Showing papers by "Durham University published in 2002"

First-principles simulation: ideas, illustrations and the CASTEP code

Abstract: First-principles simulation, meaning density-functional theory calculations with plane waves and pseudopotentials, has become a prized technique in condensed-matter theory. Here I look at the basics of the suject, give a brief review of the theory, examining the strengths and weaknesses of its implementation, and illustrating some of the ways simulators approach problems through a small case study. I also discuss why and how modern software design methods have been used in writing a completely new modular version of the CASTEP code.

Modelling one- and two-dimensional solid-state NMR spectra†

Abstract: With the description of more and more complex one- and two-dimensional NMR experiments comes the need to develop methods to make a comprehensive interpretation of the various different experiments that can be carried out on the same sample or series of related samples. We present some examples of modelling one- and two-dimensional solid-state NMR spectra of I = ½ spin and quadrupolar nuclei, using laboratory-developed software that is made available to the NMR community. Copyright © 2001 John Wiley & Sons, Ltd.

The slope of the black hole mass versus velocity dispersion correlation

Abstract: Observations of nearby galaxies reveal a strong correlation between the mass of the central dark object MBH and the velocity dispersionof the host galaxy, of the form logðMBH=M� Þ¼ � þ � logð�=� 0Þ; how- ever, published estimates of the slopespan a wide range (3.75-5.3). Merritt & Ferrarese have argued that low slopes (d4) arise because of neglect of random measurement errors in the dispersions and an incorrect choice for the dispersion of the Milky Way Galaxy. We show that these explanations and several others account for at most a small part of the slope range. Instead, the range of slopes arises mostly because of sys- tematic differences in the velocity dispersions used by different groups for the same galaxies. The origin of these differences remains unclear, but we suggest that one significant component of the difference results from Ferrarese & Merritt's extrapolation of central velocity dispersions to re= 8( re is the effective radius) using an empirical formula. Another component may arise from dispersion-dependent systematic errors in the mea- surements. A new determination of the slope using 31 galaxies yields � ¼ 4:02 � 0:32, � ¼ 8:13 � 0:06 for � 0 ¼ 200 km s � 1 . The MBH-� relation has an intrinsic dispersion in log MBH that is no larger than 0.25-0.3 dex and may be smaller if observational errors have been underestimated. In an appendix, we present a simple kinematic model for the velocity-dispersion profile of the Galactic bulge. Subject headings: black hole physics — galaxies: bulges — galaxies: fundamental parameters — galaxies: nuclei — Galaxy: bulge — Galaxy: kinematics and dynamics

Herbivory in global climate change research: direct effects of rising temperature on insect herbivores

Abstract: This review examines the direct effects of climate change on insect herbivores. Temperature is identified as the dominant abiotic factor directly affecting herbivorous insects. There is little evidence of any direct effects of CO2 or UVB. Direct impacts of precipitation have been largely neglected in current research on climate change. Temperature directly affects development, survival, range and abundance. Species with a large geographical range will tend to be less affected. The main effect of temperature in temperate regions is to influence winter survival; at more northerly latitudes, higher temperatures extend the summer season, increasing the available thermal budget for growth and reproduction. Photoperiod is the dominant cue for the seasonal synchrony of temperate insects, but their thermal requirements may differ at different times of year. Interactions between photoperiod and temperature determine phenology; the two factors do not necessarily operate in tandem. Insect herbivores show a number of distinct life-history strategies to exploit plants with different growth forms and strategies, which will be differentially affected by climate warming. There are still many challenges facing biologists in predicting and monitoring the impacts of climate change. Future research needs to consider insect herbivore phenotypic and genotypic flexibility, their responses to global change parameters operating in concert, and awareness that some patterns may only become apparent in the longer term.

