bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Late Reproduction Extend the Life Span? Findings from European Royalty
Authors: Mueller Ulrich
Published: September 2004

Statistical associations between late reproduction and female longevity led to speculations that a late birth increases a mother's life span. The database used here includes all descendants of King George I of England (1660–1727) and his wife, Sophie Dorothea (1666–1726), born in the royal dynasties in Europe up to 1939 (n=1,672). In the era of British world supremacy, these descendants formed the uppermost layer of the European aristocracy, occupying all royal thrones from 1850 onward. Novel in this study is the use of pedigree information. In pairs of ever‐married full sisters (brothers), both surviving to 45 (50) years, both having at least one child, the study examines whether the sibling with the first—or last—child born later in life also lived a longer life. This design controls for genetics, socioeconomic status, parity, social support, child mortality, birth cohort, and various environmental factors. In the 157 pairs of sisters and 191 pairs of brothers, later reproduction did not extend the life span.
China's Floating Population: New Evidence from the 2000 Census
Authors: Liang Zai , Ma Zhongdong
Published: September 2004

This article uses tabulations from the 2000 Population Census of China along with a micro‐level data sample from the census to provide a picture of China's floating population: migrants without local household registration (hukou), a status resulting in significant social and economic disadvantages. By 2000, the size of China's floating population had grown to nearly 79 million, if that category is defined as migrants who moved between provinces or counties and resided at their destinations for six months or more. Intra‐county floating migration is similarly large, contributing another 66 million to the size of the floating population. The article also discusses the geographic pattern of the floating population and the reasons for moving as reported by migrants. Policy implications are noted.
Demographers and Their Journals: Who Remains Uncited After Ten Years?
Authors: van Dalen Hendrik P. , Henkens Kène
Published: September 2004

This research note examines the level of uncitedness and the impact of articles published in the years 1990–92 in 17 demography journals. After ten years 24 percent of the demography articles are still uncited and the average number of citations per article is seven. The ten‐year citation history reveals two novel insights. First, the impact of demography journals does not slow down significantly over time. The average number of citations in the first five years hardly differs from the average in the second five years, which suggests that one should be patient in assessing the full effect of demography articles. Second, the chance of being cited for the first time does not depend on the length of time an article remains uncited. In other words, the stigma of uncitedness does not play a significant role in the allocation of citations.
Population Futures for the Next Three Hundred Years: Soft Landing or Surprises to Come?
Authors: Demeny Paul
Published: September 2004

The long‐range population projections of the United Nations issued in 2003 span three centuries and are elaborated for all countries of the world according to the present‐day political map. This note discusses the merits and limitations of this ambitious enterprise. The numerical implications of various contrasting assumptions concerning fertility, in combination with single hypothetical future schedules of mortality and international migration, provide a valuable frame of reference for contemplating possible long‐range demographic trajectories. The dominant suggestion of these projections of a surprise‐free convergence to a stationary or slowly declining population is, however, questionable: with respect to global numbers, relative magnitudes of the constituting units of the global total, and the time pattern of change the demographic future is likely to be far less orderly.
A Comparison of US and Canadian Mortality in 1998
Authors: Boyle Torrey Barbara , Haub Carl
Published: September 2004

On average, Americans die earlier than Canadians. An estimate based on comparing the number of actual US deaths with the number that would have obtained had Canadian age‐ and sex‐specific death rates applied to the US population shows an excess number of US deaths in 1998 amounting approximately to 253,000. Excess US deaths were especially numerous among older women, middle‐aged men, and nonwhites. Circulatory diseases were the major cause of excess deaths. Prevalences of two of the major risk factors for circulatory deaths—smoking and hypertension—were higher in Canada than in the US. But obesity was higher in the US, suggesting a likely important role that obesity plays in higher mortality in the US relative to Canada. Comparisons of the level, age pattern, and causes of US and Canadian mortality, however, raise more questions than currently available data can answer.
Factors predicting sexual relationships in older people: an Australian study
Authors: Minichiello Victor , Plummer David , Loxton Deborah
Published: September 2004

Objectives:  Sexuality in later life is now recognised to be an important issue. The present study identified the factors that predict sexual relationships and changes in sexual activity in a sample of 844 older persons living in Melbourne, Australia, who returned a self‐completed questionnaire.

Method:  The variables included in the two models that predicted sexual relationship status and changes in sexual activity were: sex, age, marital status, general health, incontinence, satisfaction with physical condition, knowledge of sexual issues, change in sexual interest, perceptions of sex as an important factor in general well‐being, and number of sexual partners.

Results and Conclusion:  Logistic regression analysis revealed that the variables used in the model produced correct prediction rates for 84% of respondents not in a sexual relationship, and 85% for those in a sexual relationship. Age, marital status, incontinence, satisfaction with physical condition, sexual knowledge, perceptions of sex as important to well‐being, and number of sexual partners were significantly related to sexual relationship status. The present study discusses how these findings can further inform research and be used to inform our knowledge on sexuality in later life.
Serving seniors better: service guidelines for financial planners
Authors: Pettigrew Simone , Mizerski Katherine , Donovan Robert
Published: September 2004

Objective:  Generate a list of service guidelines to enable financial planners to better accommodate the needs of their older clients.

Methods:  Focus groups and a national telephone survey were conducted with Australian seniors to generate 10 service guidelines for financial planners.

Results:  The issues covered by the 10 guidelines are considered highly important by Australian seniors, with some apparent differences in ratings between older and younger seniors.

