bluuebunny/crossref_metadata_2025_split huggingface dataset:
An overview of 60 GHz location systems operating in multipath environments
Authors: Bocquet Michael , Loyez Christophe , Rolland Nathalie 
Published: April 2011

This study deals with a non-exhaustive overview of location systems operating in the 60 GHz frequency band. Both impulse and frequency hopping topologies are considered and the performances of the two realized systems are presented. For each system, a specific signal processing has been implemented to prevent the degradation of the location error from the impact of the multipath propagation.
Design and model studies for solid-state power amplification at 210 GHz
Authors: Diebold Sebastian , Kallfass Ingmar , Massler Hermann , Seelmann-Eggebert Matthias , Leuther Arnulf , Tessmann Axel , Pahl Philipp , Koch Stefan , Ambacher Oliver 
Published: April 2011

The high millimeter-wave (mmW) frequency range offers new possibilities for high-resolution imaging and sensing as well as for high data rate wireless communication systems. The use of power amplifiers of such systems boosts the performance in terms of operating range and/or data rate. To date, however, the design of solid-state power amplifiers at frequencies about 210 GHz suffers from limited transistor model accuracy, resulting in significant deviation of simulation and measurement. This causes cost and time consuming re-design iterations, and it obstructs the possibility of design optimization ultimately leading to moderate results. For verification of the small-signal behavior of our in-house large-signal transistor model, S-parameter measurements were taken from DC to 220 GHz on pre-matched transistors. The large-signal behavior of the transistor models was verified by power measurements at 210 GHz. After model modification, based on process control monitor (PCM) measurement data, the large-signal model was found to match the measurements well. A transistor model was designed containing the statistical information of the PCM data. This allows for non-linear spread analysis and reliable load-pull simulations for obtaining the highest available circuit performance. An experimental determination of the most suitable transistor geometry (i.e. number of gate fingers and gate width) and transistor bias was taken on 100 nm gate length metamorphic high electron mobility transistor (mHEMT) transistors. The most suitable combination of number of fingers, gate width and bias for obtaining maximum gain, maximum output power, and maximum power added efficiency (PAE) at a given frequency was determined.
1st INCF Workshop on Genetic Animal Models for Brain Diseases
Authors: Riess Olaf , Graessner Holm 
Published: April 2011

AbstractThe INCF Secretariat organized a workshop to focus on the “role of neuroinformatics in the processes of building, evaluating, and using genetic animal models for brain diseases” in Stockholm, December 13–14, 2009. Eight scientists specialized in the fields of neuroinformatics, database, ontologies, and brain disease participated together with two representatives of the National Institutes of Health and the European Union, as well as three observers of the national INCF nodes of Norway, Poland, and the United Kingdom.
Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn
2+
with genetically encoded sensors
Authors: Qin Yan , Dittmer Philip J. , Park J. Genevieve , Jansen Katarina B. , Palmer Amy E. 
Published: April 2011

Zn
2+
plays essential roles in biology, and cells have adopted exquisite mechanisms for regulating steady-state Zn
2+
levels. Although much is known about total Zn
2+
in cells, very little is known about its subcellular distribution. Yet defining the location of Zn
2+
and how it changes with signaling events is essential for elucidating how cells regulate this essential ion. Here we create fluorescent sensors genetically targeted to the endoplasmic reticulum (ER) and Golgi to monitor steady-state Zn
2+
levels as well as flux of Zn
2+
into and out of these organelles. These studies reveal that ER and Golgi contain a concentration of free Zn
2+
that is 100 times lower than the cytosol. Both organelles take up Zn
2+
when cytosolic levels are elevated, suggesting that the ER and Golgi can sequester elevated cytosolic Zn
2+
and thus have the potential to play a role in influencing Zn
2+
toxicity. ER Zn
2+
homeostasis is perturbed by small molecule antagonists of Ca
2+
homeostasis and ER Zn
2+
is released upon elevation of cytosolic Ca
2+
pointing to potential exchange of these two ions across the ER. This study provides direct evidence that Ca
2+
signaling can influence Zn
2+
homeostasis and vice versa, that Zn
2+
dynamics may modulate Ca
2+
signaling.
Single-molecule analysis reveals the molecular bearing mechanism of DNA strand exchange by a serine recombinase
Authors: Bai Hua , Sun Mingxuan , Ghosh Pallavi , Hatfull Graham F. , Grindley Nigel D. F. , Marko John F. 
Published: April 2011

