bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy Balance, Obesity and Type‐2 Diabetes
Authors: Daniel Lane M
Published: March 2009

Energy balance is determined by caloric intake versus caloric expenditure. Complex control systems promote energy storage (primarily as adipose tissue fat) during periods of food surplus and mobilization of energy stores when food is scarce. These regulatory systems operate both locally within cells and between different body tissues and are mediated by circulating hormones and direct neural connection from the central nervous system to peripheral tissues. In modern society where lifestyles have shifted towards the excessive consumption of palatable ‘high energy’ foods and a sedentary life, these control mechanisms can be circumvented and in so doing lead to obesity and its pathological consequences. Prominent among these consequences are insulin resistance, i.e. the inability of cells to respond normally to insulin, and Type‐2 diabetes. Approximately 30% of the inhabitants of the United States meet the criteria for obesity.

Key concepts

Animals possess complex control systems with which to regulate energy storage and expenditure.

The concept of energy balance.

How is blood glucose level regulated?

How do changes in blood glucose level alter the secretion of hormones that regulate energy metabolism?

What are the major physiological fuels that provide energy for different cell types and how do changes in hormone level affect fuel production and utilization?

Nature of interplay between tissues/organs through the production and utilization of circulating physiological fuels.

What is insulin resistance and what are its consequences?

What constitutes the obese state and how does obesity lead to insulin resistance and Type‐2 diabetes?

how adipocytes develop from stem cells and the consequences of adipocyte hyperplasia.

How does persistent obesity lead to failure of the insulin‐secreting pancreatic β‐cell and the diabetic state?
Neuroeconomics
Authors: Hart Andrew S , Walton Mark E , Phillips Paul EM
Published: March 2009

Neuroeconomics is an emergent multidisciplinary field that strives to understand how and why humans make decisions. It brings together behavioural methods and sophisticated computational theories from microeconomics, an understanding of emotional influences on behaviour from psychology, and human functional neural imaging and electrophysiological recordings in animal models from neuroscience. Moreover, the neuroscientific contribution to this field is now beginning to incorporate molecular, pharmacological and physical interference techniques which can test the causal relationship between neural function and behaviour. Research in neuroeconomics has uncovered potential representations of value and costs within the brain. Studies of decision‐making in social environments have also revealed key emotional components of decision‐making that may help to explain some deviations from optimal or rational decision‐making in humans. Although it still has many challenges to overcome, neuroeconomics stands poised to benefit both microeconomic theory and neuroscience through shared techniques and ideas.

Key concepts

Psychology, neuroscience and economics existed as parallel fields, with the goal of understanding decision‐making behaviour.

Neuroeconomics is an emergent field that uses brain‐imaging techniques and animal models from cognitive neuroscience and computational models and behavioural experiments from economics.

A major goal of neuroeconomics is to determine how value is represented within the brain and how this representation is used towards decision‐making.

Animal studies involving primary rewards, such as food and water have given the first clues as to the representation of value within the brain, and human studies of primary and monetary rewards have made similar findings.

A second goal of neuroeconomics is to determine how costs, such as monetary payments, effort and delays in reward, are represented within the brain.

A subfield of neuroeconomics is devoted to the study of social decision‐making and incorporates concepts from game theory.

There may be multiple neural systems that dictate rational versus emotion‐based decisions, but more evidence is needed.

Neuroeconomics can be applied to the study of psychiatric disorders and addiction, in which the brain's mechanisms for representing value are disrupted.
Coffin–Lowry Syndrome
Authors: Hanauer André
Published: March 2009

The Coffin–Lowry syndrome (CLS) is a rare but well‐defined X‐linked semidominant syndrome. Cardinal features include severe mental retardation, a characteristic facial appearance, digital tapering, short stature and progressive spinal deformity. However, the clinical presentation may be markedly variable both in severity and in the expression of uncommonly associated features. In addition, a few atypical cases of the disease have been reported. Highly heterogeneous loss of function mutations in the

RPS6KA3

gene encoding the
protein kinase RSK2
are responsible for CLS. About two‐thirds of the mutations arise

de novo

.

RSK2 is a member of the
ribosomal S6 serine/threonine kinase
family, which plays a key role in the Ras‐ERK signalling pathway. RSKs are activated by phosphorylation in response to growth factors and neurotransmitters.
RSK2
substrates include transcription factors, in accordance with a major role in regulation of gene expression.
RSK2
is involved in proliferation, apoptosis and in learning and memory processes.

Key concepts

Coffin–Lowry syndrome is an X‐linked semidominant syndrome characterized typically by severe psychomotor and growth retardation, facial dysmorphism, digit abnormalities and progressive skeletal deformations.

The estimated incidence is 1 50 000–1 100 000 and approximately 70–80% of patients are sporadic cases.

There is no specific treatment.

Highly heterogeneous loss‐of‐function mutations in the
RPS6KA3
gene, encoding RSK2, are responsible for Coffin–Lowry syndrome.

Two‐thirds of cases arise from new mutations.

There is no consistent phenotype/genotype correlation.

RSK2 is a serine/threonine kinase that acts at the distal end of the Ras‐ERK pathway and is activated by phosphorylation in response to growth factors and neurotransmitters.

