bluuebunny/crossref_metadata_2025 huggingface dataset:
Jewish Counterfactualism in Recent American Poetry
Authors: Schuster Joshua
Published: April 2010

This essay argues that there is currently a cultural prohibition in Jewish literature against rewriting history. Jewish artists cannot abandon history and cannot condone historical revisionism, but they can present alternatives within history either to redeem it or critique it. Poets Rachel Blau DuPlessis and Charles Bernstein have turned to the counterfactual (the "what if") as a narrative and poetic structure in order to imagine a different, and Jewish, relation to history and to take stock of the dangers of this intervention. For both poets, the counterfactual device is used to imagine a leftist Jewish relation to history, particularly at points where history has been damaged or drained of these ways of relating to it. However, Benjamin Friedlander's poetry and essays play the foil—his poetry fakes history to show that there really is no taboo in inventing history, but the consequence is that Jewish poetry has drifted increasingly further away from anything like Jewish historical action.
Vitamin C inhibits leptin secretion and some glucose/lipid metabolic pathways in primary rat adipocytes
Authors: Garcia-Diaz D F , Campion J , Milagro F I , Boque N , Moreno-Aliaga M J , Martinez J A
Published: April 2010

Antioxidant-based treatments are emerging as an interesting approach to possibly counteract obesity fat accumulation complications, since this is accompanied by an increased systemic oxidative stress. The aim of this study was to analyze specific metabolic effects of vitamin C (VC) on epididymal primary rat adipocytes. Cells were isolated and incubated for 72 h in culture medium, in the absence or presence of 1.6 nM insulin, within a range of VC concentrations (5–1000 μM). Glucose- and lipid-related variables as well as the secretion/expression patterns of several obesity-related genes were assessed. It was observed that VC dose dependently inhibited glucose uptake and lactate production, and also reduced glycerol release in both control and insulin-treated cells. Also, VC caused a dramatic concentration-dependent fall in leptin secretion especially in insulin-stimulated cells. In addition, VC (200 μM) induced Cdkn1a and Casp8, partially inhibited Irs3, and together with insulin drastically reduced Gpdh (listed as Gpd1 in the MGI database) gene expressions. Finally, VC and insulin down-regulatory effects were observed on extracellular and intracellular reactive oxygen species production respectively. In summary, this experimental assay describes a specific effect of VC in isolated rat adipocytes on glucose and fat metabolism, and on the secretion/expression of important obesity-related proteins.
Spatial and Seasonal Patterns of Benzene, Toluene, Ethylbenzene, and Xylenes in the Gdańsk, Poland and Surrounding Areas Determined Using Radiello Passive Samplers
Authors: Zabiegała Bożena , Urbanowicz Magdalena , Namieśnik Jacek , Górecki Tadeusz
Published: April 2010

Atmospheric concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) were assessed in the Gdańsk‐Sopot‐Gdynia Tricity area and in the city of Tczew using diffusive‐type Radiello passive samplers. Samples were collected at the monitoring stations belonging to the Agency of Regional Air Quality Monitoring Foundation. The results indicated that the BTEX concentrations measured in the urban air in the Tricity area and in Tczew were dependent on the season, being somewhat higher in winter and spring than in summer. Maps of BTEX pollution in the Tricity and in Tczew were prepared by interpolating the results for the areas between the sampling points covering the mapped areas. This allowed the assessment of time‐weighted average concentrations of the compounds studied at locations where measurements were not made.
An Evaluation of the USEPA Calculations of Greenhouse Gas Emissions from Anaerobic Lagoons
Authors: Lory John A. , Massey R. E. , Zulovich J. M.
Published: April 2010

On 10 Apr. 2009, USEPA proposed and on 30 Oct. 2009 USEPA finalized reporting thresholds for a wide range of human‐derived sources of greenhouse gas (GHG) as a first step in establishing emission limits in the United States. The only on‐farm source category that required monitoring under the proposed and final rule was methane (CH4) and nitrous oxide (NO2) emissions from manure storage facilities. Our objective was to assess, through a literature review, the methodology used by USEPA to estimate current CH4 emissions from uncovered anaerobic lagoons and the proposed methodology for reporting those emissions under the proposed rule. A review of the performance of uncovered anaerobic lagoons indicates that they are more effective at degrading volatile solids (VS) than predicted using parameters provided by USEPA that had been developed for anaerobic digesters. We also documented errors in the USEPA‐ and International Panel on Climate Change–estimated methane conversion factors for uncovered anaerobic lagoons. We suggest estimating CH4 emissions from anaerobic lagoons based on VS degraded in the lagoon and B′ (m3 CH4 generated kg−1 VS destroyed). Our estimate of CH4 released from uncovered anaerobic lagoons indicated the regulatory operation size threshold could be at least 65% smaller than predicted by USEPA in the proposed rule. Our calculated estimate of CH4 emissions was substantially greater than the few estimates of CH4 loss based on direct measurements on uncovered anaerobic lagoons. More research is needed before it will be possible to provide definitive estimates of CH4 loss from uncovered anaerobic lagoons.
Making Stem Cells Infarct Avid
Authors: Zhao Ming , Barron Matthew R. , Li Zhixin , Koprowski Stacy , Hall Cherisse L. , Lough John
Published: April 2010

