bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐resolution extracted ion chromatography, a new tool for metabolomics and lipidomics using a second‐generation orbitrap mass spectrometer
Authors: Koulman Albert , Woffendin Gary , Narayana Vinod K. , Welchman Helen , Crone Catharina , Volmer Dietrich A.
Published: April 2009

Most analytical methods in metabolomics are based on one of two strategies. The first strategy is aimed at specifically analysing a limited number of known metabolites or compound classes. Alternatively, an unbiased approach can be used for profiling as many features as possible in a given metabolome without prior knowledge of the identity of these features. Using high‐resolution mass spectrometry with instruments capable of measuring m/z ratios with sufficiently low mass measurement uncertainties and simultaneous high scan speeds, it is possible to combine these two strategies, allowing unbiased profiling of biological samples and targeted analysis of specific compounds at the same time without compromises. Such high mass accuracy and mass resolving power reduces the number of candidate metabolites occupying the same retention time and m/z ratio space to a minimum. In this study, we demonstrate how targeted analysis of phospholipids as well as unbiased profiling is achievable using a benchtop orbitrap instrument after high‐speed reversed‐phase chromatography. The ability to apply both strategies in one experiment is an important step forward in comprehensive analysis of the metabolome. Copyright © 2009 John Wiley & Sons, Ltd.
The quantification of carbon dioxide in humid air and exhaled breath by selected ion flow tube mass spectrometry
Authors: Smith David , Pysanenko Andriy , Španěl Patrik
Published: April 2009

The reactions of carbon dioxide, CO2, with the precursor ions used for selected ion flow tube mass spectrometry, SIFT‐MS, analyses, viz. H3O+, NO+ and O, are so slow that the presence of CO2 in exhaled breath has, until recently, not had to be accounted for in SIFT‐MS analyses of breath. This has, however, to be accounted for in the analysis of acetaldehyde in breath, because an overlap occurs of the monohydrate of protonated acetaldehyde and the weakly bound adduct ion, H3O+CO2, formed by the slow association reaction of the precursor ion H3O+ with CO2 molecules. The understanding of the kinetics of formation and the loss rates of the relevant ions gained from experimentation using the new generation of more sensitive SIFT‐MS instruments now allows accurate quantification of CO2 in breath using the level of the H3O+CO2 adduct ion. However, this is complicated by the rapid reaction of H3O+CO2 with water vapour molecules, H2O, that are in abundance in exhaled breath. Thus, a study has been carried out of the formation of this adduct ion by the slow three‐body association reaction of H3O+ with CO2 and its rapid loss in the two‐body reaction with H2O molecules. It is seen that the signal level of the H3O+CO2 adduct ion is sensitively dependent on the humidity (H2O concentration) of the sample to be analysed and a functional form of this dependence has been obtained. This has resulted in an appropriate extension of the SIFT‐MS software and kinetics library that allows accurate measurement of CO2 levels in air samples, ranging from very low percentage levels (0.03% typical of tropospheric air) to the 6% level that is about the upper limit in exhaled breath. Thus, the level of CO2 can be traced through single time exhalation cycles along with that of water vapour, also close to the 6% level, and of trace gas metabolites that are present at only a few parts‐per‐billion. This has added a further dimension to the analysis of major and trace compounds in breath using SIFT‐MS. Copyright © 2009 John Wiley & Sons, Ltd.
Precolumn derivatization reagents for high‐speed analysis of amines and amino acids in biological fluid using liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Shimbo Kazutaka , Oonuki Takashi , Yahashi Akihisa , Hirayama Kazuo , Miyano Hiroshi
Published: April 2009

A rapid analytical method for amines and amino acids was developed, involving derivatization with the novel reagent 3‐aminopyridyl‐N‐hydroxysuccinimidyl carbamate (APDS), followed by reversed‐phase high‐performance liquid chromatography and electrospray ionization tandem mass spectrometry (HPLC/ESI‐MS/MS). More than 100 different analytes with amino groups, including amino acids in biological fluids such as mammalian plasma, could be measured within 10 min. The analytes were easily derivatized with APDS under the mild conditions. Selective reaction monitoring of ESI‐MS/MS in positive mode was carried out to include the transitions of all of the protonated molecular ions of analytes derivatized with APDS to the common fragment at m/z 121, which was derived from the amino pyridyl moiety of the reagent. We evaluated the retention time precision, the quantification limits, the linearity, the intra‐ and inter‐day precisions and the accuracy of 22 typical amino acids found in biological fluids, by analyzing a standard amino acid mixture and rat plasma. The intra‐day relative standard deviations (RSDs) of the retention times of the 22 amino acids and their internal standards were within 0.9% and the inter‐day RSDs were less than 1.1%, except for asparagines, with an RSD of 1.9%. The intra‐day and inter‐day RSDs of amino acid analyses in rat plasma were within 8.0% and 4.5%, respectively. The method, which facilitates the amino acid analysis of more than 100 samples in a day, represents an alternative to traditional amino acid analysis techniques, such as chromatography using postcolumn derivatization by ninhydrin. Copyright © 2009 John Wiley & Sons, Ltd.
Nonlinear Laguerre–Volterra observer‐controller and its application to process control
Authors: Zhang Hai‐Tao , Chen Michael Z. Q. , Chen Zhiyong
Published: April 2009