Mice models for CLS have been generated that exhibit delayed bone formation as well as learning and memory deficits.
Noncoding
RNAs
in Biology and Disease
Authors: Szymański Maciej , Barciszewski Jan
Published: March 2009

Regulatory noncoding
ribonucleic acids
(ncRNAs) play a pivotal role in the control of gene expression in all organisms. The molecular processes controlled by ncRNAs include virtually all steps of transmission of genetic information from
deoxyribonucleic acid
(DNA) to protein. They affect the structure of chromatin, activity of transcription factors, posttranscriptional modifications and the stabilty of RNA. In mammals, noncoding transcripts have been linked to regulation of many cellular mechanisms and their proper expression is crucial for normal development, growth differentiation and the maintenance of cells identity. Epigenetic and genetic aberrations disrupting ncRNA genes or changing their expression profiles often result in pathologies including developmental defects, neurobehavioural illness, cancer and other diseases. The progress in identification of novel RNA‐dependent molecular mechanisms and their medical implications makes ncRNAs attractive targets for development of new diagnostic and therapeutic approaches.

Key Concepts

Noncoding RNAs (ncRNAs) constitute a significant fraction of a total transcription from the human genome.

NcRNAs are key factors in setting up and maintaining epigenetic marks that are crucial for correct expression of genetic information.

NcRNAs regulate expression of genes by influencing the activity of transcriptional machinery.

The stability and translation of numerous mRNAs involved in cells growth and proliferation is controlled by microRNAs.

Correct expression of imprinted gene clusters depends on chromatin modifications guided by ncRNAs.

Aberrant expression of ncRNAs is often associated with human diseases.

Expression profiles of ncRNAs provide valuable information for molecular diagnostics.
Fragile Sites and Human Disease
Authors: Frank Kooy R
Published: March 2009

Fragile sites are the cytogenetic manifestation of a peculiar genome structure. Two fundamentally different types occur: rare fragile sites that are characterized by repeat expansion and common fragile sites that consist of AT (adenine/thymidine)‐rich regions which may stretch over megabases and that are prone to chromosomal rearrangements. In contrast to common fragile sites that are presumably present in all individuals, rare fragile sites are found in maximally 5% of the population. A relationship between the rare fragile site at Xq27.3 and fragile X syndrome, the most common form of inherited mental retardation has been well established. In addition, causative genomic rearrangements within the two most frequently observed common fragile sites in specific tumours were demonstrated. Currently, more than 100 different fragile sites have been described and a potential role for additional fragile sites in human disease, including mental retardation, neurodegeneration, cancer and chromosome truncation syndromes, is emerging.

Key concepts

Fragile sites are the cytogenetic expression of a peculiar genome architecture.

Rare fragile sites are caused by repeat expansion.

Common fragile sites consist of large genomic AT‐rich ‘flexible’ regions, without repeat expansion.

Rare fragile sites may be associated with mental retardation and neurodegeneration.

Common fragile sites are associated with chromosomal rearrangements in tumour cells.

Fragile sites may be involved in chromosome breakage.
Molecular Genetics of Hereditary Vascular Malformations
Authors: Aerts Virginie , Boon Laurence M , Vikkula Miikka
Published: March 2009

Vascular anomalies are divided into vascular tumours (mainly infantile haemangiomas) and vascular malformations. Vascular malformations are subdivided following the type of vessel affected: venous, capillary, arteriovenous and lymphatic. In addition to the pure forms, combined lesions are frequently encountered. Most of these malformations are sporadic, i.e. there is no family history, but familial cases, transmitted as an autosomal dominant or recessive trait, exist. During the last 10 years, the identification of disease‐causing genes implicated in the
familial
forms have resulted in a better classification of vascular anomalies, which has helped in assessment of treatment efficacy. These data have also unravelled the physiological role of the identified proteins during human vascular development.

Key concepts

Classification of vascular tumours and vascular malformations.

Vascular malformations are developmental anomalies.

Vascular malformations are classified depending on the affected vessels to capillary, venous, arterial, lymphatic or combined.

Sporadic and familial forms exist. Familial cases are often transmitted as an autosomal dominant disorder.

Several causative genes have been identified.
Molecular Genetics of Inherited Disorders of Epidermal Keratins
Authors: Sprecher Eli
Published: March 2009

Keratins
are a major constituent of the epidermal cell cytoskeleton. Apart from their contribution to cell ability to resist mechanical stress, they have been shown to regulate additional biological processes of importance such as protein synthesis, cell migration and apoptosis. Much of this knowledge has been gained through the study of rare disorders, known as keratinopathies, which are caused by mutations in genes encoding the various epidermal
keratins
. Recently, novel therapeutic approaches for
keratin
disorders have been tested successfully, thus raising new hopes for the treatment of this group of inherited skin diseases.

Key concepts

Keratins
are major constituent of epithelial cell cytoskeleton and confer to the cell the ability to resist mechanical stress.

Keratins
play additional nonstructural role such regulation of cell growth, protein synthesis, cell migration and apoptosis.

