bluuebunny/crossref_metadata_2025 huggingface dataset:
Inelastic Neutron Scattering Experiments on Van der Waals Glasses — A Test of Recent Microscopic Theories of the Glass Transition
Authors: Bartsch E. , Fujara F. , Kiebel M. , Sillescu H. , Petry W.
Published: November 2010

By performing incoherent inelastic neutron scattering experiments on the Van der Waals glass o‐terphenyl we tested predictions made by a recent microscopic theory — the mode coupling theory of the glass transition. In agreement with theory we find — besides the structural relaxation or α‐process which follows a Kohlrausch‐Williams‐Watts behaviour — the existence of a secondary relaxation process which shows very unusual neutron scattering features. This secondary or ß‐process leads to an anomalous decrease of the Debye‐Waller factor which can be interpreted in terms of a critical (Tc‐T)‐behaviour as predicted by theory. According to mode coupling theory this behaviour should be connected to a critical slowing down of the density fluctuations in the vicinity of a critical temperature Tc which is situated typically 30 to 150 degrees above the caloric glass transition temperature Tg. We find our neutron scattering data to be compatible with the predictions of theory leading to a value of Tc that is situated well above Tg i.e. in the range 285–295 K as compared to Tg = 243 K. This agrees well with a value of Tc = 290 K derived independently by use of a power law, suggested by theory to hold for the behaviour of the viscosity at temperatures higher than Tc.
Defect‐chemical Investigations of Defined YBa2Cu3Ox‐Superconductors
Authors: Maier J. , Murugaraj P. , Pfundtner G. , Sitte W.
Published: November 2010

Using our K2CO3‐method we succeeded in preparing highly oriented ceramics and large crystals tolerating unusually high currents. Both results and our techniques to determine precisely the redox‐state and to improve durability against humid atmosphere are briefly reviewed. We also report on the possibility of an elemental disorder in the Ba‐ and Y‐sublattice. The use of oriented samples allowed us to measure the anisotropy of the electronic conductivity. At higher temperatures where equilibrium with the ambient oxygen containing atmosphere is achieved, both the ionic conductivity and the chemical oxygen diffusion coefficient are determined by a chemical and an electrochemical relaxation technique. Finally, a defect model is proposed that takes account of the high non‐stoichiometries and explains the oxygen partial pressure dependence of the electronic conductivity observed in our experiments as well as in the literature.
A Chemical Model of the Variable Oxygen Content of YBa2Cu3O7 — y
Authors: Schwitzgebel G. , Junk St.
Published: November 2010

The reversible oxygen exchange of YBa2Cu3O7 — y (y: O‐deficiency) between 670 and 970 K could be discribed by a chemical equilibrium model, which is assumed between O2(g) and the ions (Cu+, Cu2+, O− or Cu3+) of the basal plane of the structure. The O2 pressure and temperature dependences of the O‐deficiency, which were derived from the model, are completely fulfilled. — The electrical conductivity at higher temperatures is approximately proportional to (1 — y)2, i.e. to the product of the concentrations of two defects, which are involved in the conductance process. It is best interpreted by the small polaron model of the h· type. The deviation from the proportionality was tentatively ascribed to the progressive disorder, which appears with increasing y in the O site occupancy of the basal plane.
A Mößbauer Investigation of the Kinetics of Internal Redox Reactions in Oxide Solid Solutions of the Type (Mg1 — xFex)O
Authors: Becker K. D. , Dreher S.
Published: November 2010

We have made a temperature dependent in‐situ Mößbauer investigation of the kinetics of internal reactions in the system Mg — Fe — O. We confirm the predicted parabolic rate law for the internal oxidation of polycrystalline (Mg1—xFex)O solid solutions with x = 0.01, x = 0.02, and x = 0.05 for temperatures between about 1000°C and 1100°C. The reaction rate constant is found to be inversely proportional to the iron content. The internal reduction of a (Mg0.85Fe0.15)O solid solution at 1000°C, i.e. for the formation of metallic precipitates, also follows the parabolic rate law. Furthermore, preliminary results are reported of an analogous internal reaction investigation in the system Al — Fe — O.
Kinetics from Indirectly Detected Hyperpolarized NMR Spectroscopy by Using Spatially Selective Coherence Transfers
Authors: Harris Talia , Giraudeau Patrick , Frydman Lucio
Published: November 2010

An important recent development in NMR spectroscopy is the advent of ex situ dynamic nuclear polarization (DNP) approaches, which are capable of yielding liquid‐state sensitivities that exceed considerably those afforded by the highest‐field spectrometers. This increase in sensitivity has triggered new research avenues, particularly concerning the in vivo monitoring of metabolism and disease by NMR spectroscopy. So far such gains have mainly materialized for experiments that focus on nonprotonated, low‐γ nuclei; targets favored by relatively long relaxation times T1, which enable them to withstand the transfer from the cryogenic hyperpolarizer to the reacting centers of interest. Recent studies have also shown that transferring this hyperpolarization to protons by indirectly detected methods could successfully give rise to 1H NMR spectra of hyperpolarized compounds with a high sensitivity. The present study demonstrates that, when merged with spatially encoded methods, indirectly detected 1H NMR spectroscopy can also be exploited as time‐resolved hyperpolarized spectroscopy. A methodology is thus introduced that can successfully deliver a series of hyperpolarized 1H NMR spectra over a minutes‐long timescale. The principles and opportunities presented by this approach are exemplified by following the in vitro phosphorylation of choline by choline kinase, a potential metabolic marker of cancer; and by tracking acetylcholine’s hydrolysis by acetylcholine esterase, an important enzyme partaking in synaptic transmission and neuronal degradation.
Functional Ultrastructure of the Proximal Tubule
Authors: Maunsbach Arvid B. , Christensen Erik Ilsø
Published: November 2010

The sections in this article are:

Location of Proximal Tubule

Fixation of Proximal Tubule Cells for Electron Microscopy

Ultrastructure of the Mammalian Proximal Tubule Cell

General Cytology

Cell Shape

Segmentation of the Mammalian Proximal Tubule

Luminal Cell Surface

Basal and Lateral Cell Surface

Junctions

Nucleus

Mitochondria

Endoplasmic Reticulum

Golgi Apparatus

Vacuolar Apparatus (Lysosomes and Endocytic Vacuoles)

Peroxisomes

Cytoskeleton

Cytoplasmic Ground Substance and Inclusions

Structure of Proximal Tubule Cells in Submammalian Species

Birds

Reptiles

Amphibians

Fishes

Ultrastructure of Experimentally Perfused Tubules

Quantitative Ultrastructure of Proximal Tubules

Transepithelial Transport Routes

The Transcellular Route

The Paracellular Route

Functions of the Vacuolar Apparatus

Protein Absorption by the Proximal Tubule Cells

Transtubular Transport of Proteins

Basolateral Binding and Uptake of Proteins

Endocytosis of Nonproteins

Autophogocytosis

Lysosomal Accumulation of Metals and Other Substances
Ion and Water Transport in Toad Urinary Epithelia in Vitro
Authors: MacKnight Anthony D. C.
Published: November 2010

The sections in this article are:

Structure of Toad Urinary Bladder

Ion Movements Across Epithelium

Apical Plasma Membrane

What ore the occurrence and characteristics of individual channels?

Basolateral Plasma Membrane

Paracellular Pathway

Representations of Transepithelial Transport

Membrane Potentials

Water Movements Across Epithelium

Composition of Epithelial Cells

Sodium

Potassium

Chloride

Calcium

pH

Metabolism and Transepithelial Transport

Regulation and Control of Transepithelial Transport and of Cell Composition

Hormonal Control of Transepithelial Transport
Mechanisms of Fluid Transport Across Renal Tubules
Authors: Schafer James A. , Reeves W. Brian , Andreoli Thomas E.
Published: November 2010

The sections in this article are:

Theoretical Foundations of Water Transport in Epithelia

Volume Absorption in the Proximal Tubule

Water Permeability of the Proximal Tubule

Measurement of Water Permeability

Importance of the Osmotic Water Permeability

Location of the Osmotic Gradient

Luminal Hypotonicity Produced by Solute Absorption

Absorbate Hypertonicity

“Passive” Driving Forces for Volume Absorption

NaCl Diffusion in Volume Absorption

Reflection Coefficient Differences

Models of Solute‐Solvent Coupling in Proximal Volume Absorption

Routes of Volume Movement in the Proximal Nephron

Measurement of Cell Membrane Osmotic Water Permeabilities

Consequences of Transcellular Volume Flow

TheADH‐Sensitive Distal Nephron

Measurement of Permeability Changes Produced byADH

Wafer Permeability ofADH‐Sensitive Nephron Segments in Vivo and in Vitro

Site of the Change in Water Permeability withADH

Evaluation of thePf/PDwRatio

Large Pore Hypothesis

Unstirred Layer Effects

The Narrow Channel Hypothesis: Single‐File Diffusion Through Small Aqueous Channels

ADHIncreases the Number of Narrow Aqueous Channels in Apical Plasma Membranes

The ApparentEAfor Water Transport in Cortical Collecting Tubules

The Raw Data

Correction for Diffusion Constraints in Series with Apical Membranes

The “True” EAfor Water Transport

Pseudo‐“Breaks” inEAMeasurements

Comparison ofADH‐Dependent Apical Membrane Water Channels with Gramicidin A Channels

Parallel Paths for Water and Solute Permeation

Morphologic Studies

Intracellular Mediators ofADHAction

Modulation ofADHAction—α‐Adrenergic Agents

Atrial Natriuretic Peptide

Prostaglandins

Calcium

Protein Kinase C
Renal Ion Channels
Authors: Palmer Lawrence G.
Published: November 2010

The sections in this article are:

Historical Overview

What is an Ion Channel?

Techniques for Studying Ion Channels

Fluctuation (Noise) Analysis

Reconstitution in Lipid Bilayers

Patch‐Clamp

Application of the Patch‐Clamp to Renal Tubules

Parameters Derived from Patch‐Clamp Measurements

Ion Channels Along the Nephron

Proximal Tubule

Thick Ascending Limb/Diluting Segment

Collecting Tubule/Urinary Bladder

Channels in Cell Volume Homeostasis
Chloride Transport
Authors: Kokko Juha P. , Baum Michel
Published: November 2010

The sections in this article are:

Proximal Tubule Chloride Transport

Amphibian Proximal Tubule

Mammalian Proximal Convoluted Tubule

Proximal Straight Tubule

Descending Limb of Henle

Thin Ascending Limb of Henle

Thick Ascending Limb of Henle

Distal Convoluted Tubule

Amphibian Distal Tubule

Mammalian Distal Tubule

Collecting Duct

Cortical Collecting Tubule

Outer Medullary Collecting Duct

Inner Medullary Collecting Duct
Renal Acidification: Integrated Tubular Responses
Authors: Cogan Martin G. , Quan Albert H.
Published: November 2010

The sections in this article are:

Normal Acidification by Nephron Segments

Overview of Mechanisms of Acidification

Rates of Acidification

pH Gradient

Physiological Roles of Normal Renal Acidification

Renal Response to Change in Glomerular Filtration Rate and Luminal Flow Rate

Bicarbonate Reabsorption

Renal Response to Decrease in Plasma Bicarbonate Concentration: Metabolic Acidosis

Bicarbonate Reabsorption

Ammonium Formation

Titratable Acid Formation

Integrated Nephron Response: Renal Net Acid Excretion

Renal Response to Increase in Plasma Bicarbonate Concentration: Metabolic Alkalosis

Exogenous Bicarbonate Administration without Extracellular Volume Contraction or Potassium Depletion

