Astrophysics

In recent years, several New England projects have promoted professional development and curriculum design in optics and photonics. Funded in part by the Advanced Technological Education (ATE) program of the National Science Foundation (NSF), these projects have prepared middle and high school teachers, college faculty and career counselors from more than 100 New England institutions to introduce fiber optics, telecommunications and photonics technology education. Four of these projects will be discussed here: (1) The New England Board of Higher Education's (NEBHE) Fiber Optics Technology Education Project, (FOTEP) was designed to teach fiber optics theory and to provide laboratory experiences at the secondary and postsecondary levels. (2) Springfield Technical Community College's Northeast Center for Telecommunications Technologies (NCTT) is developing curricula and instructional materials in lightwave, networking and wireless telecommunications technologies. (3) The Harvard-Smithsonian Center for Astrophysics project ComTech developed a 12-week, hands-on curriculum and teaching strategies for middle and high school science and technology teachers in telecommunications and focused on optical communication (fiber optics). (4) NEBHE's project PHOTON is preparing middle, secondary and postsecondary instructors to introduce theory and laboratory experiences in photonics, including geometric and wave optics as well as principles of lasers and photonics applications.

The complementary therapy known as Reiki is considered from a Catholic perspective. The irreducible content of the practice of Reiki is identified as putative manipulation of the healing energy known as ki by practitioners initiated through an attunement ritual using secret symbols. Some general problems of describing ki in the language of Catholic theology are discussed. Certain critiques of Reiki by Christian groups are found to be inadequate on the grounds of attributing guilt by association, or targeting beliefs not necessarily held by all Reiki practitioners. Nevertheless, attempting to manipulate ki according to the principles of Reiki is found not to accord with Christian revelation, and the necessity of practitioners being initiated by the use of secret symbols is particularly problematic. Some recommendations are made concerning the pastoral consequences of this conclusion: avoidance of promoting Reiki in a church context, appropriate support for Christians who have received or practiced Reiki themselves, and addressing the provision of Reiki through the public health care system.

Part I – Spirilla Theory and Cosmology
Stephen Hawking once proclaimed that String Theory may be able to unify the various forces although later he became disillusioned thinking that there may be no Theory of Everything. This very condensed book pulls together the various forces into the Spirilla Theory which supersedes String Theory and introduces the Relativity of Consciousness.

The foundation of the Spirilla Theory is based on the writings of H. P. Blavatsky, A. B. Bailey, and A. Besant. By overlaying the works of Einstein, Bohm, de Broglie, Dirac, Bell and other great scientific minds, on top of the foundation, the unification of the various forces and theories starts to appear; each field of study supplying a part of the puzzle but only a holistic view of ALL endeavors will solve the mystery. The book starts by laying the groundwork through the Introduction, a review of Bell’s Theorem and p-adic mathematics; following this, each major section begins with a quote from the foundational works followed by the quotes from scientific papers demonstrating the current known thinking on the various topics; no attempts are made to edit the works (except with a few exceptions for clarity and/or length) of the various authors and references to the scientists’ works are maintained. Each section is pulled together so that a picture can be seen.
This section;
1. Redefines the atom with the addition of a subquark;
2. Defines the Spirilla Theory which unifies Quantum Mechanics and General Relativity, and explains Quantum Entanglement;
3. Defines new particles;
4. Redefines time and space;
5. Defines and solves the mystery of Black Holes and links the cosmic and quantum black hole through the spirillae;
6. Delves into the mystery of the Macroverse;
7. Outlines the steps in the origins of the universe;
8. Adds an equation to Einstein’s original 1905 paper on relativity which sees the speed of light approaching infinity;
9. Gives the foundation for developing space travel; and, as an appendix,
10. Gives detailed information for the development of a new energy source – Quantum Energy.

Part II - Ontology, Epistemology & Manifestations
Part II is divided into three sections:
1. Ontology and the fundamental concepts of reality which discusses:
a. consciousness and delves into the mystery of human consciousness having cosmic origins;
b. reincarnation and gives the various laws affecting rebirth, with a discussion on the principle of mutation and the perfecting of form;
c. the work of form-building, transmutation of form and the building of a human form.
2. Epistemology which covers a great deal of topics however; for the purposes of NOE the subject is restricted to;
a. evolution including a definition of the Law of Evolution, the cyclic ebb and flow and the rhythmic work of creation, the process of substitution, the evolution of man and the genesis of the pithecoid stocks; and
b. death including the processes of death, two main reasons for cremation and the sequence of events at death.
3. Manifestations of the various religions including:
a. why Christians don’t believe in reincarnation;
b. the coming science of invocation and evocation;
c. Quantum Entanglement Over Time (QEoT) or The Law of Cause and Effect, and The Law of Karma with a discussion on The Golden Rule ; and
d. The New World Religion.