Hierarchical galaxy formation

Abstract: We describe the GALFORM semi-analytic model for calculating the formation and evolution of galaxies in hierarchical clustering cosmologies. It improves upon, and extends, the earlier scheme developed by Cole et al. (1994). The model employs a new Monte-Carlo algorithm to follow the merging evolution of dark matter halos with arbitrary mass resolution. It incorporates realistic descriptions of the density profiles of dark matter halos and the gas they contain; it follows the chemical evolution of gas and stars, and the associated production of dust; and it includes a detailed calculation of the sizes of disks and spheroids. Wherever possible, our prescriptions for modelling individual physical processes are based on results of numerical simulations. They require a number of adjustable parameters which we fix by reference to a small subset of local galaxy data. This results in a fully specified model of galaxy formation which can be �

Stable clustering, the halo model and nonlinear cosmological power spectra

Abstract: We present the results of a large library of cosmological N-body simulations, using power-law initial spectra. The nonlinear evolution of the matter power spectra is compared with the predictions of existing analytic scaling formulae based on the work of Hamilton et al. The scaling approach has assumed that highly nonlinear structures obey `stable clustering' and are frozen in proper coordinates. Our results show that, when transformed under the self-similarity scaling, the scale-free spectra define a nonlinear locus that is clearly shallower than would be required under stable clustering. Furthermore, the small-scale nonlinear power increases as both the power-spectrum index n and the density parameter Omega decrease, and this evolution is not well accounted for by the previous scaling formulae. This breakdown of stable clustering can be understood as resulting from the modification of dark-matter haloes by continuing mergers. These effects are naturally included in the analytic `halo model' for nonlinear structure; using this approach we are able to fit both our scale-free results and also our previous CDM data. This approach is more accurate than the commonly-used Peacock--Dodds formula and should be applicable to more general power spectra. Code to evaluate nonlinear power spectra using this method is available from this http URL Following publication, we will make the power-law simulation data available through the Virgo website this http URL

Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report.

Abstract: Significant progress and new insights have been gained in the 4 years since the first Maastricht Consensus Report, necessitating an update of the original guidelines. To achieve this, the European Helicobacter Pylori Study Group organized a meeting of specialists and experts from around the world, representatives from National Gastroenterology Societies and general practitioners from Europe to establish updated guidelines on the current management of Helicobacter pylori infection. The meeting took place on 21-22 September 2000. A "test and treat" approach is recommended in adult patients under the age of 45 years (the age cut-off may vary locally) presenting in primary care with persistent dyspepsia, having excluded those with predominantly gastro-oesophageal reflux disease symptoms, non-steroidal anti-inflammatory drug users and those with alarm symptoms. Diagnosis of infection should be by urea breath test or stool antigen test. As in the previous guidelines, the eradication of H. pylori is strongly recommended in all patients with peptic ulcer, including those with complications, in those with low-grade gastric mucosa-associated lymphoid tissue lymphoma, in those with atrophic gastritis and following gastric cancer resection. It is also strongly recommended in patients who are first-degree relatives of gastric cancer patients and according to patients' wishes after full consultation. It is advised that H. pylori eradication is considered to be an appropriate option in infected patients with functional dyspepsia, as it leads to long-term symptom improvement in a subset of patients. There was consensus that the eradication of H. pylori is not associated with the development of gastro-oesophageal reflux disease in most cases, and does not exacerbate existing gastro-oesophageal reflux disease. It was agreed that the eradication of H. pylori prior to the use of non-steroidal anti-inflammatory drugs reduces the incidence of peptic ulcer, but does not enhance the healing of gastric or duodenal ulcer in patients receiving antisecretory therapy who continue to take non-steroidal anti-inflammatory drugs. Treatment should be thought of as a package which considers first- and second-line eradication therapies together. First-line therapy should be with triple therapy using a proton pump inhibitor or ranitidine bismuth citrate, combined with clarithromycin and amoxicillin or metronidazole. Second-line therapy should use quadruple therapy with a proton pump inhibitor, bismuth, metronidazole and tetracycline. Where bismuth is not available, second-line therapy should be with proton pump inhibitor-based triple therapy. If second-line quadruple therapy fails in primary care, patients should be referred to a specialist. Subsequent failures should be handled on a case-by-case basis by the specialist. In patients with uncomplicated duodenal ulcer, eradication therapy does not need to be followed by further antisecretory treatment. Successful eradication should always be confirmed by urea breath test or an endoscopy-based test if endoscopy is clinically indicated. Stool antigen test is the alternative if urea breath test is not available.

Ethnicity and the Multicultural City: Living with Diversity:

Abstract: In the wake of the race disturbances in Oldham, Burnley, and Bradford in Summer 2001, the author explores the possibilities for intercultural understanding and dialogue. He argues that, although the national frame of racial and ethnic relations remains important, much of the negotiation of difference occurs at the very local level, through everyday experiences and encounters. Against current policy emphasis on community cohesion and mixed housing, which also tends to assume fixed minority ethnic identities, the author focuses on prosaic sites of cultural exchange and transformation, plural and contested senses of place, an agonistic politics of ethnicity and identity, and the limitations of the White legacy of national belonging in Britain.