Bicarbonate Generation or Administration in the Setting of Chloride and Potassium Deficiencies

Renal Response to Alterations in Plasma

Bicarbonate Reabsorption

Ammonium and Titratable Acid Formation

Integrated Nephron Response: Bicarbonate Reabsorption and Net Acid Excretion by the Whole Kidney
Renal Handling of Urea
Authors: Marsh Donald J. , Knepper Mark A.
Published: November 2010

The sections in this article are:

Urea Synthesis

Role of Urea in Systemic Metabolism

Role of Urea in Systemic Nitrogen Balance

Role of Urea in Systemic Acid‐Base Balance

Regulation of Urea Production and Excretion

Effects of Urea on Cellular Function: Role of Methylamines

Membrane Transport of Urea

Lipid Bilayers

Erythrocytes and Other Nonepithelial Cells

Nonrenal Epithelia

Urea Transport in the Kidney

Introduction

Individual Tubule Segments

Role of Urea in the Urinary Concentrating Mechanism

Questions Remaining
Effects of Diuretics on Renal Function
Authors: Puschett Jules B. , Winaver Joseph
Published: November 2010

The sections in this article are:

Diuretic Effects on Renal Hemodynamics

Drugs That Primarily Alter Glomerular Function

Drugs That Primarily Alter Tubular Function

Diuretic Effects on Intrarenal Blood Flow Distribution

Diuretic Interactions with the Renin–Angiotensin‐Aldosterone system

Diuretic Interactions with Prostaglandin Synthesis and with the Inhibition of Prostaglandin Synthetase

Nephron Sites of Action and Effects of Diuretics on Solute Excretion

Review and Comparison of Methodologies

Utility of the Clearance Technique for the Study of Diuretic Site and Mechanism of Action in Man

Diuretic Effects on the Excretion of Specific Solutes

Cellular and Molecular Actions of Diuretics

Carbonic Anhydrase Inhibitors

Loop Diuretics

Thiazides

Mineralcorticoid Antagonists

Amiloride
Effects of Noise Exposure on Auditory Sensitivity
Authors: Ward W. Dixon
Published: November 2010

The sections in this article are:

Decibels

The Ear as a Sound Detector and the Microtrauma Theory

Noise Levels and Exposures

Noise‐Induced Threshold Shifts, Presbyacusis, Sociacusis, and Nosoacusis

Estimation of Noise‐Induced Permanent Threshold Shifts

Temporary Threshold Shifts from Steady Noise Exposures

Temporary Threshold Shifts from Intermittent Exposures

Temporary Threshold Shifts from Impulse Noise

Damage‐Risk Contours Based on Temporary Threshold Shifts

Government Standards

Implications of Extant Data on Permanent Threshold Shifts

Risk

The Biological Baseline — Its use and Misuse
Medicines and Drugs as Environmental Agents
Authors: Cluff Leighton E.
Published: November 2010

The sections in this article are:

Drugs as Chemicals

Mechanisms of Action of Drugs

Cell Membranes

Chemical Drug Receptors

Drug Effects
Radioactive Materials — Determinants of Dose to the Respiratory Tract
Authors: Walsh P. J. , Hamrick P. E.
Published: November 2010

The sections in this article are:

Dose Definition

Aerosol Characteristics

Dose Calculations

Critical Cells

Dose from Radon Daughters

Aerosol Characteristics

Deposition Models

Clearance

Critical Tissue

Depth‐Dose Calculations

Relationship of Working‐Level Month Exposure to Dose in Rads

Assumptions in Models

Research Needs

Concluding Remarks
Tissue and Cellular Reactions to Particles, Fibers, and Aerosols Retained after Inhalation
Authors: Harington J. S. , Allison A. C.
Published: November 2010

The sections in this article are:

Nature and Origin of Materials Retained

Tissue and Cellular Reactions to Retained Materials

Effect of Size and Shape on the Fate of Inhaled Particles and Fibers

Mechanism of Phagocytosis

Silica

Amorphous Silica

Crystalline Silica

Asbestos

In Vitro Studies

In Vivo Effects

Carcinogenicity of Asbestos

Fibrogenesis and The Fibroblastic Reaction

Coal

In Vivo Effects

Phagocytosis and Cytotoxicity

Other Materials

Aerosols

Cigarette Smoke
Determinants of Xenobiotic Transport at Biological Barriers
Authors: Jackson Michael J. , Cohn Victor H.
Published: November 2010

The sections in this article are:

Transport at Simple Barriers

Nonselective Transport

Diffusion

Criteria for Diffusion

Determinants of Permeability

Unstirred Water Layers

Solvent Drag

Diffusive Transport of Weak Electrolytes

Selective Transport

Transport at Complex Barriers

Concluding Remarks
Action of Environmental Agents on Nucleic Acids and Their Metabolism
Authors: Troll Walter , Shapiro Robert
Published: November 2010

The sections in this article are:

Chemical Reactions That Modify Nucleic Acids

Noncovalent Interactions

Covalent Interactions

Chemical Consequences of Modification

Biological Consequences of Modification

Mutagenesis: Carcinogenesis

DNARepair Synthesis

Examples of Environmental Chemicals that React with Nucleic Acids

Chemicals Requiring No Prior Activation

Chemicals Requiring Prior Activation
Chemical Mechanism of Myosin‐CatalyzedATPHydrolysis
Authors: Webb Martin R. , Trentham David R.
Published: November 2010

The sections in this article are:

Kinetics ofATPBinding and Hydrolysis

Nature ofATPHydrolysis Step

Oxygen Exchange

Oxygen Isotope Incorporation

Positional Isotope Exchange

Stereochemistry of Phosphoryl Group Transfer

Structure of Magnesium‐Nucleotide Complexes

Perspectives on Mechanism and Function ofATPHydrolysis in Muscle
Electrical Properties of Striated Muscle
Authors: Adrian Richard H.
Published: November 2010