It is still unknown how molecules coordinate their activity and operate at high speeds in the crowded environment of a cell. The study focuses on the geometry of biomolecules, assuming B-DNA, α-helix, β-strand, water molecules, and chemical bonds, including hydrogen bonds, as various types of antennas. The analysis demonstrates that living systems have highly sophisticated wireless and wired communication infrastructures for regulating and coordinating molecular activities, revealing why water is essential for molecular dynamics and indicating how we evolved. The study also includes a few equations linking antenna fields with Einstein's general relativity, Kepler's law of planetary motion, and Newton's law of gravitation, which divides the gravitational field into antenna field zones and clarifies many astronomical facts. The findings, furthermore, suggest that the gravitational field is the antenna field of astronomical objects; and that nature's antennas, such as molecules and astronomical objects, communicate via gravitational waves. We hope that the study, which uses a classical approach to explain the facts of living systems and the Universe, will find applications in biology, astronomy, communication engineering, and other areas of science.

It is still unknown how molecules coordinate their activity and operate at high speeds in the crowded environment of a cell. The study focuses on the geometry of biomolecules, assuming B-DNA, α-helix, β-strand, water molecules, and chemical bonds, including hydrogen bonds, as various types of antennas. The analysis demonstrates that living systems have highly sophisticated wireless and wired communication infrastructures for regulating and coordinating molecular activities, revealing why water is essential for molecular dynamics and indicating how we evolved. The study also includes a few equations linking antenna fields with Einstein's general relativity, Kepler's law of planetary motion, and Newton's law of gravitation, which divides the gravitational field into antenna field zones and clarifies many astronomical facts. The findings, furthermore, suggest that the gravitational field is the antenna field of astronomical objects; and that nature's antennas, such as molecules and astronomical objects, communicate via gravitational waves. We hope that the study, which uses a classical approach to explain the facts of living systems and the Universe, will find applications in biology, astronomy, communication engineering, and other areas of science.

This presentation explores all the experiments on the Moon since the Apollo missions, regarding the detection of water, hydroxyl, HO-, and other indicators, such as neutron abundances. It also cover many space missions and also correlates lab tests on moon samples with experimental observational data.

he fossils described elsewhere in this issue probably left no descendants, are not very old, and were found on a remote island. Despite this, they are among the most outstanding discoveries in palaeoanthropology for half a century. The two papers concerned-by Brown et al. 1 and Morwood et al. 2-appear on pages 1055 and 1087 of this issue, and respectively describe the fossils and their archaeological context. The find is startling.It is of a pygmysized, small-brained hominin, which lived as recently as 18,000 years ago, and which was found on the island of Flores together with stone tools, dwarf elephants and Komodo dragons. Discoveries don't get better than that. The Flores fossils add a new and surprising twig to the hominin family tree, which diverged from the chimpanzee lineage about 7 million years ago. The first African hominins existed 7-1.2 million years ago, were 1-1.5 metres tall, walked upright on two legs (that is, were bipedal), and had chimpanzee-size brains. These early forms comprised as many as six genera and fourteen species, of which the australopithecines are the best known. By 2.5 million years ago, our own genus, Homo, had emerged, with its different body shape, slower growth, greater reliance on meat in the diet, and 'encephalization'-larger brains than expected for body size. These were the first hominins to make stone tools systematically and to colonize Eurasia. They include the familiar names of H. habilis, H. erectus, H. neanderthalensis and, finally, H. sapiens, which put in an appearance about 160,000 years ago. The new fossil is part of this Homo group (Fig. 1). Flores lies to the east of Java, and was probably never connected to the mainland. The presence of 800,000-year-old simple stone tools first attracted attention in 1998 (ref. 3), raising the controversial possibility that H. erectus had produced them and had crossed major sea barriers to reach Flores. Now we have the announcement of the discovery of an 18,000-year-old hominin skeleton from a cave, Liang Bua, on Flores. Although this date is more than 140,000 years after modern humans evolved in Africa, more than 25,000 years after H. sapiens reached Australia, and about 10,000 years after the last known Neanderthal, the

