bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of fire and harvest on soil organic carbon in jack pine sites
Authors: Norris C. E. , Quideau S. A. , Bhatti J. S. , Wasylishen R. E. , MacKenzie M. D.
Published: April 2009

Boreal forest soils represent a considerable reservoir of carbon on a global basis. The objective of this study was to compare the response of soil organic carbon (OC) to disturbance along two jack pine ( Pinus banksiana Lamb.) chronosequences of either fire or harvest origin. Total OC stocks were determined for the A and B horizons, and results indicated a recovery to predisturbance levels by 30 years in both chronosequences. To further characterize OC composition at all sites, we used a combination of physical fractionation of soil OC pools, 13C isotopic determination, and cross-polarization magic-angle spinning 13C nuclear magnetic resonance (NMR) spectroscopy. OC within all soils was dominated by a labile pool associated with the coarse-sand fraction. The relative importance of this labile pool increased with time since disturbance along both chronosequences. However, the fire and harvested sites differed in terms of the macromolecular composition of soil OC as determined by NMR. In particular, spectra of the forest floors from the two younger fire sites showed a high aromatic OC intensity that may be attributed to the presence of char. Interestingly, our results also indicated that with increasing time since fire, this char was transferred from the forest floors to the A horizons.
Thermoregulatory performance of fledgling American coots (Fulica americana) in air and water
Authors: Sutter Glenn C. , MacArthur Robert A.
Published: April 2009

The precision and metabolic costs of temperature regulation in air and water were studied in hand-reared fledgling American coots (Fulica americana). In birds acclimated to both 23 and 8 °C, cloacal temperature was independent of air temperature over an air temperature range of −10 to 33 °C. Minimum resting metabolic rate and thermal conductance averaged 1.2–1.6 times higher in water than in air, and neither variable was significantly affected by cold acclimation. Despite differences in minimal thermal conductance, the lower critical temperature was similar in air and water (19–21 °C). Trunk skin temperature averaged 3.4–4.3 °C below cloacal temperature in both media, and did not differ between dorsal and ventral aspects of the bird. Peripheral cooling was most pronounced in submerged appendages. Coots displayed a high resistance to immersion hypothermia; cloacal temperature remained stable at 40–41 °C during 4 h exposure to 5 °C water. Exposure to a −10 °C atmosphere of helium–oxygen (helox) similarly failed to induce even mild hypothermia in all but one of the birds tested. The unusual tolerance of F. americana to helox and immersion in cold water could not be attributed to an enhanced thermogenic ability. Maximum resting metabolic rate of birds exposed to cold was only 3.0–3.5 times the thermoneutral rate. Aquatic homeothermy in this species may instead reflect superior insulation and exceptional buoyancy provided by a dense, water-repellent plumage.
Rhabditid nematodes from seaweed deposits in Canada with a description of Rhabditis (Pellioditis) littorea n.sp.
Authors: Sudhaus Walter , Nimrich Monika
Published: April 2009

A sample of rotting seaweed from Vancouver Island contained specimens of four species of rhabditids. One is new to science and is described as Rhabditis (Pellioditis) littorea n.sp. Morphometrical comparisons were made of some individuals between measurements of the living animal and of the same specimen mounted on a permanent slide. Preliminary notes are given concerning biology and ecology of the species. A list provides information on 11 typical and 2 occasional rhabditid species inhabiting seaweed and their distribution as known so far.
Normal and blocked pregnancy in the collared lemming: morphometrical and histological changes
Authors: Rathmann Nicolle P. , Mallory Frank F.
Published: April 2009

Normal and blocked pregnancy were studied in the collared lemming, Dicrostonyx groenlandicus, in the laboratory with individuals bred from wild stock caught at Eskimo Point, N.W.T. Morphometrical changes (corpora luteal area, ovarian weight, uterine weight, fetal crown–rump lengths, spleen and adrenal weights) during normal and blocked pregnancy were documented and found to be similar to those of other microtines. Mean maximum corpora luteal area, and ovarian and uterine weights increased continuously throughout gestation, as did the fetal crown–rump lengths. Spleen and paired adrenal weights increased similarly; however, they were not significantly different when corrected for body weight. Ovulation occurred between 9 and 12 h post coitum, as evidenced by the presence of ovulated follicles with stigmata, and luteinization was observed within 24 h. No identifiable differences were observed in the histology of corpora lutea and corpora albicantia of normal and blocked females although significant differences in size occurred. Accessory luteal structures (accessory corpora lutea and luteinized follicles) were found in very high numbers in this species compared with other microtines, peaking by day 4 post coitum and declining in number and size towards the end of gestation. It is concluded that the accessory luteal structures function in a supportive role to the corpora lutea of pregnancy during the early stages of gestation but undergo atrophy towards parturition, when the corpora lutea of pregnancy reach their full size and functional capacity. The presence of large numbers of accessory luteal structures and the similarity of histology between ovarian structures in normal and blocked pregnancy makes the identification of these conditions in the field impractical at present.
Otolith microstructure of three larval gadids in the Gulf of Maine, with inferences on early life history
Authors: Campana Steven E.
Published: April 2009