Keratin
disorders manifest with clinical and pathological features that reflect the site of expression of the mutant keratins and the specific function of the keratin domain affected by the causative mutation.

Keratin disorders are characterized by genetic heterogeneity, namely a single clinical phenotype can result from mutations in different (but sometimes functionally related) genes (e.g. epidermolysis bullosa caused by mutations in at least five genes).

Keratin disorders are characterized by phenotypic heterogeneity, namely mutations in the very same gene can give rise to multiple distinct phenotypes (e.g. mutations in
KRT1
can cause at least four distinct diseases).

Keratin mutations exert a dominant negative effect; hence current approaches are aimed at eliminating the mutant proteins from the skin. Based on this concept, a first clinical trial in humans has recently been launched to test the effect of a siRNA to treat pachyonychia congenita.
Molecular Genetics of Dyslexia
Authors: Paracchini Silvia
Published: March 2009

Dyslexia is a specific impairment in learning to read which affects 5–10% of school‐age children. Family and twin studies have shown that dyslexia is caused in large part by genetic factors. Dyslexia is most likely the result of the interplay of multiple genetic and environmental factors. Recently, several genes have been proposed as candidates for dyslexia susceptibility, including

DYX1C1

on chromosome 15,

KIAA0319

and

DCDC2

on chromosome 6,

ROBO1

on chromosome 3 and

MRPL19

and

C2ORF3

on chromosome 2. Interestingly, these genes share a putative role in brain development. No functional genetic variant has been identified for any of the genes but the study of their function offers for the first time new insights in the understanding of the biology of dyslexia and the mechanisms underlying cognition and brain function.

Key concepts

Several genes have recently been proposed as candidates for dyslexia susceptibility.

Most of these genes have shown association in independent samples of individuals with dyslexia.

A specific risk haplotype has been identified for the
KIAA0319
gene.

Most of the candidates have been implicated in brain development.

No functional mutations have been identified for any of the genes.

Gene expression has been proposed as the main mechanism linking genetic susceptibility to the development of dyslexia
Molecular Genetics of Chronic Pancreatitis
Authors: Szmola Richard , Whitcomb David C
Published: March 2009

Chronic pancreatitis is a progressive inflammatory condition of the pancreas that results in impairment of both exocrine and endocrine functions of the gland. The finding that a mutation in the cationic trypsinogen gene (

PRSS1

) causes hereditary pancreatitis was a major breakthrough that stimulated intensive research into the genetics of chronic pancreatitis. Further disease‐causing mutations were identified in the

PRSS1

gene, and mutations in novel genes (

SPINK1

,

CFTR

,

CTRC

,

CASR

) have been described in patients with idiopathic chronic pancreatitis. Genetic and biochemical studies highlighted the importance of the tightly regulated balance between trypsin activation and inactivation in the pathogenesis of pancreatitis.
Molecular Genetics of Crohn Disease
Authors: Yamamoto‐Furusho Jesús K
Published: March 2009

Genetic factors play a significant role in determining inflammatory bowel disease (IBD) susceptibility. Epidemiologic data support genetic contribution to the pathogenesis of IBD, which include familial aggregation, twin studies, racial and ethnic differences in disease prevalence. Genome‐wide linkage studies pointed towards more than 10 chromosomal regions and fine‐mapping of these regions led to the identification of a number of genes, including
CARD15
(
NOD2
, nucleotide oligomerization domain 2),

Drosophila

long disc homologue 5 gene (
DLG5
),
OCTN1
and 2,
TLR4
and
CARD4
(
NOD1
). New genes have identified such as
IL23R
, immunity‐related GTPase family M (
IRGM
), prostaglandin receptors E‐serie 4 (
PTGER4
) and
ATG16L1
for Crohn disease and ulcerative colitis. Genetic factors may influence in the clinical course of IBD patients and their likelihood of responding to certain therapies. Great progress in the understanding of the molecular genetics of IBD has been made over the last 10 years and newer genes are discovering to understand the IBD pathophysiology and to have implications for clinical practice.

Key concepts

Genetic factors play a significant role in determining inflammatory bowel disease susceptibility.

Characterization of the IBD1 locus on chromosome 16 led to the discovery of the NOD2/CARD15 gene as the first susceptibility gene in Crohn disease.

Genome‐wide linkage studies pointed towards more than 10 chromosomal regions.

Genetic factors may influence in the clinical course of IBD patients and their likelihood of responding to certain therapies.
A Review of the Epidemiology and the Mechanisms Underlying
KSHV
‐induced Malignancies
Authors: Alkharsah Khaled R , Schulz Thomas F , Weidner‐Glunde Magdalena M
Published: March 2009

Kaposi's sarcoma herpesvirus
(KSHV), also called
human herpesvirus‐8
(HHV‐8), is believed to be the infectious causative agent of Kaposi's sarcoma and two other rare acquired immune deficiency syndrome (AIDS)‐associated neoplastic diseases. KSHV is relatively frequent in some countries of the Mediterranean area, and quite common in sub‐Saharan and South Africa, but rare in most other parts of the world. The virus is transmitted through sexual contact among adults. However, in endemic countries, the mode of transmission is most probably via behavioural practices using saliva from mother to child and between siblings. KSHV persists in infected cells in a latent episomal form expressing only a small number of genes to escape immune surveillance. These genes play a significant role in viral persistence and development of malignancy. A small number of KSHV‐infected cells undergo spontaneous lytic reactivation to ensure the production of new virions and provide inflammatory cytokines that participate in development of cancer.