By expanding each kernel using the orthonormal Laguerre series, a Volterra functional series is used to represent the input/output relation of a nonlinear dynamic system. With the feedback of the modeling error, we design a novel nonlinear state observer, based on which an output feedback controller is derived for both the stabilization and tracking problems. The stability of the closed‐loop system is analyzed theoretically. The algorithm is effectively applied on the continuous stirring tank reactor and chemical reactor temperature control system. Copyright © 2009 John Wiley & Sons, Ltd.
Exploring a school–aquarium collaboration: An intersection of communities of practice
Authors: Kisiel James F.
Published: April 2009

This study examines the development and ongoing activities of a collaboration between an urban elementary school and a nearby aquarium. Although the benefits of such collaborations in support of science education are touted by numerous national organizations, the pathway to creating a successful relationship between these two different institutions, with inherently different cultures, is less well documented. Using the theoretical framework of communities of practice (E. Wenger, 1998), a better understanding of the challenges and successes of this collaboration is presented. In particular, the analysis suggests that participant engagement in both communities (school and aquarium) led to the development of an overlap in these communities of practice. This resulted when common forms of mutual engagement, joint enterprise, and shared repertoire emerged over the course of the project. Consistent with Wenger's framework, boundary objects and brokers could be identified that helped secure such overlap in this particular case. Implications of this theoretical perspective for facilitating the development of such institutional collaborations are also discussed. © 2009 Wiley Periodicals, Inc. Sci Ed 94:95–121, 2010
Extracardiac lesions and chromosomal abnormalities associated with major fetal heart defects: comparison of intrauterine, postnatal and postmortem diagnoses
Authors: Song M. S. , Hu A. , Dyhamenahali U. , Chitayat D. , Winsor E. J. T. , Ryan G. , Smallhorn J. , Barrett J. , Yoo S.‐J. , Hornberger L. K.
Published: April 2009

Objectives

The clinical outcome of prenatally diagnosed congenital heart defects (CHD) continues to be affected significantly by associated extracardiac and chromosomal abnormalities. We sought to: determine the frequency and type of major extracardiac abnormalities (with impact on quality of life) and chromosomal abnormalities associated with fetal CHD; and compare the extracardiac abnormalities detected prenatally to the postnatal and autopsy findings in affected fetuses, to find the incidence of extracardiac abnormalities missed on prenatal ultrasound.

Methods

We reviewed the computerized database of the Division of Cardiology of the Hospital for Sick Children in Toronto to identify all cases of major CHD detected prenatally from 1990 to 2002. Medical records, fetal echocardiograms and ultrasound, cytogenetic and autopsy reports were reviewed. The types of CHD detected were grouped into categories and the frequencies of major extracardiac and chromosomal abnormalities in these categories were noted. Prenatal ultrasound findings were compared with those at autopsy or postnatal examination.

Results

Of 491 fetuses with major structural CHD, complete data were obtained for 382. Of these, there were 141 (36.9%) with major extracardiac abnormalities at autopsy or postnatal exam, of which 46 had chromosomal abnormalities and 95 did not. In the absence of chromosomal abnormalities, the organ systems most affected were urogenital (12.2%) and gastrointestinal (11.6%). CHDs with the highest incidence of extracardiac abnormalities (>25%) included: heterotaxy, single left ventricle and tricuspid atresia, hypoplastic left heart syndrome and tetralogy of Fallot. Ninety‐four of 334 (28.1%) fetuses tested had chromosomal abnormalities. The most common chromosomal abnormalities were trisomies 21 (43.6%), 18 (19.1%) and 13 (9.6%), monosomy X (7.4%) and 22q11.2 deletion (7.4%). Of 289 extracardiac abnormalities from the complete series, 134 (46.4%) were not identified prenatally. Of the missed extracardiac abnormalities, 65 were considered not detectable at prenatal ultrasound, so 23.9% (69/289) of detectable extracardiac abnormalities were missed prenatally.

Conclusions

Major extracardiac and chromosomal abnormalities are common in fetuses with major fetal CHD. Many important associated extracardiac abnormalities may be missed prenatally, which should be taken into consideration in the prenatal counseling for fetal CHD. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal aortic isthmus blood flow and the fraction of cardiac output distributed to the upper body and brain at 11– 20 weeks of gestation
Authors: Vimpeli T. , Huhtala H. , Wilsgaard T. , Acharya G.
Published: April 2009

Objective

To measure serial changes in fetal aortic isthmus (AI) blood flow and estimate the fraction of fetal cardiac output distributed to the upper body, including the brain, at 11–20 weeks of gestation.

Methods

Using pulsed‐wave Doppler and two‐dimensional ultrasound, blood flow velocities and inner diameter of the AI, aortic valve (AV) and pulmonary valve (PV) were measured longitudinally in 143 fetuses and volume blood flows (Q) were calculated for each site using the formula: Q (mL/min) = π× (diameter/2)2 × velocity time integral × heart rate × 60. The sum of Qav and Qpv constituted the combined cardiac output (CCO) and the fraction (%) of the upper body (including brain) blood flow was calculated as: (Qav−Qai)×100/CCO.