A detailed analysis of the assumptions underlying the application of otolith microstructure was undertaken for three gadid species from the Gulf of Maine. Daily increment counts provided a precise and accurate index of age in cod (Gadus morhua) and appeared to do so in haddock (Melanogrammus aeglefinus). However, the widths of increments formed shortly after hatch in cod and haddock otoliths approached the resolution limit of light microscopy, resulting in an underestimation of age by 2–3 d for all fish. Daily increments were also formed in the otoliths of pollock (Pollachius virens) but, perhaps because of more severe resolution problems, the microstructure associated with the early larval stage was unclear. Factors that could confound growth back-calculation efforts included differing otolith length – larval length relationships among samples and an inverse correlation between hatch check diameter and temperature. Estimates of hatch date and growth rate developed in this study were not affected by slight deviations from the underlying assumptions, but might be affected by such deviations under different environmental conditions. Larval pollock growth was comparable to that of cod and haddock, despite a later hatch date. Pollock hatched primarily in November, while peak dates for cod and haddock hatching occurred in March–April and May, respectively. Cod on Georges Bank hatched significantly earlier than those on Browns Bank, although the latter included a less abundant component that hatched in the fall.
Redescription of Pseudotelorchis compactus (Cable and Sanborn, 1970) Yamaguti, 1971 (Cercomeria: Trematoda: Digenea: Plagiorchiformes) with discussion of its phylogenetic affinities
Authors: Macdonald Cheryl A. , Brooks Daniel R.
Published: April 2009

Pseudotelorchis compactus from the oviducts of Emydoidea blandingi is redescribed and its phylogenetic affinities examined. The Ochetosomatidae is considered the sister group of the Telorchiidae based on the shared presence of a well-developed glandular and muscular metraterm, and on the use of tadpoles as second intermediate hosts in the life cycle. The monophyly of the Ochetosomatidae is supported by the presence of relatively short caeca and testes located near the posterior ends of the caeca. The monophyly of the Telorchiidae is supported by the presence of postuterine testes located near the posterior end of the body. Orchidasma is excluded from the Telorchiidae because it possesses a spinose cirrus, spinose metraterm and distal portion of the uterus, and testes separated widely in the hind body by the uterus. Pseudotelorchis is considered monophyletic by virtue of having ovaries with irregular rather than smooth margins, testes that vary from side by side to tandem rather than being consistently tandem, and by inhabiting the oviducts rather than the intestine of the definitive hosts. Pseudotelorchis is the sister group of Loefgrenia plus Telorchis, the latter group diagnosed by having ovaries that are at least half an ovarian diameter posterior to the posterior margin of the ventral sucker rather than proximal to it. Loefgrenia is diagnosed by the absence of an esophagus, while Telorchis is diagnosed by strictly tandem testes with smooth margins and well-ordered ascending and descending uterine loops.
Genetically distinct sympatric populations of resident and anadromous Atlantic salmon, Salmo salar
Authors: Verspoor E. , Cole L. J.
Published: April 2009

Atlantic salmon (Salmo salar) from Little Gull Lake on the Gander River system of central Newfoundland were found to be electrophoretically polymorphic at 5 of 20 protein loci screened. Four of the polymorphic loci were structural and one was regulatory. Major heterozygote deficiencies relative to Castle–Hardy–Weinberg expectations were detected at the two most polymorphic loci, Aat-3 and Mdh-3,4, and significant nonrandom associations between genotypes at these loci and the other polymorphic loci, Sdh-1, Me-2, and Pgm1-t, were also found. The heterozygote deficiencies and the nonrandom genotype associations were attributable to the admixture of genetically distinct gene pools of resident and anadromous salmon in the lake. This is the first documented case of coexistence of reproductively separated populations of Atlantic salmon of the two life history types, and shows that the sympatric occurrence of the two forms can represent between-population variation.
Variability in timing of egg hatch of Triaenophorus crassus Forel (Cestoda: Pseudophyllidea) as a mechanism increasing temporal dispersion of coracidia
Authors: Shostak Allen W. , Dick Terry A.
Published: April 2009

Eggs collected from 174 Triaenophorus crassus Forel over 3 years were maintained under a 12-h photocycle at 15 °C to quantify variability in three egg hatching characteristics. The percentage of eggs hatching to release coracidia varied from 20 to 90% (mean 82%). The median hatch time (time from egg release to hatch) varied from 4.3 to 14.2 days (mean 8.3 days). The duration of the egg hatching period (the time between hatch of 10 and 90% of eggs) varied from 1 to 17 days (mean 4.6 days). These three characteristics varied among years, among worms from different hosts, and among worms from the same host. Variability in egg hatching characteristics was not correlated with egg size or fecundity of the parent, but a consideration of this variability within the context of the hierarchical nature of parasite populations suggested that this variability resulted from genotypic and environmental contributions to parasite phenotype. Results of a simulation study suggested that naturally occurring levels of variability in egg hatching characteristics could increase temporal dispersion of coracidia beyond that resulting solely from temporal variation in egg release from adult worms. The time at which peak densities of coracidia occurred was affected little by variability in egg hatching characteristics. However, peak densities of coracidia were reduced because the period of egg hatching began earlier and ended later compared with expectations in the absence of variability in egg hatching characteristics.
Differentiation of Moniezia expansa and Moniezia benedeni (Eucestoda: Cyclophyllidea) by isoelectric focusing
Authors: Johnson M. R. , Hoberg E. P.
Published: April 2009

Isoelectric focusing was performed on extracts from whole specimens of Moniezia expansa recovered from sheep and Moniezia benedeni recovered from cattle. The isoelectric focusing banding patterns for mature, postmature, early gravid, and gravid proglottids from individual cestodes were compared along with those for intestinal tissue from the respective hosts. Unique, reproducible banding patterns were characteristic of each species. In addition, the patterns for these cestodes were distinctly different from those for either of the host tissues. The tracks of the gels were scanned and values for isoelectric points were assigned for the dominant peaks characteristic of each species. A range based on the mean ± 2 SD was then assigned to each of these peaks for future comparisons.
Helminth parasites of the alimentary tract of Atlantic halibut (Hippoglossus hippoglossus L.) and Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) on the Scotian Shelf
Authors: Scott James S. , Bray Shelley A.
Published: April 2009