Key concepts:

KSHV is a γ2‐herpesvirus (Rhadinovirus) that causes Kaposi sarcoma, Primary effusion lymphoma and Multicentric Castleman's disease mainly in immunocompromised individuals, e.g. AIDS patients.

Similarly to the other herpesviruses KSHV has two phases of replication, latent and lytic.

In malignancies, the virus is detected mainly in latent state, where only few proteins are expressed.

Small number of infected cells undergo spontaneous lytic reactivation producing both, new virions for infecting new cells and inflammatory cytokines, which contribute to tumourigenesis through a paracrine mechanism.

KSHV expresses several genes that play a role in inhibition of apoptosis (vFLIP, vBCL2), progression of cell cycle (vCYC, LANA), stimulation of cytokine production and angiogenesis (vGPCR, vFLIP, vIL‐6, K15).

The prevalence of KSHV is low in most parts of the world, but higher in Mediterranean area and highest in Africa.

KSHV‐induced malignancies are rare even in areas with high KSHV prevalence.

KSHV is transmitted mainly by sexual contact among adults and via behavioural practices using saliva from mother to child and between siblings in endemic countries.
Retroviral Pseudotypes
Authors: Temperton Nigel J , Wright Edward
Published: March 2009

Retroviral pseudotypes are a main research and diagnostic tool of basic and clinical scientists facilitating the detailed study of individual viral genes, receptors and highly pathogenic viruses, without the need to handle live virus. Their use as gene therapy vectors is widely documented, but their other uses are less well known. The switching of envelope proteins expressed on the surface enables them to be used as surrogate viruses in neutralization/antiviral assays and for the study of cell–virus receptor interactions. However, they have recently been used as vaccine immunogens, expressing the antigen either on the pseudotype surface or as the transfer gene for stable or transient expression. Only now is their full potential being realized.

Key concepts

Students will learn:

What are retroviral pseudotypes.

How they are constructed.

The common elements that comprise a retroviral pseudotype.

How retroviral pseudotypes can be used to deliver genes.

How they can be used as tools for the study of viral attachment, entry and receptor identification.

About using pseudotypes as surrogate viruses in neutralization assays.

The use of pseudotypes to study antiviral potency and resistance.

How pseudotypes can be used as experimental vaccines.
Delay‐dependent H∞ control of linear discrete‐time systems with time‐varying delay via switched system approach
Authors: Hu Ke , Yuan Jingqi
Published: March 2009

This paper deals with the problem of H∞ control of linear discrete‐time systems with time‐varying delay. In order to highlight the relations between all combinations of delayed states, a general Lyapunov–Krasovskii functional is introduced, from which the relation between the switched system transformation and the classical Lyapunov–Krasovskii method is established. The basic idea is to formulate the original time‐delay systems as switched systems with arbitrary switching. Therefore, the stability and the H∞ performance problems can be reduced to the corresponding problems of such switched systems. This fact bridges two distinct research fields. Finally, numerical examples are given to illustrate the effectiveness of the method and its advantage over existing results. Copyright © 2009 John Wiley & Sons, Ltd.
Sliding mode control for a class of uncertain nonlinear system based on disturbance observer
Authors: Chen Mou , Chen Wen‐Hua
Published: March 2009

In this paper, a sliding mode control (SMC) scheme is proposed for a class of nonlinear systems based on disturbance observers. For a nonlinear system, the disturbance that cannot be directly measured is estimated using a nonlinear disturbance observer. By choosing an appropriate nonlinear gain function, the disturbance observer can well approximate the unknown disturbance. Based on the output of the disturbance observer, an SMC scheme is presented for the nonlinear system, and the stability of the closed‐loop system is established using Lyapunov method. Finally, two simulation examples are presented to illustrate the features and the effectiveness of the proposed disturbance‐observer‐based SMC scheme. Copyright © 2009 John Wiley & Sons, Ltd.
Adaptive neural network output feedback stabilization of nonlinear non‐minimum phase systems
Authors: Hoseini S. M. , Farrokhi M. , Koshkouei A. J.
Published: March 2009

This paper presents an adaptive output feedback stabilization method based on neural networks (NNs) for nonlinear non‐minimum phase systems. The proposed controller comprises a linear, a neuro‐adaptive, and an adaptive robustifying parts. The NN is designed to approximate the matched uncertainties of the system. The inputs of the NN are the tapped delays of the system input–output signals. In addition, an appropriate reference signal is proposed to compensate the unmatched uncertainties inherent in the internal system dynamics. The adaptation laws for the NN weights and adaptive gains are obtained using Lyapunov's direct method. These adaptation laws employ a linear observer of system dynamics that is realizable. The ultimate boundedness of the error signals are analytically shown using Lyapunov's method. The effectiveness of the proposed scheme is shown by applying to a translation oscillator rotational actuator model. Copyright © 2009 John Wiley & Sons, Ltd.
Identification of the inertia matrix of a rotating body based on errors‐in‐variables models
Authors: Jun Byung‐Eul , Bernstein Dennis S. , McClamroch N. Harris
Published: March 2009