A major factor limiting the engraftment of transplanted stem cells after myocardial infarction is the low rate of retention in the infarcted site. Our long-term objective is to improve engraftment by enabling stem cells to recognize and bind infarcted tissue. To this end, we proposed to modify the surface of embryonic stem cells (ESCs) with the C2A domain of synaptotagmin I; this allows the engineered stem cells to bind to dead and dying cardiac cells by recognizing phosphatidylserine (PS). The latter is a molecular marker for apoptotic and necrotic cells. The C2A domain of synaptotagmin I, which binds PS with high affinity and specificity, was attached to the surface of mouse ESCs using the biotin-avidin coupling mechanism. Binding of C2A-ESCs to dead and dying cardiomyocytes was tested in vitro. After the surface modification, cellular physiology was examined for viability, pluripotency, and differentiation potential. C2A covalently attached to the ESC surface at an average of about 1 million C2A molecules per cell under mild conjugation reaction conditions. C2A-ESCs avidly bound to dying, but not viable, cardiomyocytes in culture. The normal physiology of C2A-modified ESCs was maintained. The binding of C2A-ESCs to moribund cardiomyocytes demonstrates that the retention of transplanted cells may be improved by conferring these cells with the ability to bind infarcted tissue. Once established, this novel approach may be applicable to other types of transplanted therapeutic cells.
Time-Dependent Migration of Systemically Delivered Bone Marrow Mesenchymal Stem Cells to the Infarcted Heart
Authors: Assis Ana Carolina M. , Carvalho Juliana L. , Jacoby Bruno A. , Ferreira Raphael L. B. , Castanheira Paula , Diniz Simone O. F. , Cardoso Valbert N. , Goes Alfredo M. , Ferreira Anderson J.
Published: April 2010

In this study the time course of homing and the body distribution of systemically delivered bone marrow mesenchymal stem cells (BM-MSCs) after myocardial infarction (MI) were evaluated. BM-MSCs were isolated from Wistar rats, expanded in vitro, and their phenotypical characterization was performed by flow cytometer. Rats were randomly divided into three groups: control, sham MI, and MI. BM-MSCs (5 × 106) were labeled with99mTc-HMPAO and injected through the tail vein 7 days after MI. Gamma camera imaging was performed at 5, 15, 30, and 60 min after cell inoculation. Due to the99mTc short half-life, cell migration and location were also evaluated in heart sections using DAPI-labeled cells 7 days after transplantation. Phenotypical characterization showed that BM-MSCs were CD90+, CD73+, CD54+, and CD45-. Five minutes after99mTc-HMPAO-labeled cell injection, they were detected in various tissues. The cells migrated mainly to the lungs (approximately 70%) and, in small amounts, to the heart, kidneys, spleen, and bladder. The number of cells in the heart and lungs decreased after 60 min. MI markedly increased the amount of cells in the heart, but not in the lungs, during the period of observation (4.55 ± 0.32 vs. 6.34 ± 0.67% of uptake in infarcted hearts). No significant differences were observed between control and sham groups. Additionally, 7 days after DAPI-labeled cells injection, they were still detected in the heart but only in infarcted areas. These results suggest that the migration of systemically delivered BM-MSCs to the heart is time dependent and MI specifically increases BM-MSCs homing to injured hearts. However, the systemic delivery is limited by cell entrapment in the lungs.
Transplantation of Undifferentiated Human Mesenchymal Stem Cells Protects against 6-Hydroxydopamine Neurotoxicity in the Rat
Authors: Blandini Fabio , Cova Lidia , Armentero Marie-Therese , Zennaro Eleonora , Levandis Giovanna , Bossolasco Patrizia , Calzarossa Cinzia , Mellone Manuela , Giuseppe Busca , Deliliers Giorgio Lambertenghi , Polli Elio , Nappi Giuseppe , Silani Vincenzo
Published: April 2010

Stem cells have been increasingly recognized as a potential tool to replace or support cells damaged by the neurodegenerative process that underlies Parkinson's disease (PD). In this frame, human adult mesenchymal stem cells (hMSCs) have been proposed as an attractive alternative to heterologous embryonic or neural precursor cells. To address this issue, in this study we implanted undifferentiated hMSCs into the striatum of rats bearing a lesion of the nigrostriatal pathway induced by local injection of 6-hydroxydopamine (6-OHDA), a widely recognized rodent model of PD. Before grafting, cultured hMSCs expressed markers of both undifferentiated and committed neural cells, including nestin, GAP-43, NSE, β-tubulin III, and MAP-2, as well as several cytokine mRNAs. No glial or specific neuronal markers were detected. Following transplantation, some hMSCs acquired a glial-like phenotype, as shown by immunoreactivity for glial fibrillary acid protein (GFAP), but only in animals bearing the nigrostriatal lesion. More importantly, rats that received the striatal graft showed increased survival of both cell bodies and terminals of dopaminergic, nigrostriatal neurons, coupled with a reduction of the behavioral abnormalities (apomorphine-induced turning behavior) associated with the lesion. No differentiation of the MSCs toward a neuronal (dopaminergic) phenotype was observed in vivo. In conclusion, our results suggest that grafted hMSCs exert neuroprotective effects against nigrostriatal degeneration induced by 6-OHDA. The mechanisms underlying this effect remain to be clarified, although it is likely that the acquisition of a glial phenotype by grafted hMSCs may lead to the release of prosurvival cytokines within the lesioned striatum.
Hepatocyte Transplantation and the Differentiation Fate of Host Oval Cells in Acute Severe Hepatic Injury
Authors: Yu Chun-Hsien , Chang Mei-Hwei , Chien Chin-Sung , Chen Ya-Hui , Chang Ming-Fu , Chen Hui-Ling
Published: April 2010

