bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention and Reversal of Obesity and Glucose Intolerance in Mice by DHA Derivatives
Authors: Rossmeisl Martin , Jelenik Tomas , Jilkova Zuzana , Slamova Kristyna , Kus Vladimir , Hensler Michal , Medrikova Dasa , Povysil Ctibor , Flachs Pavel , Mohamed‐Ali Vidya , Bryhn Morten , Berge Kjetil , Holmeide Anne K. , Kopecky Jan
Published: January 2009

The n‐3 polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exert hypolipidemic effects and prevent development of obesity and insulin resistance in animals fed high‐fat diets. We sought to determine the efficacy of α‐substituted DHA derivatives as lipid‐lowering, antiobesity, and antidiabetic agents. C57BL/6 mice were given a corn oil‐based high‐fat (35% weight/weight) diet (cHF), or cHF with 1.5% of lipids replaced with α‐methyl DHA ethyl ester (Substance 1), α‐ethyl DHA ethyl ester (Substance 2), α,α‐di‐methyl DHA ethyl ester (Substance 3), or α‐thioethyl DHA ethyl ester (Substance 4) for 4 months. Plasma markers of glucose and lipid metabolism, glucose tolerance, morphology, tissue lipid content, and gene regulation were characterized. The cHF induced obesity, hyperlipidemia, impairment of glucose homeostasis, and adipose tissue inflammation. Except for Substance 3, all other substances prevented weight gain and Substance 2 exerted the strongest effect (63% of cHF‐controls). Glucose intolerance was significantly prevented (∼67% of cHF) by both Substance 1 and Substance 2. Moreover, Substance 2 lowered fasting glycemia, plasma insulin, triacylglycerols, and nonesterified fatty acids (73, 9, 47, and 81% of cHF‐controls, respectively). Substance 2 reduced accumulation of lipids in liver and skeletal muscle, as well as adipose tissue inflammation associated with obesity. Substance 2 also induced weight loss in dietary obese mice. In contrast to DHA administered either alone or as a component of the EPA/DHA concentrate (replacing 15% of dietary lipids), Substance 2 also reversed established glucose intolerance in obese mice. Thus, Substance 2 represents a novel compound with a promising potential in the treatment of obesity and associated metabolic disturbances.
Innate Immunity and Adipocyte Function: Ligand‐specific Activation of Multiple Toll‐like Receptors Modulates Cytokine, Adipokine, and Chemokine Secretion in Adipocytes
Authors: Kopp Andrea , Buechler Christa , Neumeier Markus , Weigert Johanna , Aslanidis Charalampos , Schölmerich Juergen , Schäffler Andreas
Published: January 2009

The aim of this study was to analyze Toll‐like receptor (TLR) expression in preadipocytes and mature adipocytes and to investigate whether TLR ligands influence the release of cytokines, chemokines, and adipokines. Murine 3T3‐L1 preadipocytes and mature adipocytes were used for stimulation experiments. The effects of lipopolysaccharide (LPS), flagellin, Poly (U), Poly (I:C), macrophage‐activating lipopeptide‐2 (MALP2), Pam3Cys, and CpG on the release of interleukin‐6 (IL‐6), resistin, and monocyte chemoattractant protein‐1 (MCP‐1) were determined by enzyme‐linked immunosorbent assay (ELISA). Nuclear translocation and promoter binding of NFκB were analyzed by electrophoretic mobility shift assays. TLR expression was investigated by reverse‐transcriptase (RT‐PCR). All TLRs except TLR5 and TRL7 are expressed in the stromal vascular cell (SVC) fraction and in mature adipocytes of different fat stores. Whereas basal and LPS‐induced IL‐6 release is higher in preadipocytes, basal and LPS‐induced MCP‐1 release is higher in mature adipocytes. Mature adipocytes respond to corticosterone regarding MCP‐1 and resistin release. The ligands for TLRs influence IL‐6, MCP‐1, and resistin release differentially. Some of these ligands induce nuclear translocation and promoter binding of NFκB. Besides TLR5, that is not expressed in mature adipocytes, all TLR family members are involved. There exists a functional TRL pathway in adipocytes that connects innate immunity with adipocyte function. As a consequence, the role of the adipose tissue in both immunity and metabolism has to be investigated in future studies. The results of this approach will help to explain the metabolic changes such as insulin resistance observed during infection and the immunological phenomena such as macrophage infiltration of adipose tissue seen in obesity.
Exploiting Social Networks to Mitigate the Obesity Epidemic
Authors: Bahr David B. , Browning Raymond C. , Wyatt Holly R. , Hill James O.
Published: January 2009