This paper proposes a procedure for identifying the inertia matrix of a rotating body. The procedure based on Euler's equation governing rotational motion assumes errors‐in‐variables models in which all measurements, torque as well as angular velocities, are corrupted by noises. In order for consistent estimation, we introduce an extended linear regression model by augmenting the regressors with constants and the parameters with noise‐contributed terms. A transformation, based on low‐pass filtering, of the extended model cancels out angular acceleration terms in the regressors. Applying the method of least correlation to the model identifies the elements of the inertia matrix. Analysis shows that the estimates converge to the true parameters as the number of samples increases to infinity. Monte Carlo simulations demonstrate the performance of the algorithm and support the analytical consistency. Copyright © 2009 John Wiley & Sons, Ltd.
Reversible and High‐Capacity Nanostructured Electrode Materials for Li‐Ion Batteries
Authors: Kim Min Gyu , Cho Jaephil
Published: March 2009

Reversible nanostructured electrode materials are at the center of research relating to rechargeable lithium batteries, which require high power, high capacity, and high safety. The higher capacities and higher rate capabilities for the nanostructured electrode materials than for the bulk counterparts can be attributed to the higher surface area, which reduces the overpotential and allows faster reaction kinetics at the electrode surface. These electrochemical enhancements can lead to versatile potential applications of the batteries and can provide breakthroughs for the currently limited power suppliers of mobile electronics. This Feature Article describes recent research advances on nanostructured cathode and anode materials, such as metals, metal oxides, metal phosphides and LiCoO2, LiNi1–xMxO2 with zero‐, one‐, two‐, and three‐dimensional morphologies.
Soluble endoglin modulates aberrant cerebral vascular remodeling
Authors: Chen Yongmei , Hao Qi , Kim Helen , Su Hua , Letarte Michelle , Karumanchi S. Ananth , Lawton Michael T. , Barbaro Nicholas M. , Yang Guo‐Yuan , Young William L.
Published: March 2009

Objective

Brain arteriovenous malformations (AVMs) are an important cause of neurological morbidity in young adults. The pathophysiology of these lesions is poorly understood. A soluble form of endoglin (sEng) has been shown to cause endothelial dysfunction and induce preeclampsia. We tested if sEng would be elevated in brain AVM tissues relative to epilepsy brain tissues, and also investigated whether sEng overexpression via gene transfer in the mouse brain would induce vascular dysplasia and associated changes in downstream signaling pathways.

Methods

Expression levels of sEng in surgical specimens were determined by Western blot assay and enzyme‐linked immunosorbent assay. Vascular dysplasia, levels of matrix metalloproteinase (MMP), and oxidative stress were determined by immunohistochemistry and gelatin zymography.

Results

Brain AVMs (n = 33) had higher mean sEng levels (245 ± 175 vs 100 ± 60, % of control, p = 0.04) compared with controls (n = 8), as determined by Western blot. In contrast, membrane‐bound Eng was not significantly different (108 ± 79 vs 100 ± 63, % of control, p = 0.95). sEng gene transduction in the mouse brain induced abnormal vascular structures. It also increased MMP activity by 490 ± 30% (MMP‐9) and 220 ± 30% (MMP‐2), and oxidants by 260 ± 20% (4‐hydroxy‐2‐nonenal) at 2 weeks after injection, suggesting that MMPs and oxidative radicals may mediate sEng‐induced pathological vascular remodeling.

Interpretation

The results suggest that elevated sEng may play a role in the generation of sporadic brain AVMs. Our findings may provide new targets for therapeutic intervention for patients with brain AVMs. Ann Neurol 2009;66:19–27
Inhibitory actions of the gamma‐aminobutyric acid in pediatric Sturge‐Weber syndrome
Authors: Tyzio Roman , Khalilov Ilgam , Represa Alfonso , Crepel Valerie , Zilberter Yuri , Rheims Sylvain , Aniksztejn Laurent , Cossart Rosa , Nardou Romain , Mukhtarov Marat , Minlebaev Marat , Epsztein Jérôme , Milh Mathieu , Becq Helene , Jorquera Isabel , Bulteau Christine , Fohlen Martine , Oliver Viviana , Dulac Olivier , Dorfmüller Georg , Delalande Olivier , Ben‐Ari Yehezkel , Khazipov Roustem
Published: March 2009

Objective

The mechanisms of epileptogenesis in Sturge‐Weber syndrome (SWS) are unknown. We explored the properties of neurons from human pediatric SWS cortex in vitro and tested in particular whether gamma‐aminobutyric acid (GABA) excites neurons in SWS cortex, as has been suggested for various types of epilepsies.

Methods

Patch‐clamp and field potential recordings and dynamic biphoton imaging were used to analyze cortical tissue samples obtained from four 6‐ to 14‐month‐old pediatric SWS patients during surgery.

