bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison among three approaches to evaluate winter habitat selection by white-tailed deer on Anticosti Island using occurrences from an aerial survey and forest vegetation maps
Authors: Potvin François , Boots Barry , Dempster Alastair
Published: December 2003

Habitat-selection analysis involves a comparison between the proportions of different cover types that are used by the animal and the proportions that are available. Telemetry locations or animal occurrences (e.g., from aerial surveys) can provide information on habitat utilization. With telemetry data, a classical approach involves computing habitat use at the individual location sites or inside fixed circle buffers applied to the sites. We used this approach (200 m radius circles) on data from a systematic aerial survey on Anticosti Island, where 260 groups of white-tailed deer (Odocoileus virginianus) (374 animals) were counted in a 270-km2block. We compared the selection indices obtained from site occurrences with those of two approaches that define areas of high intensity (animal concentrations): 50% fixed kernels (0.52 km bandwidth) and the local K function (0.52 km distance). The results were very consistent among the three sets of approaches, with the same cover types generally identified as those having the highest or lowest indices. White-tailed deer preferred forest stands where balsam fir (Abies balsamea) was present as high regeneration or was dominant in the tree layer (>50% basal area) and stands at the regeneration stage. In the studied landscape, there seems to be a wide range of spatial scales where the selection process can be analysed from aerial survey data.
An uneasy alliance: unequal distribution of affiliative interactions among members of a captive wolf pack
Authors: Cipponeri Traci , Verrell Paul
Published: December 2003

The social groups of many vertebrates may be characterized as "uneasy alliances" that reflect tensions between benefits of group membership and costs to individual fitness among members, especially nonrelatives. The prebreeding season may be a time when these tensions become most acute and so observable for packs of gray wolves (Canis lupus). We recorded affiliative (play) interactions among two females and five males of known social ranks in a captive pack as the time of breeding approached. Substantial inequalities among pairs of wolves were apparent in frequencies of both the initiation of play and the exhibition of positive responses by recipient wolves. With the subsequent arrival of the breeding season, the pack experienced social disruption that led to the eviction of the original alpha male and a reordering of the ranks of those wolves remaining. Our data suggest that unequal affiliative interactions among pack members can be associated with (and, perhaps, even be predictive of) subsequent social disruption at a time when opportunities for personal reproduction become most available.
Response of pumpkinseed sunfish to conspecific chemical alarm cues: an interaction between ontogeny and stimulus concentration
Authors: Marcus Jason P , Brown Grant E
Published: December 2003

Recent studies have shown that juvenile centrachids undergo ontogenetic shifts in their behavioural response towards conspecific and heterospecific chemical alarm cues based on threat-sensitive trade-offs between the benefits associated with predator avoidance and foraging. We conducted laboratory studies to test the hypothesis that the relative concentration of conspecific alarm cues provides relevant information, allowing individuals to maximize these trade-offs. Juvenile (<40 mm standard length) and subadult (>95 mm standard length) pumpkinseed sunfish (Lepomis gibbosus) were exposed to conspecific skin extracts at stock (undiluted) concentration or diluted 1:1 (50%), 1:3 (25%), or 1:7 (12.5%) with distilled water. Juvenile sunfish exhibited significant antipredator responses (relative to the distilled water controls) when exposed to conspecific skin extracts at a concentration as low as 25%. Juveniles exposed to 12.5% skin extract were not significantly different from the distilled water controls. Subadult sunfish exhibited significant antipredator responses only to the two highest concentrations. In response to the two lowest concentrations (25% and 12.5%), however, subadult sunfish exhibited significant foraging responses. These data demonstrate that the relative concentration of chemical alarm cues provides reliable information and allows individuals to accurately assess local predation risk and hence maximize potential trade-offs.
Influence of prey abundance on northern spotted owl reproductive success in western Oregon
Authors: Rosenberg Daniel K , Swindle Keith A , Anthony Robert G
Published: December 2003

The hypothesis that high temporal variability of northern spotted owl (Strix occidentalis caurina) reproductive success is a response to prey abundance remains largely untested. We evaluated this relationship in the Oregon Cascade Mountains. Despite similar biomass of northern flying squirrels (Glaucomys sabrinus) (169 ± 13.9 g/ha) and deer mice (Peromyscus maniculatus) (160 ± 18.8 g/ha), flying squirrels dominated the breeding season diet based on both biomass (49%) and numbers (40%). Abundance of flying squirrels and western red-backed voles (Clethrionomys californicus) was more variable spatially ([Formula: see text]38% of process variation) than temporally (15%–24%), whereas abundance of deer mice was more similar across stands (12% spatial variation) than among years (68% temporal variation). Spotted owl reproductive success was statistically associated only with the abundance of deer mice (number of young per territory: r2 = 0.68). However, deer mice comprised only 1.6 ± 0.5% of the biomass consumed. The low temporal variability of the dominant prey species provided evidence that simple prey relationship models were not likely to explain the highly synchronous and temporally dynamic patterns of spotted owl reproductive performance. Reproductive success was likely a result of the interaction of both weather and prey and the life history strategy of this long-lived owl.
Energy deficiency alters behaviours involved in transmission ofHeligmosomoides polygyrus(Nematoda) in mice
Authors: Heitman T L , Koski K G , Scott M E
Published: December 2003