Conclusion:  Seniors have specific attributes they require in financial planners. In particular, they seek trusting relationships and wish to be treated with dignity.
Serving seniors better: service guidelines for supermarkets
Authors: Pettigrew Simone , Mizerski Katherine , Donovan Robert
Published: September 2004

Objective:  Generate a list of service guidelines to enable supermarket managers to accommodate the needs of their older customers.

Methods:  Focus groups and a national telephone survey were conducted with Australian seniors to generate 10 service guidelines for supermarkets.

Results:  The 10 guidelines produced are considered to be of significant importance by Australian seniors, with some apparent differences in importance and relevance ratings between older and younger seniors, and males and females.

Conclusions:  Seniors have distinct service preferences when grocery shopping and their needs require special attention in the supermarket environment. In particular, they feel strongly about the quality of staff and equipment with which they come into contact.
Privacy in aged care
Authors: Hughes Mark
Published: September 2004

The extension of privacy laws to cover private sector providers and the proposal of a National Health Privacy Code highlight the importance of examining privacy issues in aged care policy and practice. Although privacy in health and aged care may also include physical, psychological and social dimensions, it is informational privacy that is the focus of these recent changes. In the present paper, a range of privacy practices in aged care are examined, drawing on theoretical, policy, practice and research literature. It is argued that aged care policy makers and providers need to move beyond the setting of privacy principles and management strategies, and also examine specific day‐to‐day privacy practices as they occur in different aged care settings. While privacy is often a valued commodity, the construction of an issue as private can sometimes be seen to limit the expression of diverse identities and to reinforce social inequality.
Pilot study comparing the influence of different types of exercise intervention on the fear of falling in older adults
Authors: McCormack Gavin , Lewin Gill , McCormack Brandi , Helmes Edward , Rose Elizabeth , Naumann Fiona
Published: September 2004

Background:  Individuals who fear falling may restrict themselves from performing certain activities and may increase their risk of falling. Such fear, reflected in the form of falls efficacy, has been measured in only a small number of studies measuring the effectiveness of exercise interventions in the elderly. This may be due to the various types of exercise that can be performed. Hence the effectiveness of exercise on falls efficacy is relatively understudied. Therefore, there is a need to measure falls efficacy as an outcome variable when conducting exercise interventions in the elderly.

Methods:  A total of 43 elderly community‐dwelling volunteers were recruited and randomly allocated to a conventional exercise intervention, a holistic exercise intervention, or a control group. The interventions were performed 2 days per week for 10 weeks. Falls efficacy was measured at baseline and at the completion of the interventions using the Modified Falls Efficacy Scale (MFES).

Results:  Within group comparisons between baseline and follow‐up indicated no significant improvements in falls efficacy, however, the difference for the conventional exercise group approached statistical significance (baseline 8.9 to follow‐up 9.3; P = 0.058). Within group comparisons of mean difference MFES scores showed a significant difference between the conventional exercise group and the control group (conventional exercise group 0.4 vs control group −0.6; P < 0.05).

Conclusion:  Given the lack of significant improvements in falls efficacy found for any of the groups, it cannot be concluded whether a conventional or a holistic exercise intervention is the best approach for improving falls efficacy. It is possible that the characteristics of the exercise interventions including specificity, intensity, frequency and duration need to be manipulated if the purpose is to bring about improvements in falls efficacy.
Making Memories: pilot evaluation of a new program for people with dementia and their caregivers
Authors: Brodaty Henry , Low Lee‐Fay
Published: September 2004

Objective:  To evaluate the effects of the Alzheimer's Association's (NSW) Making Memories program on people living at home with dementia and their caregivers.

Methods:  Twenty‐four couples participated in the program that included 8 weekly education sessions, individual counselling, occupational therapy, 10 weekly diversional therapy sessions and ongoing monthly support groups. Ratings of psychological distress, quality of life and service use concerning the person with dementia, and depression, psychological distress, quality of life and physical health as regards to the caregiver were completed at baseline, 9 and 24 weeks.

Results:  Psychological distress decreased significantly over time in persons with dementia. Caregivers were significantly less distressed in relation to behavioural disturbance after controlling for the frequency of the behaviour immediately after the program, but this rose at the 6‐month follow‐up. For caregivers there was a non‐significant trend towards better quality of life but no improvement in psychological distress or depression.

Conclusions:  The Making Memories program decreased psychological distress in people with dementia. It had a short‐term beneficial effect on caregiver reactions to behavioural disturbance that was not maintained at follow‐up.
Penile Augmentation and Lengthening Procedurewith Partial Minimal Incision
Authors: Lee W.H. , Chang S.Y.
Published: September 2004

Objectives

To perform penile augmentation and lengthening procedure (PALP) for micropenis with partial minimal circumcision incision.

Material & Methods

From 1999 to 2004, 145 patients underwent PALP with partial minimal incision, dorsal one third of circumcision incision. PALP adopted dermofat graft from gluteal region. Graft length was 11cm and width was 4cm. Lengthening procedure was done with dissection of fundiform ligament. After dissection of ligament, multiple transverse sutures were done for approximation of prepubic dead space with 3-0 chromic cat gut.

Results

Postoperative penile length after 3 months was 7.3 ± 1.6cm compared with preoperative length 4.5 ± 1.2. Postoperative complications were seroma and inflammatory change (3.0%). Graft failure was 2 cases (1.4%).