Examination of the alimentary tracts of 272 Atlantic halibut (Hippoglossus hippoglossus (L.)) and 71 Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) from the Scotian Shelf yielded a total of 25 helminth parasite species, 23 from H. hippoglossus (16 Digenea, 3 Cestoda, 2 Acanthocephala, 2 Nematoda) and 16 from R. hippoglossoides (11 Digenea, 3 Cestoda, 1 Acanthocephala, 1 Nematoda). Parasite prevalence and intensity were low (< 50% and < 10%, respectively) in both hosts, except for Derogenes varicus and Steganoderma formosum in H. hippoglossus and anisakid nematodes in R. hippoglossoides. Consideration of change in parasite prevalence and mean intensity in relation to fish length and diet suggests fish prey as transport hosts for D. varicus in larger halibuts, and crustaceans as the intermediate hosts for S. formosum before transmission to its principal host, H. hippoglossus. Geographical change in parasite prevalence and intensity was in the form of southwest to northeast clines along the Shelf, probably related to environmental factors. There was no evidence for stock differentiation in either of the hosts based on parasite fauna.
Dinychus ruseki n.sp. (Acari: Uropodina) from Canada, with remarks on the habitats and distribution of the members of the genus Dinychus
Authors: Athias-Binche Françoise , Bloszyk Jerzy , Olszanowski Ziemowit
Published: April 2009

Dinychus ruseki n.sp. is a Canadian species very closely related to Dinychus micropunctatus Evans, 1955, described from Alaska, with which it may constitute an ecospecies. The family Prodinychidae and the genus Dinychus are briefly redefined. An annotated list of the currently recognized species of the genus Dinychus, with comments on their distribution and habitat characteristics, is included.
N-acetylation of p-octopamine by Malpighian tubules and other tissues of the American cockroach, Periplaneta americana L., in vitro
Authors: Martin R. J. , Downer R. G. H.
Published: April 2009

The capacity of several tissues of the American cockroach, Periplaneta americana, to remove p-octopamine from incubation medium was investigated using high performance liquid chromatography with electrochemical detection to monitor levels of p-octopamine and the N-acetylated derivative. Gut was the most active tissue in removing p-octopamine from the medium and separate analyses of the various regions of the gut indicate that the Malpighian tubules constitute the primary site of removal. Epidermal and nervous tissue are also capable of removing substantial amounts of p-octopamine. In addition to the removal of p-octopamine, Malpighian tubules remove dopamine and 5-hydroxytryptamine from incubation medium and, indeed, have a slightly greater capacity for removing these monoamines than for removing p-octopamine. However, concentrations of each amine that are considerably in excess of physiological levels do not saturate the system. Most of the p-octopamine removed by the gut tissue undergoes N-acetylation to form N-acetyl-p-octopamine; thus, this appears to be the primary degradation metabolic route for p-octopamine. Analysis of the faeces following injection of p-octopamine demonstrated the presence of both p-octopamine and the N-acetylated derivative.
Digesta retention of winter diets in white-tailed deer (Odocoileus virginianus) fawns in Maine, U.S.A.
Authors: Jenks Jonathan A. , Leslie Jr. David M.
Published: April 2009

Eight captive white-tailed deer (Odocoileus virginianus) fawns were maintained on winter diets from 15 January to 31 March 1985 (i) to determine digesta retention time for primarily coniferous diets and (ii) to test the hypothesis that lichen consumption decreased retention time. Diets contained four conifers and either 0, 5, 15, or 25 % of a fruticose lichen component. Digesta retenton time was calculated using forages that were marked with ytterbium. Feces were collected up to 168 h postdosing, and subsamples were analyzed for ytterbium by atomic absorption spectrophotometry. Across all trials, total mean retention time ranged from 48.6 to 78.8 h. Five fawns in various trials cropped off their lateral abdominal pelage and thus introduced a treatment effect into our design that restricted our statistical analysis to data from two of four trials. Those data indicated that total mean retention time decreased as proportions of dietary lichen increased for noncroppers (P = 0.007) but not for croppers (P = 0.20).
The influence of heat on the development of Babesia microti in unfed nymphs of Ixodes dammini
Authors: Lewengrub S. , Rudzinska M. A. , Piesman J. , Spielman A. , Zung J.
Published: April 2009

Several colonies of tick larvae, each colony deriving from the eggs of a separate female, were fed on hamsters infected with Babesia microti isolated from a human infection. The nymphs were used at 13, 22, and 30 weeks post-larval-feeding (plf). At each time a batch of unfed nymphs was placed at 37 °C for 3–7 days. Nymphs from each of the 22- and 30-week plf groups either remained at 21 °C or were fed on an uninfected hamster for 64 h. In the nymphs kept at 21 °C, Babesia remained in the sporoblast meshwork stage. After ticks had been feeding for 64 h, sporozoites developed in both the 22- and 30-week plf groups. In unfed numphs exposed to 37 °C for 3–7 days, sporozoites were already present in the two younger groups after 4 days, 1–2 days earlier and in better condition than those described previously. They contained all essential organelles and were similar in appearance to sporozoites from the fed nymphs, although they were fewer in number. The oldest group of nymphs contained only sporoblast meshwork. The present findings demonstrated that in unfed nymphs exposed to hyperthermia, the genetic makeup of the colony plays a decisive role in the success of sporozoite development. In both our present and previous experiments, sensitivity to hyperthermia was lost in older nymphs, and was lower in the very young, suggesting that at certain stages in the life cycle, age supersedes the genetic influence in sensitivity to hyperthermia.
Baleen whales and their prey in a coastal environment
Authors: Piatt John F. , Methven David A. , Burger Alan E. , McLagan Ruth L. , Mercer Vicki , Creelman Elizabeth
Published: April 2009