Independent studies have shown that animal behaviour is affected by nutritional deficiency and that host behaviour influences parasite transmission. The objectives of this study were to determine whether energy deficiency alters the behaviour profile of mice and the rate of exposure of mice to naturally acquired Heligmosomoides polygyrus (Nematoda) larvae. Outbred CF-1 and CD-1 female mice were fed either a control or an energy-deficient (65% of control) diet for 7 days, after which time, the mice fed the deficient diet had consumed signficantly less energy, had lower rectal temperatures, and lower masses (CD-1 mice only) compared with control mice. On day 7, mice were placed individually in natural transmission arenas containing damp peat moss and parasite larvae for 6 h, during which time, each mouse was observed 60 times and her behaviour recorded. All mice were then returned to standard caging and fed the energy-sufficient diets to eliminate confounding effects of energy deficiency on the host immune response over the following 8 days. At necropsy, parasite numbers were significantly lower in the energy-deficient mice of both strains. The behaviour profile differed significantly between diet groups and between strains; deficient mice of both strains groomed less and dug in the peat substrate less than control mice. The frequency of grooming was positively correlated with worm burden in both strains, the frequency of mouthing the peat moss and of sleeping were positively associated with worm burden in CD-1 mice, and the frequency of standing and walking low was positively associated with worm burden in CF-1 mice. These results indicate that grooming and contact with the peat moss are important behaviours in transmission of H. polygyrus, that energy deficiency causes a decrease in the frequency of these behaviours, and that these behavioural changes may contribute to reduced parasite transmission in mice fed the energy-restricted diet.
Potential of prey size and type to affect foraging asymmetries in tiger salamander (Ambystoma tigrinum nebulosum) larvae
Authors: Johnson Eric B , Bierzychudek Paulette , Whiteman Howard H
Published: December 2003

Although competitive interactions within predator populations are known to depend on their size structure, we understand less about how these interactions are influenced by prey characteristics. Most studies of such interactions for tiger salamander (Ambystoma tigrinum nebulosum) larvae have used small zooplankton prey. We investigate the potential of exploitation and interference competition to influence the success of tiger salamander larvae feeding on relatively large prey, mayfly and damselfly larvae. We measured salamander foraging efficiency for a range of salamander and prey sizes and observed aggression levels of salamanders of varying size housed together. Exploitative foraging efficiency (captures per attempts) increased with salamander size but was better predicted by relative prey size (prey size as a percentage of salamander snout–vent length) than by salamander size alone; it also depended significantly on prey type. Aggression (interference) levels were higher when prey were present, and larger salamanders were more aggressive than smaller ones but did not consume more mayfly prey. Our results suggest that investigating the environmental conditions, particularly the prey characteristics, that influence size-based competitive advantages will lead to a better understanding of predator population dynamics.
Vocalization activity of breeding shorebirds: documentation of its seasonal decline and applications for breeding bird surveys
Authors: Nebel Silke , McCaffery Brian J
Published: December 2003

We documented vocalization activity of breeding shorebirds at two sites in northern and western Alaska, on the Colville River Delta and on the Yukon  Kuskokwim Delta. At both sites, number of calling individuals decreased throughout the season. Variation in vocalization activity was significantly higher at the Colville River Delta towards the end of the season, while weather variables affected vocalization activity only on the Yukon  Kuskokwim Delta. Our results highlight the importance of timing, weather, and site-specific attributes on number of birds detected. We discuss our findings in the context of different methods to monitor breeding shorebirds.
Synchrony between caribou calving and plant phenology in depredated and non-depredated populations
Authors: Post Eric , Bøving Pernille Sporon , Pedersen Christian , MacArthur Megan A
Published: December 2003

Two main hypotheses have been proposed to explain reproductive synchrony exhibited by many species of large herbivores: the predation hypothesis and the seasonality hypothesis. Although examples supporting both hypotheses have been presented, no study has compared the intraseasonal progression of parturition and plant phenology in depredated and non-depredated populations of large herbivores. We monitored, on a daily or near-daily basis, the progression of the caribou (Rangifer tarandus) calving seasons in two populations: the Caribou River population in Alaska, U.S.A., where predators of caribou are present and the Kangerlussuaq-Sisimiut population in West Greenland where such predators have been absent for approximately 4000 years. Simultaneously, we quantified directly the phenological progression of caribou forage plants on spatially replicated plots in both study sites. Parturition was significantly more synchronous in the West Greenland (predator-free) population than in the Alaskan (depredated) population. Progression of the calving seasons in both populations was highly synchronized to the progression of forage plant phenology, and the slopes of these relationships were statistically indistinguishable, with 50% of births having occurred when approximately 60%70% of forage plant species were emergent. These results document clear synchronization of the timing of parturition by caribou to plant phenology, regardless of predation pressure.
Age determination in yellow-pine chipmunks (Tamias amoenus): a comparison of eye lens masses and bone sections
Authors: Barker Jennifer M , Boonstra Rudy , Schulte-Hostedde Albrecht I
Published: December 2003

Virtually all biological characteristics of organisms change with age, and thus, to assess the impact of these changes, accurate aging techniques are essential. However, many current methods are unable to accurately distinguish among adults of different ages. We determined the age of yellow-pine chipmunks (Tamias amoenus) from the Rocky Mountains of Alberta using eye lens masses, annuli from mandible sections, and annuli from femurs. Each of these methods was assessed against nine known-age animals and seven animals that had not been caught previously and were presumed to be juveniles. Eye lens masses could distinguish juveniles from adults but not adults of different ages. Mandibular sections were not practical in this species because of excessive tearing during sectioning. Femoral sections precisely predicted age. We found that the number of adhesion lines, minus one, accurately represented the ages of adults ranging from 1 to 5 years old. Femoral annuli have not previously been used to age mammals and our results suggest that they may be useful in aging other mammals, especially rodents.
Habitat preference of Canada lynx through a cycle in snowshoe hare abundance
Authors: Mowat Garth , Slough Brian
Published: December 2003