Oval cells and hepatocytes rarely proliferate simultaneously. This study aimed to determine the impacts of hepatocyte transplantation on the response and fate of oval cells that are activated to proliferate in acute severe hepatic injury. Retrorsine + D-galactosamine (R+D-gal) treatment was used to induce acute hepatic injury and to elicit extensive activation of oval cells in male dipeptidyl peptidase IV-deficient F344 rats. These rats were then randomized to receive wild-type hepatocyte transplantation or vehicle intraportally. The kinetics of oval cell response and their differentiation fate were analyzed. Results showed that oval cells were activated early and differentiated into hepatocytes in R+D-gal-treated rats without hepatocyte transplantation. With hepatocyte transplantation, the oval cells were recruited later and continued to proliferate in parallel with the massive proliferation of transplanted hepatocytes. They formed ductules and differentiated into biliary cells. When hepatocytes were transplanted at the day when oval cells were at their peak response, the numerous activated oval cells ceased to differentiate into hepatocytes and remained in ductular form. The ductular oval cells were capable of differentiating into hepatocytes again when the donor hepatocytes were inhibited to proliferate. We conclude that hepatocyte transplantation changes the mechanism of liver reconstitution and affects the differentiation fate of host oval cells in acute severe hepatic injury.
Shotgun Proteomics and Network Analysis between Plasma Membrane and Extracellular Matrix Proteins from Rat Olfactory Ensheathing Cells
Authors: Liu Yisong , Teng Xiaohua , Yang Xiaoxu , Song Qing , Lu Rong , Xiong Jixian , Liu Bo , Zeng Nianju , Zeng Yu , Long Jia , Cao Rui , Lin Yong , He Quanze , Chen Ping , Lu Ming , Liang Songping
Published: April 2010

Olfactory ensheathing cells (OECs) are a special type of glial cells that have characteristics of both astrocytes and Schwann cells. Evidence suggests that the regenerative capacity of OECs is induced by soluble, secreted factors that influence their microenvironment. These factors may regulate OECs self-renewal and/or induce their capacity to augment spinal cord regeneration. Profiling of plasma membrane and extracellular matrix through a high-throughput expression proteomics approach was undertaken to identify plasma membrane and extracellular matrix proteins of OECs under serum-free conditions. 1D-shotgun proteomics followed with gene ontology (GO) analysis was used to screen proteins from primary culture rat OECs. Four hundred and seventy nonredundant plasma membrane proteins and 168 extracellular matrix proteins were identified, the majority of which were never before reported to be produced by OECs. Furthermore, plasma membrane and extracellular proteins were classified based on their protein–protein interaction predicted by STRING quantitatively integrates interaction data. The proteomic profiling of the OECs plasma membrane proteins and their connection with the secretome in serum-free culture conditions provides new insights into the nature of their in vivo microenvironmental niche. Proteomic analysis for the discovery of clinical biomarkers of OECs mechanism warrants further study.
Guidance of Olfactory Ensheathing Cell Growth and Migration on Electrospun Silk Fibroin Scaffolds
Authors: Shen Yixin , Qian Yuqiang , Zhang Huanxiang , Zuo Baoqi , Lu Zhenfeng , Fan Zhihai , Zhang Peng , Zhang Feng , Zhou Chunlei
Published: April 2010

Transplantation of olfactory ensheathing cells (OECs) is a potential treatment for spinal cord injury (SCI). However, this process lacks extracellular matrix guiding cell growth, tissue morphogenesis, and remodeling. In order to solve this problem, we fabricated silk fibroin scaffolds (SFS) with different fiber diameters by electrospinning. The behaviors of OECs on 300 and 1800 nm SFS were studied by analyzing cell morphological feature, distribution, and proliferation. The results showed the 300 nm SFS with good potential to guide OECs growth. Subsequently, the properties of 300 nm SFS were further investigated along with PLL. With 300 nm SFS, the preservation of cell phenotype was confirmed by the presence of cell-specific markers, including nerve growth factor receptor p75 and glial fibrillary acidic protein. And the migration behaviors of OECs were also observed by Leica AF6000. In addition, migration tracks, turning behavior, migration distances, migration speeds, and forward migration indices were calculated. Furthermore, the expression of neurotrophic factors was assayed at transcription and protein levels using RT-PCR and ELISA. All these results indicated the diameter of the fiber played an important role in guiding cell adhesion, growth, and migration in vitro and the 300 nm SFS could be suitable to construct tissue-engineered scaffolds for SCI repair.
Effect of Neurotrophin-3 Genetically Modified Olfactory Ensheathing Cells Transplantation on Spinal Cord Injury
Authors: Ma Yu-Hai , Zhang Yong , Cao Li , Su Jia-Can , Wang Zhi-Wei , Xu A-Bing , Zhang Shao-Cheng
Published: April 2010