Patterns of abundance of humpback (Megaptera novaeangliae), fin (Balaenoptera physalus), and minke (Balaenoptera acutorostrata) whales are described in relation to the abundance of their primary prey, capelin (Mallotus villosus), during 1982–1985 at Witless Bay, Newfoundland. The abundance ratio of the three whale species was 10:1:3.5, respectively. Abundance of all whale species was strongly correlated with abundance of capelin through each season and between years. Capelin abundance accounted for 63% of the variation in whale numbers in 1983 and 1984, while environmental parameters (e.g., water temperatures) accounted for little variance. The amount of capelin consumed by whales was small (< 2%) compared with the amount available. All three species overlapped temporally at Witless Bay, but spatial overlap was reduced as fins occurred primarily offshore, minkes primarily inshore, and humpbacks in bay habitats of intermediate depth.
Swarming benthic crustaceans in the Bering and Chukchi seas and their relation to geographic patterns in gray whale feeding
Authors: Kim Stacy L. , Oliver John S.
Published: April 2009

Swarming benthic crustaceans were widespread in the Chukchi and Bering seas. Swarms differed in their geographic extent, local biomass, and life stages of swarming individuals and thus in their availability to feeding gray whales (Eschrichtius robustus). Immature amphipods apparently swarmed for dispersal, whereas cumaceans probably swarmed for mating. All life stages of the hyperbenthic mysids occurred above the sea floor. Although the geographic spread of mysid swarms and shrimp communities was much greater than for the amphipod and cumacean swarms, the latter swarmed in denser patches to produce higher local biomass. Crustacean swarms are important in describing the geographic patterns of gray whale feeding from the Chukchi Sea to Baja California, including the primary, secondary, and tertiary feeding grounds. The primary feeding ground is in the southern Chukchi Sea and especially the northern Bering Sea, where gray whales suck infaunal amphipods from fine sand, producing an extensive record of feeding excavations. The primary feeding ground is divided into a relatively deep zone (> 20 m), where tube-dwelling ampeliscid amphipods are the major prey, and a shallow zone (< 20 m), where burrowing pontoporeid amphipods dominate. The secondary feeding ground is in the southern Bering Sea along the eastern Alaska Peninsula and adjacent Alaskan mainland where shrimp and mysids are the major prey. The tertiary feeding ground is at the periphery of the primary and secondary feeding grounds in Alaskan waters and south of the Bering Sea where there is a general decrease in the availability of prey and their use by gray whales from Canada to Baja California. The tertiary prey communities include swarms of amphipods, cumaceans, and mysids as well as infaunal polychaete worms, but mysids are used the most by whales. The primary gray whale feeding ground was much smaller during low sea levels when the extensive Beringian Platform was exposed to air. This shallow shelf is a unique habitat that presently harbors the largest ampeliscid amphipod community in the world. At low sea level, swarming crustaceans like those sampled in the present study may have been equally or more important to gray whales than infaunal prey. These historical changes in prey availability may account for the catholic diet of the gray whale.
Stauromedusae of the genus Manania (= Thaumatoscyphus) (Cnidaria, Scyphozoa) in the northeast Pacific, including descriptions of new species Manania gwilliami and Manania handi
Authors: Larson Ronald J. , Fautin Daphne G.
Published: April 2009

Manania gwilliami n.sp. and Manania handi n.sp., stauromedusae belonging to the family Depastridae, are described from the west coast of North America. They are differentiated from the one species of the genus previously known from that area, M. distincta (Kishinouye, 1910) by shape, color, habitat, and geographic range. Specimens of M. gwilliami are generally red and those of M. handi are green; both lack the dark brown herringbone patterning of M. distincta medusae. Manania gwilliami is widely distributed from Mexico to Canada in exposed shallow-water coastal habitats, whereas M. handi has been found only off the San Juan Islands and Vancouver Island in protected shallow water. The occurrence of M. distincta in the northeast Pacific has been sporadic. The name Manania is a senior synonym of Thaumatoscyphus.
The haemoproteids of the avian family Phasianidae
Authors: Bennett Gordon F. , Peirce Michael A.
Published: April 2009