Despite significant efforts, obesity continues to be a major public health problem, and there are surprisingly few effective strategies for its prevention and treatment. We now realize that healthy diet and activity patterns are difficult to maintain in the current physical environment. Recently, it was suggested that the social environment also contributes to obesity. Therefore, using network‐based interaction models, we simulate how obesity spreads along social networks and predict the effectiveness of large‐scale weight management interventions. For a wide variety of conditions and networks, we show that individuals with similar BMIs will cluster together into groups, and if left unchecked, current social forces will drive these groups toward increasing obesity. Our simulations show that many traditional weight management interventions fail because they target overweight and obese individuals without consideration of their surrounding cluster and wider social network. The popular strategy for dieting with friends is shown to be an ineffective long‐term weight loss strategy, whereas dieting with friends of friends can be somewhat more effective by forcing a shift in cluster boundaries. Fortunately, our simulations also show that interventions targeting well‐connected and/or normal weight individuals at the edges of a cluster may quickly halt the spread of obesity. Furthermore, by changing social forces and altering the behavior of a small but random assortment of both obese and normal weight individuals, highly effective network‐driven strategies can reverse current trends and return large segments of the population to a healthier weight.
GAPDH binds GLUT4 reciprocally to hexokinase-II and regulates glucose transport activity
Authors: Zaid Hilal , Talior-Volodarsky Ilana , Antonescu Costin , Liu Zhi , Klip Amira
Published: January 2009

Dietary glucose is taken up by skeletal muscle through GLUT4 (glucose transporter 4). We recently identified by MS proteins displaying insulin-dependent co-precipitation with Myc-tagged GLUT4 from L6 myotubes, including GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and HKII (hexokinase-II). In the present paper we explored whether GAPDH and HKII interact directly with cytoplasmic regions of GLUT4 and their possible inter-relationship. Endogenous and recombinant GAPDH and HKII bound to a chimeric protein linearly encoding all three cytosolic domains of GLUT4 [GST (glutathione-transferase)–GLUT4-cyto]. Both proteins bound to a lesser extent the middle cytosolic loop but not individual N- or C-terminal domains of GLUT4. Purified GAPDH and HKII competed for binding to GST–GLUT4-cyto; ATP increased GAPDH binding and decreased HKII binding to this construct. The physiological significance of the GAPDH–GLUT4 interaction was explored by siRNA (small interfering RNA)-mediated GAPDH knockdown. Reducing GAPDH expression by 70% increased HKII co-precipitation with GLUT4–Myc from L6 cell lysates. GAPDH knockdown had no effect on surface-exposed GLUT4–Myc in basal or insulin-stimulated cells, but markedly and selectively diminished insulin-stimulated 3-O-methyl glucose uptake and GLUT4–Myc photolabelling with ATB-BMPA {2-N-[4-(1-azitrifluoroethyl)benzoyl]-1,3-bis-(D-mannos-4-yloxy)-2-propylamine}, suggesting that the exofacial glucose-binding site was inaccessible. The results show that GAPDH and HKII reciprocally interact with GLUT4 and suggest that these interactions regulate GLUT4 intrinsic activity in response to insulin.
Mitochondrial carrier protein biogenesis: role of the chaperones Hsc70 and Hsp90
Authors: Zara Vincenzo , Ferramosca Alessandra , Robitaille-Foucher Philippe , Palmieri Ferdinando , Young Jason C.
Published: January 2009

Metabolite carrier proteins of the mitochondrial inner membrane share homology in their transmembrane domains, which also carries their targeting information. In addition, some carriers have cleavable presequences which are not essential for targeting, but have some other function before import. The cytosolic chaperones Hsc70 (heat-shock cognate 70) and Hsp90 (heat-shock protein 90) complex with carrier precursors and interact specifically with the Tom (translocase of the mitochondrial outer membrane) 70 import receptor to promote import. We analysed how the presequences of the PiC (phosphate carrier) and CIC (citrate carrier) relate to the mechanisms of chaperone-mediated import. Deletion of the PiC presequence reduced the efficiency of import but, notably, not by causing aggregation. Instead, binding of the protein to Hsc70 was reduced, as well as the dependence on Hsc70 for import. Hsp90 binding and function in import was not greatly affected, but it could not entirely compensate for the lack of Hsc70 interaction. Deletion of the presequence from CIC was shown to cause its aggregation, but had little effect on the contribution to import of either Hsc70 or Hsp90. The presequence of PiC, but not that of CIC, conferred Hsc70 binding to dihydrofolate reductase fusion proteins. In comparison, OGC (oxoglutarate carrier) lacks a presequence and was more soluble, though it is still dependent on both Hsc70 and Hsp90. We propose that carrier presequences evolved to improve targeting competence by different mechanisms, depending on physical properties of the precursors in the cytosolic targeting environment.
The role of the renin–angiotensin–aldosterone system in cardiovascular progenitor cell function
Authors: Qian Cheng , Schoemaker Regien G. , van Gilst Wiek H. , Roks Anton J. M.
Published: January 2009