Transplantation of olfactory ensheathing cells (OECs) has emerged as a very promising therapy for spinal cord injury (SCI). Also, local delivery of NT-3 can counteract pathological events and induce a regenerative response after SCI. Supplement of exogenetic NT-3 might be a new approach to SCI repair. In this study, we examined the therapeutic effect of rat NT-3 gene-modified OECs transplantation on SCI. Rat NT-3 gene was transfected into OECs using a retroviral system. The engineered NT-3-OECs were tested for their ability to express and secrete biologically active NT-3 in vitro. Then NT-3-OECs were implanted into contused T9 spinal cord of the adult rats. Their ability of survival and NT-3 production was examined. The effect of axon regeneration was evaluated at the morphological level and promotion of locomotor functional recovery were assessed. The result showed that genetically modified OECs were capable of surviving and producing NT-3 in vivo to significantly improve the recovery after SCI.
Olfactory Ensheathing Glia Transplantation Combined with LASERPONCTURE® in Human Spinal Cord Injury: Results Measured by Electromyography Monitoring
Authors: Bohbot Albert
Published: April 2010

Preliminary results were measured by electromyography monitoring (electromyoscan) on three subjects suffering from spinal cord injury and who underwent a double therapy. The aim of this study was to evaluate regained voluntary activity below the injury in subjects who received a double therapy: 1) an olfactory ensheathing glia (OEG) transplantation using procedures developed by Dr. Hongyun Huang at the Xishan Hospital and Rehabilitation Centre, Beijing, China, and 2) LASERPONCTURE® developed by Albert Bohbot, Laboratoire de Recherches sur le LASERPONCTURE®, La Chapelle Montlinard, France. Materials uses were the LASERPONCTURE® device developed by Albert Bohbot; the PROCOMP5™ equipment with softwares BIOGRAPH INFINITI 5® and REHAB SUITE™; the sensors MYOSCAN-PRO™ EMG (SA9401M-50) to record muscle activity, and FLEX/PRO™-SA9309M to record skin conductance were fixed on the skin. An infrared laser, whose frequencies and power settings cannot be disclosed due to its proprietary nature, was applied after an OEG injection performed according to Dr. Hongyun Huang's procedures. Three cases, two males and one female, were selected for this study. Presentation and comments of the graphs recordings of voluntary muscle activity below the injury are provided. This preliminary study suggests that the double therapy restores some voluntary muscle activity as measured by electromyography monitoring.
Intracranial Transplant of Olfactory Ensheathing Cells in Children and Adolescents with Cerebral Palsy: A Randomized Controlled Clinical Trial
Authors: Chen Lin , Huang Hongyun , Xi Haitao , Xie Zihang , Liu Ruiwen , Jiang Zhao , Zhang Feng , Liu Yancheng , Chen Di , Wang Qingmiao , Wang Hongmei , Ren Yushui , Zhou Changman
Published: April 2010

Successful repair of damage in cerebral palsy (CP) needs effective clinical interventions other than simply symptomatic treatments. To elucidate the feasibility of using olfactory ensheathing cells (OECs) to treat CP in children and adolescents, we conducted a randomized controlled clinical trial (RCT) on 33 patients. The patients were randomly assigned into two groups (treatment group, n = 18; control group, n = 15), and OECs derived from aborted fetal tissue were injected into the bilateral corona radiata in the frontal lobes (a key point for neural network restoration, KPNNR). The Gross Motor Function Measure (GMFM-66) and the Caregiver Questionnaire Scale were used to evaluate the patients' neurological function and overall health status. Among the 14 patients who completed the 6-month study, six received the cell transplantation and the other eight served as controls. In OEC treatment group, GMFM-66 scores were 26.67 ± 25.33 compared with 19.00 ± 20.00 for the control group. Concurrently, the Caregiver Questionnaire Scale score decreased to 77.83 ± 15.99 in the treatment group in comparison to 138.66 ± 64.06 of the control group. This trial, albeit small in sample size, indicates OEC KPNNR transplantation is effective for functional improvement in children and adolescents with CP, yet without obvious side effects. This small-scale study suggests that the procedure may be a plausible alternative method to treat this not yet curable disorder, and we urge further evaluation with a large-scale RCT.
Jenkins−Strebel differentials
Authors: Arbarello Enrico , Cornalba Maurizio
Published: April 2010

In this mostly expository paper we revisit a fundamental result of Strebel, asserting the existence and uniqueness, on Riemann surfaces of finite type, of Jenkins−Strebel differentials having double poles with prescribed ‘‘residues’’ at prescribed points. In particular, we give a selfcontained and somewhat shortened proof of Strebel’s result.
A Stampacchia-type inequality for a fourth-order elliptic operator on Kähler manifolds and applications
Authors: Lussardi Luca
Published: April 2010

In this paper we will prove an integral inequality of Stampacchia-type for a fourth-order elliptic operator on complete and connected Kähler manifolds. Our inequality implies a Hodge–Kodaira orthogonal decomposition for the Sobolev-type space
Wp,q
(
X
). In particular we will able to prove, under suitable topological conditions on the manifold
X
, the existence of an isomorphism between the Aeppli groups Λ_p,q_(
X
) and the groups
Hp,q
(
X
) of all global harmonic forms of bidegree (
p
,
q
).
Regularity results for minimizers of integral functionals with nonstandard growth in Carnot–Carathéodory spaces
Authors: Giannetti Flavia , Passarelli di Napoli Antonia
Published: April 2010