The haemoproteids of the avian family Phasianidae are reviewed. Haemoproteus lophortyx O'Roke, 1929 and H. rileyi Malkani, 1936 of the Phasianinae and H. pratasi Tendeiro, 1947 of the Numidinae are redescribed. Four species of haemoproteids from the Phasianinae (H. chukari Tartakovskii, 1913, H. coturnix Musaev &Zeiniev, 1977, H. perdix Musaev &Zeiniev, 1977, and H. gallinarum Yakunin &Zhazyltaev, 1977) are considered nomina nuda; H. santosdiasi Son, 1960, H. chapini van den Berghe et al., 1958, H. bambusicolae Manwell et al., 1976, and H. ammoperdix Subkhonov, 1980 are considered synonyms of H. rileyi. Haemoproteus silvai Son, 1960 is considered a synonym of H. pratasi of the Numidinae while H. balfouri Sambon, 1909 is designated a nomen nudum. Haemoproteus canachites Fallis &Bennett, 1960 and H. rotundus Oliger, 1956 are considered synonyms of H. mansoni Castellani &Chalmers, 1910, while H. stableri White &Bennett, 1979 is the other valid haemoproteid of the Tetraoninae. Haemoproteus meleagridis Levine, 1961 is the only species described from the Meleagridinae. The 18 species of haemoproteids of four subfamilies of the Phasianidae are now reduced to 6 species.
Regenerative fidelity in the paired claw closer muscles of lobsters
Authors: Kent Karla S. , Pearce Joanne , Gee Christine , Govind C. K.
Published: April 2009

The paired claws in the lobster Homarus americanus are bilaterally asymmetric, consisting of a major (crusher) and a minor (cutter) claw. The fiber composition of the claw closer muscles is correspondingly asymmetric: the cutter muscle has predominantly fast fibers with a small ventral slow band, whereas the crusher muscle has 100% slow fibers. Loss of the paired claws results in regeneration of new ones, which resemble their predecessors in external morphology and in the fiber composition of the closer muscle. Such regenerative fidelity prevails even when the paired claws and closer muscles are symmetric and of the cutter type, and even when they have undergone two successive cycles of limb loss and regeneration. Therefore the type of closer muscle and the configuration of the paired claws is not altered by loss and regeneration.
Aberrant horn growth and masculine behavior in a female bighorn sheep from the North Dakota badlands
Authors: Jensen William F. , Seabloom Robert W. , Mckenzie James V.
Published: April 2009

On 11 March 1987 an adult female bighorn sheep (Ovis canadensis californiana) with abnormally large horns was captured in the badlands of North Dakota. Subsequent observations of this individual suggested malelike behavior. Possible explanations of this abnormal horn growth and behavior are a genetic defect or an endocrine imbalance.
Endohelminths of salmonids from two localities in eastern Lake Michigan, with emphasis on Echinorhynchus salmonis
Authors: Muzzall Patrick M.
Published: April 2009

Adult salmonids (101 chinook salmon, Oncorhynchus tshawytscha; 7 coho salmon, Oncorhynchus kisutch; 56 lake trout, Salvelinus namaycush; 6 steelhead, Salmo gairdneri; and 2 brown trout, Salmo trutta) were collected from eastern Lake Michigan (Ludington and Manistee, Michigan) in July–September 1986, and examined for helminths. Eight species (three Cestoda, three Nematoda, two Acanthocephala) were found in the digestive tract and other viscera. Echinorhynchus salmonis and Eubothrium salvelini were the most common helminths found. The intensity of E. salmonis significantly increased as chinook salmon became older and longer.
ON PARIKH MATRICES
Authors: SUBRAMANIAN K. G. , HUEY ANG MIIN , NAGAR ATULYA K.
Published: April 2009

Mateescu et al (2000) introduced an interesting new tool, called Parikh matrix, to study in terms of subwords, the numerical properties of words over an alphabet. The Parikh matrix gives more information than the well-known Parikh vector of a word which counts only occurrences of symbols in a word. In this note a property of two words u, υ, called "ratio property", is introduced. This property is a sufficient condition for the words uυ and υu to have the same Parikh matrix. Thus the ratio property gives information on the M–ambiguity of certain words and certain sets of words. In fact certain regular, context-free and context-sensitive languages that have the same set of Parikh matrices are exhibited. In the study of fair words, Cerny (2006) introduced another kind of matrix, called the p–matrix of a word. Here a "weak-ratio property" of two words u, υ is introduced. This property is a sufficient condition for the words uυ and υu to have the same p–matrix. Also the words uυ and υu are fair whenever u, υ are fair and have the weak ratio property.
SINGLE MACHINE SCHEDULING WITH CONTROLLABLE PROCESSING TIMES BY SUBMODULAR OPTIMIZATION
Authors: SHAKHLEVICH NATALIA V. , SHIOURA AKIYOSHI , STRUSEVICH VITALY A.
Published: April 2009

In scheduling with controllable processing times the actual processing time of each job is to be chosen from the interval between the smallest (compressed or fully crashed) value and the largest (decompressed or uncrashed) value. In the problems under consideration, the jobs are processed on a single machine and the quality of a schedule is measured by two functions: the maximum cost (that depends on job completion times) and the total compression cost. Our main model is bicriteria and is related to determining an optimal trade-off between these two objectives. Additionally, we consider a pair of associated single criterion problems, in which one of the objective functions is bounded while the other one is to be minimized. We reduce the bicriteria problem to a series of parametric linear programs defined over the intersection of a submodular polyhedron with a box. We demonstrate that the feasible region is represented by a so-called base polyhedron and the corresponding problem can be solved by the greedy algorithm that runs two orders of magnitude faster than known previously. For each of the associated single criterion problems, we develop algorithms that deliver the optimum faster than it can be deduced from a solution to the bicriteria problem.
DYNAMICALLY FORMED CLUSTERS OF AGENTS IN ECO-GRAMMAR SYSTEMS
Authors: LÁZÁR KATALIN ANNA , CSUHAJ-VARJÚ ERZSÉBET , LŐRINCZ ANDRÁS , VASZIL GYÖRGY
Published: April 2009