Cities and Climate Change

Abstract: Climate change is one of the most challenging issues of our time. As key sites in the production and management of emissions of greenhouse gases, cities will be crucial for the implementation of international agreements and national policies on climate change. This book provides a critical analysis of the role of cities in addressing climate change and the prospects for urban sustainability. Cities and Climate Change is the first in-depth analysis of the role of cities in addressing climate change. The book argues that key challenges concerning the resources and powers of local government, as well as conflicts between local goals for economic development and climate change mitigation, have restricted the level of local action on climate change. These findings have significant implications for the prospects of mitigating climate change and achieving urban sustainability. This book provides a valuable interdisciplinary analysis of these issues, and will appeal to students and researchers interested in sustainability at local and global scales.

Spatialities of Globalisation

Abstract: The focus of this paper is on the theorisation of the spatialities of globalisation. I seek to shift the emphasis away from the currently dominant discourse of scalar and territorial relativisation, towards relational processes and network forms of organisation that defy a linear distinction between place and space. I stress the importance of actor networks of varying length and duration as well as the world of practices as the central components of a topographical understanding of globalisation. What this might mean in terms of a theorisation of place is illustrated through a discussion of the geography of the urban economy and a discussion of the politics of place.

Plant glutathione transferases

Abstract: The soluble glutathione transferases (GSTs, EC 2.5.1.18) are encoded by a large and diverse gene family in plants, which can be divided on the basis of sequence identity into the phi, tau, theta, zeta and lambda classes. The theta and zeta GSTs have counterparts in animals but the other classes are plant-specific and form the focus of this article. The genome of Arabidopsis thaliana contains 48 GST genes, with the tau and phi classes being the most numerous. The GST proteins have evolved by gene duplication to perform a range of functional roles using the tripeptide glutathione (GSH) as a cosubstrate or coenzyme. GSTs are predominantly expressed in the cytosol, where their GSH-dependent catalytic functions include the conjugation and resulting detoxification of herbicides, the reduction of organic hydroperoxides formed during oxidative stress and the isomerization of maleylacetoacetate to fumarylacetoacetate, a key step in the catabolism of tyrosine. GSTs also have non-catalytic roles, binding flavonoid natural products in the cytosol prior to their deposition in the vacuole. Recent studies have also implicated GSTs as components of ultraviolet-inducible cell signaling pathways and as potential regulators of apoptosis. Although sequence diversification has produced GSTs with multiple functions, the structure of these proteins has been highly conserved. The GSTs thus represent an excellent example of how protein families can diversify to fulfill multiple functions while conserving form and structure.

Being excited by lanthanide coordination complexes: aqua species, chirality, excited-state chemistry, and exchange dynamics.

Abstract: D. Intermolecular Ligand Exchange 1996 1. Water Substitution 1996 2. Non-Covalent Binding 1997 V. Excited-State Chemistry 1998 A. Excitation and Quenching 1998 B. Emission Characteristics 1999 C. Responsive Luminescent Systems 2002 VI. Magnetic Resonance Spectroscopy Applications 2004 A. Lanthanide-Induced Shifts (LIS) 2004 B. Applications in Aqueous Media 2005 VII. Acknowledgements 2007 VIII. Supporting Information 2007 IX. References 2007

The 2dF Galaxy Redshift Survey: The environmental dependence of galaxy star formation rates near clusters