Conclusion

For penile augmentation and lengthening procedure, partial minimal incision on circumcision incision was effective surgical procedure with minimal complications.

Disclosure

Was this work supported by industry? No.
Split Plaque Incisions and Bovine Pericardium Grafts in Severe Peyronie's Disease
Authors: Gueglio G. , Piana M. , Giudice C.R. , Damia O.
Published: September 2004

Objective

surgical treatment for severe Peyronie's disease is a challenge for urologists throughout the world. The aim of this video is to show the Gelbard's technique of split plaque incisions and the use of bovine pericardium grafts in a patient with severe dorsal curvature (90o) and no hourglass deformity.

Material and Methods

the video shows the operation of a 58 years old man who consulted for severe Peyronie's disease and firm erections. First, the x-ray and the ultrasound studies are shown and so are the auto-photographs. Then the main steps of the surgery are displayed in a didactic way. A pair of split incisions are performed in the plaque after lifting the neuro-vascular bundle and measuring of the penis. After the incisions, 3 cms. are gained in the penile length. Then, 2 grafts of bovine pericardium are placed to cover the gaps, tailoring them 20% bigger than the gaps. No corporoplasty was added. After closure of Buck's fascia, circumcision is routinely performed. Once the skin is closed, a Coban dressing is applied.

Results

using this technique we have operated on 6 patients since September 2003. Mean follow-up is 6 months (9-2) and so far the results are very good in terms of straightness and firmness of the erections. As the problem is only the curvature, there is no need for an H shaped incision thus reducing the probability of post-op ED. In this small series, only one patient reported a slight decrease in the firmness of his post-op erections.

Conclusion

although the number of patients is low and the follow-up is short, it seems that split plaque incisions and bovine pericardium grafts is a sound alternative in patients with severe dorsal curvature and no hourglass deformity.

Disclosure

Was this work supported by industry? No.
Interstitial Collagenase Is a Brownian Ratchet Driven by Proteolysis of Collagen
Authors: Saffarian Saveez , Collier Ivan E. , Marmer Barry L. , Elson Elliot L. , Goldberg Gregory
Published: September 2004

We show that activated collagenase (MMP-1) moves processively on the collagen fibril. The mechanism of movement is a biased diffusion with the bias component dependent on the proteolysis of its substrate, not adenosine triphosphate (ATP) hydrolysis. Inactivation of the enzyme by a single amino acid residue substitution in the active center eliminates the bias without noticeable effect on rate of diffusion. Monte Carlo simulations using a model similar to a “burnt bridge” Brownian ratchet accurately describe our experimental results and previous observations on kinetics of collagen digestion. The biological implications of MMP-1 acting as a molecular ratchet tethered to the cell surface suggest new mechanisms for its role in tissue remodeling and cell-matrix interaction.
Curving and Frustrating Flatland
Authors: Shin Kyusoon , Xiang Hongqi , Moon Sung In , Kim Taehyung , McCarthy Thomas J. , Russell Thomas P.
Published: September 2004

Two polymer chains that occupy equal volumes when covalently linked together at one end self-assemble into an alternating lamellar morphology that has a characteristic period dictated by the molecular weight. When such copolymers are confined within alumina membranes that have cylindrical pores with diameters comparable to the repeat period, the interaction of the blocks with the confining walls and the imposed curvature induces a morphological transformation to relieve the constraints. Here, we show a lamella-to-toroid transition, captured through the dissolution of the surrounding membrane.
Geochemical Evidence for Excess Iron in the Mantle Beneath Hawaii
Authors: Humayun Munir , Qin Liping , Norman Marc D.
Published: September 2004

Chemical interaction of Earth's mantle with the liquid outer core should influence the mantle's iron content. Osmium isotope ratios in Hawaiian lavas indicate a mass flux of ≤1% core to the mantle, which is the immediate source of these lavas. We present precise measurements of the Fe/Mn ratio for Hawaiian lavas, revealing an increase of 1 to 2% in the mole fraction of iron in the mantle beneath Hawaii. This corresponds to a density anomaly of about 0.5%, about the same magnitude observed in seismic tomography models of the Pacific superswell region. These data also rule out a role for Mn-rich sediments as the source of the Hawaiian Os isotope signal.
The Genome of the Diatom
Thalassiosira Pseudonana
: Ecology, Evolution, and Metabolism
Authors: Armbrust E. Virginia , Berges John A. , Bowler Chris , Green Beverley R. , Martinez Diego , Putnam Nicholas H. , Zhou Shiguo , Allen Andrew E. , Apt Kirk E. , Bechner Michael , Brzezinski Mark A. , Chaal Balbir K. , Chiovitti Anthony , Davis Aubrey K. , Demarest Mark S. , Detter J. Chris , Glavina Tijana , Goodstein David , Hadi Masood Z. , Hellsten Uffe , Hildebrand Mark , Jenkins Bethany D. , Jurka Jerzy , Kapitonov Vladimir V. , Kröger Nils , Lau Winnie W. Y. , Lane Todd W. , Larimer Frank W. , Lippmeier J. Casey , Lucas Susan , Medina Mónica , Montsant Anton , Obornik Miroslav , Parker Micaela Schnitzler , Palenik Brian , Pazour Gregory J. , Richardson Paul M. , Rynearson Tatiana A. , Saito Mak A. , Schwartz David C. , Thamatrakoln Kimberlee , Valentin Klaus , Vardi Assaf , Wilkerson Frances P. , Rokhsar Daniel S.
Published: September 2004

Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for ∼20% of global carbon fixation. We report the 34 million–base pair draft nuclear genome of the marine diatom
Thalassiosira pseudonana
and its 129 thousand–base pair plastid and 44 thousand–base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.
Assessing the Causes of Late Pleistocene Extinctions on the Continents
Authors: Barnosky Anthony D. , Koch Paul L. , Feranec Robert S. , Wing Scott L. , Shabel Alan B.
Published: September 2004

One of the great debates about extinction is whether humans or climatic change caused the demise of the Pleistocene megafauna. Evidence from paleontology, climatology, archaeology, and ecology now supports the idea that humans contributed to extinction on some continents, but human hunting was not solely responsible for the pattern of extinction everywhere. Instead, evidence suggests that the intersection of human impacts with pronounced climatic change drove the precise timing and geography of extinction in the Northern Hemisphere. The story from the Southern Hemisphere is still unfolding. New evidence from Australia supports the view that humans helped cause extinctions there, but the correlation with climate is weak or contested. Firmer chronologies, more realistic ecological models, and regional paleoecological insights still are needed to understand details of the worldwide extinction pattern and the population dynamics of the species involved.
Basis for Structural Diversity in Homologous RNAs
Authors: Krasilnikov Andrey S. , Xiao Yinghua , Pan Tao , Mondragón Alfonso
Published: September 2004

Large RNA molecules, such as ribozymes, fold with well-defined tertiary structures that are important for their activity. There are many instances of ribozymes with identical function but differences in their secondary structures, suggesting alternative tertiary folds. Here, we report a crystal structure of the 161-nucleotide specificity domain of an A-type ribonuclease P that differs in secondary and tertiary structure from the specificity domain of a B-type molecule. Despite the differences, the cores of the domains have similar three-dimensional structure. Remarkably, the similar geometry of the cores is stabilized by a different set of interactions involving distinct auxiliary elements.
The Kondo Effect in the Presence of Ferromagnetism
Authors: Pasupathy Abhay N. , Bialczak Radoslaw C. , Martinek Jan , Grose Jacob E. , Donev Luke A. K. , McEuen Paul L. , Ralph Daniel C.
Published: September 2004

We measured Kondo-assisted tunneling via C
60
molecules in contact with ferromagnetic nickel electrodes. Kondo correlations persisted despite the presence of ferromagnetism, but the Kondo peak in the differential conductance was split by an amount that decreased (even to zero) as the moments in the two electrodes were turned from parallel to antiparallel alignment. The splitting is too large to be explained by a local magnetic field. However, the voltage, temperature, and magnetic field dependence of the signals agree with predictions for an exchange splitting of the Kondo resonance. The Kondo effect leads to negative values of magnetoresistance, with magnitudes much larger than the Julliere estimate.
Cope's Rule, Hypercarnivory, and Extinction in North American Canids
Authors: Van Valkenburgh Blaire , Wang Xiaoming , Damuth John
Published: September 2004

Over the past 50 million years, successive clades of large carnivorous mammals diversified and then declined to extinction. In most instances, the cause of the decline remains a puzzle. Here we argue that energetic constraints and pervasive selection for larger size (Cope's rule) in carnivores lead to dietary specialization (hypercarnivory) and increased vulnerability to extinction. In two major clades of extinct North American canids, the evolution of large size was associated with a dietary shift to hypercarnivory and a decline in species durations. Thus, selection for attributes that promoted individual success resulted in progressive evolutionary failure of their clades.
On the Power to Create
Authors: Morus Iwan Rhys
Published: September 2004

Promethean Ambitions
Alchemy and the Quest to Perfect Nature. by William R. Newman. University of Chicago Press, Chicago, 2004. 349 pp. $30, £21. ISBN 0-226-57712-0.

In this consideration of the history of European alchemy, Newman explores the relations between the natural and artificial and the links between art and science.
Thinking About Caring About Animals
Authors: Magnus David
Published: September 2004

Animal Rights
Current Debates and New Directions. Cass R. Sunstein and Martha C. Nussbaum, Eds. Oxford University Press, New York, 2004. 350 pp. $29.95. ISBN 0-19515217-4.

The contributors explore moral, legal, social, and epistemological aspects of our relations with nonhuman animals.
AN APPARATUS TO SEARCH FOR MIRROR DARK MATTER
Authors: GNINENKO S. N.
Published: September 2004

Among several interesting motivations for experimenting with orthopositronium (o-Ps) in vacuum the most exciting one is probably related to the search for the dark matter of a mirror-type. The mirror matter is predicted to exist if parity is an unbroken symmetry of the vacuum. The existence of the mirror matter, which in addition to gravity communicates with our world through photon-mirror photon mixing, would result in orthopositronium (o-Ps) to mirror orthopositronium (o-Ps') oscillations. The experimental signature of this effect is the invisible decay of o-Ps in vacuum.