Results

AI blood velocities as well as the vessel diameter increased with advancing gestation, resulting in a significant increase in Qai from 1.9 to 40.5 mL/min during weeks 11 to 20. The AI peak systolic velocity increased from 29 to 63 cm/s, end‐diastolic velocity from 1.2 to 5.2 cm/s, and the time‐averaged maximum velocity from 11 to 22 cm/s, resulting in a fairly stable pulsatility index (PI) of 2.4–2.6 and resistance index (RI) of 0.91–0.94. On average, 75% of blood ejected by the left ventricle (which represented about 35% of the CCO) passed through the AI to the descending aorta. The fraction of CCO distributed to the upper body, including the brain, was estimated as approximately 13%.

Conclusion

We have established longitudinal reference ranges for fetal AI diameter, blood flow velocities, PI, RI and volume blood flow at 11–20 weeks of gestation. The human fetus appears to direct a relatively small fraction (13%) of its CCO to the upper body, including the brain, during this period of pregnancy. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Sequence of the yeast protein expression plasmid pEG(KT)
Authors: Pierce B. Daniel , Wendland Beverly
Published: April 2009

The plasmid pEG(KT) is a widely used plasmid for expressing high levels of GST fusion proteins in the yeast Saccharomyces cerevisiae. Unfortunately, a complete sequence file has been lacking, thus complicating efforts to design cloning projects or to modify the plasmid for other uses (e.g. exchanging selection markers, epitope tags or protease cleavage sites to remove the epitope tag). Here, the complete sequence of the pEG(KT) plasmid is reported, thus facilitating its use. Additionally, its use as a vector backbone for high‐level expression of a TAP‐tagged protein is shown. Copyright © 2009 John Wiley & Sons, Ltd.
Sdo1p, the yeast orthologue of Shwachman–Bodian–Diamond syndrome protein, binds RNA and interacts with nuclear rRNA‐processing factors
Authors: Luz Juliana S. , Georg Raphaela C. , Gomes Carlos H. , Machado‐Santelli Gláucia M. , Oliveira Carla C.
Published: April 2009

The Shwachman–Bodian–Diamond syndrome protein (SBDS) is a member of a highly conserved protein family of not well understood function, with putative orthologues found in different organisms ranging from Archaea, yeast and plants to vertebrate animals. The yeast orthologue of SBDS, Sdo1p, has been previously identified in association with the 60S ribosomal subunit and is proposed to participate in ribosomal recycling. Here we show that Sdo1p interacts with nucleolar rRNA processing factors and ribosomal proteins, indicating that it might bind the pre‐60S complex and remain associated with it during processing and transport to the cytoplasm. Corroborating the protein interaction data, Sdo1p localizes to the nucleus and cytoplasm and co‐immunoprecipitates precursors of 60S and 40S subunits, as well as the mature rRNAs. Sdo1p binds RNA directly, suggesting that it may associate with the ribosomal subunits also through RNA interaction. Copyright © 2009 John Wiley & Sons, Ltd.
Large bending deformations of a cylindrical membrane with internal pressure
Authors: Kolesnikov A.M. , Zubov L.M.
Published: April 2009

We consider the large bending of a thin‐walled cylinder made of a rubberlike material. It is loaded by internal pressure and bending moments at the ends. The exact formulation of the problem is given within the framework of the nonlinear membrane theory taking into account large strains of the cylinder. Using the special substitution describing the pure bending of the cylinder, the problem is reduced to the system of nonlinear ordinary differential equations. The latter is solved numerically. We establish that there exists the limit value of the bending moment, which depends essentially upon the internal pressure. As an example, the Mooney–Rivlin material is considered. On the base of the calculations we propose the approximate formulae describing the bending moment dependence on the axis curvature of the cylinder and the ultimate bending moment dependence on the internal pressure.
On the linear theory of micropolar plates
Authors: Altenbach H. , Eremeyev V.A.
Published: April 2009

We discuss the general linear six‐parametric theory of plates based on the direct approach. We consider the plate as a deformable surface. Each material point of the surface can be regarded as an infinitesimal small rigid body with six degrees of freedom. The kinematics of the plate is described by using the vector of translation and the vector of rotation as the independent variables. The relations between the equilibrium conditions of a three‐dimensional micropolar plate‐like body and the two‐dimensional equilibrium equations of the deformable surface are established. Using the three‐dimensional constitutive equations of a micropolar material we discuss the determination of the effective stiffness tensors appearing in the two‐dimensional constitutive equations.
Generalized self‐consistent homogenization using the Finite Element Method
Authors: Lefik M. , Boso D.P. , Schrefler B.A.
Published: April 2009

This paper presents a development of the usual generalized self‐consistent method for homogenization of composite materials. The classical self‐consistent scheme is appropriate for phases that are “disordered”, i.e. what is called “random texture”. In the case of both linear and non linear components, the self‐consistent homogenization can be used to identify expressions for bounds of effective mechanical characteristics. In this paper we formulate a coupled thermo‐mechanical problem for non linear composites having properties depending on temperature. The solution is found in a non‐classical way, as we use the Finite Element Method to solve the elastic‐plastic problem at hand. In this sense we propose a “problem‐oriented” technique of solution. The method is finally applied to the real case of superconducting strands used for the coils of the future ITER experimental reactor.
Thermoelastic waves in a continuum with complex structure
Authors: Indeitsev D.A. , Naumov V.N. , Semenov B.N. , Belyaev A.K.
Published: April 2009

