiansen Karsten
Published: March 2010

Adipose tissue plays a pivotal role in whole body energy homeostasis. In this review, we summarize knowledge of the seemingly paradoxical roles of insulin and cyclic adenosine monophosphate (cAMP) signaling in adipocyte differentiation and function, emphasizing the interplay between the two branches of cAMP signaling, the canonical protein kinase A‐dependent pathways and the novel exchange protein activated by cAMP (Epac)‐dependent pathways, and insulin signaling. We discuss how macronutrients via changes in the balance between insulin‐ and cAMP‐dependent signaling can affect the development of obesity by changing energy expenditure and/or feed efficiency. We review results demonstrating how the balance between different classes of carbohydrates and proteins modulates the obesigenic action of saturated as well as unsaturated fatty acids pointing to insulin as a key determinant in the regulation of the metabolic/regulatory action of both n‐3 and n‐6 polyunsaturated fatty acids.
Enrichment of foods with omega‐3 fatty acids: a multidisciplinary challenge
Authors: Jacobsen Charlotte
Published: March 2010

Enrichment of foods with marine omega‐3 polyunsaturated fatty acids (PUFA) poses a multidisciplinary challenge to food industry and academia. Although our knowledge about possible health effects of omega‐3 PUFA has increased tremendously during the last 30 years, there is still a lot to be learned about these healthy fatty acids. Moreover, consumer acceptance and lipid oxidation of omega‐3 PUFA‐enriched food are other major challenges that the food industry meet when developing omega‐3–enriched foods. Two examples on multidisciplinary research projects to overcome some of these challenges are given in this article together with cases studies illustrating how lipid oxidation can be prevented in a range of different omega‐3–enriched foods.
Fructose consumption: recent results and their potential implications
Authors: Stanhope Kimber L. , Havel Peter J.
Published: March 2010

In addition to acquiring a better understanding of foods that may have intrinsic health benefits, increasing our knowledge of dietary components that may adversely impact health and wellness, and the levels of consumption at which these adverse effects may occur, should also be an important priority for the Foods for Health initiative. This review discusses the evidence that additional research is needed to determine the adverse effects of consuming added sugars containing fructose. Current guidelines recommend limiting sugar consumption in order to prevent weight gain and promote nutritional adequacy. However, recent data suggest that fructose consumption in human results in increased visceral adiposity, lipid dysregulation, and decreased insulin sensitivity, all of which have been associated with increased risk for cardiovascular disease and type 2 diabetes. A proposed model for the differential effects of fructose and glucose is presented. The only published study to directly compare the effects of fructose with those of commonly consumed dietary sweeteners, high fructose corn syrup and sucrose, indicates that high fructose corn syrup and sucrose increase postprandial triglycerides comparably to pure fructose. Dose‐response studies investigating the metabolic effects of prolonged consumption of fructose by itself, and in combination with glucose, on lipid metabolism and insulin sensitivity in both normal weight and overweight/obese subjects are needed.
Migration of Antimicrobial Silver from Composites of Polylactide with Silver Zeolites
Authors: Fernández Avelina , Soriano Eva , Hernández‐Muñoz Pilar , Gavara Rafael
Published: March 2010

ABSTRACT:  Silver ion migration and antimicrobial activity of PLA (polylactic acid‐polylactide)/silver zeolite composites were investigated. Films prepared by solution‐casting/solvent evaporation, or by melt‐mixing/compression molding were compared. Silver migration to food simulants and TSB (tryptone soy broth) was quantified at different temperatures. Antimicrobial activity against Staphylococcus aureus and Escherichia coli was measured following the Japanese Industrial Standard JIS Z 2801. All types of PLA/silver zeolite composites released Ag+ ions. A more intense ionic exchange with the zeolites and a significant, but low, antimicrobial activity in solution were found in cast films. To attain antimicrobial effects, however, migrated ions ought to be in the range of the legal limit of 0.05 mg Ag+/kg food stated by the European Food Safety Agency (EFSA). Silver migration and antimicrobial activity were sensitive to the methodology chosen to process the PLA films, the ionic strength of the medium, and the ion motility in the polymer matrix.