In this paper we extend the conditions of dynamic team constitution in simple eco–grammar systems, motivated by the bottom–up–clustering algorithm. The relationships of simple eco–grammar systems formed according to the newly introduced conditions to each other as well as to certain language classes of the Chomsky hierarchy and L systems are established. We prove that any recursively enumerable language can be obtained as the intersection of a regular language and the language of simple eco–grammar systems where the active teams are organized according to different conditions of team constitution. We also propose some further research directions.
TESTING EMBEDDABILITY BETWEEN METRIC SPACES
Authors: CHANG CHING-LUEH , LYUU YUH-DAUH , TI YEN-WU
Published: April 2009

Let L ≥ 1, ε > 0 be real numbers, (M, d) be a finite metric space and (N, ρ) be a metric space. A query to a metric space consists of a pair of points and asks for the distance between these points. We study the number of queries to metric spaces (M, d) and (N, ρ) needed to decide whether (M, d) is L-bilipschitz embeddable into (N, ρ) or ∊-far from being L-bilipschitz embeddable into N, ρ). When (M, d) is ∊-far from being L-bilipschitz embeddable into (N, ρ), we allow an o(1) probability of error (i.e., returning the wrong answer "L-bilipschitz embeddable"). However, no error is allowed when (M, d) is L-bilipschitz embeddable into (N, ρ). That is, algorithms with only one-sided errors are studied in this paper. When |M| ≤ |N| are both finite, we give an upper bound of [Formula: see text] on the number of queries for determining with one-sided error whether (M, d) is L-bilipschitz embeddable into (N, ρ) or ∊-far from being L-bilipschitz embeddable into (N, ρ). For the special case of finite |M| = |N|, the above upper bound evaluates to [Formula: see text]. We also prove a lower bound of Ω(|N|3/2) for the special case when |M| = |N| are finite and L = 1, which coincides with testing isometry between finite metric spaces. For finite |M| = |N|, the upper and lower bounds thus match up to a multiplicative factor of at most [Formula: see text], which depends only sublogarithmically in |N|. We also investigate the case when (N, ρ) is not necessarily finite. Our results are based on techniques developed in an earlier work on testing graph isomorphism.
ON THE TERMINATING DERIVATION MODE IN COOPERATING DISTRIBUTED GRAMMAR SYSTEMS WITH FORBIDDING COMPONENTS
Authors: MASOPUST TOMÁŠ
Published: April 2009

This paper discusses the terminating derivation mode in cooperating distributed grammar systems where components are forbidding grammars instead of context-free grammars. Such systems are called forbidding cooperating distributed grammar systems, and it is demonstrated that the number of their components can be reduced to two without changing the generative power and that these systems are computationally complete. Without erasing productions, however, these systems are less powerful than context-sensitive grammars.
A NEW CONVERTIBLE AUTHENTICATED ENCRYPTION SCHEME BASED ON THE ELGAMAL CRYPTOSYSTEM
Authors: LEE CHENG-CHI , HWANG MIN-SHIANG , TZENG SHIANG-FENG
Published: April 2009

A convertible authenticated encryption scheme allows a designated receiver to retrieve an authenticated ciphertext and convert the authenticated ciphertext into an ordinary signature. The receiver can prove the dishonesty of the sender to anyone if the sender repudiates his/her signature. Recently, many researchers have proposed convertible authenticated encryption schemes based on cryptological algorithms. In this paper, the authors shall present a new convertible authenticated encryption scheme based on the ElGamal cryptosystem. The proposed scheme is more efficient than Wu-Hsu's scheme in terms of computational complexity.
GEOMETRIC ALGORITHMS FOR THE CONSTRAINED 1-D K-MEANS CLUSTERING PROBLEMS AND IMRT APPLICATIONS
Authors: CHEN DANNY Z. , HEALY MARK A. , WANG CHAO , XU BIN
Published: April 2009

In this paper, we present efficient geometric algorithms for the discrete constrained 1-D K-means clustering problem and extend our solutions to the continuous version of the problem. One key clustering constraint we consider is that the maximum difference in each cluster cannot be larger than a given threshold. These constrained 1-D K-means clustering problems appear in various applications, especially in intensity-modulated radiation therapy (IMRT). Our algorithms improve the efficiency and accuracy of the heuristic approaches used in clinical IMRT treatment planning.
HADRON PHYSICS AT COSY
Authors: KHOUKAZ ALFONS
Published: April 2009

One major focus of the physics studied at the COoler SYnchrotron COSY of the Forschungszentrum Jülich is the production of mesons and hyperons in the hadron-hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. Due to the excellent experimental conditions at COSY also single- and double-polarization measurements can be performed with high reaction rates. This contribution gives an overview about the physics program which is currently under investigation at the three big COSY installations ANKE, COSY-TOF and WASA-at-COSY.
MEASUREMENT OF THE ω MESON POLARIZATION IN THE pd → 3He ω REACTION AT 1360 AND 1450 MeV
Authors:   for the WASA/CELSIUS collaboration, SCHÖNNING K. , CALÉN H. , FRANSSON K. , HÖISTAD B. , JOHANSSON T. , KUPSĆ A. , WILKIN C. , ZŁOMAŃCZUK J.
Published: April 2009

The tensor polarization of ω mesons produced in the pd → 3 He ω reaction has been measured at two energies near threshold. The 3 He nuclei were detected in coincidence with the π0π+π- or π0γ decay products of the ω. The ω mesons are found to be unpolarised, which is in complete contrast to the case of ϕ-meson production from the corresponding reaction pd → 3 He ϕ. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions.
TETRAQUARK $X(ud\bar s\bar s)$ PRODUCTION IN pn → ΛΛX
Authors: LIU XIAO-HAI , ZHAO QIANG
Published: April 2009