A mechanical two‐component model of the solid of complex structure is presented. The suggested structural‐rheological model is governed by a system of equations describing dynamics of thermoelastic body of complex structure and accounting for the force and energy exchange between the material components of the body. Propagation of mechanical and temperature disturbances due to a pulse laser excitation is considered. The influence of the material structure on the character of transfer of the temperature disturbances is studied. The possibility of transfer of temperature disturbances with the velocity close to that of the mechanical pulse propagation is shown.
Intra‐Abdominal Hypertension in Acute Pancreatitis
Authors: De Waele Jan J. , Leppäniemi Ari K.
Published: April 2009

The incidence of intra‐abdominal hypertension (IAH) in patients with severe acute pancreatitis (SAP) is approximately 60–80%. It is usually an early phenomenon, partly related to the effects of the inflammatory process, causing retroperitoneal edema, fluid collections, ascites, and ileus, and partly iatrogenic, resulting from aggressive fluid resuscitation. It also can manifest at a later stage, often associated with local pancreatic complications. IAH is associated with impaired organ dysfunction, especially of the cardiovascular, respiratory, and renal systems. Using current definitions, the incidence of the clinical manifestation, abdominal compartment syndrome (ACS), has been reported as 27% in the largest study so far. Despite several intervention options, the mortality in patients developing ACS remains high: 50–75%. Prevention with judicious use of crystalloids is important, and nonsurgical interventions, such as nasogastric decompression, short‐term use of neuromuscular blockers, removal of fluid by extracorporeal techniques, and percutaneous drainage of ascites should be instituted early. The indications for surgical decompression are still not clearly defined, but undoubtedly some patients benefit from it. It can be achieved with full‐thickness laparostomy (midline or transverse subcostal) or through a subcutaneous linea alba fasciotomy. Despite the improvement in physiological variables and significant decrease in IAP, the effects of surgical decompression on organ function and outcome are less clear. Because of the significant morbidity associated with surgical decompression and the management of the ensuing open abdomen, more research is needed to define better the appropriate indications and techniques for surgical intervention.
Intraabdominal Hypertension and the Abdominal Compartment Syndrome in Burn Patients
Authors: Kirkpatrick Andrew W. , Ball Chad G. , Nickerson Duncan , D’Amours Scott K.
Published: April 2009

Severe burns represent a devastating injury that induces profound systemic inflammation requiring large volumes of resuscitative fluids. The consequent massive swelling and peritoneal ascites raises intraabdominal pressures (IAP) to supraphysiologic levels commensurate with intraabdominal hypertension (IAH) and with the abdominal compartment syndrome (ACS) if consistently associated with IAP >20 mmHg and associated with new organ failure. Severe burn injuries are an example of the secondary ACS (2° ACS), wherein there has been no primary inciting intraperitoneal injury, yet severe IAH/ACS develops, setting the stage for progressive multiorgan dysfunction. These definitions along with practice management guidelines have recently been promulgated by the World Society of the Abdominal Compartment Syndrome (WSACS) in an effort to standardize terminology and communication regarding IAH/ACS in critical care. It is currently unknown whether these syndromes are iatrogenic consequences of excessive or poorly managed fluid resuscitation or unavoidable sequelae of the primary injury. It occurs frequently with burns of >60% body surface area, especially with associated inhalational injury, delayed resuscitation, and abdominal wall injuries. IAH/ACS is often a hyperacute phenomenon that occurs within the first hours of admission and thereafter with any complication requiring aggressive fluid resuscitation. Despite a number of noninvasive management strategies, interventions such as percutaneous peritoneal drainage and, ultimately, decompressive laparotomy are often required once the ACS is established. Whether novel resuscitation strategies can avoid or minimize IAH/ACS is unproven at present and requires further study. Truly understanding postburn ACS may require further insights into the basic mechanisms of injury and resuscitation.
The Stiff Elbow
Authors: Nandi Sumon , Maschke Steven , Evans Peter J. , Lawton Jeffrey N.
Published: April 2009

Elbow motion is essential for upper extremity function to position the hand in space. Unfortunately, the elbow joint is prone to stiffness following a multitude of traumatic and atraumatic etiologies. Elbow stiffness can be diagnosed with a complete history and physical exam, supplemented with appropriate imaging studies. The stiff elbow is challenging to treat, and thus, its prevention is of paramount importance. When this approach fails, non-operative followed by operative treatment modalities should be pursued. Upon initial presentation in those who have minimal contractures of 6-month duration or less, static and dynamic splinting, serial casting, continuous passive motion, occupational/physical therapy, and manipulation are non-operative treatment modalities that may be attempted. A stiff elbow that is refractory to non-operative management can be treated surgically, either arthroscopically or open, to eliminate soft tissue or bony blocks to motion. In the future, efforts to prevent and treat elbow stiffness may target the basic science mechanisms involved. Our purpose was to review the etiologies, classification, evaluation, prevention, operative, and non-operative treatment of the stiff elbow.
Highly Uniform Epitaxial ZnO Nanorod Arrays for Nanopiezotronics
Authors: Volk J. , Nagata T. , Erdélyi R. , Bársony I. , Tóth A. L. , Lukács I. E. , Czigány Zs , Tomimoto H. , Shingaya Y. , Chikyow T.
Published: April 2009