Abstract: We have measured the equivalent width of the Hα emission line for 11 006 galaxies brighter than M_b-=-−19 (Ω_Λ = 0.7, Ω_m = 0.3, H_0 = 70 km s^(−1) Mpc^(−1)) at 0.05 < z < 0.1 in the 2dF Galaxy Redshift Survey (2dFGRS), in the fields of 17 known galaxy clusters. The limited redshift range ensures that our results are insensitive to aperture bias, and to residuals from night sky emission lines. We use these measurements to trace μ*, the star formation rate normalized to L*, as a function of distance from the cluster centre, and local projected galaxy density. We find that the distribution of μ* steadily skews toward larger values with increasing distance from the cluster centre, converging to the field distribution at distances greater than ∼3 times the virial radius. A correlation between star formation rate and local projected density is also found, which is independent of cluster velocity dispersion and disappears at projected densities below ∼1 galaxy Mpc^(−2) (brighter than M_b = −19). This characteristic scale corresponds approximately to the mean density at the cluster virial radius. The same correlation holds for galaxies more than two virial radii from the cluster centre. We conclude that environmental influences on galaxy properties are not restricted to cluster cores, but are effective in all groups where the density exceeds this critical value. The present-day abundance of such systems, and the strong evolution of this abundance, makes it likely that hierarchical growth of structure plays a significant role in decreasing the global average star formation rate. Finally, the low star formation rates well beyond the virialized cluster rule out severe physical processes, such as ram pressure stripping of disc gas, as being completely responsible for the variations in galaxy properties with environment.

Maternal Mind–Mindedness and Attachment Security as Predictors of Theory of Mind Understanding

Abstract: This study investigated relations between social interaction during infancy and children's subsequent theory of mind (ToM). Infant-mother pairs (N = 57) were observed in a free-play context at 6 months. Interactions were coded for (a) mothers' use of mental state language that commented appropriately on the infants' mental states, and (b) mothers' use of mental state language that did not appropriately reflect their infants' minds. A third variable was (c) security of attachment, which was assessed using the Strange Situation procedure at 12 months. Performance on a battery of ToM tasks at 45 and 48 months was positively correlated with (a), but was not related to (b) or (c). A regression analysis showed that mothers' use of appropriate mental state comments independently predicted overall ToM performance, accounting for 11% of the variance. Children's verbal ability was the only other independent predictor of ToM performance, accounting for 16% of the variance. These findings represent the earliest known social predictor of individual differences in ToM.

Boron Chemistry Lights the Way: Optical Properties of Molecular and Polymeric Systems†

Abstract: Electrooptical and electronic materials are the subject of much research interest, whereby the focus has often been on electron-rich organic molecules. In the past years, new routes to electron-deficient systems have been developed that take advantage of the fact that three-coordinate boron is isoelectronic and isostructural with a positively charged carbocation, which allows neutral, p-type materials to be synthesized directly. This minireview summarizes recent work on compounds with 3- and 4-coordinate boron as well as boron clusters, placing it in the context of prior studies by the research groups of Williams and Glowgowski, Kaim, Lequan, and Marder.

In pursuit of a new ‘enterprise’ and ‘entrepreneurship’ paradigm for learning: creative destruction, new values, new ways of doing things and new combinations of knowledge

Abstract: The paper argues for a new approach to the study of entrepreneurship and a new paradigm as a basis for entrepreneurship education. It also argues that such an approach is unlikely to come from university business schools. It needs an organisational revolution which, however, can be managed within a university as a whole. The paper is divided into two parts. The first explores the political imperative in Europe for development of the ‘enterprise culture’ and attributes this mainly to pressures for greater international competitiveness. The educational response is then examined and, with the help of a number of recent surveys, some of the key issues pertaining to the development of entrepreneurship education in higher education institutions in the UK and Europe are reviewed. The second part attempts to address the imperative at a more conceptual level. The pursuit of entrepreneurial behaviour is seen as a function of the degree of uncertainty and complexity in the task and broader environment and/or the desire of an individual, in pursuit of an opportunity or problem solution, to create it. It is argued that the key trigger for the growing interest in entrepreneurship is globalization. The way in which this has impacted on the role of the state, the organization of business activity and public services and on individuals to create greater uncertainty and complexity in the environment is explored. This leads to a conclusion that a wide range of stakeholders are being confronted with the need for entrepreneurial behaviour, for example, priests, doctors, teachers, policemen, pensioners and community workers and, indeed, potentially everyone in the community. Entrepreneurship is therefore not solely the prerogative of business. It follows that the traditional focus of entrepreneurship education on business, and new venture management in particular, provides an inadequate basis for response to societal needs. Moreover, the pervasive ideology of the ‘heroic’ entrepreneur can be seen as a dysfunctional when viewed against the needs of a wider community. The wider notion of ‘enterprise’ is therefore introduced as a means of moving away from the hitherto narrow paradigm. How this relates to the development of the individual and the design of enterprising organizations is explored. The paper explores the challenge of this broader context by reference to a number of issues central to the globalization debate including: culture, market liberalization, forms of governance and democracy. It then links these with the ontological and epistemological challenge to education. It concludes with discussion as to how this relates to the traditional concept of a university and argues that universities as a whole are in a much better position to respond to the challenge than are business schools.