The antimicrobial peptide human α-defensin 5 (HD5) is expressed in Paneth cells, secretory epithelial cells in the small intestine. Unlike other characterized defensins, HD5 is stored in secretory vesicles as a propeptide. The storage quantities of HD5 are ∼90-450 µg per cm 2 of mucosal surface area, which is sufficient to generate microbicidal concentrations in the intestinal lumen. HD5 peptides isolated from the intestinal lumen are proteolytically processed forms-HD5(56-94) and HD5(63-94)-that are cleaved at the Arg 55 -Ala 56 and Arg 62 -Thr 63 sites, respectively.We show here that a specific pattern of trypsin isozymes is expressed in Paneth cells, that trypsin colocalizes with HD5 and that this protease can efficiently cleave HD5 propeptide to forms identical to those isolated in vivo. By acting as a prodefensin convertase in human Paneth cells, trypsin is involved in the regulation of innate immunity in the small intestine.

The purpose this work is to study density function of Dark Matter (D.M.) depending on E, total  intensity of gravitational field,  in a  group of  six  big spiral galaxies and try to explore a possible  Universal law between both magnitudes.
Galaxies selected are the following ones: Milky Way, M31, NGC 3031, NGC 3992, NGC 7331, NGC 2841 
The reason why it has been made this work is  to check the model of DM  proposed by the author in his previous paper [5] Abarca,M.2014 viXra. Dark Matter model by quantum vacuum.
Briefly, in that work was exposed a original  theory of DM.  This new theory defends  that  DM  is generated by the own gravitational field according an unknown quantum gravitational mechanism. In other words, Density of Dark Matter in a point P of space,  depend on E,  according a Universal law.  Therefore if  two different points P and Q belonging different  galaxies had the same  E, intensity of gravitational field,  then they should have the same density of DM. In short,  If  E(P) = E(Q)  then  Density DM(P) = Density DM (Q).
In the present paper, for each galaxy it will be calculated  E, total  intensity of gravitational field, depending on R. This  calculus is carry out through the Rotational Curve and the Virial Theorem.
In addition, for each galaxy it is considered a Dark matter density function, which is tabulated depending on R. After, it is plotted  DM density depending on E.
Data of eight galactic set are studied statistically and it is concluded that its coefficient correlation is enough high to fit a potential function to DM density depending on E.  Statistical process has been carefully detailed through the paper, so I have found plausible to postulate this function as Universal  for big galaxies. I have considered a big galaxy if its velocity inside its flat region of  rotation curve is up to 200 Km/s.
Dark matter function Density as Universal law for big galaxies
Density DM = 1,26 • 10^ - 6  • E^ B  where B = 1,74  inside a dominion  100 < E < 6500
Where  Unit for Density D.M. is 10^ -3 MSUN /pc^3  or m MSUN /pc^3    and  Unit for E is Km^ 2 / s^ 2 / Kpc
The same function with other suitable system of units is Density DM = 3,7323 • 10^ 17  • E^ B  being B = 1,74  Where  Unit for Density D.M. is mMSUN /pc^3    and  Unit for E is m/s^2.

In chapter 12 it is calculated Local DM density (Sun region).  Recent measures of  Sun are Radius =  and Sun Velocity =    With  such values, intensity of gravitational field in Sun Region  ESUN = Km^2/s^2/ Kpc  and  Density DM in Sun region  = 6,45 mMSUN / pc^3 = 0,245 GeV/cm^3 . This value agrees with direct measures of Local DM density.
In chapter 14, DM density potential function has been checked with NFW profile  in Milky Way and it has been found that  agreement between both curves are mainly under 10 % inside the whole dominion up to 375 Kpc which is an excellent agreement in astrophysics¡.
Finally in chapter 15, DM density potential  function has been checked with NFW profile  in M31.Although the agreement between both functions is not so good as in Milky Way case, relative error is enough small to accept that M31 supports DM density potential function.
I think that it has been justified properly that results could confirm DM density as universal law, especially if it is considered experimental error in rotation curves and error in calculus of DM density functions.
The author think that it may be worth to study a bigger number of  galaxies in order to check  or reject results got in this paper because Dark matter nature is one of the most important challenges for astrophysics science nowadays.