Highly uniform and c-axis-aligned ZnO nanorod arrays were fabricated in predefined patterns by a low temperature homoepitaxial aqueous chemical method. The nucleation seed patterns were realized in polymer and in metal thin films, resulting in, all-ZnO and bottom-contacted structures, respectively. Both of them show excellent geometrical uniformity: the cross-sectional uniformity according to the scanning electron micrographs across the array is lower than 2%. The diameter of the hexagonal prism-shaped nanorods can be set in the range of 90–170 nm while their typical length achievable is 0.5–2.3 μm. The effect of the surface polarity was also examined, however, no significant difference was found between the arrays grown on Zn-terminated and on O-terminated face of the ZnO single crystal. The transmission electron microscopy observation revealed the single crystalline nature of the nanorods. The current–voltage characteristics taken on an individual nanorod contacted by a Au-coated atomic force microscope tip reflected Schottky-type behavior. The geometrical uniformity, the designable pattern, and the electrical properties make the presented nanorod arrays ideal candidates to be used in ZnO-based DC nanogenerator and in next-generation integrated piezoelectric nano-electromechanical systems (NEMS).
Brief report: Prevalence of psychiatric disorders in pregnant teenagers
Authors: Mitsuhiro Sandro Sendin , Chalem Elisa , Moraes Barros Marina Carvalho , Guinsburg Ruth , Laranjeira Ronaldo
Published: April 2009

Purpose

To evaluate the prevalence of ICD‐10 psychiatric disorders in a population of pregnant teenage women from a Brazilian public hospital.

Method

1000 pregnant teenage women were evaluated using the Composite International Diagnostic Interview, a structured interview which establishes diagnoses according to the International Classification of Diseases.

Results

325 of the 1000 patients were found to have at least one psychiatric disorder; 33.2% of them had a second psychiatric diagnosis. The most prevalent disorders were depression (12.9%), post‐traumatic stress disorder (10%), and tobacco dependence/harmful use (10.3%). The most prevalent co‐morbidity was ICD‐10 Affective Disorders versus Neurotic, Stress‐related, and Somatoform Disorders. Substance‐related disorders are significantly correlated with all of the ICD‐10 psychiatric diagnoses but Psychotic Disorders.

Conclusion

The prevalence of psychiatric disorders in this population is high, and one third of them had co‐morbidities, a condition usually associated with a more serious course of illness. This finding has important implications for clinical management and prognosis, and demands preventive public policies.
A proposed reaction mechanism for rice NADPH thioredoxin reductase C, an enzyme with protein disulfide reductase activity
Authors: Pérez-Ruiz Juan Manuel , Cejudo Francisco Javier
Published: April 2009

MINT‐7017101, MINT‐7017183: NTRC (uniprotkb:Q70G58) and 2cys Prx (uniprotkb:Q6ER94) bind (MI:0407) by enzymatic studies (MI:0415)
Proteomic analyses of the response of cyanobacteria to different stress conditions
Authors: Castielli Ornella , De la Cerda Berta , Navarro José A. , Hervás Manuel , De la Rosa Miguel A.
Published: April 2009

Cyanobacteria are significant contributors to global photosynthetic productivity, thus making it relevant to study how the different environmental stresses can alter their physiological activities. Here, we review the current research work on the response of cyanobacteria to different kinds of stress, mainly focusing on their response to metal stress as studied by using the modern proteomic tools. We also report a proteomic analysis of plastocyanin and cytochrome c
6 deletion mutants of the cyanobacterium Synechocystis sp. PCC 6803 grown under copper or iron deprivation, as compared to wild‐type cells, so as to get a further understanding of the metal homeostasis in cyanobacteria and their response to changing environmental conditions.
Expression of the nociceptin receptor during zebrafish development: Influence of morphine and nociceptin
Authors: Macho Sanchez‐Simon F. , Rodriguez R.E.
Published: April 2009

The NOP system is considered to be part of the opioid system, although it exerts antiopioid actions depending on the anatomical region where it is localized. This apparent controversy has lead to the hypothesis that the NOP system interacts with the classical opioid systems (mu, delta, kappa) and regulates/modulates their activity in relation to analgesia and the development of addiction to drugs. In order to shed light into the importance of the NOP system, we have analyzed the expression of NOP during zebrafish development, and the effect of its endogenous agonist nociceptin and the opioid agonist morphine on NOP expression. Our qPCR study show that the number of NOP transcripts is different at each developmental stage studied (0.5 hpf, 2.75 hpf, 3 hpf, 8 hpf, 16 hpf, 19 hpf, 22 hpf, 24 hpf, 30 hpf, 48 hpf, 60 hpf and 72 hpf). Nociceptin enhances NOP expression at 24 hpf but decreases the number of NOP copies at 48 hpf, whereas NOP expression decreases after morphine exposure at 24 hpf and 48 hpf. Also, our ISH analysis demonstrates that nociceptin causes a change in the distribution of NOP towards rostral areas at both developmental stages. Morphine produces similar changes to those of nociceptin although only at 48 hpf. The present work leads to the conclusion that the NOP system is important during embryogenesis. Exposure to drugs changes the expression level and localization of NOP, suggesting that also during development, NOP plays a role in the apparition of dependence and addiction to drugs.
Gas1 inhibits cell proliferation and induces apoptosis of human primary gliomas in the absence of Shh
Authors: Domínguez‐Monzón Gabriela , Benítez Jorge A. , Vergara Paula , Lorenzana Rodrigo , Segovia José
Published: April 2009

