bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES OF VIRUS DISEASES OF STRAWBERRIES IN BRITISH COLUMBIA: II THE SEPARATION OF THE COMPONENT VIRUSES OF YELLOWS
Authors: Mellor Frances C. , Fitzpatrick Randal E.
Published: August 2008

Progressive transfers of Capitophorus fragaefolii Ckll. from yellows-infected Marshall plants through a succession of Fragaria vesca L. plants resulted in the separation of at least two component viruses. One was of the nonpersistent type; it caused reduction in leaf size, mottle, crinkle, and leaf distortion, but the severity and dominance of these symptoms varied so widely that it is assumed that this component itself is a complex of viruses or strains. The other was of the persistent type; its principal effect was to reduce the vigor of the plant although there was some cupping of the leaves, and in the fall, under green-house conditions, a transitory yellow mottling of the tips and margins of some of the younger leaves.
BIOCHEMISTRY OF THE USTILAGINALES: VII. ANTIBIOTIC ACTIVITY OF USTILAGIC ACID
Authors: Haskins R. H. , Thorn J. A.
Published: August 2008

The antibiotic activity of Ustilago zeae (PRL 119) cultures is associated mainly with the culture solids and it has been shown that a mixture of glucolipids, called ustilagic acid and produced in good yields by the fungus, is responsible for part, if not all, of the observed activity. The antibiotic activity of ustilagic acid corresponds to that originally attributed to ustizeain B and therefore these two are considered to be identical. All samples of ustilagic acid obtained showed antibiotic activity and it has not been possible by paper chromatography to separate an active principle from the acid. Recrystallization of ustilagic acid did not alter its antibiotic properties. Alkaline hydrolysis of the acid destroyed its activity. Heating the culture mixture for up to an hour at temperatures less than 100° C. did not alter materially the antibiotic properties of the mixture or of the acid extracted therefrom. The antifungal spectrum is broad and the antibacterial spectrum includes more Gram-positive than Gram-negative organisms. Preliminary tests with rats indicated that ustilagic acid is nontoxic when administered orally up to at least 5% of the diet, and with mice, orally up to at least 1% of the diet or intraperitoneally in amounts up to 1.5 gm. per kgm. of body weight.
MICROFLORA AND THE HEATING OF DAMP STORED WHEAT
Authors: James Norman , Lejeune A. R.
Published: August 2008

Studies on damp wheat, bin-burned under conditions simulating natural storage and under adiabatically controlled conditions, produced evidence which provides the basis for the belief that: (1) heating and bin-burning of damp grain during storage are caused primarily by microorganisms; (2) many species of bacteria and of fungi, normally present on grain, are associated with this spoilage; (3) these species are mesophilic, rather than thermophilic; (4) under natural storage, although the grain shows evidence of increased combustion, most of the heat is dissipated. Consequently, the temperature does not rise sufficiently high for thermophiles; and (5) if the temperature in isolated pockets in the mass rises high enough, the thermophiles probably are the result rather than the cause of the high temperature.
A STUDY OF MEIOSIS IN A HAPLOID OF TRITICUM VULGARE VILL. AND ITS PROGENIES
Authors: McGinnis R. C. , Unrau John
Published: August 2008

Meiosis was studied in the haploid of Triticum vulgare and in its second and third generation selfed progenies derived from pollination of the haploid with normal pollen. In the haploid, 57.6% of the metaphase cells showed one to three bivalents. This is assumed to be evidence of a degree of homology between chromosomes of the haploid set. Random distribution of univalents to the poles was apparently restricted by bivalent and secondary associations. Cells with 42 chromosomes were observed in a few instances. In one case the complement was made up of 21 bivalents. A high frequency of trivalents and quadrivalents was observed in the second and third generations. Presumably crossing over between partially homologous chromosomes, occurring in the haploid, resulted in reciprocal translocations which were transmitted to succeeding generations. Plants with chromosomal deficiency or duplication, observed in the second and third generations, probably originated from union of unbalanced gametes in first generation plants heterozygous for translocations or deficient or duplicated for one or more chromosomes.
SEASONAL VARIATION IN THE CHEMICAL COMPOSITION OF THE FUGACEAE IN THE MARITIME PROVINCES
Authors: Macpherson Margaret G. , Young E. Gordon
Published: August 2008