By exploiting the data of three large surveys (WINGS, NFPS and SDSS), we present here a comparative analysis of the Fundamental Plane Log(R e) = a Log(σ) + b µ e + c (FP hereafter) of the early-type galaxies (ETGs) belonging to 59 galaxy clusters in the redshift range 0.04 < z < 0.07. We show that the variances of the distributions of the FP coefficients derived for the clusters in our sample are just marginally consistent with the hypothesis of universality of the FP relation. By investigating the origin of such remarkable variances we find that, besides a couple of obvious factors, such as the adopted fitting technique and the method used to measure the photometric and kinematic variables, the coefficients of the FP are also influenced by the distribution of photometric/kinematic properties of galaxies in the particular sample under analysis. In particular, some indication is found that the FP coefficients intrinsically depend on the particular luminosity range of the sample, suggesting that bright and faint ETGs could have systematically different FPs. We speculate

Detrital zircons more than 4 billion years old from the Jack Hills metasedimentary belt, Yilgarn craton, Western Australia, are the oldest identified fragments of the Earth's crust 1,2 and are unique in preserving information on the earliest evolution of the Earth. Inclusions of quartz, K-feldspar and monazite in the zircons 3 , in combination with an enrichment of light rare-earth elements 4,5 and an estimated low zircon crystallization temperature 6 , have previously been used as evidence for early recycling of continental crust, leading to the production of granitic melts in the Hadean era. Here we present the discovery of microdiamond inclusions in Jack Hills zircons with an age range from 3,058 6 7 to 4,252 6 7 million years. These include the oldest known diamonds found in terrestrial rocks, and introduce a new dimension to the debate on the origin of these zircons and the evolution of the early Earth 6-10. The spread of ages indicates that either conditions required for diamond formation were repeated several times during early Earth history or that there was significant recycling of ancient diamond. Mineralogical features of the Jack Hills diamonds-such as their occurrence in zircon, their association with graphite and their Raman spectroscopic characteristics-resemble those of diamonds formed during ultrahigh-pressure metamorphism and, unless conditions on the early Earth were unique, imply a relatively thick continental lithosphere and crust-mantle interaction at least 4,250 million years ago. Research on .3,900-Myr-old zircon grains from the Jack Hills has mainly focused on their chemical and isotopic compositions. In this study, we have investigated the mineral inclusions in 1,000 randomly chosen zircon grains, collected from a sample of the Jack Hills conglomerate from the initial 'discovery' site 1. U-Pb ages of the zircon grains were determined using a sensitive high-resolution ion microprobe (SHRIMP II), following the analytical procedure described in detail elsewhere 11,12. Optical examination revealed that about half of the zircon population contains inclusions larger than ,1 mm. These inclusions were further investigated by confocal micro-Raman spectroscopy. A Raman spectrum of a mineral reflects both its structural and chemical properties and can thus be used as a fingerprint for its identification. We have identified apatite, quartz, xenotime, monazite, rutile, biotite, amphibole, K-feldspar and plagioclase inclusions in the Jack Hills zircon, some of which have also been recognized in previous studies 3,4. In addition, we unambiguously identified diamond inclusions in 45 zircon grains, mostly associated with graphite, but in some cases with apatite and quartz. The Raman spectrum of diamond is characterized by a single firstorder band near 1,332 cm 21 with a typical width (full-width at halfmaximum, FWHM) of ,1.7 cm 21 , reflecting a triply degenerate CC stretching vibration with F 2g symmetry, and sometimes by a secondorder feature near 2,600 cm 21 (ref. 13). The Raman spectra of most of the diamond inclusions ('diamond 1') in the Jack Hills zircons Nature

The measured characteristics of binary pulsars provide valuable insights into the evolution of these systems. We study the aspects of binary evolution particularly relevant to binary Millisecond Pulsars (MSPs), and the formation of close binaries involving degenerate stars through a spin-evolution diagram (spin-up line). For this task, we use a wide variety of binaries, including those with compact components that observed in different energy bands, which we analyze them according to the spin-up line. Their formation and evolution over timescales of binary evolution models are investigated in order to grab any constraint on their evolution, and to estimate the masses of neutron stars with different mass-transfer histories.