We assessed habitat preference of a lynx (Lynx canadensis) population through 8 years of a snowshoe hare (Lepus americanus) cycle. Seventy-four percent of our southern Yukon study area was approximately 30-year-old regenerating forest resulting from a large wildfire. The study area was not trapped and lynx density was very high compared with other populations in North America. Contrary to our prediction, there was no discernable shift in habitat preference through the hare cycle; however, our habitat types were coarsely mapped and our radiolocations relatively inaccurate. Lynx may have altered their habitat preferences at finer scales (for patches <2 ha). Lynx showed strong preference for regenerating habitats over mature white spruce (Picea glauca) and alpine–subalpine. Lodgepole pine (Pinus contorta) dominated regenerating stands were preferred over spruce–willow (Salix spp.) stands of equal age. Riparian willow stands were also preferred over mature spruce forest and alpine. Lynx used riparian willow stands more in winter, but we detected no other shifts in habitat preference between snow-free and winter periods. We did not detect any difference in habitat preference between sexes. Independent juveniles made greater use of mature forest and perhaps riparian willow than adults, but no other difference in preference between the two age groups was noted. Lynx preference for regenerating habitat over mature forest suggests that burns will benefit lynx, especially if the regenerating community is pine dominated. Logging will only likely provide similar benefits if a dense pine understory results, which is unlikely in intensively managed stands. The suppression of forest fires in recent decades may have contributed to the decline of lynx numbers in the south of their range.
ON THE AUTOMATIC SELECTION OF THE ONSET OF SCALING
Authors: VEITCH DARRYL , ABRY PATRICE , TAQQU MURAD S.
Published: December 2003

A method is developed for the automatic detection of the onset of scaling for long-range dependent (LRD) time series and other asymptotically scale-invariant processes. Based on wavelet techniques, it provides the lower cutoff scale for the regression that yields the scaling exponent. The method detects the onset of scaling through the dramatic improvement of a goodness-of-fit statistic taken as a function of this lower cutoff scale. It relies on qualitative features of the goodness-of-fit statistic and on features of the wavelet analysis. The method is easy to implement, appropriate for large data sets and highly robust. It is tested against 34 time series models and found to perform very well. Examples involving telecommunications data are presented.
THE DIMENSION OF SETS DETERMINED BY THEIR CODE BEHAVIOR
Authors: LI WEN XIA
Published: December 2003

By prescribing their code run behavior, we consider some subsets of Moran fractals. Fractal dimensions of these subsets are exactly obtained. Meanwhile, an interesting decomposition of Moran fractals is given.
A RENORMALIZATION APPROACH TO REACTION-DIFFUSION PROCESSES ON FRACTALS
Authors: ABDULBAKE JANAN , MULHOLLAND ANTHONY J. , GOMATAM JAGANNATHAN
Published: December 2003

Of fundamental importance to wave propagation in a wide range of physical phenomena is the structural geometry of the supporting medium. Recently, there have been several investigations on wave propagation in fractal media. We present here a renormalization approach to the study of reaction-diffusion (RD) wave propagation on finitely ramified fractal structures. In particular we will study a Rinzel-Keller (RK) type model, supporting travelling waves on a Sierpinski gasket (SG), lattice.
NEW UNIVERSALITY CLASS OF IMPACT FRAGMENTATION
Authors: INAOKA HAJIME , OHNO MAREKAZU
Published: December 2003

We conducted a set of experiments of impact fragmentation of samples with voids, such as pumice stones and bricks. We discovered that the fragment size distribution follows a power law, but that the exponent of the distribution is different from that of the distribution by the fragmentation of a space-filling sample like a gypsum ball. The value of the exponent is about 0.9. And the value seems universal for samples with voids.
SURFACE FRACTAL DIMENSION OF SWELLING CLAY MINERALS
Authors: XU YONGFU
Published: December 2003

A simple method is proposed to determine the surface fractal dimension of swelling clay minerals. When swelling clay mineral is immersed into the water solution, swelling deformation and swelling pressure will occur. The swelling deformation and swelling pressure are proportional to the amount of water volume absorbed by swelling clay minerals. The water volume absorbed by swelling clay minerals is related to its surface fractality. The correlation of the normalized water volume by the volume of swelling clay minerals (Vw/Vm) to vertical overburden pressure (p) is obtained as Vw/Vm = KpDs-3, from which the surface fractal dimension of swelling clay minerals can be estimated. The surface fractal dimension (Ds) of Wyoming bentonite is 2.64, obtained from the swelling tests. The surface fractal dimension of Wyoming bentonite determined from the swelling tests nearly equals to that obtained from the nitrogen adsorption isotherms, and is larger than that measured using the mercury intrusion porosimetry.
ANA'S GOLDEN FRACTAL
Authors: PE JOSEPH L.
Published: December 2003

In his fascinating book Wonders of Numbers, Clifford Pickover introduces the Ana sequence and fractal, two self-referential constructions arising from the use of language. This paper answers Pickover's questions on the relative composition of sequence terms and the dimension of the fractal. In the process, it introduces a novel way of obtaining fractals from iterative set operations. Also, it presents a beautiful variant of the Ana constructions involving the golden ratio. In conclusion, it suggests ways of constructing similar fractals for the Morse-Thue and "Look and Say" sequences.
DENDRITIC BRANCHING OF PYRAMIDAL CELLS IN THE VISUAL CORTEX OF THE NOCTURNAL OWL MONKEY: A FRACTAL ANALYSIS
Authors: JELINEK HERBERT F. , ELSTON GUY N.
Published: December 2003