Growth arrest specific1 (Gas1) is a protein expressed during development and when cells arrest their growth. The potential of Gas1 as an adjuvant in the treatment of cancer, and its role as a tumor suppressor have also been proposed. In this work we are addressing the molecular mechanisms by which Gas1 induces cell arrest and apoptosis of cancer cells, using primary cultures of human gliomas as a model. We had previously demonstrated the structural relationship between Gas1 and the α receptors for the Glial‐cell line‐Derived Neurotrophic Factor (GDNF) family of ligands, and showed that Gas1 acts by inhibiting the intracellular signaling induced by GDNF. There are also reports indicating that Gas1 positively cooperates with Sonic Hedgehog (Shh) during embryonic development and in this paper we analyzed the potential interactions between Gas1 and Shh. We show that human gliomas do not express Shh, whereas GDNF and the molecular components necessary to transduce its signaling are present in human gliomas. Furthermore, the over‐expression of Gas1 induces cell arrest, apoptosis and prevents the activation of Akt, a crucial mediator of survival and cellular proliferation pathways. In the present work, we present evidence demonstrating that Gas1 exerts its effects inhibiting cell growth and inducing apoptosis of glioma cells in the absence of Shh.
Timing and determinants of mother‐to‐child transmission of HIV in Nigeria
Authors: Charurat Man , Datong Pam , Matawal Bitrus , Ajene Anuli , Blattner William , Abimiku Alash'le
Published: April 2009

Objective

To characterize the timing and determinants of mother‐to‐child transmission (MTCT) of HIV among mothers receiving single‐dose nevirapine to prevent MTCT in Nigeria.

Methods

Three hundred and seventy‐one HIV‐infected mothers and their infants were followed from birth, at 1 week, and at 1, 3, 6, and 12 months. Risks of in utero (IU), intrapartum (IP/EPP), and postnatal (PP) transmission were quantified using conditional Cox regressions.

Results

Maternal viral load was the only risk factor for IU transmission after controlling for known risk factors. Low birth weight, premature birth, mixed feeding, and maternal viral load were associated with IP/EPP transmission. Increased PP transmission was associated with low birth weight and mixed feeding. At 6 months, mixed‐fed infants were more likely to acquire infection than formula‐fed infants (hazard ratio = 5.74; 95% CI, 1.26–26.2).

Conclusion

Risk factors for IU transmission differed from those of IP and PP transmission. Reducing mixed feeding and low birth weight delivery among HIV‐infected mothers can further decrease IP and PP transmission.
The value of neurostimulation and intraoperative nerve monitoring of inferior laryngeal nerve in thyroid surgery
Authors: Cavicchi Ottavio , Caliceti Umberto , Fernandez Ignacio Javier , Macrì Giovanni , Di Lieto Cristiana , Marcantoni Alessandra , Ceroni Alberto Rinaldi , Piccin Ottavio
Published: April 2009

Objective

To determine the accuracy of neurostimulation with laryngeal palpation (NSLP) and intraoperative neuromonitoring (IONM) to predict the postoperative function of recurrent laryngeal nerve (RLN) in thyroid surgery.

Study Design

Historical cohort study.

Subjects and Methods

A retrospective case control study with 993 patients. The control group (799 patients with 1450 nerves at risk) included patients who underwent NSLP and the case group (194 patients with 354 nerves at risk) consisted of those who underwent NSLP in association with IONM. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and accuracy were calculated for NSLP and IONM, with nerve palsy as the target outcome.

Results

A significant difference in nerve injury between the case and the control group (P = 0.31) was not observed. The presence or absence of laryngeal twitch (LT) (P < 0.0001) and the acoustic response to electrical stimulation (P = 0.003) were significantly associated with nerve function at the end of the surgery.

Conclusion

Our results indicate that NSLP is a safe and reliable intraoperative method of RLN monitoring. Moreover our data confirm that IONM is not a helpful tool to reduce the rate of palsy in thyroid surgery.
The importance of preoperative swallowing therapy in subtotal laryngectomies
Authors: Cavalot Andrea L. , Ricci Eugenia , Schindler Antonio , Roggero Nicolò , Albera Roberto , Utari Cristina , Cortesina Giorgio
Published: April 2009

Objective

To examine the utility of swallowing therapy (ST) before and after surgery in patients undergoing subtotal laryngectomy.

Study Design and Setting

From 1990 to 2000, 43 patients underwent subtotal laryngectomy. Prior to 1997 patients received ST only after surgery, while from 1997 on, patients scheduled for subtotal laryngectomy also received some sessions of ST before surgery.

Results

The average time to swallowing resumption was 27.76 ± 5.206 days for the 25 patients who received ST only after surgery, and 16.38 ± 2.953 for those who underwent ST both before and after surgery.

Conclusion

The difference between the two groups was significant on Student's t test (P < 0.001) and shows that preoperative rehabilitation is of significant help in the early resumption of normal deglutition.