We present a model of a dusty disk with an inner hole which accounts for the Spitzer Space Telescope Infrared Spectrograph observations of the low-mass pre-main sequence star CoKu Tau/4. We have modeled the mid-IR spectrum (between 8 and 25 µm) as arising from the inner wall of a disk. Our model disk has an evacuated inner zone of radius ∼ 10 AU, with a dusty inner "wall", of half-height ∼ 2 AU, that is illuminated at normal incidence by the central star. The radiative equilibrium temperature decreases from the inner disk edge outward through the optically-thick disk; this temperature gradient is responsible for the emission of the silicate bands at 10 and 20 µm. The observed spectrum is consistent with being produced by Fe-Mg amorphous glassy olivine and/or pyroxene, with no evidence of a crystalline component. The mid-infrared spectrum of CoKu Tau/4 is reminiscent of that of the much older star TW Hya, where it has been suggested that the significant clearing of its inner disk is due to planet formation. However, no inner disk remains in CoKu Tau/4, consistent with the star being a weak-emission (non-accreting) T Tauri star. The relative youth of CoKu Tau/4 (∼ 1 Myr) may indicate much more rapid planet formation than typically assumed.

This paper proposes a Modular Universe toy-model (MUTM) predicting all elementary particles (EPs) to be actually quantum black-holes (QBHs) (gravitational quasi-singularities) governed by self-gravity and self-antigravity. This paper continues (from an alternative angle of view) the work of other past articles/preprints of the same author in physics (cited in anti-chronological order, from the latest to the oldest.
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This paper will utilize advanced computational mathematics and Quantum statistics for an algorithmic view on our universe. We will look at the theoretical nature of wave propagation, different Quantum states and propose a mathematical analysis for how it ties all together. Sequential equations applicable to nature and a utilization of Quantum similarity as proposed in my previous papers will also be used. The purpose of this paper is to provide a new approach to algorithmic Quantization in terms of describing the biggest complexities in Quantum Mechanics.

Based upon previous discussions on the structure of compact stars geared towards undergraduate physics students, a real experiment involving two upper-level undergraduate physics students, a beginning physics graduate, and two advanced graduate students was conducted. A recent addition to the physics curriculum at Florida State University, "The Physics of Stars", sparked quite a few students' interests in the subject matter involving stellar structure. This, coupled with "Stars and Statistical Physics" by Balian and Blaizot and "Neutron Stars for Undergraduates" by Silbar and Reddy, is the cornerstone of this small research group who tackled solving the structure equations for compact objects in the Summer of 2004. Through the use of a simple finite-difference algorithm coupled to Microsoft Excel and Maple, solutions to the equations for stellar structure are presented in the Newtonian regime appropriate to the physics of white dwarf stars.

Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic and homogeneous models: Kantowski-Sachs, Bianchi type-I and Bianchi type-III universes, with dust and a cosmological constant, in order to find out which are physically permitted. We find that these models undergo isotropization up to the point that the observations will not be able to distinguish between them and the standard model, except for the Kantowski-Sachs model $(\Omega_{k_{0}}<0)$ and for the Bianchi type-III $(\Omega_{k_{0}}>0)$ with $\Omega_{\Lambda_{0}}$ smaller than some critical value $\Omega_{\Lambda_{M}}$. Even if one imposes that the Universe should be nearly isotropic since the last scattering epoch ($z\approx 1000$), meaning that the Universe should have approximately the same Hubble parameter in all directions (considering the COBE 4-Year data), there is still a large range for the matter density parameter compatible with Kantowsky-Sachs and Bianchi type-III if $|\Omega_0+\Omega_{\Lambda_0}-1|\leq \delta$, for a very small $\delta$ . The Bianchi type-I model becomes exactly isotropic owing to our restrictions and we have $\Omega_0+\Omega_{\Lambda_0}=1$ in this case. Of course, all these models approach locally an exponential expanding state provided the cosmological constant $\Omega_\Lambda>\Omega_{\Lambda_{M}}$.

Mars in unearthly, unchartered, unknown & yet attracts all of humanity. The hazards of the endeavor are overwhelmed by the hype & hope surrounding the enterprise. A variety of individuals, private companies, commercial firms and national space agencies are engrossed in efforts at landing & inhabiting Mars. However, these efforts are disjoint and there exists little or no coordination. The aspirations as also hazards are immense, the resources scarce & costly. Consequently, left ungoverned, the potential for conflict in space exploration is high. There exists a critical need to regulate and coordinate affairs in this area right now when the technologies and legislation are yet immature. This calls for a credible institutionalized governance structure. This paper proposes an expansion of the existing United Nations Office of Outer Space Affairs (UNOOSA) to take on the mantle of space exploration governance and to continue with incremental progressions later.