We discuss an experiment to search for o-Ps→invisible decay in vacuum with a sensitivity in the branching ratio Br(o-Ps→invisible)≃10-7, which is an order of magnitude better than the present limit on this decay mode from the Big Bang Nucleosynthesis. Details of the design are presented. The effect of various environments on o-Ps→o-Ps' oscillation probability is also discussed.
C, P, T, CP, CPT AND POSITRONIUM
Authors: KRASNIKOV N. V.
Published: September 2004

We discuss the C, P, T, CP, CPT symmetries and possible searches for violation of these symmetries in positronium decays.
A TEST OF CP SYMMETRY IN POSITRONIUM
Authors: FELCINI MARTA
Published: September 2004

The aim of this CP symmetry test in positronium is to measure the CP violation amplitude parameter CCP. This is derived from the measurement of the asymmetry in an angular distribution of the photons from the decay of the ortho-positronium in a magnetic field. The Standard Model prediction for CCP is a value of the order of 10-9. Thus the observation of a larger CCP value would be signal of physics beyond the Standard Model. A previous measurement has found CCP consistent with zero, with an uncertainty of ~ 10-2. We have investigated the possibility of using the existing ETHZ-INRM-IN2P3 BGO crystal detector, set-up for positronium physics studies, to improve the sensitivity on the CCP measurement. Preliminary calculations indicate that, using such an apparatus, with some modification, in a magnetic field of 4 kGauss, CCP could be measured with an uncertainty in the range between ~ 10-4 and ~ 10-3, depending mainly on the uncertainty in the asymmetry measurement and the angular resolution of the photon detectors. If CCP is less than ~ 10-4, the experimental technique outlined here appears to be inadequate to observe a CP violating effect and new techniques or different observables must be exploited for better sensitivity.
WHAT COULD BE LEARNT FROM POSITRONIUM FOR QUARKONIUM?
Authors: SMITH CHRISTOPHER
Published: September 2004

In order to fulfill Low's theorem requirements, a new lowest order basis for bound state decay computations is proposed, in which the binding energy is treated non-perturbatively. The properties of the method are sketched by reviewing standard positronium decay processes. Then, it is shown how applying the method to quarkonia sheds new light on some longstanding puzzles.
STATUS OF ORTHOPOSITRONIUM DECAY RATE MEASUREMENTS
Authors: SILLOU DANIEL
Published: September 2004

The so-called orthopositronium lifetime puzzle have existed from more than 10 years. Recent measurements seems in good agreeement with the predicted values now. Should we consider that the problem is solved now as claim a recent paper? We present a short review of the last 15 years experiments.
SOLUTION OF THE ORTHOPOSITRONIUM LIFETIME PUZZLE
Authors: ASAI S. , JINNOUCHI O. , KOBAYASHI T.
Published: September 2004

The intrinsic decay rate of orthopositronium formed in SiO 2 powder is measured using the direct 2γ correction method such that the time dependence of the pick-off annihilation rate is precisely determined. The decay rate of orthopositronium is found to be 7.0396±0.0012(stat.)±0.0011(sys.)μs-1, which is consistent with our previous measurements with about twice the accuracy. Results agree well with the O(α2) QED prediction, and also with a result reported very recently using nanoporous film.
POSITRON INTERACTION IN POLYMERS
Authors: BAS CORINE , ALBÉROLA N. DOMINIQUE , BARTHE MARIE-FRANCE , De BAERDEMAEKER JÉRÉMIE , DAUWE CHARLES
Published: September 2004

A series of dense copolyimide membranes was characterized using positron annihilation spectroscopy. The positron annihilation lifetime spectroscopy performed on film with a classical positron source gives informations on the positronium fraction formed and also on the hole size within the film. The Doppler broadening spectra (DBS) of the gamma annihilation rays coupled with a variable energy positron beam allow the microstructural analyses as a function of the film depth. Experimental data were also linked to the chemical structure of the polyimides. It was found that the presence of the fluorine atoms strongly affects the positron annihilitation process and especially the DBS responses.
POSITRONIUM AS A PROBE FOR NEW PHYSICS BEYOND THE STANDARD MODEL
Authors: RUBBIA ANDRÉ
Published: September 2004

We discuss and summarize some aspects concerning the study of the positronium system to probe new physics beyond the Standard Model.
ENERGY GAP DEPENDENCE ON ANION CONCENTRATION FORGaxIn1-xAsyP1-yQUATERNARY ALLOY BY RECURSION METHOD
Authors: EL-HASAN MUSA , ESTATIEH REZEK
Published: September 2004

Three terminators have been tested, square root terminator, quadreture terminator and linear terminator, it was found that the linear terminator is the best, so it was used in calculating local density of states (LDOS) and it's orbital decomposition, alloy average density of states, and energy gap for different anion concentrations for InP lattice matched alloy. The results were compared with our previous calculations of (LDOS), and results from other methods. Energy gap was compared with experimental measurements. A five orbital sp3s* per atom model was used in the tight-binding representation of the Hamiltonian.
SURFACE PLASMON POLARITON RADIATION FROM METALLIC PHOTONIC CRYSTAL SLABS BREAKING THE DIFFRACTION LIMIT: NANO-STORAGE AND NANO-FABRICATION
Authors: LUO XIANGANG , SHI JIEPING , WANG HAO , YU GUOBIN
Published: September 2004

The near-field distribution of surface plasmon polariton (SPP) on metallic photonic crystal slabs has been studied. Preliminary numerical simulations indicate that the interference of SPP on the exit side of metallic photonic crystal slabs can redistribute the illumination light into nano-scale spatial distribution, which beats the Rayleigh diffraction limit. The electric field distribution of SPP with a resolution of 50 nm was measured by recording the high intensity range into photoresist with a wavelength of 436 nm. Because of the small wavelength of the plasmon wave, a much higher spatial resolution can be obtained, which can provide a new nano-fabrication or nano-storage method by using optical light with a long wavelength.
THE SEARCH FOR SYMMETRIES IN THE GENETIC CODE: FINITE GROUPS
Authors: ANTONELI FERNANDO , FORGER MICHAEL , HORNOS JOSÉ EDUARDO M.
Published: September 2004