Intervention in the RAAS (renin–angiotensin–aldosterone system) is one of the leading pharmacotherapeutic strategies, among others, used for the treatment of cardiovascular disease to improve the prognosis after myocardial infarction and to reduce hypertension. Recently, regenerative progenitor cell therapy has emerged as a possible alternative for pharmacotherapy in patients after myocardial infarction or ischaemic events elsewhere, e.g. in the limbs. Angiogenic cell therapy to restore the vascular bed in ischaemic tissues is currently being tested in a multitude of clinical studies. This has prompted researchers to investigate the effect of modulation of the RAAS on progenitor cells. Furthermore, the relationship between hypertension and endothelial progenitor cell function is being studied. Pharmacotherapy by means of angiotensin II type 1 receptor antagonists or angiotensin-converting enzyme inhibitors has varying effects on progenitor cell levels and function. These controversial effects may be explained by involvement of multiple mediators, e.g. angiotensin II and angiotensin-(1–7), that have differential effects on mesenchymal stem cells, haematopoietic progenitor cells and endothelial progenitor cells. Importantly, angiotensin II can either stimulate endothelial progenitor cells by improvement of vascular endothelial growth factor signalling, or invoke excessive production of reactive oxygen species causing premature senescence of these cells. On the other hand, angiotensin-(1–7) stimulates haematopoietic cells and possibly also endothelial progenitor cells. Furthermore, aldosterone, bradykinin and Ac-SDKP (N-acetyl-Ser-Asp-Lys-Pro) may also affect progenitor cell populations. Alternatively, the variability in effects of angiotensin II type 1 receptor and angiotensin-converting enzyme inhibition on cardiovascular progenitor cells might reflect differences between the various models or diseases with respect to circulating and local tissue RAAS activation. In the present review we discuss what is currently known with respect to the role of the RAAS in the regulation of cardiovascular progenitor cells.
The power of light: Self-organized formation of macroscopic amounts of silica melts controlled by laser light
Authors: Günster J. , Oelgardt C. , Heinrich J. G. , Melcher J.
Published: January 2009

C O 2 laser systems with a power output of up to 12kW continuous wave have been employed for melting high purity amorphous silica (SiO2) powders. Under the intense light irradiation, the migration of matter on the silica sample has been observed. A net mass transport results in the formation of macroscopic structures in the liquid phase. Protrusions of up to 7mm height are formed against gravitational force and surface tension. For the first time, this work reports on the self-organized formation of macroscopic structures by viscous flow of a dielectric melt driven by laser light.
Phimsy
Authors: Ellis R. Hobart , Alvarez Luis W. , Sears Francis W.
Published: January 2009

The new Trieste prizes; A break for Galileo; Allison and positronium; Perpetual-motion solution; When a super is a semi.
The status-discussion meeting as an antidote to superconferences
Authors: Moravcsik Michael J.
Published: January 2009

IN 1931 ENRICO FERMI organized a small meeting to deal with the new, small field of nuclear physics. The handful of active and generally young physicists who were invited each reviewed a different aspect of nuclear physics. They spent the rest of this status-discussion meeting in informal discussions, accentuated by excursions.
Phimsy
Authors: Ellis R. Hobart
Published: January 2009

A visit from Daedalus; How do you get it across?.
A Visit to the Physics Institute of the USSR Academy of Sciences
Authors: Lubkin Gloria B.
Published: January 2009

The Physics Institute of the Academy of Sciences, also known as FIAN or the Lebedev Institute, is the largest physics research establishment in the Soviet Union, employing 1000 scientists and 2000 other staff. When we recently visited Moscow, Nikolai G. Basov, who shared the Nobel Prize for discovery of the laser, gave us a tour of the quantum-electronics laboratory. His laboratory is famous for its diversity of research and the talent of its physicists.
We need more intense thermal-neutron beams
Authors: Brugger Robert M.
Published: January 2009

NEW SCHEMES FOR producing neutrons can dramatically increase thermal fluxes. One proposed method would produce short, intense pulses (figure 1) while another would make steady fluxes at a greater average intensity than sources that now exist.
A Visit to the Ioffe Physicotechnical Institute in Leningrad
Authors: Lubkin Gloria B.
Published: January 2009

One of the leading Soviet centers for research in solid state, quantum electronics, nuclear and plasma physics, the Ioffe Physicotechnical Institute in Leningrad employs 2000 persons. When we visited the institute last summer we spoke with V. M. Tuchkevich, recently named director, and many others, and learned of varied work in semiconductors, including heterojunction lasers, II-IV-V compounds, cyclotron waves in semimetals, and band tailing.
Further Tests to Decide Between Gravity Theories
Authors: Present Gerald
Published: January 2009

Several experiments, either in preparation or in operation, may provide further evidence for deciding between general relativity and the scalar-tensor theories of gravitation.
A Correction
Authors: Roemer Elizabeth
Published: January 2009

PHYSICS TODAY stated my address incorrectly in September. Since June 1966 I have been an associate professor of astronomy at the University of Arizona, Tucson and in the Lunar and Planetary Laboratory.
Group theory in particle studies
Authors: Tuan San Fu
Published: January 2009

UNITARY-SYMMETRY theories have had great success in the classification of particles in group-theory representations and the prediction of the dimensions of these representations. Yet many particle physicists now believe that symmetry-breaking effects of a given symmetry scheme, by mediumstrong, electromagnetic and weak interactions, are their most beautiful feature. Mass spectra and selection rules for transitions can be derived from these effects; so that we are taken into the heart of the physics. Quarks, or other triplets, are still hiding from experimenters; it is to group-theory studies that we look for information on their probable properties and the best places to look for them. Group theory is also required to assign the higher baryon and meson resonances (figures 1 and 2) into their classification schemes.
Introductory physics textbooks
Authors: Roll Peter G.
Published: January 2009