The branching structure of neurones is thought to influence patterns of connectivity and how inputs are integrated within the arbor. Recent studies have revealed a remarkable degree of variation in the branching structure of pyramidal cells in the cerebral cortex of diurnal primates, suggesting regional specialization in neuronal function. Such specialization in pyramidal cell structure may be important for various aspects of visual function, such as object recognition and color processing. To better understand the functional role of regional variation in the pyramidal cell phenotype in visual processing, we determined the complexity of the dendritic branching pattern of pyramidal cells in visual cortex of the nocturnal New World owl monkey. We used the fractal dilation method to quantify the branching structure of pyramidal cells in the primary visual area (V1), the second visual area (V2) and the caudal and rostral subdivisions of inferotemporal cortex (ITc and ITr, respectively), which are often associated with color processing. We found that, as in diurnal monkeys, there was a trend for cells of increasing fractal dimension with progression through these cortical areas. The increasing complexity paralleled a trend for increasing symmetry. That we found a similar trend in both diurnal and nocturnal monkeys suggests that it was a feature of a common anthropoid ancestor.
LA RUE DANS LA VILLE DE L'OCCIDENT MUSULMAN MÉDIÉVAL D'APRÈS LES SOURCES JURIDIQUES MALIKITES
Authors: Nejmeddine Hentati
Published: December 2003

Dans cet article, quatre thèmes ont retenu notre attention. Le premier concerne la place des problèmes de la construction et de la rue dans les sources juridiques malikites et son évolution historique. Le second se rattache à la terminologie de la voirie dans ces sources et aux genres de rues : rue privée, généralement étroite et non passante, pouvant être possédée par une personne ou deux ou par un groupe, rue publique, passante et relativement large, elle ne peut pas être possédée, mais elle a fait l'objet d'empiètements. C'est au problème de l'empiètement sur la rue et à l'attitude des juristes malikites sur ce problème que se rapporte le troisième thème de cet article. Si R. Brunschvig a taxé le fiqh malikite de laxisme vis-à-vis de l'empiètement sur la rue, nous avons pu démontrer que ce fiqh comporte deux options : une option laxiste qui prévalait généralement en Andalousie et une option rigide qui prévalait à Kairouan. Le quatrième thème concerne les retombées de ce phénomène sur le plan de la ville islamique. Nous cherchons à examiner aussi bien les théories orientalistes qui prônent l'option anarchiste dans le plan de la ville islamique que les théories qui tendent à faire l'éloge de ce genre de ville.
WHAT WAS AL-FĀRĀBĪ'S 'IMAMIC' CONSTITUTION?
Authors: Crone Patricia
Published: December 2003

This paper seeks to identify the nature of a constitution called 'imamic' by al-Fārābī in one of his lost works, according to Ibn Bāgga and Ibn Rušd. It argues that this constitution was simply the virtuous regime under a different name. Ibn Rušd, who identifies is it in somewhat puzzling terms, must have worked with corrupt version of al-Fārābī's passage. Already Todros Todrosi, who translated Ibn Rušd into Hebrew in the fourteenth century, tried to emend it. What follows is another attempt at the same.
PERSPEKTIVEN EINER COMPUTERGESTÜTZTEN ANALYSE DER QUR'ĀNISCHEN MORPHO-SYNTAX UND SATZ-SYNTAX IN KOLOMETRISCHER DARSTELLUNG
Authors: Edzard Lutz
Published: December 2003

En suivant des opinions émises par Gotthelf Bergsträsser et Angelika Neuwirth, nous explorons dans cet article la possibilité de présenter le texte coranique divisé en "kôlons", c'est-à-dire en brèves unités syntaxiques indépendantes. Concernant la méthode nous recourons au modèle de présentation du texte de l'Ancien Testament proposé par Wolfgang Richter (Biblia Hebraica Transcripta). Ainsi le texte coranique apparaît sous forme de colonnes parallèles en écriture arabe et en transcription. En partant du texte présenté de cette manière, nous proposons une analyse morpho-syntaxique automatisée du texte coranique. Dans ce cas aussi nous adaptons les résultats de la recherche informatique sur l'Ancien Testament effectuée par un groupe travaillant autour de Wolfgang Richter. Following proposals by Gotthelf Bergsträsser and Angelika Neuwirth, in this paper I will discuss what is involved in presenting the Qur' nic text in a "colometric" way, i.e. divided into small prosodic units that are syntactically independent. In so doing I follow the method applied in the presentation of the text of the Old Testament by Wolfgang Richter (Biblia Hebraica Transcripta). The text will appear in parallel columns, both in Arabic script and in transcription, in accordance with the said colometric division. Based on this presentation, a computer-aided approach to morpho-syntactic analysis will be developed. Again this will be oriented towards the results of research in computational linguistics done by a team working with Wolfgang Richter.
A dominant-negative mutant of C/EBPα, associated with acute myeloid leukemias, inhibits differentiation of myeloid and erythroid progenitors of man but not mouse
Authors: Schwieger Maike , Löhler Jürgen , Fischer Meike , Herwig Uwe , Tenen Daniel G. , Stocking Carol
Published: December 2003