We give a full classification of the possible schemes for obtaining the distribution of multiplets observed in the standard genetic code by symmetry breaking in the context of finite groups, based on an extended notion of partial symmetry breaking that incorporates the intuitive idea of "freezing" first proposed by Francis Crick, which is given a precise mathematical meaning.
MASSIVE SCALAR FIELDS IN THE EARLY UNIVERSE
Authors: ZHUK ALEXANDER , GÜNTHER UWE
Published: September 2004

We discuss the role of gravitational excitons/radions in different cosmological scenarios. Gravitational excitons are massive moduli fields which describe conformal excitations of the internal spaces and which, due to their Planck-scale suppressed coupling to matter fields, are WIMPs. It is demonstrated that, depending on the concrete scenario, observational cosmological data set strong restrictions on the allowed masses and initial oscillation amplitudes of these particles.
A RELATIVISTIC MEAN FIELD THEORY FOR NUCLEAR MATTER AT T≠0
Authors: MESQUITA ALEXANDRE , RAZEIRA MOISÉS , VASCONCELLOS CÉSAR A. Z. , DILLIG MANFRED , BODMANN BARDO E. J.
Published: September 2004

We study effects of temperature in hadron dense matter within a generalized relativistic mean field approach based on the naturalness of the various coupling constants of the theory, The Lagrangian density of our formulation contains the fundamental baryon octet, nonlinear self-couplings of the σ and δ meson fields coupled to the baryons and to the ω and ρ meson fields. By adjusting the model parameters, after inclusion in a consistent way of chemical equilibrium, baryon number and electric charge conservation, our model describes static bulk properties of ordinary nuclear matter and neutron stars. In the framework of the Sommerfeld approximation, we extend our approach to the T≠0 domain. The Sommerfeld approximation allows a drastic simplification of computational work while improving the capability of the theoretical analysis of the role of temperature on static properties of protoneutron stars. We perform the calculations by using our nonlinear model, which we extend by considering trapped neutrinos introduced into the formalism by fixing the lepton fraction. Integrating the Tolman–Oppenheimer–Volkoff equations we have obtained standard plots for the mass and radius of protoneutron stars as a function of the central density and temperature. Our predictions include the determination of an absolute value for the protoneutron star limiting mass at low and intermediate temperature regimes.
ISOBARIC PROCESSES CLOSE TO THE SPINODAL
Authors: DELFINO ANTONIO , Da SILVA JOÃO B. , De Sá MARTINS JORGE S. , De OLIVEIRA SUZANA MOSS , CORDEIRO CLAUDETTE E.
Published: September 2004

We construct a generalized Landau free energy expansion around any spinodal point, for which the usual expansion around the critical point is a particular case. The decay of deeply quenched metastable states close to the spinodal through isobaric processes is analyzed and their mean life time is related to a barrier height, which we compute. The results are compared with those obtained through the use of the usual Landau free energy expansion around the critical point.
ANALYSIS OF THE ANGULAR DISTRIBUTION OF COSMIC OBJECTS
Authors: BERNUI ARMANDO , VILLELA THYRSO , FERREIRA IVAN
Published: September 2004

We investigate a method that reveals anisotropies in the angular distribution of cosmic objects. In particular, we investigate ensembles with ~ 1000 objects, which is the interesting case of some astronomical catalogs. Considering test ensembles generated with a variable degree of anisotropy, we calculate the probability of any pair of objects to be separated by a given angular distance and compare this result with the same probability for a purely isotropic ensemble. We show that the use of sub-ensembles of the original full sky test ensemble, namely partial catalogs containing objects in the polar cap regions, can reveal, at any scale, possible angular correlations in the original full sky distribution. We also show the robustness of this method by comparing it with the Kolmogorov–Smirnov and χ2 statistical tests.
MIXED PHASE IN COMPACT STARS: M–R RELATIONS AND RADIAL OSCILLATIONS
Authors: GOYAL ASHOK
Published: September 2004

It is believed that quark stars or neutron stars with mixed phase in the core have smaller radii compared to ordinary compact stars. With the recent observation of several low radius objects, typically a radius of <10 km for star of mass <1 M⊙ in low mass X-ray binaries (LMXB), it has become very important to understand the nature of these objects. An accurate determination of the mass–radius relationship of these objects provide us with a physical laboratory to study the composition of high density matter and the nature of phase transition. We study the effect of quark and nuclear matter mixed phase on the mass radius relationship and radial oscillations of neutron stars. We find that the effect of the mixed phase is to decrease the maximum mass of a stable neutron star and to decrease the radial frequencies.
BOSE–EINSTEIN CONDENSATION OF CHARGED PARTICLES AND SELF-MAGNETIZATION
Authors: MARTÍNEZ AURORA PÉREZ , ROJAS HUGO PÉREZ , CUESTA HERMAN MOSQUERA
Published: September 2004

We discuss the Bose–Einstein condensation of relativistic vector charged particles in a strong external magnetic field in very dense matter, as may be paired spin-up electrons. We show that for electrons such systems may maintain self-consistently magnetic fields of order in between the interval 1010–1013 Gauss. This could be the origin of large magnetic fields in some white dwarfs, but may also impose bounds due to the arising of strong anisotropy in the pressures, which may produce a transverse collapse of the star.
THE PULSATING WHITE DWARF G 185-32
Authors: CASTANHEIRA BÁRBARA GARCIA , KEPLER S. O.
Published: September 2004