Practical Application: Silver exchanged zeolites incorporated in food contact polymers are gaining importance as antimicrobial agents. Migration of silver ions from polymer matrices, however, is legally restricted. Therefore a compromise between silver migration and antimicrobial activity needs to be critically analyzed to validate novel materials in food packaging applications.
A mbassador of Israel: Peace for Peace
Authors: Clarke Andrew
Published: March 2010

[Israeli Ambassador to the United States Zalman Shoval spoke in Milwaukee, Wisconsin, on May 20, 1992. The ambassador's presentation was a session in the Wisconsin International Trade Conference at the Pfister Hotel.]
Kuwait: Elections and Issues of Democratization in a Middle Eastern State
Authors: Ghabra Shafeeq
Published: March 2010

In 1992, elections were held in Kuwait to vote for the four‐year assembly. The elections were essentially a compromise formula between two systems and political cultures in Kuwait: traditional hereditary rule and representative and modern forms. The successful conclusion of the election campaign, one of the most intensive in the history of Kuwait, may be the first step in the direction of much‐needed political reform that may tilt the country more and more toward a true parliamentary system.

The elections resulted in a victory for the opposition forces and their supporters, who together won thirty‐five seats. For the first time in the history of Kuwait, government ministers can vote in parliament against a government‐backed policy, should they feel the need to do so. Kuwait, as far as conditions allow today, is progressively shifting toward a parliamentary system. But, despite Kuwait's political steps forward, many questions and immense dangers still surround the democratic process.
Librarianship in Kuwait after the Gulf War
Authors: Abdel‐Motey Yaser Y. , Al‐Hmood Nahla
Published: March 2010

A general view of the field of librarianship in Kuwait is presented with special emphasis on the impact of the Iraqi aggression on libraries and information centers in the country.

First, a review of the damages and future plans of the main library and information sectors is presented (school, public, academic, central libraries), followed by a summary of the effect of the Iraqi occupation on education in library and information science.
Planned International Technology Transfer:
Authors: Thompson Chris
Published: March 2010

Since the mid‐1980s, Saudi Arabia has required that a percentage of all defense contracts awarded to foreign suppliers be reinvested back in the kingdom into new technology companies. The result has been three “economic offset” programs, encompassing Western defense producers and their home‐country governments in the world's largest example of planned international technology transfer.

This paper reviews the three main Saudi offsets—attached to the Peace Shield (United States), al‐Yamamah (United Kingdom) and Sawari (France) arms deals—for their genesis, operations, achievements, and problems, using interviews with participants and statistical data on companies formed. It then attempts some evaluation of them against their own original explicit and implicit goals, and draws out some lessons and implications.
Islamic Manuscripts
Authors: Khalifa Shaban A.
Published: March 2010

Book reviewed in this article:

The Book in the Islamic World: The Written Word and Communication in the Middle East, George N. Attiyeh, editor

A Manuscript Catalogue of Some Private Collections in Yemen, Abdullah Mohammed Al‐Hibshy, compiler Julian Yohansin, editor
Reviews
Authors: Menicucci Garay
Published: March 2010

Book reviewed in this article:

Russia and Azerbaijan: A Borderland in Transition: Tadeusz Swietochowski

Baku Documents: Touraj Atabaki, Solmaz Rustamova‐Towhidi
Two Books for Juveniles
Authors: Aman Mary Jo
Published: March 2010

Book reviewed in this article:

The Wonder Child & Other Jewish Fairy Tales: Howard Schwartz and Barbara Rush

Magid Fasts for Ramadan: Mary Matthews
The Impact of Social and Psychological Factors on Car accidents in Kuwait
Authors: Alsaleh Amer
Published: March 2010

The objective of study was to identify select demographic, driving habits, aggressive driving, road rage and risk factors associated with involvement in road traffic accidents (RTAs) among young Kuwaiti drivers. Logistic linear regression tests these factors according to the Modified Youth Risk Behavior scales. The total sample of this study was 1619 Kuwaiti drivers, aged 18–30 years. The source for the sample consisted of self‐reported young drivers who were selected from high schools and universities in the six governorates in Kuwait. For the purposes of this study, the author defined cases (N=984) as drivers who reported being involved in a car crash during their lifetime. Controls (N=635) were identified as those drivers who were never involved in a car crash during the same period. The sample was selected during an eight‐month period, from November 2004 to June 2005.