DURING THE ACADEMIC YEAR 1961–62, the only year for which reliable information has been collected, almost 190 000 students were enrolled in the first term of one of approximately 1700 introductory physics courses offered by the nation's two- and four-year colleges, universities and technical institutes. A reasonable extrapolation of these figures from the intervening six years suggests that this spring and summer about 2000 physics professors must decide either to continue using their present introductory texts or to select a new one from among a dozen or two that are intended for their particular kind of introductory course. These decisions determine what books are purchased by well over 200 000 students next fall, and how the $1 or $2 million gross receipts from the sale of new introductory physics textbooks are distributed among the various publishers.
Phimsy
Authors: Ellis R. Hobart
Published: January 2009

Cerenkov acoustics; Few reprint requests. Why?; Poet Gove of Oak Ridge; The physicists' secretary; Do it with a ruler; Sorry about that ad.
Thermodynamics of critical points
Authors: Domb Cyril
Published: January 2009

NEW EXPERIMENTAL TECHNIQUES have been joined by novel theoretical approaches to give great impetus to the study of phase transitions. The systems studied include vapors near their critical points, ferromagnets near their Curie temperatures, antiferromagnets near their Néel points and the superfluid transitions. All these phase transitions, although apparently very different, show surprising similarities in their behavior near the critical point.
A Visit to Argonne Laboratory—I: High-Energy Physics Research
Authors: Lubkin Gloria B.
Published: January 2009

Although the reputation of Argonne National Laboratory was founded on its reactor-development program, the laboratory is now perhaps equally famous for work in high-energy physics with the Zero Gradient Synchrotron (ZGS), nuclear, solid-state and atomic physics.
Five four-year colleges: Carleton College
Authors: Reitz Robert A.
Published: January 2009

A STRONG BASIS FOR GRADUATE STUDY underlies the physics curriculum at Carleton College. The staff of the physics department at our small liberal-arts college in Northfield, Minn, consists of five physicists and two technicians, and with this limited personnel we have not been able to set up an alternate track for those students intending to go into high-school teaching or to seek employment with only the bachelor's degree.
Five four-year colleges: Swarthmore College
Authors: Elmore William C.
Published: January 2009

THE SWARTHMORE HONORS PROGRAM, initiated in 1922 by President Frank Ayedelotte, has come to distinguish Swarthmore's educational processes and results from those of most other colleges and universities. In recent years about 90% of those majoring in physics have either obtained doctoral degrees or are currently pursuing graduate work in physics at schools such as Cornell, Yale, Harvard and Princeton; the complete list includes at least 20 different universities. Swarthmore graduates are on the physics faculties of more than 25 colleges and universities, as well as on the staffs of most of the national laboratories.
Four universities: University of California at Berkeley
Authors: Moyer Burton J.
Published: January 2009

THE DEPARTMENT OF PHYSICS at Berkeley is a member of the College of Letters and Science. As such it shares actively in the efforts of the college to evolve and provide the components of a liberal education. Furthermore such efforts are intended to be consistent with the increasing demand that the physical sciences should make themselves more generally understood in spirit and significance by the nonscientist in the educated populace.
Four universities: University of Chicago
Authors: Inghram Mark G.
Published: January 2009

THE EMPHASIS IN the physics curriculum at the University of Chicago is strongly influenced by two rare characteristics of the university. First, it is one of the very few universities with neither an engineering nor an applied science program. Second, the university is one of the few schools in which graduate students outnumber undergraduates. At Chicago there are 5700 graduate students and 2600 undergraduates. Within the physics department the corresponding numbers are 200 and 120. Because of both of these characteristics, the department does not have the heavy undergraduate teaching load common to most universities.
An English university: Imperial College, London
Authors: Butler Clifford C.
Published: January 2009

MOST STUDENTS IN BRITAIN who intend to become professional physicists study for a Bachelor of Science degree with honors. The undergraduate physics school at Imperial College consists almost entirely of physics majors preparing for this degree of the University of London; they devote almost all of their time to physics and the necessary required mathematics. They are unlikely to take any humanities courses although some universities expect a modest performance in one or more foreign languages. In England and Wales the physics honors courses are spread over three years, but in Scotland they usually last four years.
Spectroscopy, quantum chemistry and molecular physics
Authors: Mulliken Robert S.
Published: January 2009

CERTAIN AREAS OF RESEARCH that used to be actively pursued by people called physicists in physics laboratories have now to a large extent, although not entirely, migrated to chemistry laboratories. Among the most prominent of the areas that have moved from physics toward chemistry are molecular spectroscopy, the theory of molecular structure and spectra and certain related areas, for example molecular mass spectroscopy. All these various areas are usually called “molecular physics” if carried on in physics departments or “chemical physics” if in chemistry departments.
Berkeley Balloon to Do High-Energy Physics Experiments
Authors: Lubkin Gloria B.
Published: January 2009

You can still do high-energy physics these days with cosmic rays, but the detectors are 15 meters high and you fly them with a balloon.
Twenty years of physics: Atoms, molecules and electrons
Authors: Branscomb Lewis M.
Published: January 2009