The sections in this article are:

Cable Theory for Striated Muscle

Voltage‐Clamp Methods for Striated Muscle

Gap Methods

Microelectrode‐Clamping Methods

Action Potential in Striated Muscle

Sodium Current

Potassium Current

Calcium Current

Action‐Potential Calculations

Currents in the Inactive Membrane

Potassium Conductance

Chloride Conductance

Voltage‐Dependent Membrane Capacitance
Impedance Measurement of the Electrical Structure of Skeletal Muscle
Authors: Eisenberg Robert S.
Published: November 2010

The sections in this article are:

Methods and Techniques

Microelectrode Techniques

Analysis of Sinusoidal Data

Impedance Analysis With Fourier Techniques

Instrumentation Noise

Manipulation of Impedance Data

Theory and Curve Fitting

Electrical Models of the T System

Necessity for Morphometry

Results of Impedance Measurements

Impedance Measurements of Normal Frog Fibers

Other Preparations of Skeletal Muscle

Impedance Measurements of Muscle Fibers in Various Conditions

Comparison With Other Results

Discussion

Impedance Measurements of Nonlinearities

Other Methods
Design and Analysis of Aging Studies
Authors: Costa Paul T. , McCrae Robert R.
Published: November 2010

The sections in this article are:

Stability and Change in Mean Levels

Cross‐Sectional Designs

Longitudinal Designs

Cross‐Sequential Designs

Demonstrating Stability of Mean Levels

Elaborations of the Basic Design

Representativeness and Attrition in Longitudinal Studies

Screening for Clinical Conditions

Stability and Change in Individual Differences

Potential Problems in the Measurement of Rank‐Order Stability

Advanced Topics in Design and Analysis of Aging Studies

Changes in Variance and in Structure

Biomarkers and Functional Age: Flawed Concepts

Growth Curves and Age Changes

Survival Analysis and the Identification of Risk Factors

Correlates of Change

Causal Inferences from Observational Data

Some Considerations for the Design of Longitudinal Studies

Combining Cross‐Sectional and Longitudinal Designs

Combining Hypothesis‐Driven and Exploratory Research

Creative Exploitation of the Data
Animal Models
Authors: Weindruch Richard
Published: November 2010

The sections in this article are:

Selection of an Appropriate Animal Model

Animal Models and the Main Ways of Studying Aging

Defined Longevity Characteristics

Awareness of Late‐Life Disease Patterns

Defined Environmental Conditions

Diet

Genetic Characteristics

Availability and Cost

Patterns of Animal Use in Aging Studies

Animal Use in Aging Research, 1972–1992

Overuse of the Male Fischer 344 Rat

Need for the Use of a Wide Spectrum of Models

Lessons from Nonmammals

Rodents

Carnivores

Nonhuman Primates

Summary and Conclusions
Gene Expression and Protein Degradation
Authors: Van Remmen Holly , Ward Walter F. , Sabia Robert V. , Richardson Arlan
Published: November 2010

The sections in this article are:

Transcription

RNASynthesis

mRNALevels

Transcriptional and Posttranscriptional Processing ofmRNA

Factors That Regulate Transcription

Effect of Dietary Restriction on Transcription

Translation

Protein Synthesis

Effect of Dietary Restriction on Protein Synthesis

Fidelity of Protein Synthesis

Various Steps of Protein Synthesis

Protein Degradation

Degradation of Mixed Protein Populations

Degradation of Individual Proteins

Degradation of Abnormal Proteins

Effect of Dietary Restriction on Protein Degradation

Summary and Conclusions
Skin
Authors: Chuttani Anjali , Gilchrest Barbara A.
Published: November 2010

The sections in this article are:

In Vitro Studies

Intrinsic Aging

Clinical Features

Histopathology

Extrinsic Aging

Photoaging

Cigarette Smoking

Physiological Changes

Barrier Function

Immune Function

Inflammatory Response

Wound Healing

Vitamin D Production
The Potential Role of Selected Endocrine Systems in Aging Processes
Authors: Nelson James F.
Published: November 2010

The sections in this article are:

Hormones and Aging: An Overview

Hormonal Alterations During Aging

Gonadal Steroids

Adrenal Steroids

Growth Hormone
Bone
Authors: Kalu Dike N.
Published: November 2010

The sections in this article are:

Bone Composition

Bone Cells

Bone Remodeling

Bone Loss as A Major Occurrence During Aging

Osteoporosis

Parathyroid Hormone, 1,25(OH)2Vitamin D, and Calcitonin

Altered Calcium Homeostatic Control Hypotheses

Rat Model of Postmenopausal Bone Loss

Altered Hematopoiesis and Local Factor Hypothesis

Risk Factors for Age‐Related Bone Loss

Peak Bone Mass

Exercise

Nutrition

Smoking, Alcohol, and Caffeine

Estrogen Receptors in Intestinal Cells
Immune System
Authors: Miller Richard A.
Published: November 2010

The sections in this article are:

T Lymphocyte Subsets

Helper (CD4) and Cytotoxic (CD8) T Cell Subsets

Naive and Memory T Cell Subsets

Other T Cell Subsets

T Lymphocyte Function

IL‐2 Production

Response toIL‐2

Production of Other Lymphokines

T Cell Activation

Clonal Diversify. A “Mosaic” Model for T Cell Senescence

T Cell Development

Thymic Involution

Prothymocyles

B Lymphocytes

B Cell Number and Subsets

Proliferation and Antibody Production

Antibodies: Levels, Repertoire, and Autoreactivity

B Cell Development

Accessory Cells and Their Cytokines

Dendritic Cells and Langerhans Cells

Cytokine Production

Natural Cytotoxicity

Restoration of Immune Function

Immunity, Disease, and Longevity

Summary: Immune Models for Aging Research
Neuromuscular Adaptation
Authors: Edgerton V. R. , Bodine‐Fowler S. , Roy R. R. , Ishihara A. , Hodgson J. A.
Published: November 2010

The sections in this article are:

Matching of Motoneurons and Muscle Fiber Properties During Normal Development

Muscle Development

Motoneuron Development

Synapse Elimination

Neural and Nonneural Sources of Control of Adult Skeletal Muscle Properties

Cross‐Reinnervation

Prolonged Electrical Silence

Morphological and Metabolic Properties of Motoneurons

Relationship of Soma Size and Metabolic Properties

Adaptability of Soma Size and Metabolic Properties

Gene Amplification Within a Motor Unit

Overall Summary
Vertebrate Nervous System
Authors: Ulinski Philip S.
Published: November 2010

The sections in this article are:

How Many Parts Does the Nervous System Have?