Significance

The authors find that the duration of nasogastric tube feeding is reduced in subjects who underwent ST.
Last resort gambles, risky debt and liquidation policy
Authors: Agliardi Elettra , Andergassen Rainer
Published: April 2009

This paper develops a real option model in which the interaction between debt, liquidation policy and risky investments is studied. We consider a manager who owns the firm and faces the opportunity to invest in risky projects which may boost current profits at the cost of bankruptcy if they turn out to be unsuccessful. These investments are “last resort gambles” in the sense that, if successful, they save the company from insolvency, while, if unsuccessful, they make liquidation unavoidable. It is shown that last resort gambles delay liquidation. We study how the liquidation trigger and the last resort investment decisions are affected by the firm's capital structure.
Formal and functional assessment of the pyramid method for summary content evaluation
Authors: PASSONNEAU REBECCA J.
Published: April 2009

Pyramid annotation makes it possible to evaluate quantitatively and qualitatively the content of machine-generated (or human) summaries. Evaluation methods must prove themselves against the same measuring stick – evaluation – as other research methods. First, a formal assessment of pyramid data from the 2003 Document Understanding Conference (DUC) is presented; this addresses whether the form of annotation is reliable and whether score results are consistent across annotators. A combination of interannotator reliability measures of the two manual annotation phases (pyramid creation and annotation of system peer summaries against pyramid models), and significance tests of the similarity of system scores from distinct annotations, produces highly reliable results. The most rigorous test consists of a comparison of peer system rankings produced from two independent sets of pyramid and peer annotations, which produce essentially the same rankings. Three years of DUC data (2003, 2005, 2006) are used to assess the reliability of the method across distinct evaluation settings: distinct systems, document sets, summary lengths, and numbers of model summaries. This functional assessment addresses the method's ability to discriminate systems across years. Results indicate that the statistical power of the method is more than sufficient to identify statistically significant differences among systems, and that the statistical power varies little across the 3 years.
Anaemia and associated factors among under-fives and their mothers in Bushenyi district, Western Uganda
Authors: Kikafunda Joyce K , Lukwago Fred B , Turyashemererwa Florence
Published: April 2009

Objective

To determine the prevalence of anaemia and associated factors among under-fives and their mothers in a rural area of Western Uganda.

Design

A cross-sectional investigation using both qualitative and quantitative methods of data collection. Stratified multistage sampling methods were used to select the study sample. A haemoglobinometer was used to assess Hb levels in the blood.

Setting

A rural district in Western Uganda.

Subjects

Children aged 6–59 months and their mothers aged 15–49 years.

Results

The overall prevalence of Fe-deficiency anaemia among children and their mothers was 26·2 % and 17·9 %, respectively. There was a significant correlation (r= 0·5,P= 0·008) between the Hb levels of the mothers and their children. Place of birth, age of the child, factors related to complementary foods, and formal education and nutrition knowledge of the mother were major factors that were significantly associated (r= 0·05,P= 0·05) with low Hb levels among the children. The most important factors that were associated with low Hb levels of the mothers were their formal education, nutrition knowledge and health status.

Conclusions

Fe-deficiency anaemia was found to be a major problem in this cohort of children and their mothers. Dietary factors and sociodemographic factors were the major factors associated with high levels of anaemia among the children and their mothers. It is therefore recommended that rural mothers should be sensitized on best practices for prevention of anaemia among both women and children.
Increasing dissimilarity of water chemical compositions in a warmer climate
Authors: Weyhenmeyer Gesa A.
Published: April 2009

Understanding variability patterns of biogeochemical conditions in water is a key issue for water management strategies. Here a unique homogeneous data set of 1041 Swedish boreal lakes, sampled during three lake inventories along an 8° latitudinal temperature gradient, revealed a systematic increase in the variability of the water chemical composition between lakes with increasing temperatures. The variability pattern was consistent on a spatial and temporal scale and became especially apparent for water chemical variables showing an in‐lake biological process–driven seasonality, such as nitrogen, pH, silica, and organic carbon. The degree of dissimilarity in the chemical composition between lakes was well related to the duration of the main growing and runoff season (DT>0), both on a spatial scale (R2 = 0.57–0.79, P < 0.05) and a temporal scale (R2 = 0.99, P < 0.05). It is suggested that DT>0 is a very suitable proxy to explain biogeochemical variability patterns between lakes. According to this study, a further temperature increase will result in an increased biogeochemical dissimilarity between lakes.
Spatial variations of the effective elastic thickness, Te, using multitaper spectral estimation and wavelet methods: Examples from synthetic data and application to South America
Authors: Pérez‐Gussinyé M. , Swain C. J. , Kirby J. F. , Lowry A. R.
Published: April 2009

Improved recovery of the spatial variability in the effective elastic thickness, Te, of the lithosphere is important to interpret Earth's structure and geodynamics. Here we use synthetic topography and gravity data to systematically compare the recovery of Te using the multitaper windowing scheme of Pérez‐Gussinyé et al. (2004, 2007) with the wavelet approach of Kirby and Swain (2008). We find that spuriously high Te estimates previously present in synthetic tests with the multitaper are artifacts arising from Fourier transform edge effects introduced by splitting the data into land and ocean areas prior to load deconvolution. Hence, we adopt the mixed land‐ocean loading scheme of Kirby and Swain (2008). Using this approach we find that underestimation of Te when the transitional wavelength approaches the window size is largely related to the limited size of the analysis window and not to random correlations of initial loading surfaces as occurs in the wavelet method. To attenuate this bias we apply a correction factor to our resulting multitapered Te and find that this technique more accurately recovers steep Te gradients and small‐scale Te anomalies than the wavelet method. Finally, we recalculate Te of South America using the multitaper and the mixed land‐ocean approach. The new Te distribution is very similar to that of Pérez‐Gussinyé et al. (2007, 2008), suggesting that Fourier transform edge effects are less severe in the real Earth than in synthetic data. This difference arises because coastlines are much less rough in the real Earth than in our synthetic data. On the basis of the synthetic results, we interpret that most of the small‐scale features present in the multitaper but not in wavelet Te estimates of South America presented by Tassara et al. (2007) are real. These include high Te over the Andean flat subduction zones and low Te along the dyke swarms of the Paraná flood basalts, the Tacutu graben, and Amazonian basin.
Horizontal shortening versus vertical loading in accretionary prisms
Authors: Raimbourg Hugues , Tadahiro Shibata , Asuka Yamaguchi , Haruka Yamaguchi , Kimura Gaku
Published: April 2009