Fucus vesiculosus, F. evanescens, and Ascophyllum nodosum have been analyzed monthly for their content of moisture, mineral salts, organic nitrogen, mannitol, laminarin, and alginate over a period of two years. Plants were collected from two localities, St. Andrews, N.B., and Halifax, N.S. In general, when the ash content was at a minimum in the winter months, alginate was at a maximum. The converse was true in spring and summer. Organic nitrogen and laminarin remained relatively constant throughout the year. Mannitol was highest in the summer and autumn, fluctuating with the temperature of the water. No essential difference was detected between the results of St. Andrews and at Halifax, or between the three species examined. Analyses carried out on samples collected at different times on the same day showed no significant differences.
A SURVEY OF CERTAIN SEAWEEDS OF COMMERCIAL IMPORTANCE IN SOUTHWEST NOVA SCOTIA
Authors: MacFarlane Constance
Published: August 2008

The Nova Scotia Research Foundation is making an extensive survey of seaweeds of the Province that are of potential commercial importance. The area in which the survey has been completed extends from Cape Sable Island, Shelburne County to Chebogue, Yarmouth County, and includes also a small part of Digby County. The survey includes both quantitative measurements and biological studies of fucoids, Laminaria spp., and Chondrus, in all of which the region abounds. Of 325 miles of coastline surveyed for rockweed, 140 miles are harvestable, bearing approximately 200,000 tons. Results obtained at 255 stations, examined in detail, showed the average density to be 37 lb. per sq. yd. The width of the zone is from 2 to 300 yd., the average being 50 yd. Ascophyllum nodosum forms the greatest percentage of rockweed, Fucus vesiculosus ranking next. Fucus serratus is recorded for the first time in this part of the Province. Laminaria beds totalling 12,000 ac. in extent and bearing 900,000 tons were charted. Mortality among Laminaria sporophytes is high and the number in a bed varies from year to year. In 1950 7,997,739 lb. of Chondrus were harvested. Density varies from 1 to [Formula: see text] lb. per sq. ft. Chondrus beds are listed and their ecology discussed. Recolonization of denuded areas is described and succession of algal cover noted on denuded areas and on concrete blocks placed in Chondrus and Laminaria beds. The survey region is compared with regions surveyed in Scotland. A map of the survey region is included.
STUDIES ON THE LEGUME ROOT NODULE BACTERIA: II. THE PRODUCTION AND BEHAVIOR OF COLONIAL MUTANTS PRODUCED BY X-RAY IRRADIATION
Authors: Jordan D. C.
Published: August 2008

Four distinct types of colonial mutation were obtained by X-ray irradiation of a parasitic strain of alfalfa Rhizobium. Two types were procured from an effective strain. Colonial morphology remained stable throughout serial transfer on artificial medium, but changed considerably after one plant passage. Three variants derived from the parasitic parent were found to be efficient in nitrogen fixation when tested by sterile plant growth procedures and the Virtanen technique. This efficiency increased during the course of two plant passages. Colonial variation and effectivity changes occurred independently of one another.
THE EFFECTS OF SALTS ON THE NITRITASE AND LACTIC ACID DEHYDROGENASE ACTIVITY OFMICROCOCCUS HALODENITRIFICANS
Authors: Robinson J.
Published: August 2008

With Micrococcus halodenitrificans, maximum production of nitritase occurs just after nitrite has been reduced completely to nitrogen. Maximum denitrifying activity takes place at pH 7.6 in the presence of 0.38 to 0.75 molar sodium chloride or sodium bromide. The activity is slightly less in the presence of lithium chloride but reaches a peak at 0.19 to 0.38 molar concentration. The reduction of nitrate to nitrite is inhibited by azide whereas reduction of nitrite to nitrogen is not, suggesting the possibility that at least two separate enzymes may be involved in these reactions. The lactic acid dehydrogenase of this organism shows maximum activity in the presence of 0.75 molar sodium chloride.
THE OCCURRENCE OF FUSARIUM SPECIES IN CANADA: II. PREVALENCE AND TAXONOMY OF FUSARIUM SPECIES IN CEREAL SEED
Authors: Gordon W. L.
Published: August 2008