We prove regularity results for minimizers of integral functionals of the type

∫_Ω f(Xu)dx

where

f

satisfies a nonstandard growth condition and

Xu

stands for the horizontal gradient of

u

. More precisely, we obtain regularity in the scale of Campanato spaces without assuming any restriction on the growth exponents and, under a suitable assumption on them, we get the local boundedness as well as an higher integrability result for the gradient.
Remarks on the $H$ Theorem for a non involutive Boltzmann like kinetic model
Authors: Furioli Giulia , Terraneo Elide
Published: April 2010

In this paper, we consider a one-dimensional kinetic equation of Boltzmann type in which the binary collision process is described by the linear transformation

v^* = pv + qw

,

w^* = qv + pw

, where

(v, w)

are the pre-collisional velocities and

(v^*, w^*)

the post-collisional ones and

p ≥ q > 0

are two positive parameters. This kind of model has been extensively studied by Pareschi and Toscani (in
J. Stat. Phys.
, 124(2–4):747–779, 2006) with respect to the asymptotic behavior of the solutions in a Fourier metric. In the conservative case

p^2 + q^2 = 1

, even if the transformation has Jacobian

J ≠ 1

and so it is not involutive, we remark that the

H

Theorem holds true. As a consequence we prove exponential convergence in

L^1

of the solution to the stationary state, which is the Maxwellian.
Pharmaceuticals
Authors: Rzeszotarski W. Janusz
Published: April 2010

The many types of drug product dosage forms are presented. Contemporary forms are discussed, as are technologies of design and manufacture to deliver safe and effective therapeutic responses each time administered. A brief outline of information that is available on the Web pertinent to the FDA and regulatory issues is given. The process of new drug approval and its continuous modification reflects both the progress of science and the globalization of the world’s economy. The reader is encouraged to follow the changes by constant monitoring of the FDA and the industry sites dedicated to these issues. The history of drug regulation in the United States, the evolving structure of the FDA, the steps to be taken in the process of obtaining the approval to market the new molecular entity, and the post‐approval requirements are briefly described.
Petroleum Refinery Processes
Authors: Speight James G.
Published: April 2010

Petroleum refining or petroleum processing is the recovery and/or generation of usable or salable fractions and products from crude oil, either by distillation or by chemical reaction of the crude oil constituents under the effects of heat and pressure. Petroleum refining also involves treating the raw products by a variety of finishing processes to yield marketable products. A refinery is an integrated group of manufacturing plants that vary in number according to the variety of products produced; it must be flexible and able to change operations as needed. Refinery processes must be selected to produce products according to demand. This article deals with the processes used to refine petroleum, from the initial pretreating of the well fluids to the finishing processes for products as well as the gas treating processes for reducing emissions to the environment.
Meat Products, Hydrodynamic Pressure Processing
Authors: Solomon Morse B. , Liu Martha N. , Callahan Janice A.
Published: April 2010

Food safety and inconsistency in meat quality, in particular tenderness, are two of the top priorities facing the meat industry. Development of commercial methods to ensure consistently tender meat products is of primary importance for enhanced consumer acceptance of meat. Hydrodynamic pressure processing (HDP) is a technology for tenderizing meat using shock waves from underwater detonation of explosives. Upon cooking HDP‐treated meat is found to be 25% more tender than nontreated control samples and displays no outward visual signs of change.

However, the effects of HDP treatment on further processed meat products are not fully understood and additional studies on further processed meat products of varying textures are necessary to determine the effect of HDP.
Sampling Techniques
Authors: Diwekar Urmila M. , Ulas Saadet
Published: April 2010

Sampling is a statistical procedure used for uncertainty analysis and stochastic modeling in many applications related to process design, operation, control and optimization. The increased efforts for pollution prevention and sustainability necessitate a more contemporary approach for process design, in which objectives such as reducing environmental and health impacts, increasing reliability, safety and controllability, reducing risk and achieving better profitability are considered simultaneously. In this multifaceted approach to process design and operation, uncertainties need to be considered and included in process models and simulations. These uncertainties can be static or dynamic. A review of sampling techniques such as Monte Carlo sampling, importance sampling, Latin Hypercube Sampling (LHS) and Hammersley Sequence Sampling (HSS) are provided here. These sampling techniques have a wide range of use in chemical and process synthesis, process scheduling, supply chain management, process control and reliability as well as risk management. Apart from uncertainty analysis, sampling and sampling accuracy plays an important role in discrete, stochastic, and multi‐objective optimization algorithms. This article also describes the recent developments in this area. In addition, future trends in process design and sampling techniques are also presented.
Vegetable Fibers
Authors: Young Raymond A.
Published: April 2010