Logistic linear regression results showed that driving habits, aggressive driving, and road rage situations would result in high rates in sensation, anxiety and anger, which leads to risky driving behavior (e.g. drivers forcing a car off the road, deliberate obstruction, running red lights, running stop signs, and tailgating), which leads to involvement in traffic accidents.
Does enhanced respiratory–sympathetic coupling contribute to peripheral neural mechanisms of angiotensin II–salt hypertension?
Authors: Toney Glenn M. , Pedrino Gustavo R. , Fink Gregory D. , Osborn John W.
Published: March 2010

Hypertension caused by chronic infusion of angiotensin II (Ang II) in experimental animals is likely to be mediated, at least in part, by an elevation of ongoing sympathetic nerve activity (SNA). However, the contribution of SNA relative to non‐neural mechanisms in mediating Ang II‐induced hypertension is an area of intense debate and remains unresolved. We hypothesize that sympathoexcitatory actions of Ang II are directly related to the level of dietary salt intake. To test this hypothesis, chronically instrumented rats were placed on a 0.1 (low), 0.4 (normal) or 2.0% NaCl diet (high) and, following a control period, administered Ang II (150 ng kg−1 min−1, s.c.) for 10–14 days. The hypertensive response to Ang II was greatest in rats on the high‐salt diet (Ang II–salt hypertension), which was associated with increased ‘whole body’ sympathetic activity as measured by noradrenaline spillover and ganglionic blockade. Indirect and direct measures of organ‐specific SNA revealed a distinct ‘sympathetic signature’ in Ang II–salt rats characterized by increased SNA to the splanchnic vascular bed, transiently reduced renal SNA and no change in SNA to the hindlimbs. Electrophysiological experiments indicate that increased sympathetic outflow in Ang II–salt rats is unlikely to involve activation of rostral ventrolateral medulla (RVLM) vasomotor neurons with barosensitive cardiac rhythmic discharge. Instead, another set of RVLM neurons that discharge in discrete bursts have exaggerated spontaneous activity in rats with Ang II–salt hypertension. Although their discharge is not cardiac rhythmic at resting levels of arterial pressure, it nevertheless appears to be barosensitive. Therefore, these burst‐firing RVLM neurons presumably serve a vasomotor function, consistent with their having axonal projections to the spinal cord. Bursting discharge of these neurons is respiratory rhythmic and driven by the respiratory network. Given that splanchnic SNA is strongly coupled to respiration, we hypothesize that enhanced central respiratory–vasomotor neuron coupling in the RVLM could be an important mechanism that contributes to exaggerated splanchnic sympathetic outflow in Ang II–salt hypertension. This hypothesis remains to be tested directly in future investigations.
Diarrhoeal disease through enterocyte secretion: a doctrine untroubled by proof
Authors: Lucas Michael L.
Published: March 2010

For almost 40 years, one of the principal causes of diarrhoeal disease has been thought to be fluid secretion emanating from the epithelial cells of the small and large intestine. Given the extremely large fluid losses seen in cholera, where secretion can be up to several litres per day, this seems a plausible hypothesis. The enterocyte (epithelial cell) secretion hypothesis rapidly displaced all other alternatives, such as vasodilatation coupled with enhanced paracellular permeability. An essential mechanism underlying enterocyte secretion has always been assumed to be electrogenic chloride secretion, leading to a localized osmotic imbalance at the mucosal surface of the enterocytes that causes fluid entry into the lumen by osmosis. The chloride secretion basis for enterotoxin‐deranged secretion is assumed to be measurable by changes in electrical currents and by altered transport of chloride ion. These can be detected after the small intestine is exposed to a heat‐stable enterotoxin (STa) produced by Escherichia coli. However, in vivo, when the recovered volume technique is used, STa is found not to be secretory. The heat‐stable enterotoxin is therefore a test case toxin, because the complex techniques used to demonstrate enterocyte secretion after STa exposure show apparent secretion, while the simplest technique based on fluid recovery and genuinely measuring the mass transport of fluid does not. This review scrutinizes the nature of the evidence put forward for enterocyte secretion and reaches the conclusion that there is no evidence for it. Debilitating secretion undoubtedly does take place in severe diarrhoeal disease, but secretion from enterocytes is unlikely to be the cause.
Repeated administration of angiotensin II reduces its dipsogenic effect without affecting saline intake
Authors: Vento Peter J. , Daniels Derek
Published: March 2010