We study the structure of pulsating white dwarf stars, which present multi-periodic light variations with periods around minutes, defining instability strips along their cooling sequence. We analyze the ultraviolet (HST) and optical (WET) light curves of the pulsating white dwarf G185-32. Among all pulsating white dwarfs, this star has the shortest periodicity so far observed. We detected 18 periodicities, including non-linear effects, which can be used to study the stellar structure, constraining the physics of the degenerate matter.
FINITE TEMPERATURE EQUATIONS OF STATE FOR MIXED STARS
Authors: MENEZES DÉBORA P. , PROVIDÊNCIA C.
Published: September 2004

We investigate the properties of mixed stars formed by hadronic and quark matter in β-equilibrium described by appropriate equations of state (EOS) in the framework of relativistic mean-field theory. The calculations were performed for T=0 and for finite temperatures and also for fixed entropies with and without neutrino trapping in order to describe neutron and proto-neutron stars. The star properties are discussed. Maximum allowed masses for proto-neutron stars are much larger when neutrino trapping is imposed.
SIGNATURES OF ISOVECTOR COMPONENTS OF THE SCALAR σ-MESON IN NEUTRON STARS
Authors: LÜTZ EDUARDO , RAZEIRA MOISÉS , VASCONCELLOS CÉSAR A. Z. , DILLIG MANFRED
Published: September 2004

Based on non-crossed, crossed and correlated ππ exchanges with irreducible N, Δ intermediate states, we predict an isovector component for the σ meson. We study dense hadronic matter in a generalized relativistic mean field approach with nonlinear self-couplings of the I=0,1 components of the scalar field and compare its predictions for neutron star properties with results from different models found in the literature.
EFFECT OF A MAGNETIC FIELD ON THE ELECTROWEAK SYMMETRY
Authors: QUERTS ELIZABETH RODRÍGUEZ , ROJAS HUGO PÉREZ , MARTÍNEZ AURORA PÉREZ
Published: September 2004

We discuss the effect of a strong magnetic field in the behavior of the symmetry of an electrically neutral electroweak plasma. We analyze the case of a strong magnetic field and low temperatures as compared with the W rest energy. If the magnetic field is large enough, it is self-consistently maintained. Charged vector bosons play the most important role, leading only to a decrease of the symmetry breaking parameter, the symmetry restoration not being possible.
NUCLEAR MATTER SYMMETRY ENERGY AND MATTER–ANTI-MATTER STATES
Authors: BRAGHIN FÁBIO L.
Published: September 2004

In this work we discuss points of interest for a general phase diagram of nuclear matter at alternative conditions (such as isospin broken phase and existence of anti-matter state(s)) which are relevant for the description of astrophysics. The inclusion of light isovector spin zero mesons in relativistic models of nuclear systems is discussed and deviation from the usual results for the symmetry energy description is found in agreement with a development done for a non-relativistic description of nuclear matter.
SUPERNOVAE, PROTONEUTRON STARS AND RELATED HIGH ENERGY PHENOMENA
Authors: LUGONES GERMÁN , HORVATH JORGE E.
Published: September 2004

We present a brief review of the present status of the standard model of core collapse supernovae and neutron star formation outlining the basic concepts and paying attention to the possibility of a transition to quark matter. We evaluate the consequences of this transition on the whole explosion mechanism, analyze the possible generation of beamed gamma ray bursts, and discuss the nature of the compact star born as a result of the supernova explosion.
NEW ASPECTS ON GRAVITATIONAL WAVE EMISSION BY NEUTRON STARS
Authors: MARRANGHELLO GUILHERME F. , VASCONCELLOS CÉSAR A. Z. , de FREITAS PACHECO JOSÉ A. , DILLIG MANFRED , COELHO HÉLIO T.
Published: September 2004

We discuss, in this work, new aspects related to the emission of gravitational waves by neutron stars, which undergo a phase transition, from nuclear to quark matter, in its inner core. Such a phase transition would liberate around 1052–53 erg of energy in the form of gravitational waves which, if detected, may shed some light in the structure of these compact objects and provide new insights on the equation of state of nuclear matter.
NEUTRINO OSCILLATIONS AT SUPERNOVA CORE BOUNCE GENERATE THE STRONGEST GRAVITATIONAL-WAVE BURSTS
Authors: CUESTA HERMAN J. MOSQUERA , FIUZA KAREN
Published: September 2004

During the core bounce of a supernova collapse resonant active-to-active (νa→νa), as well as active-to-sterile (νa→νs) neutrino (ν) oscillations can take place. Besides, over this phase weak magnetism increases antineutrino [Formula: see text] mean free paths, and thus its luminosity. Because the oscillation feeds mass-energy into the target ν species, the large mass-squared difference between species (νa→νs) implies a huge amount of power to be given off as gravitational waves (L GWs ~1049 erg s -1), due to anisotropic but coherent ν flow over the oscillation length. This anisotropy in the ν-flux is driven by both the universal spin-rotation and the spin-magnetic coupling. The new spacetime strain estimated this way is still several orders of magnitude larger than those from ν diffusion (convection and cooling) or quadrupole moments of the neutron star matter. This new feature turns these bursts the more promising supernova gravitational-wave signal that may be detected by observatories as LIGO, VIRGO, etc., for distances far out to the VIRGO cluster of galaxies.
MASS INHOMOGENEITIES AND THE ANGULAR SIZE-REDSHIFT RELATION
Authors: ALCANIZ JAILSON S. , LIMA JOSÉ A. S. , SILVA RAIMUNDO
Published: September 2004