Structural and topological data suggest that serine site-specific DNA recombinases exchange duplex DNAs by rigid-body relative rotation of the two halves of the synapse, mediated by a flat protein-protein interaction surface. We present evidence for this rotational motion for a simple serine recombinase, the Bxb1 phage integrase, from a single-DNA-based supercoil-release assay that allows us to follow crossover site cleavage, rotation, religation, and product release in real time. We have also used a two-DNA braiding-relaxation experiment to observe the effect of synapse rotation in reactions on two long molecules. Relaxation and unbraiding are rapid (averaging 54 and 70 turns/s, respectively) and complete, with no discernible pauses. Nevertheless, the molecular friction associated with rotation is larger than that of type-I topoisomerases in a similar assay. Surprisingly we find that the synapse can stay rotationally “open” for many minutes.
Preexisting Cognitive Impairment and Mild Cognitive Impairment in Subjects Presenting for Total Hip Joint Replacement
Authors: Evered Lisbeth A. , Silbert Brendan S. , Scott David A. , Maruff Paul , Ames David , Choong Peter F. 
Published: April 2011

Background
The prevalence of preexisting cognitive impairment (PreCI) is documented before cardiac surgery, but there is less information before noncardiac surgery. In addition, the prevalence of mild cognitive impairment, defined by different cognitive criteria and subjective complaints, and which may progress to Alzheimer disease, is unknown in these subjects. Because anesthesia and surgery have been implicated in Alzheimer disease pathology, we prospectively measured PreCI and mild cognitive impairment in subjects scheduled for total hip joint replacement surgery in an observational study.

Methods
One hundred fifty-two subjects 60 y of age and older who were scheduled for total hip joint replacement surgery underwent assessment, including neuropsychologic testing, 1 week before surgery. Test results were compared with published norms. PreCI was defined as impairment in two or more of seven cognitive tests, for which impairment in an individual test was defined as ≥ 2 SD below norms for that test. Amnestic mild cognitive impairment (aMCI) was defined as impairment ≥1.5 SD below norms for results of the immediate and/or delayed Auditory Verbal Learning Test plus a subjective complaint.

Results
Subjects performed worse compared with normative data on five of seven neuropsychologic tests. Thirty (20% [95% CI, 13-26%]) subjects were classified as having PreCI. Thirty-four (22% [95% CI, 16-29%]) were classified as having aMCI. Ten (7%) subjects were classified as having both PreCI and aMCI, representing 33% of the 30 subjects with PreCI.

Conclusions
The prevalence of aMCI in subjects scheduled for total hip joint replacement surgery is similar to that in the general community. PreCI and aMCI tend to identify different subjects. Because aMCI is known to progress to Alzheimer disease, future studies that track cognition before and after anesthesia and surgery should document the presence or absence of aMCI so that the rate of conversion to Alzheimer disease after anesthesia and surgery can be compared with the rate in the nonsurgical population.
Direct Endoscopy-Guided Mitral Valve Repair in the Beating Heart An Acute Animal Study
Authors: Horai Tetsuya , Fukamachi Kiyotaka , Fumoto Hideyuki , Takaseya Tohru , Shiose Akira , Arakawa Yoko , Rao Santosh , Dessoffy Raymond , Mihaljevic Tomislav 
Published: April 2011

Objective The purpose of this study was to develop a new method for minimally invasive mitral valve repair under direct endoscopic visualization in the beating heart. Methods Fiberoptic cardioscopy of the left heart was conducted in 12 calves. Systemic perfusion was maintained by cardiopulmonary bypass through a median sternotomy. A clear solution (Ringer's lactate) was temporarily administered via the pulmonary artery to flush out the pulmonary vasculature, and additional perfusion of the left heart chambers enhanced visualization of the intracardiac anatomy. The endoscope, with an open-ended transparent flexible outer sheath, was inserted through the left ventricular apex, and an endoscopic clip was used for edge-to-edge mitral valve repair. Hemodilution was avoided by the drainage of irrigation fluid via a left ventricular cannula. Results Direct endoscopic visualization of the mitral valve in an in vivo beating heart was obtained clearly, avoiding systemic hemodilution. In the last experiment, edge-to-edge repair using an endoscopic clip was successfully performed. Use of an effective intracardiac irrigation method was important for successful image acquisition and achievement of repair procedures. Conclusions This acute animal study showed the technical feasibility of beating-heart mitral valve surgery under direct endoscopic imaging. Although this study was performed under open-chest conditions, our successful experiment is a first step toward closed-chest intracardiac surgery with direct endoscopic visualization.
Cortisol Diurnal Rhythm and Stress Reactivity in Constipation and Abdominal Pain
Authors: Kiefte‐de Jong Jessica C. , Saridjan Nathalie S. , Escher Johanna C. , Jaddoe Vincent W.V. , Hofman Albert , Tiemeier Henning , Moll Henriette A. 
Published: April 2011