CAN WE EVEN REMEMBER atomic, molecular and electron physics 20 years ago? When fine-structure states of atomic hydrogen were still happily degenerate according to Dirac theory, and there was no conclusive demonstration to the contrary? When the dissociation energies of the simplest molecules such as nitrogen and carbon monoxide were unknown? When you could call an electron beam with 1-eV energy spread a “monoenergetic beam” and leave the audience smiling approvingly?
Twenty years of physics: High-polymer physics
Authors: Mark Herman F.
Published: January 2009

STUDY OF ORGANIC polymers in the solid state began in the early 1920's with x-ray investigation of natural representatives such as cellulosic fibers, starch, silk, wool, rubber and certain resins; the general, qualitative result was that all these materials, despite their chemical dissimilarity, produce x-ray diffraction patterns indicating a certain degree of molecular regularity. Together with the concept of substantially linear chain-like macromolecules, these findings led to the conclusion that, in the polymeric solid state, there are volume elements or domains with essentially parallel chains. They have a three-dimensional geometrical regularity that resembles the structure of a crystal. Other volume elements, however, are occupied by other portions of the same chains; here individual segments are irregularly arranged so that these domains possess the structural characteristics of a liquid or a glass.
Twenty years of physics: Rheology
Authors: Marvin Robert S.
Published: January 2009

IN ITS PAST two decades rheology has been mainly concerned with development of models that represent the mechanical behavior of various types of materials, measurements required to test such models and evaluate the functions they predict, and theories required to relate models and measurements. The results are important not only for their academic significance but also for industrial processes like extrusion.
Twenty years of physics: Acoustics
Authors: Lindsay R. Bruce
Published: January 2009

THE SCIENCE OF ACOUSTICS touches on practically every aspect of human experience; hence it advances on broad fronts ranging all the way from basic physics and chemistry through most branches of engineering to the life sciences. The extent of its development during the past two decades may in some measure be gauged by the growth in membership of the Acoustical Society of America from 1300 in 1947 to 4150 in 1967. During the same period the number of pages published per year in the Society's Journal grew from less than 1000 in 1947 to 4150 in 1967. This is typical of the world progress in acoustics.
Twenty years of physics: The solar system
Authors: Cameron A. G. W.
Published: January 2009

BOUNCING RADAR SIGNALS off the moon was considered quite a feat 20 years ago. Today they are being bounced off planets on the other side of the sun. This accomplishment is symbolic of the enormous expansion in our knowledge of the solar system that has taken place in the last two decades. The expansion has resulted jointly from the development of new technology and from the large investment in the space program and in geophysical and astrophysical research.
Twenty years of Physics Today: The early years
Authors: Barton Henry A.
Published: January 2009

WHEN, AT LAST, IN May 1948 the first issue of PHYSICS TODAY appeared, it ended a long stretch of wishing, dreaming, planning and figuring. Such a periodical had long been wanted to vivify the whole idea of the American Institute of Physics-bringing mutually unacquainted specialists in all branches of physics together into a kind of operational unity for enhancement of physics as an important field of human endeavor. We expected PHYSICS TODAY to provide a better cement than just a paper constitution or even the zeal of those few who served terms on the institute governing board. Part of the essential aim was to present the special fields in interesting terms that all physicists and most laymen could understand.
The AIP in 1967
Authors: Johnsrud John
Published: January 2009

IN 1967 THE American Institute of Physics took some important steps into the future.
Los Alamos Prototype Tests Meson-Factory Linac Design
Authors: Ellis R. Hobart
Published: January 2009

Something new in accelerator design is the electron linear accelerator that recently came into operation at Los Alamos. Although it produces a useful beam of its own, it is mainly a prototype for the 800-MeV, 1-milliampere proton linac that will one day be the Los Alamos meson factory LAMPF (PHYSICS TODAY, December 1966, page 21, November 1967, page 75 and April 1968, page 81). Louis Rosen, director of the medium-energy-physics division, is in overall charge of meson-factory development. This month a users' meeting is being held at Los Alamos.
Phimsy
Authors: Ellis R. Hobart
Published: January 2009

Launching pad at Jodrell Bank; Ruark named positronium; A little learning—and too much; Telescope king dethroned; Particles and Zen tunnels; Sorry about that.
High Uniaxial Stress on Germanium Causes Gunn-Effect Oscillations
Authors: Lubkin Gloria B.
Published: January 2009

By applying 10 000–20 000 atmospheres along the [111] axis of n-type germanium at room temperature, John E. Smith Jr at IBM Watson Research Center has produced microwave current oscillations. Smith attributes the oscillations to bulk negative differential conductivity.
Astronomers Need More Observations to Explain Pulsars
Authors: Scott John T.
Published: January 2009

More information is available now on the four pulsed radio sources discovered last December at Cambridge, but no new ones have been found and theoreticians still argue about what they are. Called “pulsars,” these sources emit pulses at radio wavelengths with remarkably constant repetition intervals that range in the four known cases from 0.25 to 1.33 sec (PHYSICS TODAY, May, page 75). We recently visited the Mullard Radio Observatory at Cambridge and the Nuffield Radio Observatory of the University of Manchester at Jodrell Bank to talk to astronomers engaged in these observations.
Electric Fields May Bedevil Falling-Electron Experiment
Authors: Ellis R. Hobart
Published: January 2009