Early Development of the Nervous System

Body and Brain Segments

Neurogenetic Compartments

Cell Lineage Clusters

Brain and Body Size

How is Sensory Information Represented in the Brain?

Receptor‐Based Maps

Evolution of Receptor‐Based Maps

Constructed Maps

Distributed Representations

How Are Movements Generated and Controlled?

Reflexes

Central Pattern Generators

Orienting Movements

Ongoing Movements

Grasping Movements

How Are Different Kinds of Information Integrated in the Pallium?

Association Cortex and Pallial Organization

Categorizing Sequences

Cognitive Maps

Traditional Hypotheses of Vertebrate Brain Evolution Reconsidered
Vertebrate Cardiovascular Systems
Authors: Burggren W. , Farrell A. , Lillywhite H.
Published: November 2010

The sections in this article are:

Diversity of Vertebrate Cardiovascular Patterns

Vertebrate Origins and Driving Forces behind Cardiovascular Evolution

Cardiovascular Patterns in Vertebrates

Functional Properties of Vertebrate Hearts

Overview

Electrical Properties of Cardiac Cells

Excitation–Contraction Coupling

Mechanical Properties of Cardiac Muscle

Cardiac Output and Cardiac Performance

Coronary Circulations, Myocardial O2Consumption, and Myocardial O2Supply

Peripheral Circulation and Hemodynamics

Arterial Blood Pressure and Its Regulation

Blood Volume and Its Regulation

Cardiovascular Performance Under Special Conditions

Aerobic Exercise

Breath Holding and Diving

Reduced Metabolism

Digestive State

Responses to Gravity

Development of Cardiovascular Systems

Conclusions and Future Directions

Mechanistic Unknowns

Adaptive Unknowns

Integrative Unknowns

Developmental Unknowns
Mechanical and Metabolic Design of the Muscular System in Vertebrates
Authors: Rome Lawrence C. , Lindstedt Stan L.
Published: November 2010

The sections in this article are:

An Integrative and Absolute Approach to Adaptation and Design

Caveats and Potential Limitations of the Approach

Science and Semantics of Adaptation and Design

Organization of the Chapter

Components of the Mechanical System

Molecular Level

Cellular Level

Organ Level/Anatomical Level

Design Constraints of the Mechanical System

Design Constraint 1: Myofilament Overlap

Design Constraint 2: V/Vmaxfor Maximum Power Production

Design Constraint 3: Setting of Kinetics of Force Generation and Muscle Relaxation

Final Considerations about Mechanical Design Constraints

Components of the Metabolic System

Molecular/Enzyme Level

Cellular Level

Organ Level

System Level

Emergent Design Principles of the Metabolic System

Molecular/Enzyme Level—Design Constraint 1:ATPDemand Is a Function of Contractile Speed

Cellular Level—Design Constraint 2: Maximum Oxygen Uptake of Skeletal Muscle Mitochondria Is a Constant Function of Mitochondrial Inner‐Membrane Surface Area

Organ Level—Design Constraint 3: Oxygen Conductance through the Tissue Must Be Set to Meet theATPDemand

System Level—Design Constraint 4: The Capacities of the Most Phenotypically Plastic Structures Will Be “Just Adequate” to Match the Maximum Oxidative Requirements of the Muscles

Final Considerations about Metabolic Design Constraints

Mechanical and Metabolic Design of the Muscular System

Design for Power Generation

Design for Steady Terrestrial Locomotion

Design for Sound Production

Design for Heat Production

Conclusion: Principles of Design
Membrane Fusion
Authors: Blumenthal R. , Dimitrov D. S.
Published: November 2010

The sections in this article are:

Observation of Fusion Requires Physical Techniques for Monitoring Mixing of Membranes and the Compartments they Enclose

Morphological Changes Following Fusion Are Observed by Light Microscopy but Membrane Fusion May Occur without such Changes

Fluorescence Microscopy and Spectrofluorometry Allow Quantitation of Membrane Fusion Events in Living Cells

Electron Microscopy Provides Direct Observation of Structural Rearrangements Due to Fusion

Patch‐Clamp Techniques Allow the Monitoring of Very Fast Openings of Fusion Pores

What Do We Learn from “Nonbiological” Fusion Processes?