Angiotensin II (Ang II) acts at central type 1 (AT1) receptors to increase intake of water and saline. In vitro studies demonstrated rapid desensitization of the AT1 receptor after Ang II exposure, and behavioural studies in rats suggest that exposure to Ang II decreases the dipsogenic potency of subsequent Ang II. Nevertheless, the effect of repeated Ang II injections on saline intake remains untested, and a reliable protocol for examining this purported behavioural desensitization has not emerged from the literature. To address these issues, we established a reliable approach to study Ang II‐induced dipsetic desensitization and used this approach to test the requirement of central AT1 receptors and the specificity of the effect for water intake. Rats given a treatment regimen of three injections of Ang II (300 ng, intracerebroventricular), each separated by 20 min, drank less water than control rats after a subsequent test injection of Ang II. The effect was relatively short lasting, dependent on the dose and timing of Ang II, and was almost completely blocked by the AT1 receptor antagonist losartan. In further testing, when rats were given access to both water and 1.5% saline, animals that received an Ang II treatment regimen drank less water than control animals, but saline intake was unaffected. These data support previous suggestions that Ang II‐induced water and saline intakes are separable. Given the role of G protein uncoupling in desensitization of the AT1 receptor, these data are consistent with the emerging hypothesis that AT1 receptor G protein‐dependent intracellular signalling pathways are more relevant for water, but not saline, intake.
Control of wrist position and muscle relaxation by shifting spatial frames of reference for motoneuronal recruitment: possible involvement of corticospinal pathways
Authors: Raptis Helli , Burtet Liziane , Forget Robert , Feldman Anatol G.
Published: March 2010

It has previously been established that muscles become active in response to deviations from a threshold (referent) position of the body or its segments, and that intentional motor actions result from central shifts in the referent position. We tested the hypothesis that corticospinal pathways are involved in threshold position control during intentional changes in the wrist position in humans. Subjects moved the wrist from an initial extended to a final flexed position (and vice versa). Passive wrist muscle forces were compensated with a torque motor such that wrist muscle activity was equalized at the two positions. It appeared that motoneuronal excitability tested by brief muscle stretches was also similar at these positions. Responses to mechanical perturbations before and after movement showed that the wrist threshold position was reset when voluntary changes in the joint angle were made. Although the excitability of motoneurons was similar at the two positions, the same transcranial magnetic stimulus (TMS) elicited a wrist extensor jerk in the extension position and a flexor jerk in the flexion position. Extensor motor‐evoked potentials (MEPs) elicited by TMS at the wrist extension position were substantially bigger compared to those at the flexion position and vice versa for flexor MEPs. MEPs were substantially reduced when subjects fully relaxed wrist muscles and the wrist was held passively in each position. Results suggest that the corticospinal pathway, possibly with other descending pathways, participates in threshold position control, a process that pre‐determines the spatial frame of reference in which the neuromuscular periphery is constrained to work. This control strategy would underlie not only intentional changes in the joint position, but also muscle relaxation. The notion that the motor cortex may control motor actions by shifting spatial frames of reference opens a new avenue in the analysis and understanding of brain function.
Inferring Signaling Pathway Topologies from Multiple Perturbation Measurements of Specific Biochemical Species
Authors: Xu Tian-Rui , Vyshemirsky Vladislav , Gormand Amélie , von Kriegsheim Alex , Girolami Mark , Baillie George S. , Ketley Dominic , Dunlop Allan J. , Milligan Graeme , Houslay Miles D. , Kolch Walter
Published: March 2010

Bayesian inference–based modeling identifies the most likely paths through a signaling network.
Death Transferred
Authors: Foley John F.
Published: March 2010

The interaction between cytochrome c and Apaf-1 is blocked by tRNA, thus inhibiting the activation of caspases.
Thalidomide Target Identified
Authors: VanHook Annalisa M.
Published: March 2010

Thalidomide binding to a component of an E3 ubiquitin ligase induces developmental defects in vertebrates.
Enhancement of Biofilm Formation by Subinhibitory Concentrations of Macrolides in
icaADBC-
Positive and -Negative Clinical Isolates of
Staphylococcus epidermidis
Authors: Wang Qian , Sun Feng-Jun , Liu Yao , Xiong Li-Rong , Xie Lin-Li , Xia Pei-Yuan
Published: March 2010