Results

Neurons in SWS cortex were characterized by a relatively depolarized resting membrane potential, as was estimated from cell‐attached recordings of N‐methyl‐D‐aspartate channels. Many cells spontaneously fired action potentials at a rate proportional to the level of neuronal depolarization. The reversal potential for GABA‐activated currents, assessed by cell‐attached single channel recordings, was close to the resting membrane potential. All spontaneously firing neurons recorded in cell‐attached mode or imaged with biphoton microscopy were inhibited by GABA. Spontaneous epileptiform activity in the form of recurrent population bursts was suppressed by glutamate receptor antagonists, the GABA(A) receptor agonist isoguvacine, and the positive allosteric GABA(A) modulator diazepam. Blockade of GABA(A) receptors aggravated spontaneous epileptiform activity. The NKCC1 antagonist bumetanide had little effect on epileptiform activity.

Interpretation

SWS cortical neurons have a relatively depolarized resting membrane potential and spontaneously fire action potentials that may contribute to increased network excitability. In contrast to previous data depicting excitatory and proconvulsive actions of GABA in certain pediatric and adult epilepsies, GABA plays mainly an inhibitory and anticonvulsive role in SWS pediatric cortex. Ann Neurol 2009;66:209–218
Effect of chorioamnionitis on brain development and injury in premature newborns
Authors: Chau Vann , Poskitt Kenneth J. , McFadden Deborah E. , Bowen‐Roberts Tim , Synnes Anne , Brant Rollin , Sargent Michael A. , Soulikias Wendy , Miller Steven P.
Published: March 2009

Objective

The association of chorioamnionitis and noncystic white matter injury, a common brain injury in premature newborns, remains controversial. Our objectives were to determine the association of chorioamnionitis and postnatal risk factors with white matter injury, and the effects of chorioamnionitis on early brain development, using advanced magnetic resonance imaging.

Methods

Ninety‐two preterm newborns (24–32 weeks gestation) were studied at a median age of 31.9 weeks and again at 40.3 weeks gestation. Histopathological chorioamnionitis and white matter injury were scored using validated systems. Measures of brain metabolism (N‐acetylaspartate/choline and lactate/choline) on magnetic resonance spectroscopy, and microstructure (average diffusivity and fractional anisotropy) on diffusion tensor imaging were calculated from predefined brain regions.

Results

Thirty‐one (34%) newborns were exposed to histopathological chorioamnionitis, and 26 (28%) had white matter injury. Histopathological chorioamnionitis was not associated with an increased risk of white matter injury (relative risk: 1.2; p = 0.6). Newborns with postnatal infections and hypotension requiring therapy were at higher risk of white matter injury (p < 0.03). Adjusting for gestational age at scan and regions of interest, histopathological chorioamnionitis did not significantly affect brain metabolic and microstructural development (p > 0.1). In contrast, white matter injury was associated with lower N‐acetylaspartate/choline (−8.9%; p = 0.009) and lower white matter fractional anisotropy (−11.9%; p = 0.01).

Interpretation

Histopathological chorioamnionitis does not appear to be associated with an increased risk of white matter injury on magnetic resonance imaging or with abnormalities of brain development. In contrast, postnatal infections and hypotension are associated with an increased risk of white matter injury in the premature newborn. Ann Neurol 2009;66:155–164
A simulated auto‐thermal membrane reformer process for a PEM fuel cell micro cogeneration unit
Authors: Ersöz Atilla
Published: March 2009

There are several methods of producing hydrogen‐rich gas from fossil resources such as natural gas or naphtha, for example, steam reforming, partial oxidation and auto‐thermal reforming. In this paper, an integrated ATR membrane reactor system was simulated. The effect of operating parameters on the product distribution, fuel cell hydrogen utilization and the net electric efficiency of the overall system were discussed. The overall system was integrated with a 1‐kWe PEM fuel cell. The ASPEN‐HYSIS 3.2 software has been utilized for the simulations and calculations of the fuel processing reactions. Natural gas fuel has been used as feedstock and applied to the simulated flow‐sheet model. It was desired to produce hydrogen‐rich gas with a low CO formation using an autothermal membrane reformer. A very low CO content with higher content of hydrogen was provided by the membrane reformer, eliminating the use of the conventional preferential oxidation (PrOx) reactor. Different combinations of TATR, S/C, O2/C ratios and UH2 have been parametrically studied. Fuel processing efficiency and net electrical efficiency of all selected operating conditions have been calculated as well. Results indicate that the system parameters are very critical for the appropriate operation of the residential cogeneration system with ATR membrane unit. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Membrane bioreactors: overview of the effects of module geometry on mixing energy
Authors: Wang Yuan , Brannock Matthew , Leslie Greg
Published: March 2009