Ca2+Induces Aggregation Destabilization, and Fusion of Liposomes Containing Phospholipids with Negatively Charged Head‐groups

Fusion of Lipid Membranes by Amphipathic and Nonpolar Molecules Correlates with Their Lytic and Aggregational Activity

Dehydration, Aggregation, and Destabilization of Membranes by Polyethelene Glycol Are Essential for Fusion of Lipid Membranes

Destabilization by High‐Voltage Electric Pulses Leads to Fusion of Adjoining Membranes

Molecular Rearrangements in the Lipid Bilayers during the Very Act of Fusion May Involve Intermediate Structures

Specialized Proteins Mediate Fusion in Life Processes

Viral Envelope Proteins Contain Hydrophobic “Fusion Peptide” Sequences

To Enter a Cell a Virus Must Find the Receptor That Invites It In

Some Viruses Require More Than One Type of Envelope Protein for Entry

Influenza Hemagglutinin Was the Only Fusion Protein with Known Three‐Dimensional Structure

The Process ofHA‐mediated Membrane Fusion Can Be Dissected into a Number of Elementary Steps

Human Immunodeficiency Virus Type 1 (HIV‐1), the Primary Etiological Agent of the Acquired Immunodeficiency Syndrome (AIDS), Enters Cells by Membrane Fusion at Neutral pH

The ReceptorCD4 Plays Both a Passive and an Active Role in Allowing Entry of the Virus into the Cell

Stable Envelope Glycoprotein‐Receptor Complex Formation Is Rate‐limiting in the Overall Fusion Process

Multiple Copies of theHIV‐1 Envelope Glycoprotein May Be Required for Fusion Pore Formation

Sperm Membrane Proteins Involved in Sperm‐Egg Fusion May Resemble Viral Fusion Proteins

Toward A Resolution of Fusion Proteins in Exocytosis

Multiple Proteins May Be Required for Intracellular Fusion

Toward A Physicochemical Analysis of Fusion Kinetics

Delays in Fusion Are Proportional to the Fusion Barriers and Decrease with an Increase in the Strength of the Fusogen

Rates of Fusion Can Provide Information for the Time Course of Membrane Merging and Fusion Pore Expansion

Fusion Yields and Delays Are Related but May Reflect Different Properties of the Fusing Membranes

Does Understanding Membrane Fusion Need New Breakthroughs in Methodology?

Note Added in Proof
Epithelial Cell Polarity: Challenges and Methodologies
Authors: Caplan Michael J. , Rodriguez‐Boulan Enrique
Published: November 2010

The sections in this article are:

Questions

Tools and Techniques with Which to Study Epithelial Polarity

Epithelial Monolayers Grown on Permeable Substrata

Morphological Techniques

Biochemical Techniques

Protein Trafficking Pathways in Epithelial Cells

Biogenetic Pathways

Transcytosis

Recycling Pathways

Tissue‐Specific Variation of Protein Polarity and Targeting Pathways in Epithelial Cells

Sorting Signals and Mechanisms

Establishment of Epithelial Polarity

The Role of E‐Cadherin

Future Prospects: In Vitro Systems, Genetic Models, and the Search for Sorting Machinery
Activation of Sperm and Egg During Fertilization
Authors: Epel David
Published: November 2010

The sections in this article are:

Chemotaxis (or, the Dating Game)

Historical Background

Motility and Chemotactic Substances in Sea Urchin Gametes

Does Chemotaxis Exist in the Real World?

The Acrosome Reaction

Description of the Phenomenon

Signal Transduction Molecules

Sperm‐Egg Binding

Passage of the Sperm Through the Egg Coat

Sperm‐Egg Receptors and Speciation

A Description of Egg Activation

What Happens When Sperm Meets Egg?

The Role of Calcium in Egg Activation

Historical Background

The Natural History of Calcium Changes at Fertilization

Mechanisms of the Calcium Increase

How Does the Sperm Trigger the Calcium Increase?

What is Calcium Doing to Activate the Egg?

The Timetable of Fertilization Responses in the Sea Urchin Egg

Intracellular pH Changes

Entry into the Cell Cycle

Synthesis of Cyclin as a Prerequisite for Mitosis

Activation of Protein Kinase Activity As a Prerequisite for Mitosis

Structural Changes as an Important Concomitant of Fertilization

Microfilaments

Microtubules

Endoplasmic Reticulum

Introduction of the Centrosome as a Critical Event

Ooplasmic Segregation

Epilogue—Is Fertilization a Unique Event in the Life History of the Organism?
Partitioned iterative solution methods for fluid–structure interaction
Authors: van Brummelen E. H.
Published: November 2010

The basic subiteration method for fluid–structure interaction (FSI) problems is based on a partitioning of the fluid–structure system into a fluidic part and a structural part. The effect of the fluid on the structure can be represented by an added mass to the structural operator. This added mass can be identified as an upper bound on the norm or spectral radius of the Poincar'e–Steklov operator of the fluid. The convergence behavior of the subiteration method depends sensitively on the ratio of the added mass to the actual structural mass. For FSI problems with large added‐mass effects, the subiteration method is either unstable or its convergence behavior is prohibitively inefficient. In recent years, several more advanced partitioned iterative solution methods have been proposed for this class of problems, which use subiteration as a component. The rudimentary characterization of the Poincaré–Steklov operator provided by the added mass is, however, inadequate to analyze these methods. Moreover, this characterization is inappropriate for compressible flows. In this paper, we investigate the fine properties of the Poincaré–Steklov operators and of the corresponding subiteration operators for incompressible‐ and compressible flow models and for two distinct structural operators. Based on the characteristic properties of the subiteration operators, we subsequently examine the convergence behavior of several partitioned iterative solution methods for FSI, viz. subiteration, subiteration in conjunction with underrelaxation, the modified‐mass method, Aitken's method, and interface‐GMRES and interface‐Newton–Krylov methods. Copyright © 2010 John Wiley & Sons, Ltd.
Block response‐adaptive randomization in clinical trials with binary endpoints
Authors: Magirr Dominic
Published: November 2010

In a clinical trial, response‐adaptive randomization (RAR) uses accumulating data to weigh the randomization of remaining patients in favour of the better performing treatment. The aim is to reduce the number of failures within the trial. However, many well‐known RAR designs, in particular, the randomized play‐the‐winner‐rule (RPWR), have a highly myopic structure which has sometimes led to unfortunate randomization sequences when used in practice.