Biofilm formation in
Staphylococcus epidermidis
is mediated by
icaADBC
-dependent and -independent pathways. Subinhibitory concentrations of erythromycin, azithromycin, and clarithromycin enhanced, in a dose-dependent manner, the level of biofilm formation by 20% (21/105 isolates) by macrolide-resistant
ica
-positive and -negative isolates tested
in vitro
. The presence of
ica
, however, apparently produced an enhanced effect on biofilm formation. The levels of expression of the biofilm-related genes
icaA
,
atlE
,
fruA
,
pyrR
,
sarA
, and
sigB
were increased in response to erythromycin. The results likely underscore the potential clinical relevance of macrolide-induced biofilm growth.
Nucleotide Selectivity of Antibiotic Kinases
Authors: Shakya Tushar , Wright Gerard D.
Published: March 2010

Antibiotic kinases, which include aminoglycoside and macrolide phosphotransferases (APHs and MPHs), pose a serious threat to currently used antimicrobial therapies. These enzymes show structural and functional homology with Ser/Thr/Tyr kinases, which is suggestive of a common ancestor. Surprisingly, recent
in
vitro
studies using purified antibiotic kinase enzymes have revealed that a number are able to utilize GTP as the antibiotic phospho donor, either preferentially or exclusively compared to ATP, the canonical phosphate donor in most biochemical reactions. To further explore this phenomenon, we examined three enzymes, APH(3′)-IIIa, APH(2″)-Ib, and MPH(2′)-I, using a competitive assay that mimics
in
vivo
nucleotide triphosphate (NTP) concentrations and usage by each enzyme. Downstream analysis of reaction products by high-performance liquid chromatography enabled the determination of partitioning of phosphate flux from NTP donors to antibiotics. Using this ratio along with support from kinetic analysis and inhibitor studies, we find that under physiologic concentrations of NTPs, APH(3′)-IIIa exclusively uses ATP, MPH(2′)-I exclusively uses GTP, and APH(2″)-Ib is able to use both species with a preference for GTP. These differences reveal likely different pathways in antibiotic resistance enzyme evolution and can be exploited in selective inhibitor design to counteract resistance.
Controlled Release of Protein from Viable
Lactococcus lactis
Cells
Authors: Stentz Régis , Bongaerts Roy J. , Gunning A. Patrick , Gasson Mike , Shearman Claire
Published: March 2010

Overexpression of the lactococcal CsiA protein affects the cell wall integrity of growing cells and leads to leakage of intracellular material. This property was optimized and exploited for the targeted release of biologically active compounds into the extracellular environment, thereby providing a new delivery system for bacterial proteins and peptides. The effects of different levels of CsiA expression on the leakage of endogenous lactate dehydrogenase and nucleic acids were measured and related to the impact of CsiA expression on
Lactococcus lactis
cell viability and growth. A leakage phenotype was obtained from cells expressing both recombinant and nonrecombinant forms of CsiA. As proof of principle, we demonstrated that CsiA promotes the efficient release of the heterologous
Listeria
bacteriophage endolysin LM4 in its active form. Under optimized conditions, native and heterologous active-molecule release is possible without affecting cell viability. The ability of CsiA to release intracellular material by controlled lysis without the requirement for an external lytic agent provides a technology for the control of both the extent of lysis and its timing. Taken together, these results demonstrate the potential of this novel approach for applications including product recovery in industrial fermentations, food processing, and medical therapy.
Biogeography and Biodiversity in Sulfide Structures of Active and Inactive Vents at Deep-Sea Hydrothermal Fields of the Southern Mariana Trough
Authors: Kato Shingo , Takano Yoshinori , Kakegawa Takeshi , Oba Hironori , Inoue Kazuhiko , Kobayashi Chiyori , Utsumi Motoo , Marumo Katsumi , Kobayashi Kensei , Ito Yuki , Ishibashi Jun-ichiro , Yamagishi Akihiko
Published: March 2010