Membranes used in municipal membrane bioreactor (MBR) plants can be configured as flat sheet (FS) membranes or hollow fibre (HF) membranes. The HFs can be mounted either horizontally or vertically. The membranes can be immersed in their own vessel or within the aerobic vessel. These various configurations combine to give a unique reactor design. Current methods of design assume the mixing characteristics (e.g. each reactor vessel is completely mixed); hence the energy necessary to achieve complete mixing cannot be optimised. This paper presents an overview of mixing studies undertaken by the authors' research group on pilot‐ and full‐scale MBRs through residence time distribution (RTD) analysis and computational fluid dynamics (CFD) modelling. The drawbacks of current technique for the sizing of MBRs (e.g. compartmental modelling) are highlighted. The use of CFD as a design tool to evaluate the mixing and energy of MBRs with different configurations (e.g. HF vs FS, inside submerged vs outside submerged) is presented. The MBR CFD model was validated using field‐measured RTD data and compared with compartmental model. Results from mixing studies suggest that HF membranes are more energy efficient in terms of creating completely mixed conditions than the FS membranes. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Transport characteristics of L‐citrulline in renal apical membrane of proximal tubular cells
Authors: Mitsuoka Keisuke , Shirasaka Yoshiyuki , Fukushi Akimasa , Sato Masanobu , Nakamura Toshimichi , Nakanishi Takeo , Tamai Ikumi
Published: March 2009

L‐Citrulline has diagnostic potential for renal function, because its plasma concentration increases with the progression of renal failure. Although L‐citrulline extracted by glomerular filtration in kidney is mostly reabsorbed, the mechanism involved is not clearly understood. The present study was designed to characterize L‐citrulline transport across the apical membranes of renal epithelial tubular cells, using primary‐cultured rat renal proximal tubular cells, as well as the human kidney proximal tubular cell line HK‐2. L‐Citrulline was transported in a Na+‐dependent manner from the apical side of both cell types cultured on permeable supports with a microporous membrane. Kinetic analysis indicated that the transport involves two distinct Na+‐dependent saturable systems and one Na+‐independent saturable system in HK‐2 cells. The uptake was competitively inhibited by neutral and cationic, but not anionic amino acids. Relatively large cationic and anionic compounds inhibited the uptake, but smaller ones did not. In HK‐2 cells, mRNA expression of SLC6A19 and SLC7A9, which encode B0AT1 and b0,+AT, respectively, was detected by RT‐PCR. In addition, L‐citrulline transport was significantly decreased in HK‐2 cells in which either SLC6A19 or SLC7A9 was silenced. Hence, these results suggest that amino acid transporters B0AT1 and b0,+AT are involved in the reabsorption of L‐citrulline in the kidney, at least in part, by mediating the apical membrane transport of L‐citrulline in renal tubule cells. Copyright © 2009 John Wiley & Sons, Ltd.
Boundaries of Britishness in British Indian and Pakistani young adults
Authors: Vadher Kiren , Barrett Martyn
Published: March 2009

This study explored what it means to be British from the perspective of young British Indian and Pakistani adults. Fifteen respondents were interviewed using a semi‐structured schedule in order to explore their self‐descriptions and self‐categorizations, how different contexts influence their identifications as British and as Indian/Pakistani, their sense of patriotism, and their perceptions of racism, discrimination and multiculturalism. Grounded theory methodology was used to analyse the interviews. The respondents' identifications and the role of context, threat and racism were studied in detail, and a model of how these individuals defined the boundaries of Britishness, and how they positioned themselves in relationship to these boundaries, was derived from the data. Six boundaries of Britishness were identified, these being the racial, civic/state, instrumental, historical, lifestyle and multicultural boundaries. Participants used these boundaries flexibly, drawing on different boundaries depending on the particular context in which Britishness was discussed. The implications of these multiple boundaries for the conceptualization of national identification are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Environmental representations of local communities' spokespersons in protected areas
Authors: Hovardas Tasos , Korfiatis Konstantinos J. , Pantis John D.
Published: March 2009

Despite the popularization of the environmental discourse, rural environmental belief‐systems should not be viewed as homogenous. Focusing on the largest protected area in Greece, we examined heterogeneity in local environmental views. Local spokespersons elicited word associations to two stimulus terms, namely, ‘environmentalists’ and ‘protected area’. Based on association categories for both terms, we identified two sample segments. ‘Naturalists’ appealed to a naturalistic image, which shaped the core compartment of their representations. On the other hand, ‘skeptics’ provided both environmentalist claims and critical accounts. Our findings revealed that the environmental discourse was widely diffused among local spokespersons. Issues of power and participation in decision‐making processes within protected areas are discussed. For instance, dimensions of power and legitimacy were reflected in the frequency of association categories and their allocation among sample segments. Specifically, environmentalist accounts were overtly expressed by both ‘naturalists’ and skeptics, while a more socially, politically and critically inclined view was revealed by a small percentage of associations that were all elicited by ‘skeptics’. We conclude that appreciating the heterogeneity of rural environmental views can reinforce the democratic mandate in environmental policy‐making. Copyright © 2009 John Wiley & Sons, Ltd.
Detection of Biologically Important Anions in Aqueous Media by Dicationic Azaborines Bearing Ammonio or Phosphonio Groups
Authors: Agou Tomohiro , Sekine Masaki , Kobayashi Junji , Kawashima Takayuki
Published: March 2009

Not common sense, but specific: Dicationic azaborines bearing ammonio or phosphonio groups showed enhanced Lewis acidity as well as improved water solubility. Complexation between the azaborines and fluoride or cyanide ions was observed in aqueous media (see figure; DMSO= dimethyl sulfoxide).