During the last decade, there was a paradigm-shift in order to consider terrestrial planets within liquid-water habitable zones (LW-HZ) around M stars, as suitable places for the emergence and evolution of life. Here we analyze the influence of UV boundary conditions to three planetary systems around dM (HIP 74995, HIP 109388 and HIP 113020). We apply our model of UV habitable zone (UV-HZ) (Buccino et al. 2006) to these cases and show that during the quiescent UV output there would not be enough UV radiation within the LW-HZ in order to trigger biogenic processes. We also analyze the cases of two other M flare stars and show that the flares of moderate intensity could provide the necessary energy to trigger those biogenic processes, while the strong flares not necessary rule-out the possibility of life-bearing planets.

I review various aspects of the role neutrinos have played in shaping various cosmological observables: the nature of large scale structure, observed fluctuations in the CMB, the nature of matter, and the shape of things to come. (Invited review lecture III International Workshop on NO-VE, Venice, 2006)

The fundamental holographic principle is first proposed, then demonstrated in its validity and viability through a thought experiment and then finally derived. The Heisenberg uncertainty relations are shown to follow from this fundamental relation. The quantum blackhole entropy is then demonstrated using this holographic uncertainty relation along with the application of the Landauer’s principle for the thermodynamic erasure of a bit yielding a formula with a logarithmic correction. The blackhole entropy is found to be half the value normally delivered by any other method. So, it is proposed that there is a real relevant physical horizon at the twice the Schwarzschild radius dubbed the holographic information geometric horizon.

insight review articles "For it is simply a fact of observation that the guiding principle in every cell is embodied in a single atomic association existing only in one copy (or sometimes two)-and a fact of observation that it results in producing events which are paragons of orderliness […] the situation is unprecedented, it is unknown anywhere else except in living matter.

Despite their importance for urban planning [1], traffic forecasting [2], and the spread of biological [3, 4, 5] and mobile viruses [6], our understanding of the basic laws governing human motion remains limited thanks to the lack of tools to monitor the time resolved location of individuals. Here we study the trajectory of 100, 000 anonymized mobile phone users whose position is tracked for a six month period. We find that in contrast with the random trajectories predicted by the prevailing Lévy flight and random walk models [7], human trajectories show a high degree of temporal and spatial regularity, each individual being characterized by a time independent characteristic length scale and a significant probability to return to a few highly frequented locations. After correcting for differences in travel distances and the inherent anisotropy of each trajectory, the individual travel patterns collapse into a single spatial probability distribution, indicating that despite the diversity of their travel history, humans follow simple reproducible patterns. This inherent similarity in travel patterns could impact all phenomena driven by human mobility, from epidemic prevention to emergency response, urban planning and agent based modeling. Given the many unknown factors that influence a population's mobility patterns, ranging from means of transportation to job and family imposed restrictions and priorities, human trajectories are often approximated with various random walk or diffusion models [7, 8]. Indeed, early measurements on albatrosses, bumblebees, deer and monkeys [9, 10] and more recent ones on marine predators [11] suggested that animal trajectory is approximated by a Lévy flight [12, 13], a random walk whose step size ∆r follows a power-law distribution P (∆r) ∼ ∆r −(1+β) with β < 2. While the Lévy statistics for some animals require further study [14], Brockmann et al. [7] generalized this finding to humans, documenting that the distribution of distances between consecutive sight

Could it be that fetal liver cells and adult bone-marrow cells originate from a subset of endothelial cells that line blood vessels in the mouse embryo? Several lines of evidence suggest that this might be the case. During development, haematopoietic stem cells, which give rise to blood cells, and endothelial cells, which line blood vessels, both form from the mesodermal germ-cell layer; exactly how though is debatable. On one hand, a controversial, century-old theory proposes that both haematopoietic and endothelial cells arise from a mesoderm-derived common precursor called haemangioblast. On the other hand, a competing, relatively younger theory proposes that haematopoietic stem cells form from a subset of early endothelial cells known as haemogenic endothelium. The relationship between the haemangioblasts and haemogenic endothelium has never been resolved. In this issue, however, three papers 1-3 clarify the potential relatedness and significance of these cell types.

The application of physics to art history, art conservation and archaeology is currently a growing area of research. Astronomy and astrophysics have made significant contributions to imaging science which has in turn contributed to the developments of many other fields ranging from biological science to the study of art history, archaeology and art conservation. This paper will discuss how knowledge traditionally associated with astrophysics have made impact on the
study of cultural heritage. Examples will be drawn from recent research carried out in my research group.