We propose to search for a tetraquark candidate [Formula: see text] in [Formula: see text] or ΛΛKK*. The existence of tetraquark state [Formula: see text] was predicted in the literature due to specific diquark effective degrees of freedom inside hadrons. In order to understand the underlying dynamics for exotic hadrons, a search for the tetraquark [Formula: see text] is strongly recommended. We make an estimate of the production rate of [Formula: see text] in an effective lagrangian theory. The proposed reaction involves two Λ production, of which the narrow widths make it a great advantage in the analysis of the final state missing mass spectrum.
HIRFL-CSR PHYSICS PROGRAM
Authors:   for HIRFL-CSR team, XU HUSHAN
Published: April 2009

The research activities at HIRFL-CSR cover the fields of the radio-biology, material science, atomic physics, and nuclear physics. This talk will mainly concentrate on the program on nuclear physics with the existing and planned experimental setups at HIRFL-CSR.
ATOMIC PHYSICS RESEARCHES AT COOLER STORAGE RING IN LANZHOU
Authors:   HIRFL-CSR team, MA X. , CAI X. H. , ZHU X. L. , ZHANG S. F. , MENG L. J. , ZHANG D. C. , YANG X. D. , MAO R. S. , HU Z. G. , Liu Y. , Yang J. C. , XU H. S. , XIAO G. Q. , XIA J. W. , YUAN Y. J. , ZHAN W. L.
Published: April 2009

The commissioning of the cooler storage rings (CSR) was successful, and the facility provides new possibilities for atomic physics with highly charged ions. Bare carbon, argon ions, were successfully stored in the main ring CSRm, cooled by cold electron beam, and accelerated up to 1 GeV/u. Heavier ions as Xe 44+ and Kr 28+ were also successfully stored in the CSRs. Both of the rings are equipped with new generation of electron coolers which can provide different electron beam density distributions. Electron-ion interactions, high precision X-ray spectroscopy, complete kinematical measurements for relativistic ion-atom collisions will be performed at CSRs. Laser cooling of heavy ions are planned as well. The physics programs and the present status will be summarized.
HIGH ENERGY DENSITY PHYSICS WITH INTENSE PARTICLE AND LASER BEAMS
Authors: HOFFMANN D. H. H. , BLAZEVIC A. , TAHIR N. A. , UDREA S. , VARENTSOV D. , ZHAO Y.
Published: April 2009

Interaction of intense ion radiation with matter has numerous applications in different fields of science, ranging from basic research of plasma properties to application in energy science. Energy loss processes of heavy ions in plasma and cold matter are important to understand the generation of high energy density states in matter. The hot dense plasma of an inertial fusion target is just one example. Of special interest are phase transitions, when irradiated matter passes through the parameter regime of warm dense matter, which is located in the phase diagram at high density but relatively low temperature. Typical parameters are in the pressure range of kbar to Mbar and temperatures ranging into the few eV regime. We present an overview on recent results and developments of beam plasma, and beam matter interaction processes studied with heavy ion beams from the GSI accelerator facilities, which consist of an rf-accelerator (UNILAC: Universal Linear Accelerator), a heavy ion synchrotron (SIS 18) and an experimental storage ring (ESR). The synchrotron SIS18 currently delivers an intense uranium beam that deposits about 1 kJ/g specific energy in solid matter. Using this beam, high energy density states close to the critical point of lead, have been reached and solid lead foils have been heated to a measured brightness temperature on the order of 5000 K.
OVERVIEW ON THE HIRFL-CSR FACILITY
Authors: XIAO G. Q. , XIA J. W. , YUAN Y. J. , MAO R. S. , ZHENG J. H. , TU X. L. , WANG M. , HUANG W. X. , XU H. S. , ZHAN W. L.
Published: April 2009

The status of the HIRFL (Heavy Ion Facility in Lanzhou) – Cooler Storage Ring (CSR) at the IMP is reported. The main physics goals at the HIRFL-CSR are the researches on nuclear structure and decay property, EOS of nuclear matter, hadron physics, highly charged atomic physics, high energy density physics, nuclear astrophysics, and applications for cancer therapy, space industries, materials and biology sciences. The HIRFL-CSR is the first ion cooler-storage-ring system in China, which consists of a main ring (CSRm), an experimental ring (CSRe) and a radioactive beam line (RIBLL2). The two existing cyclotrons SFC ( K = 70) and SSC ( K = 450) are used as its injectors. The 7 MeV/u 12 C 6+ ions were stored successfully in CSRm with the stripping injection in January 2006. After that, realized were the accelerations of 12 C 6+, 36 Ar 18+, 78 Kr 28+ and 129 Xe 27+ ions with energies of 1 GeV/u, 1 GeV/u, 450 MeV/u and 235 MeV/u, respectively, including accumulation, electron cooling and acceleration. In 2008, the first two isochronous mass measurement experiments with the primary beams of 36 Ar 18+ and 78 Kr 28+ were performed at CSRe with the Δp/p ~ 10-5.
STATUS OF THE DESIGN OF THE FAIR STORAGE RINGS
Authors: STECK M. , DIMOPOULOU C. , DOLINSKII A. , GORDA O. , GOSTISHCHEV V. , KNIE K. , LITVINOV S. , NOLDEN F. , PESCHKE C. , OBRADORS-CAMPOS D.
Published: April 2009