The abundance, diversity, activity, and composition of microbial communities in sulfide structures both of active and inactive vents were investigated by culture-independent methods. These sulfide structures were collected at four hydrothermal fields, both on- and off-axis of the back-arc spreading center of the Southern Mariana Trough. The microbial abundance and activity in the samples were determined by analyzing total organic content, enzymatic activity, and copy number of the 16S rRNA gene. To assess the diversity and composition of the microbial communities, 16S rRNA gene clone libraries including bacterial and archaeal phylotypes were constructed from the sulfide structures. Despite the differences in the geological settings among the sampling points, phylotypes related to the
Epsilonproteobacteria
and cultured hyperthermophilic archaea were abundant in the libraries from the samples of active vents. In contrast, the relative abundance of these phylotypes was extremely low in the libraries from the samples of inactive vents. These results suggest that the composition of microbial communities within sulfide structures dramatically changes depending on the degree of hydrothermal activity, which was supported by statistical analyses. Comparative analyses suggest that the abundance, activity and diversity of microbial communities within sulfide structures of inactive vents are likely to be comparable to or higher than those in active vent structures, even though the microbial community composition is different between these two types of vents. The microbial community compositions in the sulfide structures of inactive vents were similar to those in seafloor basaltic rocks rather than those in marine sediments or the sulfide structures of active vents, suggesting that the microbial community compositions on the seafloor may be constrained by the available energy sources. Our findings provide helpful information for understanding the biogeography, biodiversity and microbial ecosystems in marine environments.
Nested PCR and New Primers for Analysis of Sulfate-Reducing Bacteria in Low-Cell-Biomass Environments
Authors: Giloteaux Ludovic , Goñi-Urriza Marisol , Duran Robert
Published: March 2010

New primers were designed for the amplification of
dsrAB
genes by nested PCR to investigate the diversity of sulfate-reducing prokaryotes (SRP) in environments with low bacterial cell density. The success of the nested PCR for the determination of SRP diversity was estimated by terminal-restriction fragment length polymorphism analysis in the Reigous, a small creek at an inactive mine (Carnoulès, France), which constitutes an extreme acidic arsenic-rich environment. Nested PCR limits were evaluated in
dsrAB
-rich sediments, and this technique was compared to direct PCR using either known primers (DSR1F/DSR4R) or new primers (dsr619AF/dsr1905BR). The comparison of clone libraries revealed that, even if the levels of diversity observed were not identical, nested PCR did not reduce the diversity compared to that of direct DSR1F/DSR4R PCR. Clone sequences were affiliated mainly with the
Desulfobacteraceae
and
Desulfohalobiaceae
families. Many sequences (∼30%) were related to a deeply branching lineage unaffiliated with any cultured SRP. Although this
dsrAB
cluster was found in all libraries, the new primers better amplified this lineage, providing more information on this unknown bacterial group. Thanks to these new primers in nested PCR, the SRP community from Carnoulès could be characterized. Specific SRP populations were obtained according to environmental characteristics.
Desulfomicrobiaceae
-related sequences were recovered in samples with low pH, low levels of dissolved oxygen, and high As content, while sequences belonging to the deeply branching group were found in a less extreme sample. Furthermore, for the first time,
dsrAB
sequences related to the latter group were recovered from freshwater.
Annual Variations in the Diversity, Viability, and Origin of Airborne Bacteria
Authors: Fahlgren Camilla , Hagström Åke , Nilsson Douglas , Zweifel Ulla Li
Published: March 2010

The presence of bacteria in aerosols has been known for centuries, but information on their identity and role in dispersing microbial traits is still limited. This study monitored the airborne bacterial community during an annual survey using samples collected from a 25-m tower near the Baltic Sea coast. The number of CFU was estimated using agar plates while the most probable number (MPN) of viable bacteria was estimated using dilution-to-extinction culturing assays (DCAs). The MPN and CFU values produced quantitatively similar results, displaying a pronounced seasonal pattern, with the highest numbers in winter. The most dominant bacteria growing in the DCAs all formed colonies on agar plates, were mostly pigmented (80%), and closely resembled (>97%) previously cultured bacteria based on their 16S rRNA gene sequences. 16S rRNA gene clone libraries were constructed on eight occasions during the survey; these revealed a highly diverse community with a few abundant operational taxonomic units (OTUs) and a long tail of rare OTUs. A majority of the cloned sequences (60%) were also most closely related to previously “cultured” bacteria. Thus, both culture-dependent and culture-independent techniques indicated that bacteria able to form colonies on agar plates predominate in the atmosphere. Both the DCAs and clone libraries indicated the dominance of bacteria belonging to the genera
Sphingomonas
sp. and
Pseudomonas
sp. on several sampling occasions. Potentially pathogenic strains as well as sequences closely resembling bacteria known to act as ice nuclei were found using both approaches. The origin of the sampled air mass was estimated using backward trajectories, indicating a predominant marine source.
Diversity of Anaerobic Microbes in Spacecraft Assembly Clean Rooms
Authors: Probst Alexander , Vaishampayan Parag , Osman Shariff , Moissl-Eichinger Christine , Andersen Gary L. , Venkateswaran Kasthuri
Published: March 2010