Plant‐derived vegetable fibers are classified according to their source in plants as bast, leaf, or seed‐hair. The fibers in bast and leaf plants are integral to the plant structure, providing strength and support. The principal chemical component of vegetable fibers is cellulose, with varying amounts of lignin and hemicelluloses also usually present; thus the fibers are also referred to as cellulosic or lignocellulosic. Vegetable fibers are usually stiffer but less tough than synthetic fibers. The fibers are grown throughout the world but mostly in tropical and subtropical climates in developing countries. The principal bast fibers are flax, jute, and hemp, which are utilized primarily for fabrics (linen‐flax, hessian‐jute), bags, ropes, in newer biobased composites, and as a source of papermaking fibers, principally cigarette papers. The primary leaf fibers are abaca and sisal, which have uses similar to bast fibers, except fabrics are not produced from the leaf fibers. Cotton, coir, and kapok are the principal seed‐hair fibers, with cotton by far the most important commercial vegetable fiber. Bast fibers are obtained from the plant, after harvest, by water retting (rotting) in ponds or streams. The leaf fibers are obtained by crushing and scraping followed by washing. Vegetable fibers are generally graded according to color, luster, cleanliness, strength, fineness, and uniformity. The world market for vegetable fibers has dropped dramatically in recent years because of periods of economic recession and synthetic fiber replacements.
Processing, Modeling
Authors: Denn Morton
Published: April 2010

A model is a quantitative abstraction of a physical process, in which the description of the process is represented by the solution to a set of mathematical equations. The mathematical formulation enables the model to be used for a variety of purposes, including design, control, and exploration of operating strategies; the effects of changes in process variables and material properties can be inferred from the model without extensive experimentation. This article addresses the modeling of polymer melt processes, including extrusion, coating, calendaring, injection and compression molding, spinning, film blowing, and mixing. The topics include melt rheology, process classification, numerical methods, continuous low Deborah number processes, periodic low Deborah number processes, free‐surface processes, numerics, boundaries, mixing, stability and sensitivity, and anisotropic materials.
Postsynaptic Membranes at the Neuromuscular Junction: Molecular Organisation
Authors: Cartaud Jean , Kordeli Ekaterini , Cartaud Annie
Published: April 2010

Accurate neurotransmission between motor nerve and muscle fibres at the vertebrate cholinergic neuromuscular junction (NMJ) depends on the differentiation of highly specialised structures both pre‐ and postsynaptically. The accumulation of nicotinic acetylcholine receptors (AChRs) and voltage‐gated sodium channels represents the hallmark of postsynaptic membrane differentiation. Several synaptic organising proteins are required for the aggregation of postsynapticAChRs. Themuscle‐specific receptor tyrosine kinase(MuSK) provides a structural scaffold necessary to initiate aggregates of postsynaptic molecules.Agrin– a nerve‐derived extracellular matrix glycoprotein – is required forAChRclustering probably by activating MuSK activity.Rapsyn– theAChR‐associated peripheral protein acting downstream ofagrin–MuSK signalling – is essential forAChRclustering. These proteins, together with a wealth of other components of the synapse, cooperate in multiple ways to play both structural and signalling roles in synaptic differentiation. Synaptopathies of the NMJ result from mutations in several key players of synaptic differentiation.

Key Concepts:

Efficient communication between neurons or between neurons and their targets requires the enrichment of synaptic proteins, in particular, ligand‐gated ion channels at postsynaptic sites.

The NMJ represents a particularly striking example of accumulation of nicotinic acetylcholine receptors in the postsynaptic membrane and is an ideal model to study receptor clustering.

Formation and maintenance of the postsynaptic membrane is a complex mechanism involving synaptic organising molecules derived both from nerve and muscle.

The muscle tyrosine kinase, MuSK, is the master organiser of the NMJ capable to initiate clustering of postsynaptic components, even in the absence of neuronal cues.

Mutations in several components of the postsynaptic membrane (not only in AChR subunits genes but also in agrin, ColQ, DOK‐7, laminin, MuSK, rapsyn, etc.) result in severe dysfunction of the NMJ: the congenital myasthenic syndromes.
Evolution of the Genetic Code
Authors: Yokobori Shin‐ichi , Ueda Takuya , Watanabe Kimitsuna
Published: April 2010

From the present situation of genetic code so far elucidated for various species of extant organisms, it is speculated that the genetic code system had started from a limited number of amino acids and evolved to the universal genetic code which is being used by most extant organisms. During evolution, the genetic code is changeable by some factors such as directional mutational pressure on genomes, genome economization and evolution of tRNA (and its cognate aminoacyl transferribonucleic acid synthetase). The metazoan (multicellular animal) mitochondrial genetic code is interesting issue as the model case of evolution of genetic code, since the metazoan mitochondrial genetic code is greatly deviated from the universal genetic code, and varied among lineages. The present situation on the genetic code is discussed.

Key Concepts:

Genetic code has evolved along (with) evolution of life.

Codon reassignment requires both elimination of tRNAs for sense codons or release factors for termination codons recognizing the concerned codon and creation or recruitment of ‘novel’ tRNAs or release factors that can recognize the concerned codon.

Wobble base pairing between anticodon first position and codon third position is an important constraint for codon reassignment.

Simple mitochondrial genetic system (small genome size, reduced number of tRNA species) allowed larger variation of genetic code than other genetic systems.
S‐Adenosylmethionine
Authors: Markham George D
Published: April 2010

S‐adenosylmethionine is one of the few sulfonium ions found in nature and it plays essential roles in the metabolism of all known organisms. The positively charged sulfonium centre endowsS‐adenosylmethionine with a chemical versatility matched by few other biochemicals, perhaps exceeding even adenosine triphosphate (ATP).S‐adenosylmethionine is used in a multitude of metabolic pathways, and the types of chemical reactions in which it partakes are highly varied, ranging from alkylation to free‐radical formation.S‐sdenosylmethionine is methyl donor in many biosynthetic reactions, whereas methylation of bothdeoxyribonucleic acid(DNA) and proteins is part of the epigenetic control of cell growth and development. In other pathways, the propylamine moiety is incorporated into the pervasive polyamines spermidine and spermine. Unusual reactions consumeS‐adenosylmethionine in the formation of plant growth factor ethylene, of cyclopropane fatty acids and in sulfur insertion in the biosynthesis of biotin, lipoic acid and thiamine.S‐adenosylmethionine appears to be one of the molecules required for life.