The analysis of two‐phased deformation of subducted turbidites within the Shimanto Belt on Kyushu (Japan) shows strongly contrasted kinematics between an earlier, noncoxial “fold‐and‐thrust”‐type stage and a later, metamorphic, coaxial vertical shortening stage. The deep deformation is characterized by the development of a subhorizontal muscovite‐chlorite metamorphic foliation, associated with pure shear deformation, which overprinted the structures inherited from the earlier stage. We associate the metamorphic deformation stage with the lower levels of accretionary prism landward segment (inner wedge), which was therefore deformed by vertical loading and horizontal extension, much in contrast with prism trenchward segment (outer wedge), which often shows fold‐and‐thrust structures indicative of horizontal shortening. A possible explanation, based on Wang and Hu's (2006) model, for these longitudinal variations in deformation kinematics of the prism may lie in the contrasted rheology of its basal surface, strain weakening in the seismic portion below the inner wedge while strain strengthening in the aseismic portion below the outer wedge. The vertical shortening active within the inner wedge revealed by this study possibly represents a large contribution to the exhumation of the deeper levels of accretionary prisms.
Rupture imaging of the Mw 7.9 12 May 2008 Wenchuan earthquake from back projection of teleseismic P waves
Authors: Xu Yan , Koper Keith D. , Sufri Oner , Zhu Lupei , Hutko Alexander R.
Published: April 2009

The Mw 7.9 Wenchuan earthquake of 12 May 2008 was the most destructive Chinese earthquake since the 1976 Tangshan event. Tens of thousands of people were killed, hundreds of thousands were injured, and millions were left homeless. Here we infer the detailed rupture process of the Wenchuan earthquake by back‐projecting teleseismic P energy from several arrays of seismometers. This technique has only recently become feasible and is potentially faster than traditional finite‐fault inversion of teleseismic body waves; therefore, it may reduce the notification time to emergency response agencies. Using the IRIS DMC, we collected 255 vertical component broadband P waves at 30–95° from the epicenter. We found that at periods of 5 s and greater, nearly all of these P waves were coherent enough to be used in a global array. We applied a simple down‐sampling heuristic to define a global subarray of 70 stations that reduced the asymmetry and sidelobes of the array response function (ARF). We also considered three regional subarrays of seismometers in Alaska, Australia, and Europe that had apertures less than 30° and P waves that were coherent to periods as short as 1 s. Individual ARFs for these subarrays were skewed toward the subarrays; however, the linear sum of the regional subarray beams at 1 s produced a symmetric ARF, similar to that of the groomed global subarray at 5 s. For both configurations we obtained the same rupture direction, rupture length, and rupture time. We found that the Wenchuan earthquake had three distinct pulses of high beam power at 0, 23, and 57 s after the origin time, with the pulse at 23 s being highest, and that it ruptured unilaterally to the northeast for about 300 km and 110 s, with an average speed of 2.8 km/s. It is possible that similar results can be determined for future large dip‐slip earthquakes within 20–30 min of the origin time using relatively sparse global networks of seismometers such as those the USGS uses to locate earthquakes in near–real time.
Rocket‐based measurements of ion velocity, neutral wind, and electric field in the collisional transition region of the auroral ionosphere
Authors: Sangalli L. , Knudsen D. J. , Larsen M. F. , Zhan T. , Pfaff R. F. , Rowland D.
Published: April 2009

The JOULE‐II sounding rocket salvo was launched from Poker Flat Rocket Range into weak pulsating aurora following a moderate substorm at 0345 LT on 19 January 2007. We present in situ measurements of ion flow velocity and electric and magnetic fields combined with neutral wind observations derived from ground observations of in situ chemical tracers. Measured ion drifts in the 150–198 km and 92–105 km altitude ranges are consistent with × motion to within 16 m s−1 rms and with neutral wind velocity to within 20 m s−1, respectively. From these measurements we have calculated the ratio κ of the ion cyclotron and ion collision frequencies, finding κ = 1 at an altitude of 118 ± 0.3 km. Using direct measurements of ion current, we calculate the Joule heating rate and Pedersen and Hall conductivity profiles for this moderately active event and find height‐integrated values of 390 W km−2 and 0.59 and 2.22 S, respectively. We also find that these values would have errors of up to tens of percent without coincident neutral wind measurements, and presumably more so during more active conditions. Ion flow vectors were measured at a rate of 125 s−1; however, no significant fluctuations were observed at spatial/temporal scales below ∼350 m and 0.5 s. Observational limits were 5.5 m and 0.016 s.