The CCAAT/enhancer binding protein alpha (C/EBPα) is an essential transcription factor for granulocytic differentiation. C/EBPα mutations are found in approximately 8% of acute myeloid leukemia (AML) patients. Most of these mutations occur in the N-terminal coding region, resulting in a frame shift and the enhanced translation of a dominant-negative 30-kDa protein, which may be responsible for the differentiation block observed in AML. To test this hypothesis, we introduced a cDNA encoding an N-terminal mutated C/EBPα (mut10) into primary hematopoietic progenitors using a retroviral vector. Expression of mut10 in human CD34+ cord blood cells dramatically inhibited differentiation of both myeloid and erythroid lineages. Immunohistochemical analysis demonstrated coexpression of both myeloid and erythroid markers in the immature transformed cells. Surprisingly, mut10 did not block myelocytic differentiation in murine progenitors but did alter their differentiation kinetics and clonogenicity. Experiments were performed to confirm that the differential effect of mut10 on murine and human progenitors was not due to species-specific differences in C/EBPα protein sequences, expression levels, or inefficient targeting of relevant cells. Taken together, our results underline the intrinsic differences between hematopoietic controls in mouse and human and support the hypothesis that mutations in CEBPA are critical events in the disruption of myeloid differentiation in AMLs. (Blood. 2004;103:2744-2752)
Transgenic rescue of GATA-1–deficient mice with GATA-1 lacking a FOG-1 association site phenocopies patients with X-linked thrombocytopenia
Authors: Shimizu Ritsuko , Ohneda Kinuko , Engel James Douglas , Trainor Cecelia D. , Yamamoto Masayuki
Published: December 2003

Association of GATA-1 and its cofactor Friend of GATA-1 (FOG-1) is essential for erythroid and megakaryocyte development. To assess functions of GATA-1–FOG-1 association during mouse development, we used the GATA-1 hematopoietic regulatory domain to generate transgenic mouse lines expressing a mutant GATA-1, which contains a substitution of glycine 205 for valine (V205G) that abrogates its association with FOG-1. We examined whether the transgenic expression of mutant GATA-1 rescues GATA-1 germ line mutants from embryonic lethality. In high-expressor lines we observed that the GATA-1V205G rescues GATA-1–deficient mice from embryonic lethality at the expected frequency, revealing that excess GATA-1V205G can eliminate the lethal anemia that is due to GATA-1 deficiency. In contrast, transgene expression comparable to the endogenous GATA-1 level resulted in much lower frequency of rescue, indicating that the GATA-1–FOG-1 association is critical for normal embryonic hematopoiesis. Rescued mice in these analyses exhibit thrombocytopenia and display dysregulated proliferation and impaired cytoplasmic maturation of megakaryocytes. Although anemia is not observed under steady-state conditions, stress erythropoiesis is attenuated in the rescued mice. Our findings reveal an indispensable role for the association of GATA-1 and FOG-1 during late-stage megakaryopoiesis and provide a unique model for X-linked thrombocytopenia with inherited GATA-1 mutation.
Hemochromatosis mutations in the general population: iron overload progression rate
Authors: Andersen Rolf Værn , Tybjærg-Hansen Anne , Appleyard Merete , Birgens Henrik , Nordestgaard Børge Grønne
Published: December 2003

The progression rate of iron overload in hereditary hemochromatosis in individuals in the general population is unknown. We therefore examined in the general population iron overload progression rate in C282Y homozygotes. Using a cohort study of the Danish general population, The Copenhagen City Heart Study, we genotyped 9174 individuals. The 23 C282Y homozygotes identified were matched to 2 subjects each of 5 other HFE genotypes with respect to sex, age, and alcohol consumption. As a function of biologic age, transferrin saturation increased from 50% to 70% from 25 to 85 years of age and from 70% to 80% from 35 to 80 years of age in female and male C282Y homozygotes, respectively. Equivalently, ferritin levels increased from 100 to 500 μg/L and decreased from 800 to 400 μg/L in female and male C282Y homozygotes. As a function of 25 years follow-up irrespective of age, transferrin saturation and ferritin levels increased slightly in male and female C282Y homozygotes. None of the C282Y homozygotes developed clinically overt hemochromatosis. In conclusion, individuals in the general population with C282Y homozygosity at most demonstrate modest increases in transferrin saturation and ferritin levels, and clinically overt hemochromatosis is rare. Therefore, C282Y homozygotes identified during population screening, and not because of clinically overt hemochromatosis, at most need to be screened for manifestations of hemochromatosis every 10 to 20 years. (Blood. 2004;103: 2914-2919)
Isolation and Reaction of (Indolin-3-ylidene)pentacarbonyltungsten Generated from Tungsten-containing Azomethine Ylide
Authors: Takaya Jun , Kusama Hiroyuki , Iwasawa Nobuharu
Published: December 2003

(Indolin-3-ylidene)pentacarbonyltungsten, a non-heteroatom-stabilized carbene complex of group 6 metal, was successfully isolated by the reaction of N-(o-alkynylphenyl)imine derivative, vinyl ether and tungstenhexacarbonyl under photoirradiation. This complex was moderately stable and fully characterized by spectroscopic analysis.
2-Hydroxyphenyl-1,3-dimethylbenzimidazolines. Formal Two Hydrogen Atom-donors for Photoinduced Electron Transfer Reactions
Authors: Hasegawa Eietsu , Chiba Naoki , Takahashi Tomoya , Takizawa Shinya , Kitayama Takashi , Suzuki Toshio
Published: December 2003