Key concepts:

S‐adenosylmethionine is a branch point compound with components from purine, amino acid and reduced sulfur metabolism, and thus is potentially able to coordinate these three areas of metabolism.S‐adenosylmethionine appears to be required for life.

The sulfonium centre ofS‐adenosylmethionine is able to transfer any of the three attached alkyl groups, providing a metabolic versatility matched by few other biological molecules.

S‐adenosylmethionine is a progenitor of free radicals that occur as protein‐bound reaction intermediates in unusual chemical transformations catalysed by the ‘Radical SAM’: family of enzymes.

S‐adenosylmethionine metabolism is commonly disrupted in liver disease, and hereditary defects have been found in a few patients with abnormal sulfur metabolism.

S‐adenosylmethionine is under investigation as a potential drug in treatment of depression, arthritis and liver disease.
Bacterial Primosome
Authors: Tanaka Taku , Masai Hisao
Published: April 2010

DNA (deoxyribonucleic acid) replication requires operation of a molecular machinery which efficiently synthesises of nucleotide chains on both strands. This process requires not only the enzymes synthesising DNA (DNA polymerases) but also those providing primer RNAs (ribonucleic acid) and continuously melting the duplex DNA. The primosome refers to a protein complex capable of processive unwinding of duplex DNA and primer RNA synthesis on the lagging strand at a replication fork. The prepriming proteins,DNA helicaseandprimaseare sequentially assembled on the template DNA to generate primosome. Once assembled, it, in conjunction withDNA polymerases, facilitates DNA chain elongation. The assembly of bacterial primosome is triggered by an ‘initiator’ protein includingDnaAandPriA, which recognise the site of assembly. Primosome is reassembled in replication restart process at stalled or processed replication forks, triggered byPriA. Thus, primosome constitutes an essential component for active replication fork machinery.

Key concepts:

Replication fork is the site of DNA replication where two replicating single‐stranded DNA separates.

Primer RNA is a short stretch of RNA, the 3′‐terminus of which is utilised by DNA polymerases for DNA elongation.

Primosome is a name given to the protein complex capable of duplex DNA unwinding and primer RNA synthesis at the replication fork.

oriCis the replicationorigin ofchromosome. The initiation site of bacterial chromosomal DNA replication under a normal growth condition.

DnaA is the initiator protein for bacterial chromosomal replication, which binds tooriCto assemble a primosome.

PriA is a conserved replication factor which triggers assembly of the so‐called ϕX174‐type primosome, which is assembled at a stalled replication fork for replication restart.

Stalled replication fork, the replication fork the movement of which is blocked by internal and external ‘replication stress’ including DNA damages and depletion of nucleotide precursors.

Replication restart is a process of reassembly of primosome at a stalled replication fork to resume DNA chain elongation.

Recombination intermediate is the intermediate structure (e.g. D‐loop structure) of homologous recombination reaction.

DNA helicase is a protein capable of unwinding a duplex DNA at a replication fork by using the energy derived from the hydrolysis of nucleotides.

Prepriming proteins are proteins required for the stage preceding the association of the primase (an enzyme synthesising primer RNAs) during the assembly of a primosome.
Protein–Ligand Interactions: General Description
Authors: Dunn Michael F
Published: April 2010

Protein–ligand interactions are fundamental to almost all processes occuring in living organisms. Ligand‐mediated signal transmission via molecular complementarity is essential to all life processes; these chemical interactions comprise biological recognition at the molecular level. The evolution of protein function is dependent in part on the development of highly specific sites designed to bind small‐molecule ligands with affinities tuned to the needs of the cell. Cooperativity in ligand binding is critically important to the regulation of competing biological functions. Regulation of cellular processes via cooperative protein–ligand interactions occurs through molecular mechanisms involving protein conformational transitions among low‐ and high‐affinity states. Consequently, ligand‐binding interactions are used to switch proteins among states of different function. Examples ranging from dioxygen transport to gene expression are presented. The structures of protein–ligand complexes at atomic resolution make possible the design of small‐molecule drugs for the treatment of disease.

Key Concepts:

Molecular recognition via protein–ligand interactions is of fundamental importance to most processes occurring within living organisms.

Transmission of signals via molecular complementarity is essential to all life processes.

The evolution of protein function includes the development of highly specific sites for the binding of ligands with affinities tailored to meet the needs of biological function.

Cooperativity in ligand binding plays an important role in the regulation of biological function.

Cooperativity in ligand binding is linked to conformational change in the protein.

Well‐defined mathematical expressions based on the stoichiometry of the binding equilibrium provide a means for quantifying ligand‐binding interactions.

The equilibrium constants of ligand–macromolecule interactions provide a thermodynamic measure of the strength of the interaction.