We investigate the influence of mass inhomogeneities on the angular size-redshift test through a statistical analysis of angular size data for a large sample of milliarcsecond radio sources. The results are based on flat models driven by nonrelativistic matter plus a dark energy component in the form of a relic cosmological constant. To model the mass inhomogeneities we use the Zeldovich–Kantowski distance formula (also known as Dyer–Roeder distance redshift relation) which is characterized by the smoothness parameter α. Marginalizing over the characteristic angular size l and assuming a Gaussian prior on the matter density parameter, i.e., Ωm=0.35±0.07, the best fit model occurs at Ωm=0.35 and α=0.8. For an analysis without priors and minimizing χ2 for the parameters l, Ωm and α we find that a conventional homogeneous scenario (α=1) with Ωm=0.2 and D=22.6h-1 pc constitutes the best fit model for the present angular size data.
THE EXISTENCE OF AN OLD QUASAR AT z=3.91 AND ITS IMPLICATIONS FOR Λ(t) DEFLATIONARY COSMOLOGIES
Authors: CUNHA JOÃO VITAL , SANTOS ROSE CLÍVIA
Published: September 2004

We investigate some observational constraints on decaying vacuum cosmologies based on the recently discovered old high redshift quasar APM 08279+5255. This object is located at z=3.91 and has an estimated age of 2–3 Gyr. The class of Λ(t) cosmologies is characterized by a positive β parameter smaller than unity which quantifies the ratio between the vacuum and the total energy density. Assuming the lower limit age (2 Gyr) and that the cold dark matter contributes with Ω M =0.2 we show that β is constrained to be ≥0.07 while for an age of 3 Gyr and Ω M =0.4 the β parameter must be greater than 0.32. Our analysis includes closed, flat and hyperbolic scenarios, and it strongly suggests that there is no age crisis for this kind of Λ(t) cosmologies. Lower limits to the redshift quasar formation are also briefly discussed to the flat case. For Ω M =0.4 we found that the redshift formation is constrained by zf≥8.0.
PULSAR ASTROPHYSICS: THE GLITCH PHENOMENON
Authors: HORVATH JORGE E.
Published: September 2004

We briefly discuss a handful of topics in pulsar astrophysics, first some general well-known features, then an overview of the glitch phenomenon and the sort of information gathered about the internal structure and dynamics, and finally the quandary posed by the precession of PSR B1828-11 a very important clue pointing towards a novel paradigm for structure of the core regions. We point out that "exotic" solutions for the precession puzzle would force a consideration of exotic glitch mechanisms as well.
DARK MATTER IN THE UNIVERSE
Authors: de FREITAS PACHECO JOSÉ A. , PEIRANI S.
Published: September 2004

Evidences for the existence of dark matter in the Universe are briefly reviewed and, in particular, the nature of the galactic halo. Possible candidates, point-like or not, issued from extensions of the Standard Model or Supersymmetric theories are examined. Finally, direct and indirect searches for dark matter particles are summarized.
MASS FUNCTION OF HALOS: A NEW ANALYTICAL APPROACH
Authors: LIMA JOSÉ A. S. , MARASSI LUCIO
Published: September 2004

A generalization of the Press–Schechter (PS) formalism yielding the mass function of bound structures in the Universe is given. The extended formula is based on a power law distribution which encompasses the Gaussian PS formula as a special case. The new method keeps the original analytical simplicity of the PS approach and also solves naturally its main difficult (the missing factor 2) for a given value of the free parameter.
THE IMPORTANCE OF THE RELATIVISTIC CORRECTIONS IN HYPERON STARS
Authors: LINARES LUIS PAULO , MALHEIRO MANOEL , RAY SUBHARTI
Published: September 2004

We investigate the importance of the relativistic corrections in the Tolman–Oppenheimer–Volkoff equation for hyperon stars. In order to describe the hyperon dense matter we use two extreme cases of relativistic equation of state (EOS), a stiff one from the Walecka (W) model and a soft one from the Zimanyi–Moszkowski (ZM) model. We analyze the individual effect of these relativistic factors as well the global one f. We conclude that they are always important and larger for a stiff EOS, fw≈3.8 in comparison with f ZM ≈2.2, not very sensitive to the inclusion of hyperons, and the factor coming from the metric is the dominant one near the surface of the star.
EFFECTIVE MESONIC AND BARYONIC DEGREES OF FREEDOM IN NEUTRON STARS
Authors: DILLIG MANFRED , SCHOTT MATHIAS , LÜTZ EDUARDO F. , MESQUITA ALEXANDRE , VASCONCELLOS CÉSAR A. Z.
Published: September 2004

We present a sketchy survey on the role of effective mesonic and baryonic degrees of freedom in dense hadronic matter and briefly mention still very crude attempts to include constituent quarks degrees of freedom for a transition to a quark gluon plasma.
A NEW SIGNATURE FOR GLUEBALLS
Authors: da SILVA MÁRIO L. L. , VASCONCELLOS CÉSAR A. Z. , HADJIMICHEF DIMITER
Published: September 2004

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock–Tani formalism.