Both 2-(2′-hydroxyphenyl)-1,3-dimethylbenzimidazoline and 2-(4′-hydroxyphenyl)-1,3-dimethylbenzimidazoline were found to act as formal two hydrogen atom-donors for photoinduced electron transfer reactions of epoxy ketones and other carbonyl compounds.
Synthesis of Mesoporous Ce-doped TiO2 with High Thermal Stability
Authors: Wang Chao , Xi Hong-an , Wang Ruo-Ding
Published: December 2003

Mesoporous Ce-doped TiO2 with a high thermal stability was prepared by using inexpensive glycerin as a pore former via sol-gel and hydrothermal processes. The product has a high specific surface area (129.7 m2/g) and a pore volume (0.41 cm3/g) even after calcination at 600 °C for 2 h.
Synthesizing Hyperbranched Azo Polymer through Azo-coupling Reaction
Authors: Che Pengchao , He Yaning , Zhang Yue , Wang Xiaogong
Published: December 2003

An AB2 monomer N,N-bis[2-(4-aminobenzoyloxy)ethyl]aniline was synthesized by nucleophilic substitution reaction between N,N-bis(2-chloroethyl)aniline and 4-aminobenzonic acid. Based on the monomer, the azo-coupling reaction was explored for the first time to prepare a hyperbranched azo polymer. The results showed that the scheme was a feasible way to synthesize hyperbranched azo polymers under extremely mild conditions.
Optical rotation in RbTiOAsO4(point groupmm2)
Authors: Kaminsky W. , Thomas P. A. , Glazer A. M.
Published: December 2003

Measurement of optical rotation in RbTiOAsO4(RTA) with the tilter method resulted in an optical rotation ofρ12= +17(3)o/mm at a wavelength of 670nm, when a (100) sample was tilted about [001]. A tilt about [010] showed no rotation, as expected from the directional dependence of optical rotation calculated from the tensor in point groupmm2. The absolute Miller-indices of the sam-les were found using X-ray anomalous scattering. The calculations with a dipole-dipole model show that the As5+-ions in RTA correlate with the main structural contribution of the optical rotation. However, there seems to be an even larger intrinsic contribution due to the Ti4+– ions as a result of the distorted octahedral co-ordination with oxygen.
X-ray crystal structure analysis of lanthanide trihydrogeno hydroxy-1-ethanebis(phosphonate)-1,1,dihydrogeno hydroxy-1ethanebis(phosphonate)-1,1 hemiundecahydrate, Ln{[C(CH3)(OH)(P2O6H3)][C(CH3)(OH)(P2O6H2)]}⋅5.5H2O with Ln = Y, Ho, Er; and energy parametrization of the absorption spectrum of the Er compound
Authors: Van Meervelt L. , Martello P. , Silvestre J.-P. , Rochdaoui R. , Lee M.-R. , Quy Dao N. , Görller-Walrand C.
Published: December 2003

The crystal structures of Ln{[C(CH3)⋅(OH)(P2O6H3)][C(CH3)(OH)(P2O6H2)]}⋅5.5H2O, with Ln = Y (compound 1), Ln = Ho (compound 2) and Ln = Er (compound 3), have been determined by single crystal X-ray diffraction. The three compounds are isomorphous and crystallize in the monoclinic space group P21/n (n°14). The cell parameters of 1 are a = 10.451(2) Å, b = 11.395(3) Å, c = 17.173(3) Å, β = 94.28(1)°, those of 2 are a = 10.447(2) Å, b = 11.382(2) Å, c = 17.129(4) Å, β = 94.32(3)°, and those of 3 are a = 10.432(1) Å, b = 11.398(2) Å, c = 17.134(2) Å, β = 94.35(2)°.The coordination polyhedron around the lanthanide cations is a distorted monocapped trigonal prism with a slightly distorted C
2

v
symmetry. The UV and visible light absorption spectrum was recorded for 3. A detailed theoretical simulation of the energy level scheme of the 4f11 configuration of Er3+ was carried out. The angular parts were accurately calculated by group-theoretical and tensorial methods and the radial integrals were left as parameters to be determined semi-empirically. The C
2

v
symmetry was described by free ion and crystal field parameters after refinement of these parameters on the absorption spectroscopic data of 3.
The crystal structure of the decomposition product NH4HC2O4 from powder diffraction data
Authors: Audebrand N. , Louër D.
Published: December 2003

The crystal structure of anhydrous ammonium acid oxalate, NH4HC2O4, obtained from the thermal decomposition of the related hemihydrate has been determined from powder diffraction data collected with monochromatic laboratory X-rays, using the capillary technique. The crystal structure is monoclinic, P21/c, Z = 4, a = 4.3629(1) Å, b = 13.5657(1) Å, c = 7.7100(1) Å, β = 102.602(1)° and V = 445.3(1) Å3. The structure has been solved with the direct methods and refined with the Rietveld method, from which the agreement factors R
wp = 8.19% and R
B = 5.18% have been obtained. The crystal structure consists of corrugated layers built from seven-fold ammonium coordination polyhedra and connected by oxalate groups. The hydrogen atom positions have been located and the hydrogen bond network is extensively discussed.
Nitridocompounds of manganese: manganese nitrides and nitridomanganates
Authors: Niewa R.
Published: December 2003