The atomic resolution structures of ligand complexes provide a chemical basis for understanding protein–ligand interactions and these structures are often used as the basis for the design of small‐molecule drugs for the treatment of disease.
Haemoglobin: Cooperativity in Protein–Ligand Interactions
Authors: Ho Chien , Yuan Yue
Published: April 2010

Haemoglobin(Hb) is an essential component of the circulatory system of vertebrates. Its chief physiological function is to transport oxygen from the lungs to the tissues. Hb binds oxygen cooperatively, that is the affinity of the protein for the first oxygen molecule is less than that for subsequent oxygen molecules. Human adult Hb was among the first proteins whose complete three‐dimensional structure was determined by X‐ray crystallography and it has been used as a model for understanding allosteric proteins. Recent X‐ray crystallographic and multinuclear NMR (nuclear magnetic resonance) studies of both ligated and unligated forms of Hb have shown that many structures exist in crystalline and solution states. These results have challenged the classical two‐structure allosteric model of this protein. To understand Hb at the atomic level, we need to correlate the structural, dynamic and functional properties of hemoglobin in solution.

Key Concepts:

There are many T‐ and R‐types of crystal structures of unligated and ligated forms of haemoglobin, in contrast to the classical two‐structure model for haemoglobin allostery.

The structures of haemoglobin in both unligated and ligated forms in solution are different from those in crystals and exist as dynamic ensembles of various structures.

The ligand‐binding data for proximal histidyl‐detached recombinant haemoglobins show that Perutz's proximal histidyl coupling mechanism contributes approximately two‐thirds to the total interaction energy between haems and that there are alternative coupling pathways for the remaining third.

The Bohr effect, a heterotropic effect, is an excellent example of a global network of electrostatic interactions, rather than a few specific amino acid residues, that play a dominant role in an important physiological function of haemoglobin.

Recent experimental results strongly suggest that allosteric proteins, such as haemoglobin, may require multiple pathways for signal communication, as is illustrated in the cooperative oxygenation and in the Bohr effect.

Haemoglobin is a molecule with considerable plasticity.

The classical two‐structure mechanism for haemoglobin allostery cannot account for the structure, dynamics and function of the haemoglobin molecule and needs revision.
Eusociality and Cooperation
Authors: Keller Laurent , Chapuisat Michel
Published: April 2010

The evolution of eusociality, here defined as the emergence of societies with reproductive division of labour and cooperative brood care, was first seen as a challenge to Darwin's theory of evolution by natural selection. Why should individuals permanently forgo direct reproduction to help other individuals to reproduce? Kin selection, the indirect transmission of genes through relatives, is the key process explaining the evolution of permanently nonreproductive helpers. However, in some taxa helpers delay reproduction until a breeding opportunity becomes available. Overall, eusociality evolved when ecological conditions promote stable associations of related individuals that benefit from jointly exploiting and defending common resources. High levels of cooperation and robust mechanisms of division of labour are found in many animal societies. However, conflicts among individuals are still frequent when group members that are not genetically identical compete over reproduction or resource allocation.

Key Concepts:

Eusociality is a form of highly integrated social organisation that is characterised by reproductive division of labour, cooperative brood care and overlap of generations.

Eusociality confers a great ecological success, but has a scattered taxonomic distribution.

Kin selection is the key process explaining the evolution of permanently nonreproductive helpers. However, in some taxa helpers delay reproduction until a breeding opportunity becomes available.

Eusociality evolved in family groups under ecological conditions promoting the joint exploitation and defence of common resources.

Eusociality is linked with division of labour, which is sometimes associated with morphological castes.

The allocation of workers to tasks is a self‐organising process that occurs without central control and emerges from local interactions.

In social insects, division of labour is remarkably robust and flexible to cope with unpredictable changes in the environment.

Individuals in animal societies are not clones: they have partially divergent genetic interests, which can lead to various forms of conflicts.

Some types of conflicts can be controlled by social means such as bribing, coercion or punishment.
Molecular Genetics of Ischaemic Stroke
Authors: Floßmann Enrico
Published: April 2010

Rare examples of single gene disorders have been described for all major subtypes of ischaemic stroke; accelerated atherosclerosis and subsequent thrombo‐embolism (e.g. homocysteinuria), connective tissue disease resulting in arterial dissections (e.g. Ehler‐Danlos type IV), disorders of cerebral small vessels (e.g. CADASIL), cardiac embolism (e.g. hypertrophic cardiomyopathy), mitochondrial cytopathies increasing cerebral tissue susceptibility to insults (e.g. MELAS) and coagulopathies (e.g. sickle cell disease).

Although animal models, family history and twin studies suggest that hereditary factors might contribute to the risk of sporadic stroke, no single gene has so far been conclusively shown to do so. It is unlikely that the direct genetic contribution of any single gene towards stroke is more than modest and it is likely that the effects are mainly mediated through genetic influences on risk factors and intermediate phenotypes. Single genes are unlikely to be helpful for any risk stratification in clinical practice.

Key Concepts:

Rare examples of single gene disorders have been described for all major subtypes of ischaemic stroke.

Although animal models, family history and twin studies suggest that hereditary factors might contribute to the risk of sporadic stroke, no single gene has so far been conclusively shown to do so.

It is unlikely that the direct genetic contribution of any single gene towards stroke is more than modest.

It is likely that genetic effects are mainly mediated through genetic influences on risk factors and intermediate phenotypes.

Single genes are unlikely to be helpful for any risk stratification in clinical practice.