This paper introduces random permuted blocks into two RAR designs, the RPWR and sequential maximum likelihood estimation, for trials with a binary endpoint. Allocation ratios within each block are restricted to be one of 1:1, 2:1 or 3:1, preventing unfortunate randomization sequences. Exact calculations are performed to determine error rates and expected number of failures across a range of trial scenarios. The results presented show that when compared with equal allocation, block RAR designs give similar reductions in the expected number of failures to their unmodified counterparts. The reductions are typically modest under the alternative hypothesis but become more impressive if the treatment effect exceeds the clinically relevant difference. Copyright © 2010 John Wiley & Sons, Ltd.
Prospective Identification and Isolation of Enteric Nervous System Progenitors Using Sox2
Authors: Heanue Tiffany A. , Pachnis Vassilis
Published: November 2010

The capacity to identify and isolate lineage-specific progenitor cells from developing and mature tissues would enable the development of cell replacement therapies for disease treatment. The enteric nervous system (ENS) regulates important gut functions, including controlling peristaltic muscular contractions, and consists of interconnected ganglia containing neurons and glial cells. Hirschsprung's disease (HSCR), one of the most common and best understood diseases affecting the ENS, is characterized by absence of enteric ganglia from the distal gut due to defects in gut colonization by neural crest progenitor cells and is an excellent candidate for future cell replacement therapies. Our previous microarray experiments identified the neural progenitor and stem cell marker SRY-related homoebox transcription factor 2 (Sox2) as expressed in the embryonic ENS. We now show that Sox2 is expressed in the ENS from embryonic to adult stages and constitutes a novel marker of ENS progenitor cells and their glial cell derivatives. We also show that Sox2 expression overlaps significantly with SOX10, a well-established marker of ENS progenitors and enteric glial cells. We have developed a strategy to select cells expressing Sox2, by using G418 selection on cultured gut cells derived from Sox2βgeo/+ mouse embryos, thus allowing substantial enrichment and expansion of neomycin-resistant Sox2-expressing cells. Sox2βgeo cell cultures are enriched for ENS progenitors. Following transplantation into embryonic mouse gut, Sox2βgeo cells migrate, differentiate, and colocalize with the endogenous ENS plexus. Our studies will facilitate development of cell replacement strategies in animal models, critical to develop human cell replacement therapies for HSCR.
Compositional refinement in agent-based security protocols
Authors: McIver A. K. , Morgan C. C.
Published: November 2010

A truly secure protocol is one which
never
violates its security requirements, no matter how bizarre the circumstances, provided those circumstances are within its terms of reference. Such cast-iron guarantees, as far as they are possible, require formal, rigorous techniques: proof or model-checking. Informally, they are difficult or impossible to achieve. Our rigorous technique is
refinement
, until recently not much applied to security. We argue its benefits by using refinement-based program algebra to develop several security case studies. That is one of our contributions here. The soundness of the technique follows from its compositional semantics, one which we defined (elsewhere) to support a specialisation of standard refinement by enriching standard semantics with information that tracks correlations between hidden state and visible behaviour. A further contribution is to extend the basic theory of secure refinement (Morgan in Mathematics of program construction, Springer, Berlin, vol. 4014, pp. 359–378,
2006
) with special features required by our case studies, namely agent-based systems with complementary security requirements, and looping programs.
C-arm fluoroscopy for the removal of an intraorbital foreign body in a cat
Authors: Kim Se Eun , Park Young Woo , Ahn Jae Sang , Son Won Gyun , Jeong Manbok , Yoon Junghee , Seo Kangmoon
Published: November 2010

This report describes the clinical manifestations, diagnosis and minimally surgical intervention of a cat with an intraorbital foreign body. A spayed female cat of unknown age was presented with a recurrent cutaneous sinus tract of the left suborbital region. The cat had not vocalized at all since the adoption. A sharp-edged radiopaque foreign body was visualized on dental radiography. Computed tomography outlined the length of the foreign body from the intraorbital soft tissue to the pharynx. The foreign body was removed under the guide of C-arm fluoroscope with minimal skin incision. The surgical site healed completely on the 11th postoperative day, and the cat vocalized normally after healing.
The sociolinguistics of a short-lived innovation: Tracing the development of quotative all across spoken and internet newsgroup data
Authors: Buchstaller Isabelle , Rickford John R. , Traugott Elizabeth Closs , Wasow Thomas , Zwicky Arnold
Published: November 2010

This paper examines a short-lived innovation, quotative all, in real and apparent time. We used a two-pronged method to trace the trajectory of all over the past two decades: (i) Quantitative analyses of the quotative system of young Californians from different decades; this reveals a startling crossover pattern: in 1990/1994, all predominates, but by 2005, it has given way to like. (ii) Searches of Internet newsgroups; these confirm that after rising briskly in the 1990s, all is declining. Tracing the changing usage of quotative options provides year-to-year evidence that all has recently given way to like. Our paper has two aims: We provide insights from ongoing language change regarding short-term innovations in the history of English. We also discuss our collaboration with Google Inc. and argue for the value of newsgroups to research projects investigating linguistic variation and change in real time, especially where recorded conversational tokens are relatively sparse.
Un reencuentro con Mundo Perido, Tikal, Guatemala
Authors: Laporte Juan Pedro , Fialko Vilma
Published: November 2010

Como parte integral del área central de Tikal se encuentra un amplio conjunto arquitectónico conocido como Mundo Perdido. Entre 1979 y 1984 se llevaron a cabo trabajos de exploración arqueológica en las estructuras que le conforman, las cuales son un claro indicio de que se trató del Complejo de Conmemoración Astronómica o de Ritual Público de Tikal, en donde se condujeron actividades de conducción ritual, calendárica y, en algunos momentos, también politica. Su largo proceso evolutivo dio inicio desde el preclásico medio y continuó en forma ininterumpida hasta el clásico terminal. Este largo espectro cronológico, aunado a la importancia que este conjunto tuvo en la estructura política de Tikal, permite observar una parte de la historia del sitio a través de 1500 años. Se obtuvo una serie de elementos que permiten referir procesos históricos, preferencias cerámicas en la tradición funeraria, estilos arquitectónicos particulars y otros desarrollos, con lo cual se trata de ampliar el criterio con el cuai se ha planteado por lo general el panorama de Tikal en las tierras bajas centrales.
The Investigation of Obsidian Craft Production at Xochicalco, Morelos
Authors: Hirth Kenneth G.
Published: November 2010