Although the cultivable and noncultivable microbial diversity of spacecraft assembly clean rooms has been previously documented using conventional and state-of-the-art molecular techniques, the occurrence of obligate anaerobes within these clean rooms is still uncertain. Therefore, anaerobic bacterial communities of three clean-room facilities were analyzed during assembly of the Mars Science Laboratory rover. Anaerobic bacteria were cultured on several media, and DNA was extracted from suitable anaerobic enrichments and examined with conventional 16S rRNA gene clone library, as well as high-density phylogenetic 16S rRNA gene microarray (PhyloChip) technologies. The culture-dependent analyses predominantly showed the presence of clostridial and propionibacterial strains. The 16S rRNA gene sequences retrieved from clone libraries revealed distinct microbial populations associated with each clean-room facility, clustered exclusively within gram-positive organisms. PhyloChip analysis detected a greater microbial diversity, spanning many phyla of bacteria, and provided a deeper insight into the microbial community structure of the clean-room facilities. This study presents an integrated approach for assessing the anaerobic microbial population within clean-room facilities, using both molecular and cultivation-based analyses. The results reveal that highly diverse anaerobic bacterial populations persist in the clean rooms even after the imposition of rigorous maintenance programs and will pose a challenge to planetary protection implementation activities.
Listeria seeligeri
Isolates from Food Processing Environments Form Two Phylogenetic Lineages
Authors: Müller Andrea A. , Schmid Michael W. , Meyer Ortwin , Meussdoerffer Franz G.
Published: March 2010

Seven different
actA
subtypes forming two phylogenetic lineages could be distinguished by sequencing the
actA
gene of
Listeria seeligeri
isolates from different habitats. Isolates of the two lineages differ in hemolytic as well as phospholipase activities and in the arrangement of the virulence gene cluster. The presence of a serine protease gene resembling
orf2110
of
L. monocytogenes
in some isolates further supports the hypothesis that
L. seeligeri
is subject to ongoing adaptation to changing environments.
Relationship between Oral Malodor and the Global Composition of Indigenous Bacterial Populations in Saliva
Authors: Takeshita Toru , Suzuki Nao , Nakano Yoshio , Shimazaki Yoshihiro , Yoneda Masahiro , Hirofuji Takao , Yamashita Yoshihisa
Published: March 2010

Oral malodor develops mostly from the metabolic activities of indigenous bacterial populations within the oral cavity, but whether healthy or oral malodor-related patterns of the global bacterial composition exist remains unclear. In this study, the bacterial compositions in the saliva of 240 subjects complaining of oral malodor were divided into groups based on terminal-restriction fragment length polymorphism (T-RFLP) profiles using hierarchical cluster analysis, and the patterns of the microbial community composition of those exhibiting higher and lower malodor were explored. Four types of bacterial community compositions were detected (clusters I, II, III, and IV). Two parameters for measuring oral malodor intensity (the concentration of volatile sulfur compounds in mouth air and the organoleptic score) were noticeably lower in cluster I than in the other clusters. Using multivariate analysis, the differences in the levels of oral malodor were significant after adjustment for potential confounding factors such as total bacterial count, mean periodontal pocket depth, and tongue coating score (
P
< 0.001). Among the four clusters with different proportions of indigenous members, the T-RFLP profiles of cluster I were implicated as the bacterial populations with higher proportions of
Streptococcus
,
Granulicatella
,
Rothia
, and
Treponema
species than those of the other clusters. These results clearly correlate the global composition of indigenous bacterial populations with the severity of oral malodor.