In an evacuated field-free space pennies, feathers and electrons should all fall with the same acceleration according to all the standard theories of gravitation. At the Washington meeting of the American Physical Society Fred C. Witteborn reported on an experiment he and William M. Fairbank have been doing at Stanford. It seems to confirm this expectation for individual electrons although not everyone is convinced of its results.
Dualism in quantum theory
Authors: Born Max , Biem Walter
Published: January 2009

IN RECENT YEARS Alfred Landé has tried to give a new foundation for quantum theory, starting with statistical nonquantal principles that have not been taken from classical physics. In his books and articles he attacks the basic concept of quantum theory that is generally taken for granted by most physicists nowadays. He calls this concept “dualistic” and maintains that he can replace it by another more unified one.
Nuclear research as a source of technology
Authors: Havens William W.
Published: January 2009

RECENTLY THE VALUE of pure research to the US nation has come into question. Although the federal government has steadily increased its support of pure research since the Second World War, attempts to determine the value of pure-research activities to the national economy have been inconclusive. Project Hindsight concluded that very little basic research carried on in university laboratories had contributed to the development of weapons systems since the war and implied that consequently there was little point in the Defense Department's continued support of pure research in universities. On the other hand, those individuals who support increased funding of pure research by the federal government point out that the nation's most rapidly growing industries are those that have invested most heavily in research, with the implied conclusion that an investment in pure research will result in an expanded national economy.
Lasers Offer Satellites Better Ways to Communicate
Authors: Boyer Howard
Published: January 2009

What happens to the wavefront of a beam of coherent light as it is propagated through the atmosphere? The question has become one of vital interest to space scientists, and is answerable now that we can study, for the first time, light sent out into space by lasers, as well as that originating from an external source such as a star. The answer will affect the development of optical space-communication systems (destined to supplement present microwave telemetry channels) and precision laser tracking for satellite-orbit determination, geodesy and lunar-motion studies.
The national register looks at manpower
Authors: Barisch Sylvia , Johnides Theodora
Published: January 2009

DATA FROM THE 1968 National Register of Scientific and Technical Personnel showed that the physics and astronomy group

• earned a median salary of $14 000, the highest in the physical sciences and $800 higher than the median for all scientists.

• had the largest proportion of PhD's (447%) in the physical sciences and had 33% at a master's-degree level.

• was chiefly employed by educational institutions (48%) but only 21% were primarily teachers. 50% worked in research and development.

• had 56% receiving support for federal programs. This group did not include government employees.
Nuclear safeguards: 2. The US program
Authors: Higinbotham William A.
Published: January 2009

THE DOMESTIC PROBLEM of nuclear safeguards is that of ensuring, so far as possible, that significant amounts of nuclear materials do not become lost, strayed or stolen, and to do so without interfering unnecessarily with free enterprise and at a price that the nation can reasonably afford. In the US responsibility lies largely with the Atomic Energy Commission, in its Office of Safeguards and Materials Management (OSMM) and its Division of Nuclear Materials Safeguards (DNMS). Physicists are contributing to the safeguards program by perfecting the technical means to carry out policy.
Hundred-Joule Lasers Are Producing High-Temperature Plasmas
Authors: Lubkin Gloria B.
Published: January 2009

Lasers producing hundreds of joules in pulses lasting nanoseconds to picoseconds are now being used to produce high-temperature plasmas.
Phimsy
Authors: Ellis R. Hobart
Published: January 2009

Physicists can paint doors; New in nuclear power.
Nucleon–nucleon scattering
Authors: Mac Gregor Malcolm H.
Published: January 2009

DETERMINATION OF THE fundamental law of force between two nucleons has occupied many physicists for the past three decades. Because the proton and electron have obvious similarities (elementarily, spin of 1/2, equal-but opposite electric charge, Fermi statistics, antiparticles) the derivation of a nuclear “Coulomb's law” would seem to be a just reward for working in this area. As we have rather slowly and laboriously learned, however, simplicity appears to be inversely proportional to some power of the coupling constant.
New information program for AIP
Authors: Herschman Arthur , Alt Franz L. , Koch H. William
Published: January 2009

THE AMERICAN INSTITUTE OF PHYSICS, with support from the National Science Foundation, is currently engaged in a major effort to develop and implement a computer-assisted “National Information System for Physics.” Designed by physicists, for physicists, the new system is scheduled to begin pilot operations early next year. We at AIP believe the system to be urgently needed, but how do you, the physicists, feel about it?
Phimsy
Authors: Ellis R. Hobart , Mackay Alan
Published: January 2009

Physicists on coins; Some meetings are informative; The Special Theory of Relativity; The Fairbank Anti-Murphy Law; D'Abro: the search goes on.
Form factors of elementary particles
Authors: Wilson Richard
Published: January 2009