The chemistry of nitrides and nitridometalates is a rapidly growing field in solid state chemistry. This short review is intended to give a brief but comprehensive over-view on the compounds and phases formed with manga-nese, which cover an especially broad range of oxidation states. Furthermore, the present paper tries to put the ob-served structures and properties of the compounds into a broader context.
Analysis of short and long range atomic order in nanocrystalline diamonds with application of powder diffractometry
Authors: Palosz B. , Grzanka E. , Gierlotka S. , Stel´makh S. , Pielaszek R. , Bismayer U. , Neuefeind J. , Weber H.-P. , Proffen Th. , Von Dreele R. , Palosz W.
Published: December 2003

Fundamental limitations, with respect to nanocrystalline materials, of the traditional elaboration of powder diffraction data like the Rietveld method are discussed. A tentative method of the analysis of powder diffraction patterns of nanocrystals based on the examination of the variation of lattice parameters calculated from individual Bragg lines (named the “apparent lattice parameter”, alp) is introduced. We examine the application of our methodology using theoretical diffraction patterns computed for models of nanocrystals with a perfect crystal lattice and for grains with a two-phase, core-shell structure. We use the method for the analysis of X-ray and neutron experimental diffraction data of nanocrystalline diamond powders of 4, 6 and 12 nm in diameter. The effects of an internal pressure and strain at the grain surface are discussed. The results are based on the dependence of the alp values on the diffraction vector Q and on the PDF analysis. It is shown, that the experimental results lend a strong support to the concept of a two-phase structure of nanocrystalline diamond.
The crystal structure of non-stoichiometric monoclinic Cr5+

x
S8 (x = 0.20 and 0.26) prepared under high pressure and high temperature
Authors: Bensch W. , Lühmann H. , Näther C. , Huppertz H.
Published: December 2003

Two non-stoichiometric chromium rich Cr5+

x
S8 (x = 0.20 and 0.26) samples were prepared under high pressure and high temperature conditions. In the crystal structures three different metal atom sites are fully and the fourth site is only partially occupied. The results of single crystal and Rietveld refinements are in good agreement. The CrS6 octahedra share common corners and common faces. Across common faces extraordinary short Cr—Cr distances are observed suggesting metal-to-metal bonding. On the basis of the distortion of the CrS6 octahedra Cr4+ is located on two of the four Cr sites. With increasing Cr content the amount of Cr4+ is lowered and the distortion of two of the four CrS6 octahedra is significantly reduced.
Study of effect of thermal annealing on crystalline perfection of bismuth germanate single crystals grown by low thermal gradient Czochralski method
Authors: Choubey A. , Bhagavannarayana G. , Shubin Yu. V. , Chakraborty B. R. , Lal K.
Published: December 2003

Bismuth germanate single crystals containing low angle and very low angle boundaries were selected as specimen for annealing experiments at 1000 °C for varying lengths of time in the range: 8 h to 80 h. Specimen with larger surface along (111) and (100) planes were investigated. The tilt angles of the boundaries were found to be in the range: 16 arc sec to 88 arc sec. Half widths of the diffraction curves of different subgrains were in the range: 15 arc sec to 39 arc sec. High resolution X-ray diffractometry and topography were employed for structural characterization and secondary ion mass spectrometry (SIMS) was used for study of impurity distribution. Annealing led to significant improvement in the crystalline perfection of specimen and all but one of the boundaries could be removed. The very low angle boundaries, which could not be annealed out, had a tilt angle of 41 arc sec. The half widths of diffraction curves of the two remaining subgrains were: 10 arc sec and 17 arc sec. The growth of subgrains as a result of annealing was investigated. SIMS investigation of annealed specimen, in which a very low angle boundary persisted, showed the boundary was decorated with silicon impurity, which presumably acted as a pining center. Detailed diffractometric and topographic experiments helped in delineating the two subgrains around the very low angle boundary. The morphological features of the very low angle boundary were studied in detail.
The high-pressure behaviour of 3R-NbS2
Authors: Ehm L. , Knorr K. , Depmeier W.
Published: December 2003

The high pressure behaviour of 3R-NbS2 has been investigated by angle-dispersive X-ray powder diffraction using diamond anvil cells up to 14 GPa. The compression behaviour of the structure is highly anisotropic. The compressibility perpendicular to the layers is 2.5 times higher than within the layers. A fit of a 3
rd
-order Birch-Murnaghan equation of state gave a volume at zero pressure V
0=174(1) Å3 and a bulk modulus b
0=57(1) GPa, with a pressure derivative b'=8.6(5).
Crystal structure analysis and extremely long-living light-induced metastable states in RbY[Fe(CN)5NO]2·10H2O and CsY[Fe(CN)5NO]2·10H2O
Authors: Woike Th. , Held P. , Mühlberg M. , Imlau M.
Published: December 2003

Crystal structures of both isostructural com-pounds were solved from single crystal X-ray diffraction data (space group P21/n; Z = 4; Rb-compound: a = 9.812(1) Å, b = 25.793(3) Å, c = 11.777(2) Å, β = 104.68(1)°, R
gt(F) = 0.0458, wR
ref(F
2) = 0.0918; Cs-compound: a = 9.9058(8) Å, b = 25.919(2) Å, c = 11.883(1) Å,β = 105.542(7)o, Rgt(F) = 0.0450,wRref(F2) = 0.0951. The main structural feature is the nitrosylpentacyanoferrate(II)-complex [Fe(CN)5NO]2–. The iron atoms are coordinated to five cyanide and one nitrosyl ligand. The coordination polyhedron of the Y3+ cation is a distorted tetragonal antiprism built up from three nitrogen atoms of three complexes and five water molecules. Both rubidium and cesium ions are surrounded by seven cyanide groups of five complexes and one water molecule to form a distorted bicapped trigonal prism. One metastable state (SI) can be excited by irradiation with light in the spectral range of 400–500 nm at temperatures below 180 K. The radiationless thermal decay is detected by Differential Scanning Calorimetry by heating above T = 180 K. Evaluating the exothermal heat flow using the Arrhenius law yields an activation energy of EA
= 0.64(2) eV and a frequency factor of Z = 20(8)·1012s–1 for the rubidium compound and EA
= 0.56(2) eV, Z = 30(8)·1010s–1 for the cesium compound. The contribution of the cations on the decay temperature of the metastable states is discussed on the basis of the atomic distances and coordinations.
Structural investigation of the phase transitions of [N(CH3)4]2HgCl4
Authors: Amami M. , van Smaalen S. , Palatinus L. , Ben Salah A. , Helluy X. , Sebald A.
Published: December 2003