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New cationic triarylboranes bearing ammonio or phosphonio groups on the periphery were synthesized from a common intermediate, a dibromodibenzoazaborine. These cationic molecules are soluble in highly polar organic solvents as well as water, and they exhibit strong light absorption and photoluminescence emission in water. Complexation of the cationic azaborines with fluoride and cyanide ions in aqueous media proceeded and could be monitored by NMR, UV/Vis, and fluorescence spectroscopy.
On the Reaction of Glycerol Dehydratase with But‐3‐ene‐1,2‐diol
Authors: Sandala Gregory M. , Kovačević Borislav , Barić Danijela , Smith David M. , Radom Leo
Published: March 2009

Intriguing inactivation: Calculations suggest that the ability of relatively high‐energy radical intermediates to inactivate glycerol dehydratase (GDH) may reflect a general and hitherto unidentified inactivation mechanism in the reaction of coenzyme B12‐dependent enzymes and 3‐unsaturated 1,2‐diols (see scheme; AdoCbl: adenosylcobalamin or coenzyme B12).

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High‐level conventional ab initio and density functional theory (DFT) calculations have been performed to examine the fate of the native substrate glycerol (1) and its analogue but‐3‐ene‐1,2‐diol (7) in the coenzyme B12‐dependent enzyme glycerol dehydratase (GDH). Experimental studies find that 7 irreversibly inactivates GDH, though the mechanism for the inactivation remains unknown. Interestingly, the EPR data suggest that the spin density for an observed radical is located in the vicinity of the C1 atom, which has been interpreted to indicate termination of the pathway at the substrate‐derived radical 8. Our calculations show that if analogue 7 were to follow a similar mechanistic pathway to that followed by 1, then the reaction would be unlikely to stop at 8 but would rather proceed to the highly stabilized product‐related radical 9. However, the EPR characteristics of 9 would not be consistent with the observed EPR data. Calculations involving an initial H‐atom abstraction from the C2 position of 7 identify alternative radicals that might account for the EPR data, though they are of relatively high energy. A proposal that could explain the experimental observations is that the enzyme binds 7 in such a manner as to prevent the efficient transformation of 8. Recent work with the related enzyme diol dehydratase suggests that a common, but as yet unexplained, inactivation mechanism may be operative for both enzymes. Finally, we note the good overall performance of the MPWB1K, BMK, M05‐2X, and B2‐PLYP DFT procedures for these reactions, with the BMK method producing the best results.
Cobalt‐Catalyzed Formation of Symmetrical Biaryls and Its Mechanism
Authors: Moncomble Aurélien , Le Floch Pascal , Gosmini Corinne
Published: March 2009

Effective devotion: An efficient cobalt‐catalyzed method devoted to the formation of symmetrical biaryls is described avoiding the preparation of organometallic reagents. Various aromatic halides functionalized by a variety of reactive group reagents are employed. Preliminary DFT calculations have shown that the involvement of a CoI/CoIII couple is realistic at least in the case of 1,3‐diazadienes as ligands (FG=functional group).

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ChemInform Abstract: Band Edge Electronic Structure of BiVO4: Elucidating the Role of the Bi s and V d Orbitals.
Authors: Walsh Aron , Yan Yanfa , Huda Muhammad N. , Al‐Jassim Mowafak M. , Wei Su‐Huai
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: (π,π) Electronic Order in Iron Arsenide Superconductors.
Authors: Zabolotnyy V. B. , et al. et al.
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Co—Co2B, Ni—Ni3B and Co—Ni—B Nanocomposites Catalyzed Ammonia—Borane Methanolysis for Hydrogen Generation.
Authors: Kalidindi Suresh Babu , Vernekar Amit Ashok , Jagirdar Balaji R.
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reaction of Selenium with Bromine in the Presence of Methyltriphenylphosphonium Bromide: Syntheses and Crystal Structures of [PMePh3]2[Se2Br6] and [PMePh3]2 [SeBr6(SeBr2)2].
Authors: Janickis Vitalijus , Klinga Martti
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Valence‐Tautomeric RbMnFe Prussian Blue Analogues: Composition and Time Stability Investigation.
Authors: Salmon Lionel , Vertelman Esther J. M. , Murgui Carlos Bartual , Cobo Saioa , Molnar Gabor , van Koningsbruggen Petra J. , Bousseksou Azzedine
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Asymmetric Carbonyl‐Ene Reaction Catalyzed by Chiral N,N′‐Dioxide‐Nickel(II) Complex: Remarkably Broad Substrate Scope.
Authors: Zheng Ke , Shi Jian , Liu Xiaohua , Feng Xiaoming
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Catalytic Method for Room‐Temperature Michael Additions Using 12‐Tungstophosphoric Acid as a Reusable Catalyst in Water.
Authors: Chen Xiang , She Jin , Shang Zhicai , Wu Jun , Zhang Peizhi
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Visible‐Light‐Induced Aerobic Oxidation of Alcohols in a Coupled Photocatalytic System of Dye‐Sensitized TiO2 and TEMPO.
Authors: Zhang Miao , Chen Chuncheng , Ma Wanhong , Zhao Jincai
Published: March 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.