How BIG ARE the elementary particles? How is their charge distributed? These questions are tackled with form factors, which are measures of the charge and magnetic-moment distributions in the particles. Scattering of electrons on nucleons, and recent measurements made with electron–positron colliding beams, give form factors for the proton, neutron and pion. The behavior of the pion form factor can be fairly well understood by the “rho-dominance model,” but the nucleon form factors are not so easy to understand. Different models are currently being examined in an attempt to solve this basic problem in strong-interaction physics.
AAPT–APS meeting returns to New York
Authors: Wiley John P.
Published: January 2009

THE JOINT ANNUAL MEETING of the American Physical Society and the American Association of Physics Teachers returns to the New York Hilton 3–6 Feb. after its first venture to Chicago last year. Lagging support for physics promises to be a leading topic of hallway conversation, perhaps symbolized by the first drop in the number of contributed papers at a New York APS meeting since 1945.
Atoms
Authors: Hughes Vernon W.
Published: January 2009

A WEALTH OF KNOWLEDGE, theoretical and experimental, is encompassed in the ever expanding field of atomic study, one of the oldest branches of modern physics. Quantum electrodynamics, one of the most complete and best verified modern physical theories, has been developed largely through studies in atomic physics and has sustained all experimental challenges of the past 20 years, including precise measurements of the Lamb shift, electron and muon gyromagnetic ratios, and of positronium and muonium hyperfine structure. Yet major questions remain unsolved, such as the divergences in the theory, the calculation of the value of the fine-structure constant and the relation of the muon and the electron—questions that must be formulated in the broader framework of elementary-particle physics. Invariance and symmetry principles play an important role in atomic physics; space reflection, time reversal and charge-conjugation invariances can be tested for the electromagnetic interactions. Atomic structure, atomic collisions, muonic and mesic atoms, quantum electronics and applications in astrophysics and other fields of science are parts of the frontier of modern atomic physics.
Positron beams
Authors: Yount David E.
Published: January 2009

POSITIVE ELECTRONS, which offer interesting comparisons with negative electrons and can be a useful source of photons, may be made by pair production in a target placed in the electron path of a linear accelerator. Greater intensity can be achieved by acceleration, by a coaxial solenoid, with magnetic quadrupoles or by a solenoid-quadrupole combination. One important application of these positron beams is the production of “tertiary” beams of annihilation photons that can provide a partially monochromatic photon beam. Other applications include positron-proton and electron-proton scattering comparisons and colliding-beam experiments in which electrons are injected at high energies into storage rings.
Space, time and elementary interactions in relativity
Authors: Sachs Mendel
Published: January 2009

A REASONABLE COURSE of investigation in fundamental physics should fully exploit Einstein's approach to the meaning of space—time; it would proceed by exploring, in a unified way, the predictions of generalized equations of general relativity that would encompass in one formalism all of the domains of interaction—from fermis to light years.
How does he fare in Britain?
Authors: Butler Clifford C.
Published: January 2009

DURING THE LAST FEW YEARS there has been a remarkable growth in the numbers of graduate students reading for the PhD in physics at British universities. A time of financial stringency has now arrived, however, and, inevitably, many searching questions are being asked. For example: Are we training too many physicists up to the PhD standard? How does the quality of our PhD's compare with that from the best graduate schools in the US?
What does he study?
Authors: Strassenburg Arnold A. , Llano Margaret T.
Published: January 2009

DIVERSITY AND QUALITY of academic programs offered by a university as well as the undergraduate physics prerequisites that a prospective graduate student must satisfy are two of the most important criteria that determine selection of a graduate school. Students are attracted to a particular university by the research specialities available, the quality of the faculty and the size of the department.
Where does he come from? Where does he go?
Authors: Ellis Susanne D.
Published: January 2009

STATISTICAL ANALYSIS of US graduate physics education in the last five years reveals fairly stable patterns of where the students come from and where they go. Now, however, changes in these patterns are widely expected because of the drafting of graduate students and shrinking federal support.
Crab Pulsar Optically Identified; Other Pulsars Show Slowdown
Authors: Lubkin Gloria B.
Published: January 2009

Pulsar NP 0532, near the center of the Crab Nebula, pulses optically with the same period as its radio emissions, according to W. John Cocke, Michael J. Disney and Donald J. Taylor of the Steward Observatory (International Astronomical Union Circular No. 2128, 1969). The University of Arizona group, using a 36-inch reflector, discovered light flashing at the apparent radio period of 0.033095 sec from the region of a well known starlike object in the nebula.
Phimsy
Authors: Ellis R. Hobart , Swing Richard E.
Published: January 2009

The geography of parity; Physics learns the hard sell; To learn big, study small; The cost of calories; Sonnet on Maxwell's Equations; Fusion power at last; Quarks are up—and down.
Continental drift
Authors: Turcotte Donald L. , Oxburgh E. Ronald
Published: January 2009

TODAY MOST EARTH SCIENTISTS accept continental drift as a geological fact. Relative movements between continents on a time scale of 108 years are necessary to explain many geological observations. The remarkable similarity in shape between the west coast of Africa and the east coast of South America has been recognized for nearly as long as accurate maps of the Atlantic have been available; many have assumed that these continents once were connected. It is also accepted that the continents float on the mantle much like blocks of wood on water.
Isobaric analog resonances
Authors: Coker W. Rory , Moore C. Fred
Published: January 2009