The crystal structures of [N(CH3)4]2HgCl4 between 191 K and 350 K have been studied by single crystal X-ray diffraction. Below Tc

1 = 277 K the structure is monoclinic P21/a with lattice parameters a = 12.320 (7), b = 9.034 (4), c = 15.402 (4) Å, and β = 89.64 (1)° at T = 191 K. Above Tc

1 the structure is orthorhombic Pnma with lattice parameters 12.419 (7), b = 9.068 (4), and c = 15.684 (2) Å at room temperature, and with lattice parameters a = 12.421 (9), b = 9.125 (1), and c = 15.777(4) Å at T = 350 K. At room temperature each TMA cation disorderly occupies two orientations (TMA is tetramethylammonium). At low temperature the structure is fully ordered, with additional shifts and rotations of all ions, in accordance with the results of Asahi et al., J. Phys. Soc. Jpn. 60 (1991) 921. Refinements using restrictions of the non-crystallographic tetrahedral point group for the TMA cations and refinements without restrictions are used to show that TMA has tetrahedral symmetry at all temperatures. The HgCl4 anions are distorted, but the distortions are independent of the temperature. The phase transition at Tc

1 is described as an order/disorder transition accompanied by major rotations and shifts of the ions. New evidence for a previously reported phase transition at Tc

2 = 320 K (Zangar et al. Phase Transitions 12 (1988) 141) is obtained from NMR. This transition is shown to be a non symmetry breaking structural transition, that correspond to a gradual loss of the orientational order of the TMA cations.
Phase transitions in solid solution series bismutocolumbite – stibiocolumbite (Bi-Sb)(Nb0.79Ta0.21)O4
Authors: Kazantsev S. S. , Pushcharovsky D. Yu. , Maximov B. , Molchanov V. , Werner S. , Schneider J. , Sapozhnikov A. N.
Published: December 2003

The crystal structure of bismutocolumbite, Bi(Nb0.79Ta0.21)O4 with orthorhombic (sp. gr. Pnna) stibio-tantalite structure type at ambient conditions has been de-termined at 2.59 and 9.56 GPa, and 23oC. Crystal data and results of structure refinement using powder X-ray diffrac-tion and Rietveld analysis for Bi-rich stibiocolumbite, (Sb0.52Bi0.48)(Nb0.71Ta0.29)O4, are reported. At the pressure ~2.9 GPa bismutocolumbite exhibits phase transition which is accompanied by the change of its symmetry: sp. gr. Pnna is replaced by the sp. gr. Pn21
a. This kind of transformation is anticipated at ambient pressure in bismutocolumbite- stibiocolumbite solid solution series in the compounds with Sb/(Bi+Sb) ratio higher than 0.52 which characterises the studied crystals of stibiotantalite. Similarly with scheelite-like BiVO4, in bismutocolumbite the reduction of the unit cell volume under HP is mainly a result of Bi-O polyhedral compression, which is accompanied by a rearrangement of (Nb,Ta)O6 octahedra within octahedral sheets parallel to (010). (Nb,Ta)O6 octahedra remain rigid with smaller change in size at high pressure.
A reinvestigation of Wilm's salt, (NH4)4[RhCl6]NO3 -structure, spectroscopy and thermal analysis-
Authors: Reiß G. J.
Published: December 2003

The redetermination of the crystal structure of Wilm's salt, tetraammonium hexachlororhodate(III) nitrate, (NH4)4[RhCl6]NO3 from single crystal data, necessitated a change in space group symmetry description, as a conse-quence of comparative structure refinements, from the polar space group R3m to the chiral space group R32 for the room temperature structure. In contrast to the former structure determination it is shown, that in the correct space group a structure model can be derived, in which all parts of the structure – including the H atom positions of the ammonium ions – appear completely ordered on their sites. The ammonium cations and the hexachlororhodate as well as the nitrate anions form a three-dimensional framework via weak N-H···Cl and N-H···O hydrogen bonds. Reproducing the original synthesis conditions and analysing the products by powder diffraction methods, the by-products have been identified as ammonium nitrate and diammonium aquapentachlororhodate(III). Doing DTA experiments on the title compound, two endothermic effects at 54°C and 128°C have been detected that may be related to phase transitions from the ordered room temperature structure to disordered high temperature sub structures. According to the results of thermo gravimetry the title compound decomposes at temperatures above 140°C. The temperature dependant IR spectroscopy in the range of RT-60 C it is probable that the above mentioned thermal effect at 54°C is associated with an order disorder phase transition introduced by the ammonium cations. The UV/Vis spectroscopy show that at 8 K a significant distortion of the [RhCl6]3–octahedron from highest 32 point symmetry is plausible.