The Diagnostic Interview for Social and Communication Disorders: background, inter-rater reliability and clinical use.

Abstract: Background: The Diagnostic Interview for Social and Communication Disorders (DISCO) is a schedule for the diagnosis of autistic spectrum and related disorders and assessment of individual needs. It enables information to be recorded systematically for a wide range of behaviours and developmental skills and is suitable for use with all ages and levels of ability. In addition to helping the clinician to obtain a profile of each individual's pattern of development and behaviour, the DISCO also enables identification of specific features found in autistic spectrum disorders that are relevant for use with established diagnostic systems. Method: This paper describes the historical background of the DISCO, outlines its structure and reports the results of an inter-rater reliability study with parents of 82 children aged 3 to 11 years with autistic spectrum disorder, learning disability, language disorder or typical development. Results: Inter-rater reliability for the items in the interview was high (kappa coefficient or intra-class correlation at .75 or higher). This level of agreement was achieved for over 80% of the interview items.

Delayed apoptotic cell clearance and lupus-like autoimmunity in mice lacking the c-mer membrane tyrosine kinase.

Abstract: Mice lacking the membrane tyrosine kinase c-mer have been shown to have altered macro-phage cytokine production and defective phagocytosis of apoptotic cells despite normal phagocytosis of other particles. We show here that c-mer–deficient mice have impaired clearance of infused apoptotic cells and that they develop progressive lupus-like autoimmunity, with antibodies to chromatin, DNA, and IgG. The autoimmunity appears to be driven by endogenous antigens, with little polyclonal B cell activation. These mice should be an excellent model for studying the role of apoptotic debris as an immunogenic stimulus for systemic autoimmunity.

The 2dF Galaxy Redshift Survey: The bias of galaxies and the density of the Universe

Abstract: We compute the bispectrum of the 2dF Galaxy Redshift Survey (2dFGRS) and use it to measure the bias parameter of the galaxies. This parameter quantifies the strength of clustering of the galaxies relative to the mass in the Universe. By analysing 80 x 10 6 triangle configurations in the wavenumber range 0.1 < k < 0.5 h Mpc - 1 (i.e. on scales roughly between 5 and 30 h - 1 Mpc) we find that the linear bias parameter is consistent with unity: b 1 = 1.04 ′ 0.11, and the quadratic (non-linear) bias is consistent with zero: b 2 = -0.054 ′ 0.08. Thus, at least on large scales, optically selected galaxies do indeed trace the underlying mass distribution. The bias parameter can be combined with the 2dFGRS measurement of the redshift distortion parameter β ≃ Ω 0 . 6 m /b 1 , to yield Ωm = 0.27 ′0.06 for the matter density of the Universe, a result that is determined entirely from this survey, independent of other data sets. Our measurement of the matter density of the Universe should be interpreted as Ω m at the effective redshift of the survey (z = 0.17).

Molecular Biologist's Guide to Proteomics

Abstract: The emergence of proteomics, the large-scale analysis of proteins, has been inspired by the realization that the final product of a gene is inherently more complex and closer to function than the gene itself. Shortfalls in the ability of bioinformatics to predict both the existence and function of genes have also illustrated the need for protein analysis. Moreover, only through the study of proteins can posttranslational modifications be determined, which can profoundly affect protein function. Proteomics has been enabled by the accumulation of both DNA and protein sequence databases, improvements in mass spectrometry, and the development of computer algorithms for database searching. In this review, we describe why proteomics is important, how it is conducted, and how it can be applied to complement other existing technologies. We conclude that currently, the most practical application of proteomics is the analysis of target proteins as opposed to entire proteomes. This type of proteomics, referred to as functional proteomics, is always driven by a specific biological question. In this way, protein identification and characterization has a meaningful outcome. We discuss some of the advantages of a functional proteomics approach and provide examples of how different methodologies can be utilized to address a wide variety of biological problems.