Surface reconnaissance at the site of Xochicalco, Morelos, identified 12 areas believed to be production locales where obsidian tools were manufactured during the Epiclassic period (A.D. 700-900). Production locales were identified from concentrations of chipped stone debitage located in both residential and nonresidential contexts at Xochicalco. Differences in the size and location of these production locales suggested obsidian craft activity was carried out in three different production contexts similar to those reported at the large urban center of Teotihuacan: small domestic workshops, large nonresidential workshops, and civic-ceremonial precinct workshops. Stratigraphic excavations were initiated to test whether the inferences about the context of production based on surface concentrations of obsidian debitage would be confirmed by subsurface testing. The results show that in most cases surface concentrations of obsidian debitage accurately reflect the presence of in situ craft activity.
Complications with Assessing Disability in Care of the Aged
Authors: Helmes Edward , Campbell Alistair
Published: November 2010

Cases of severe disability present both practical and psychometric problems when the disability limits function in domains other than the primary one. A re-analysis of the normative sample for the Multidimensional Observation Scale for Elderly Subjects (MOSES; Helmes, Csapo, & Short, 1987 ) contrasted different approaches to dealing with its 18 items that include a “does not apply” option. Confirmatory factor analysis was used to compare scoring options for such items. Items were also analyzed using item response theory, which revealed several distinct options for the 18 items in question. Several MOSES items do not need the use of the “does not apply” scoring option. A revision of MOSES to incorporate the revised scoring for those 10 items is in order.
Understanding the North Atlantic Oscillation and Its Effects in the Mediterranean: ESF‐MedCLIVAR Workshop on Hydrological, Socioeconomic and Ecological Impacts of the North Atlantic Oscillation in the Mediterranean; Zaragoza, Spain, 24–27 May 2010
Authors: Trigo Ricardo M. , Vicente Serrano Sergio M.
Published: November 2010

According to the latest Intergovernmental Panel on Climate Change report, the Mediterranean basin represents one of the most important hot spots of climate change in the world, with recent trends toward a hotter and drier climate being related to changes in atmospheric circulation patterns. Among these patterns the North Atlantic Oscillation (NAO) is the most important one and the only one that exerts a clear influence throughout the year, although with stronger intensity and extension during winter. In the framework of the European Science Foundation's Mediterranean Climate Variability and Predictability (MedCLIVAR) program (http://www.medclivar.eu/), a thematic workshop devoted to the hydrological, socioeconomic, and ecological impacts of the NAO in the Mediterranean area was held in Spain.
Observing the Greatest Earthquakes: AGU Chapman Conference on Giant Earthquakes and Their Tsunamis: Viña del Mar and Valparaíso, Chile, 16–20 May 2010
Authors: Atwater Brian , Barrientos Sergio , Cifuentes Inés , Cisternas Marco , Wang Kelin
Published: November 2010

An AGU Chapman Conference commemorated the fiftieth anniversary of the 1960 M 9.5 Chile earthquake. Participants reexamined this earthquake, the largest ever recorded instrumentally, and compared it with Chile's February 2010 M 8.8 earthquake. They also addressed the giant earthquake potential of subduction zones worldwide and strategies for reducing losses due to tsunamis. The conference drew 96 participants from 18 countries, and it reached out to public audiences in Chile.
Note: A novel integrated microforce measurement system for plane-plane contact research
Authors: Dong W. , Rostoucher D. , Gauthier M.
Published: November 2010

The evaluation of plane-plane contact force has become a big issue in micro-/nano research, for example in microassembly. However with the lack of effective experimental equipments, the research on plane-plane contact has been limited to theoretical formulations or virtual simulation. In this paper, a microforce sensor and precision parallel robot integrated system is proposed for the microforce measurement of plane-plane contact. In the proposed system, the two objects are fixed on the parallel robot end-platform and the microforce sensor probe tip, respectively, and the high precision robot system is employed to provide six degree-of-freedom motions between both objects. So it is convenient for the microforce measurement between the planar objects with different orientations. As a significant application, the proposed system is utilized for measurements of pull-off force between planar objects, in which the validation of the system is demonstrated in practice. The proposed microforce measurement system is generic, which can be extended to a variety of microforce measurements in plane-plane contact.
Calibration study of the CCSD(T)-F12a/b methods for C2 and small hydrocarbons
Authors: Feller David , Peterson Kirk A. , Hill J. Grant
Published: November 2010

Explicitly correlated CCSD(T)-F12a/b methods combined with basis sets specifically designed for this technique have been tested for their ability to reproduce standard CCSD(T) benchmark data covering 16 small molecules composed of hydrogen and carbon. The standard method calibration set was obtained with very large one-particle basis sets, including some aug-cc-pV7Z and aug-cc-pV8Z results. Whenever possible, the molecular properties (atomization energies, structures, and harmonic frequencies) were extrapolated to the complete basis set limit in order to facilitate a direct comparison of the standard and explicitly correlated approaches without ambiguities arising from the use of different basis sets. With basis sets of triple-ζ quality or better, the F12a variant was found to overshoot the presumed basis set limit, while the F12b method converged rapidly and uniformly. Extrapolation of F12b energies to the basis set limit was found to be very effective at reproducing the best standard method atomization energies. Even extrapolations based on the small cc-pVDZ-F12/cc-pVTZ-F12 combination proved capable of a mean absolute deviation of 0.20 kcal/mol. The accuracy and simultaneous cost savings of the F12b approach are such that it should enable high quality property calculations to be performed on chemical systems that are too large for standard CCSD(T).