ABSTRACTObjectives:The aim of this study was to assess whether diurnal cortisol rhythm and cortisol stress reactivity were associated with functional constipation and abdominal pain in infancy.Patients and Methods:This study was embedded in a subset of the Generation R Study, a prospective cohort study from fetal life onward in Rotterdam, the Netherlands. Data of infants between 14 and 24 months of age (N = 483) were used. Salivary cortisol diurnal rhythm and salivary cortisol stress reactivity after a Strange Situation Procedure were assessed at age 14 months. Data on functional constipation were available according to the Rome II criteria, and data on abdominal pain on the basis of the Abdominal Pain Index were available from questionnaire data at 24 months.Results:In the second year of life, 13% of the infants had functional constipation and 17% had abdominal pain. Only 4% had symptoms of both functional constipation and abdominal pain. Diurnal cortisol rhythm did not differ significantly between children with and children without functional constipation and abdominal pain. Cortisol stress reactivity was slightly higher in infants with abdominal pain than in those without it, but this was not statistically significant (odds ratio 1.41; 95% confidence interval 0.46–4.31). No association was found between the cortisol stress reactivity and functional constipation.Conclusions:Our results suggest that cortisol as a marker for stress does not play a major role in functional constipation or abdominal pain in infancy.
The Phosphate Transporter Gene OsPht1;8 Is Involved in Phosphate Homeostasis in Rice
Authors: Jia Hongfang , Ren Hongyan , Gu Mian , Zhao Jianning , Sun Shubin , Zhang Xiao , Chen Jieyu , Wu Ping , Xu Guohua 
Published: April 2011

Abstract
Plant phosphate transporters (PTs) are active in the uptake of inorganic phosphate (Pi) from the soil and its translocation within the plant. Here, we report on the biological properties and physiological roles of OsPht1;8 (OsPT8), one of the PTs belonging to the Pht1 family in rice (Oryza sativa). Expression of a β-glucuronidase and green fluorescent protein reporter gene driven by the OsPT8 promoter showed that OsPT8 is expressed in various tissue organs from roots to seeds independent of Pi supply. OsPT8 was able to complement a yeast Pi-uptake mutant and increase Pi accumulation of Xenopus laevis oocytes when supplied with micromolar 33Pi concentrations at their external solution, indicating that it has a high affinity for Pi transport. Overexpression of OsPT8 resulted in excessive Pi in both roots and shoots and Pi toxic symptoms under the high-Pi supply condition. In contrast, knockdown of OsPT8 by RNA interference decreased Pi uptake and plant growth under both high- and low-Pi conditions. Moreover, OsPT8 suppression resulted in an increase of phosphorus content in the panicle axis and in a decrease of phosphorus content in unfilled grain hulls, accompanied by lower seed-setting rate. Altogether, our data suggest that OsPT8 is involved in Pi homeostasis in rice and is critical for plant growth and development.
Flavonols Accumulate Asymmetrically and Affect Auxin Transport in Arabidopsis
Authors: Kuhn Benjamin M. , Geisler Markus , Bigler Laurent , Ringli Christoph 
Published: April 2011