Validation of European System for Cardiac Operative Risk Evaluation (EuroSCORE) in North American cardiac surgery

Abstract: Objective: To assess the performance of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) when applied in a North American cardiac surgical population. Methods: The simple additive EuroSCORE model was applied to predict operative mortality (in-hospital or 30-day) in 401 684 patients undergoing coronary or valve surgery in 1998 and 1999 as well as in 188 913 patients undergoing surgery in 1995 in the Society of Thoracic Surgeons (STS) database. Results: The proportion of isolated coronary artery bypass grafting (CABG) was greater in STS patients (84%) than in Europe (65%). STS patients were also older (mean age 65.3 versus 62.5), and had more diabetes (30 versus 17%) and prior cardiac surgery (11 versus 7%). Other comorbidity was also significantly more prevalent in STS patients. EuroSCORE predicted overall mortality was virtually identical to the observed mortality (1998/1999: predicted 3.994%, observed 3.992%; 1995: observed and predicted 4.156%). Predicted mortality also closely matched observed mortality across the risk groups. Discrimination was good to very good for the population overall and for isolated CABG in both time periods, with the area under the receiver operating characteristic curve between 0.75 and 0.78. Conclusion: Despite substantial demographic differences between Europe and North America, EuroSCORE performs very well in the STS database, and can be recommended as a simple, additive risk stratification system on both sides of the Atlantic. q 2002 Elsevier Science B.V. All rights reserved.

Plant resistance towards insect herbivores : a dynamic interaction

Abstract: Plant defences against insect herbivores can be divided into 'static' or constitutive defences, and 'active' or induced defences, although the insecticidal compounds or proteins involved are often the same. Induced defences have aspects common to all plants, whereas the accumulation of constitutive defences is species-specific. Insect herbivores activate induced defences both locally and systemically by signalling pathways involving systemin, jasmonate, oligogalacturonic acid and hydrogen peroxide. Plants also respond to insect attack by producing volatiles, which can be used to deter herbivores, to communicate between parts of the plant, or between plants, to induce defence responses. Plant volatiles are also an important component in indirect defence. Herbivorous insects have adapted to tolerate plant defences, and such adaptations can also be constitutive or induced. Insects whose plant host range is limited are more likely to show constitutive adaptation to the insecticidal compounds they will encounter, whereas insects which feed on a wide range of plant species often use induced adaptations to overcome plant defences. Both plant defence and insect adaptation involve a metabolic cost, and in a natural system most plant-insect interactions involving herbivory reach a 'stand-off' where both host and herbivore survive but develop suboptimally. Contents Summary 145 I. Introduction 146 II. Accumulation of defensive compounds and induced resistance 146 III. Signalling pathways in wound-induced resistance 147 IV. Insect modulation of the wounding response 155 V. Insects which evade the wounding response 156 VI. Insect-induced emission of volatiles and tritrophic interactions 157 VII. Insect adaptation to plant defences 160 Conclusions 163 Acknowlegements 163 References 163.

Submicrometer ferromagnetic NOT gate and shift register.

Abstract: An all-metallic submicrometer device is demonstrated experimentally at room temperature that performs logical NOT operations on magnetic logic signals. When this two-terminal ferromagnetic structure is incorporated into a magnetic feedback loop, the junction performs a frequency division operation on an applied oscillating magnetic field. Up to 11 of these junctions are then directly linked together to create a magnetic shift register.

The survival of organic matter in bone: a review

Abstract: If bone is considered as a composite of collagen (protein) and bioapatite (mineral), then three pathways of diagenesis are identified: (1) chemical deterioration of the organic phase; (2) chemical deterioration of the mineral phase; and (3) (micro) biological attack of the composite. The first of these three pathways is relatively unusual and will only occur in environments that are geochemically stable for bone mineral. However, because rates of biomolecular deterioration in the burial environment are slow, such bones would yield useful biomolecular information. In most environments, bones are not in thermodynamic equilibrium with the soil solution, and undergo chemical deterioration (path 2). Dissolution of the mineral exposes collagen to biodeterioration, and in most cases the initial phase of dissolution will be followed by microbial attack (path 3). Biological attack (3) also proceeds by initial demineralization; therefore paths 2 and 3 are functionally equivalent. However,in a bone that follows path 3 the damage is more localized than in path 2, and regions equivalent to path 1 may therefore exist outside these zones of destruction. Other biomolecules, such as blood proteins, cellular lipids and DNA, exist within the physiological spaces within bone.For these biomolecules, death history may be particularly important for their survival.