Three storage rings with a maximum magnetic rigidity of 13 Tm are foreseen as part of the FAIR project. They will mainly serve the preparation of intense secondary beams of antiprotons and rare isotopes, which are produced with high intensity proton and heavy ion beams, respectively. Cooling, by stochastic and electron cooling, and accumulation as well as deceleration of the secondary beams are manipulation techniques which are foreseen. Internal targets and collisions of rare isotope beams with electrons or antiprotons in a collider set-up will be employed in physics experiments studying the properties of the secondary beams. This report summarizes the latest design work for the FAIR storage rings.
BEAM DYNAMICS OF THE HIGH-ENERGY STORAGE RING (HESR) FOR FAIR
Authors: LEHRACH A. , BONGARDT K. , LORENTZ B. , MAIER R. , PRASUHN D. , STOCKHORST H. , TÖLLE R. , WELSCH D. M.
Published: April 2009

The High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an antiproton storage ring in the momentum range from 1.5 to 15 GeV/c.1,2 The HESR is being designed and built by a consortium consisting of IKP at Forschungszentrum Jülich, TSL at Uppsala University, and GSI Darmstadt. An important feature of this new facility is the combination of phase-space cooled beams and thick internal targets (e.g. pellet targets) which results in demanding beam parameter requirements for two operation modes: high luminosity mode with peak luminosities of up to 2 · 1032 cm -2 s -1 and high resolution mode with a relative momentum spread in the order of a few times 10-5. To reach these beam parameters one needs a very powerful phase-space cooling utilizing high-energy electron cooling and high-bandwidth stochastic cooling. In this paper different beam dynamics issues like closed orbit correction, performance of cooled beams interacting with internal targets and luminosity considerations are discussed.
SOME EXPERIMENTAL TECHNIQUES AT STORAGE RINGS
Authors:   for the COSY accelerator group and the ANKE collaboration, HARTMANN M.
Published: April 2009

Two experimental techniques that have been developed at the COoler SYnchrotron COSY-Jülich are presented:

(i) The energy of a stored polarized proton or deuteron beam can be precisely determined by sweeping an rf magnetic dipole or solenoid field over a spin resonance. This perturbation induces a beam depolarization, which is maximal at the spin resonance's frequency. That frequency, together with the beam revolution frequency, determines the beam's kinematic γ factor, which can thus be measured with high accuracy. Therefore, the beam energy can be determined about one order of magnitude more precisely than with conventional methods based on orbit length measurements. The technique has been used at COSY for an experiment aiming at a high-precision measurement the mass of the η meson.

(ii) The repeated passage of a coasting ion beam through a thin internal target leads to a beam-energy loss and a shift of its revolution frequency. This shift is proportional to the beam-target overlap and thus allows one to measure the target thickness and hence the luminosity during the corresponding experiment. This effect has been studied quantitatively with a 2.65 GeV proton beam impinging on a hydrogen cluster-jet target at the ANKE spectrometer. After a careful error evaluation the luminosity, could be determined with an accuracy of better than 5%.
BEAMS AT STORAGE RINGS — FROM PROTON TO URANIUM
Authors: NOLDEN FRITZ
Published: April 2009

This article gives an overview of storage rings from proton to uranium. Only medium energy rings with Lorentz factors γ < 10 are treated.

After a concise historical overview the main tasks of these rings will be discussed: storage of polarized beams, beam cooling, accumulation and deceleration.
PERSPECTIVES FOR POLARIZED ANTIPROTONS
Authors: LENISA PAOLO
Published: April 2009

In the framework of the FAIR project the PAX Collaboration has suggested new experiments using polarized protons and antiprotons. In order to provide polarized antiprotons, the proposed mechanisms for the production of a polarized stored have to be investigated. To this aim a series of experiments have already been started with protons at the COSY ring. Additional experiment have to be foreseen at AD ring with antiprotons to define to working parameters of a dedicated Antiproton Polarizer Ring.
BEAM OPTICS SIMULATION OF RARE-RI RING AT RI BEAM FACTORY IN RIKEN
Authors: ARAI I. , OZAWA A. , YASUDA Y. , FUJINAWA T. , FUKUNISHI N. , OHNISHI T. , GOTO A. , HARA K. Y. , SAKURAI H. , WAKASUGI M. , YAMAGUCHI Y. , YANO Y. , SUZUKI T. , YAMAGUCHI T. , KIKUCHI T. , OHTSUBO T.
Published: April 2009

The cyclotron-like storage ring dedicated to Rare-RI Ring project consists of 6 magnetic sectors and 6 straight sections, having a circumference of 56.13 m. The magnetic sector works for both bending and focusing. The total circulation is assumed to be 1,000 turns. Over the momentum range from -1% to +1% in ∆p/p, the required isochronisity is 10-6 while the beam emittance is sevaral tens of π mm-mrad. To examine the design of cyclotron-like storage ring and fix its parameters, we have developed a high precision beam optics simulation. To achieve the precision as high as possible within a feasible computational time, we have adopted a geometrical tracking assuming a circular orbit for a small spatial segment. For that purpose, it is enough that the magnetic sector is divided into 150 sub-sectors in calculation. In each sub-sector, the magnetic field is given as a function of radial position but uniform around the vicinity of beam trajectory. The beam trajectory is evaluated in 4th order Runge-Kutta algorithm. Finally, we have achieved a precision of 10-9 in ∆T/T and a computational time of 1.8 sec on a typical PC server for ray tracing of single particle undergoing a circulation of 1,000 turns.