WITHIN THE LAST FIVE YEARS, exploitation of isobaric analog resonances to obtain detailed information concerning the structure of atomic nuclei has become a standard, if somewhat mysterious, technique in the repertoire of experimental nuclear physicists. The precise nature and structure of isobaric analog resonances in nuclei are apparently not well understood by anyone at the present time, because the nuclear configurations involved are exceedingly complicated. Fortunately, however, it is easy to understand many of the properties of analog resonances that make them valuable to experimentalists and a topic of lively interest and sometimes controversy among students of nuclear structure.
Artsimovich talks about controlled-fusion research
Authors: Tuck James L. , Lubkin Gloria B.
Published: January 2009

LEV ARTSIMOVICH is secretary of the physics–mathematics section of the USSR Academy of Sciences, chairman of its council on plasma physics and directs the plasma-physics division of the Kurchatov Institute in Moscow. He is also involved in construction of the great 6-meter optical telescope, which will probably be the world's largest when completed.
Phimsy
Authors: Ellis R. Hobart , Sickle Clay
Published: January 2009

Our growing Gamow Collection; Physics has versatility; American physicist on a coin.
Biomedical applications of holography
Authors: Feleppa Ernest J.
Published: January 2009

WITH THE SIMPLICITY of its fundamental theory and the simplicity of its application, holography is an elegant concept. Moreover it is versatile, being applicable to a variety of imaging and nonimaging problems. Holography certainly warrants serious consideration by biological and medical researchers as a valuable addition to the list of physical techniques that have become essential to them.
Probing quantum efficiency by laser-induced hot-electron cooling
Authors: Vitiello Miriam S. , Scamarcio Gaetano , Faist Jerome , Scalari Giacomo , Walther Christophe , Beere Harvey E. , Ritchie David A.
Published: January 2009

Experimental evidence of a physical phenomenon characteristic of semiconductor lasers, i.e., cooling of the electrons above the threshold for stimulated emission, is reported. We show that this effect is directly related with the internal quantum efficiency (ηint), which is one of the central physical quantities in the theory of semiconductor lasers. As a model system we selected the terahertz quantum-cascade laser that is particularly suitable for the investigation of nonequilibrium electronic ensembles. The reported procedure for the assessment of ηint can be easily extended to other model systems, enlightening the relevance of including hot-electron distributions in semiconductor laser modeling.
Fedosov and Riemannian supermanifolds
Authors: Asorey M. , Lavrov P. M.
Published: January 2009

Generalizations of symplectic and metric structures for supermanifolds are analyzed. Two types of structures are possible according to the even/odd character of the corresponding quadratic tensors. In the even case, one has a very rich set of geometric structures: even symplectic supermanifolds (or, equivalently, supermanifolds with nondegenerate Poisson structures), even Fedosov supermanifolds, and even Riemannian supermanifolds. The existence of relations among those structures is analyzed in some detail. In the odd case, we show that odd Riemannian and Fedosov supermanifolds are characterized by a scalar curvature tensor. However, odd Riemannian supermanifolds can only have a constant curvature. Supersymmetric extensions of Anti de Sitter spaces are considered.
Theory of antibunching of photon emission I
Authors: Seki Kazuhiko , Tachiya M.
Published: January 2009

The photon emission statistics from a single molecule containing multichromophores under pulsed excitation is theoretically studied. Fast nonradiative pair annihilation of excitons efficiently produces a single exciton, which acts as a single photon emitter. By taking into account the discrete nature of exciton numbers and the competition among pair annihilation, and unimolecular radiative and nonradiative decay of excitons, we obtain analytical expressions of photon emission statistics, the average number of emitted photons, and the normalized photon pair correlation which represents the ratio of the number of photon pairs created by the same pulse to that created by different pulses. The normalized photon pair correlation is influenced by the ratio of the pair annihilation rate to the total unimolecular decay rate including both radiative and nonradiative processes but is not influenced by the ratio of the unimolecular radiative and nonradiative rates. On the other hand, the single photon emission intensity depends on the ratio of the unimolecular radiative and nonradiative rates from the exciton left alone after pair annihilation. The conclusion is consistent with recent experimental results on conjugated polymers with various sizes in different host materials.
Kinetic energy density study of confined noninteracting fermions: The importance of the angular momentum
Authors: Martín-Blas T. , García-Aldea David , Alvarellos J. E.
Published: January 2009

In this work we present a study of the kinetic energy density of an arbitrary number of noninteracting fermions confined in a Coulombic potential. We present the results for the total kinetic energy and the kinetic energy density using three simple but representative functionals: Thomas–Fermi, von Weizsäker, and the second order gradient expansion approximation. In order to assess their quality, the deviation of the kinetic energy density of every functional is measured through a parameter that reflects the quality of the functionals in a better way than their relative errors (for that reason, we call it quality factor). Trying to understand the performance of the different functionals we study degenerate states with the same energy but different angular momenta and densities. Therefore, the functionals’ ability to capture the effects of each density corresponding to the different angular momenta is discussed, as well as the trends of these contributions.