Abstract
Flavonoids represent a class of secondary metabolites with diverse functions in plants including ultraviolet protection, pathogen defense, and interspecies communication. They are also known as modulators of signaling processes in plant and animal systems and therefore are considered to have beneficial effects as nutraceuticals. The rol1-2 (for repressor of lrx1) mutation of Arabidopsis (Arabidopsis thaliana) induces aberrant accumulation of flavonols and a cell-growth phenotype in the shoot. The hyponastic cotyledons, aberrant shape of pavement cells, and deformed trichomes in rol1-2 mutants are suppressed by blocking flavonoid biosynthesis, suggesting that the altered flavonol accumulation in these plants induces the shoot phenotype. Indeed, the identification of several transparent testa, myb, and fls1 (for flavonol synthase1) alleles in a rol1-2 suppressor screen provides genetic evidence that flavonols interfere with shoot development in rol1-2 seedlings. The increased accumulation of auxin in rol1-2 seedlings appears to be caused by a flavonol-induced modification of auxin transport. Quantification of auxin export from mesophyll protoplasts revealed that naphthalene-1-acetic acid but not indole-3-acetic acid transport is affected by the rol1-2 mutation. Inhibition of flavonol biosynthesis in rol1-2 fls1-3 restores naphthalene-1-acetic acid transport to wild-type levels, indicating a very specific mode of action of flavonols on the auxin transport machinery.
Blocking induction of T helper type 2 responses prevents development of disease in a model of childhood asthma
Authors: Siegle J S , Hansbro N , Dong C , Angkasekwinai P , Foster P S , Kumar R K 
Published: April 2011

Summary
Early-life respiratory viral infections are linked to subsequent development of allergic asthma in children. We assessed the underlying immunological mechanisms in a novel model of the induction phase of childhood asthma. BALB/c mice were infected neonatally with pneumonia virus of mice, then sensitized intranasally with ovalbumin following recovery. Animals were challenged with low levels of aerosolized ovalbumin for 4 weeks to induce changes of chronic asthma, then received a single moderate-level challenge to elicit mild acute allergic inflammation. To inhibit the initial induction of a T helper type 2 (Th2) response, we administered neutralizing antibodies against interleukin (IL)-4 or IL-25, then assessed development of airway inflammation and remodelling. Anti-IL-4 administered during chronic challenge prevented development of chronic and acute allergic inflammation, as well as goblet cell hyperplasia/metaplasia, but features of remodelling such as subepithelial fibrosis and epithelial hypertrophy were unaffected. In contrast, anti-IL-25 had limited effects on the airway inflammatory response but prevented key changes of remodelling, although it had no effect on goblet cells. Both antibodies suppressed development of a Th2 response, while anti-IL-25 also promoted a Th17 response. In further experiments, anti-IL-25 was administered in early life alone, and again had limited effects on airway inflammation, but prevented development of airway wall remodelling. We conclude that in this murine model of childhood asthma, administration of anti-IL-4 or anti-IL-25 prevents development of some key features of asthma, suggesting that suppression of development of a Th2 response during the neonatal period or later in childhood could be effective for primary prevention.
Cellular immune responses in human immunodeficiency virus (HIV)-1-infected children: is immune restoration by highly active anti-retroviral therapy comparable to non-progression?
Authors: Hainaut M , Verscheure V , Ducarme M , Schandené L , Levy J , Mascart F 
Published: April 2011

SummaryThe objective of this study was to investigate whether the restored immune functions of vertically human immunodeficiency virus (HIV)-infected children who were severely immunodeficient before the initiation of highly active anti-retroviral therapy (HAART) are comparable to those of untreated slow progressors. We therefore assessed T cell proliferation and cytokine [interferon (IFN)-γ, interleukin (IL)-5 and IL-13] secretions after mitogen, recall antigens and HIV-1-specific stimulation in 12 untreated slow progressors, 16 untreated progressors and 18 treated patients. Treated children were profoundly immunodeficient before the initiation of HAART and had long-lasting suppression of viral replication on treatment. We demonstrated that slow progressors are characterized not only by the preservation of HIV-1-specific lymphoproliferative responses but also by the fact that these responses are clearly T helper type 1 (Th1)-polarized. Children on HAART had proliferative responses to HIV-1 p24 antigen, purified protein derivative (PPD) and tetanus antigen similar to slow progressors and higher than those of progressors. However, in contrast to slow progressors, most treated children exhibited a release of Th2 cytokines accompanying the IFN-γ secretion in response to the HIV-1 p24 antigen. Moreover, despite higher proliferative responses to phytohaemagglutinin (PHA) than the two groups of untreated children, treated children had lower levels of IFN-γ secretion in response to PHA than slow progressors. These data show that in severely immunodeficient vertically HIV-infected children, a long-lasting HAART allows recovering lymphoproliferative responses similar to untreated slow progressors. However, alterations in IFN-γ secretion in response to the mitogen PHA persisted, and their cytokine release after HIV-specific stimulation was biased towards a Th2 response.
Forage herbs improve mineral composition of grassland herbage
Authors: Pirhofer‐Walzl K. , Søegaard K. , Høgh‐Jensen H. , Eriksen J. , Sanderson M. A. , Rasmussen J. , Rasmussen J. 
Published: April 2011

AbstractProvision of an adequate mineral supply in the diets of ruminants fed mainly on grassland herbage can present a challenge if mineral concentrations are suboptimal for animal nutrition. Forage herbs may be included in grassland seed mixtures to improve herbage mineral content, although there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro‐ and micromineral concentrations than forage legumes and grasses, we conducted a 2‐year experiment on a loamy‐sand site in Denmark sown with a multi‐species mixture comprised of three functional groups (grasses, legumes and herbs). Herb species included chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), caraway (Carum carvi L.) and salad burnet (Sanguisorba minor L.). We also investigated the effect of slurry application on the macro‐ and micromineral concentration of grasses, legumes and herbs. In general, herbs had greater concentrations of the macrominerals P, Mg, K and S and the microminerals Zn and B than grasses and legumes. Slurry application indirectly decreased Ca, S, Cu and B concentrations of total herbage because of an increase in the proportion of mineral‐poor grasses. Our study indicates that including herbs in forage mixtures is an effective way of increasing mineral concentrations in herbage.
Influence of leaching on the chemical composition of grassland biomass for combustion
Authors: Tonn B. , Dengler V. , Thumm U. , Piepho H.‐P. , Claupein W. 
Published: April 2011

AbstractBioenergy production from grassland biomass is an alternative use for semi‐natural grasslands, but chemical composition of grassland herbage can limit its suitability for combustion. Leaching by precipitation during the field period is currently used to remove unwanted elements from other herbaceous biofuels. The aims of this study were to assess the influence of leaching on chemical composition of grassland biomass, to establish the influence of leaching intensity and to evaluate the feasibility of a simplified laboratory method for leaching studies. Freshly cut and dried herbage from two contrasting grasslands were leached using 12 and 36 mm of simulated rain. A second experiment compared three methods of different leaching intensity. Leaching resulted in strong reduction in Cl and K concentrations; ash was moderately reduced and Mg slightly reduced. Concentrations of N, S and Ca were not affected. Leaching occurred in dried, but not in fresh herbage, and Cl leaching was affected by herbage type. Cl, K and ash responded differently to increased leaching intensity. Slagging, fouling and corrosion problems during combustion, which are closely linked to Cl and K concentrations, could be reduced by natural leaching under suitable weather conditions. A standardized laboratory leaching method is suggested for further investigating the influence of herbage characteristics on the leachability of K and Cl.
Increased sensitivity to antigen in high avidity CD8+ T cells results from augmented membrane proximal T‐cell receptor signal transduction
Authors: Sharma Sharad K. , Alexander‐Miller Martha A. 
Published: April 2011

SummaryThe functional avidity of a cytotoxic T lymphocyte (CTL) is known to be a critical determinant of the efficacy with which it clears pathogens. High avidity cells, which are by definition highly sensitive to peptide antigen, are superior for elimination of viruses and tumours. Our studies have established the ability of T cells to undergo avidity modulation as a result of antigen encounter. High and low avidity cells established in this manner exhibit significant differences in the amount of peptide required to elicit effector function. However, how signalling is regulated in these cells as it relates to the control of peptide sensitivity remains to be defined. To address this question, we compared T‐cell receptor (TCR) signal transduction events in high and low avidity CTL generated from OT‐Irag2− TCR transgenic mice. Our data suggest that divergent signalling is initiated at the TCR‐associated CD3ζ, with low avidity CTL requiring higher amounts of pMHC to achieve threshold levels of phosphorylated CD3ζ compared with high avidity CTL. Further, this difference is transduced further downstream to mitogen‐activated protein kinase and Ca2+ signalling pathways. These results suggest that regulated control of the initiation of TCR signalling in high versus low avidity cells determines the amount of peptide required for T‐cell activation.