During the present investigation, a total of 1579 seed samples of wheat, 1042 of barley, and 1152 of oats (100 kernels per sample), were examined microbiologically for the presence of Fusarium. Of these samples, 402 of wheat, 513 of barley, and 636 of oats originated in the seed inspection districts of Eastern Canada, and 1177 of wheat, 529 of barley, and 516 of oats in those of Western Canada. Isolates of Fusarium were obtained from approximately 41.8% of the samples of wheat (1.5% of the kernels), 76.2% of the samples of barley (3.9% of the kernels), and 79.6% of the samples of oats (5.7% of the kernels) that originated in Eastern Canada, whereas only 13,8% of the samples of wheat (0.2% of the kernels), 36.3% of the samples of barley (0.7% of the kernels), and 38.9% of the samples of oats (1.1% of the kernels) from Western Canada yielded Fusarium. In classifying the different wild types of Fusarium that were obtained from cereal seed the system of taxonomy and nomenclature of Wollenweber and Reinking was chiefly followed, but certain sections of the genus were revised extensively, partly in accordance with Snyder and Hansens' concept of species in this genus. Four new combinations are proposed, namely F. compactum (Wr.) n. eomb., F. lateritium Nees emend. Snyder & Hansen forma cajani (Padwick) n. comb., F. lateritium Nees emend. Snyder &. Hansen forma crotalariae (Padwick) n. comb., and F. oxysporum Schlecht. emend. Snyder & Hansen var. redolens (Wr.) n. comb. A total of 16 species and varieties of Fusarium, classified in nine sections of the genus, was isolated from cereal seed during this investigation. These species and varieties are, namely, F. poae (Pk.) Wr., F. sporotrichioides Sherb., F. avenaceum (Fr.) Sacc, F. arthrosporioides Sherb., P. semitectum Berk. & Rav., F. equiseti (Cda.) Sacc, F. acuminatum Ell. & Ev., F. culmorum (W. G. Sm.) Sacc, F. graminearum Schwabe, F. sambucinum Fuckel, F. sambucinum var. coeruleum Wr., F. lateritium Nees emend. Snyder & Hansen, F. moniliforme Sheld. emend. Snyder & Hansen, F. oxysporum var. redolens (Wr.) n. comb., and F. solani (App. & Wr.) Wr. emend. Snyder & Hansen. F. poae, F. avenaceum, and F. acuminatum were most frequently isolated. F. concolor Rg. and F. sambucinum f. 6 Wr,, that were previously recorded from cereal seed in Manitoba, and three additional species, namely, F. dimerum Penz., F. merismoides Cda., and F. nivale (Fr.) Ces., that may be encountered in the future among isolates from cereal seed in Canada, were also included in this study.
BROWN STAIN IN PINE SAPWOOD CAUSED BY CYTOSPORA SP.
Authors: Fritz Clara W.
Published: August 2008

A fungus isolated from naturally brown-stained red pine sapwood was found to produce characteristic chocolate brown stain in sterilized red pine sapwood in culture; it is identified as a species of Cytospora. The fungus develops in the ray parenchyma, may proliferate in the tracheids, but penetrates the walls only through the pits. A technique is described for producing brown stain in culture in sticks of the size required for static bending and toughness tests. Two series of sticks were subjected to each test; the samples used were end-matched sticks in groups of three, which provided a green control, sterilized control, and specimen stained in culture by Cytospora sp. The results showed some variation in the relative strength of samples in different groups, but a statistical analysis indicated that the effect of Cytospora sp. on both bending strength and toughness is negligible.
THE CARBOXYLASES OF LEAVES AND THEIR ROLE IN PHOTOSYNTHESIS
Authors: Clendenning K. A. , Waygood E. R. , Weinberger P.
Published: August 2008

"Malic" enzyme isolated from the cytoplasm of parsley and sugar beet leaves was linked with illuminated spinach chloroplast fragments to effect photosynthesis in vitro. The model photosynthesis system containing excess "malic" enzyme was not inhibited by 5 × 10−4 M hydrogen cyanide. The "malic" enzyme system was inhibited by cyanide, however, at very low enzyme concentrations. The richest source of "malic" enzyme found in this study was the mature parsley leaf. Expressed on the same basis, the enzymatic capacities of parsley leaf "malic" enzyme and the Hill reaction capacity of isolated spinach chloroplasts are of similar magnitude. Higher "malic" enzyme and oxalacetic carboxylase activities were found in purified extracts of parsley leaves than in the corresponding root extracts. Oxalacetic, oxalsuccinic, α-ketoglutaric, and pyruvic carboxylases were not inhibited by 10−3 M hydrogen cyanide. The α-ketoglutaric and pyruvic carboxylases were much less abundant in leaves than in other plant organs; formic dehydrogenase was not detected in leaves although it is abundant in seeds. Glutamic carboxylase was found in the cytoplasm of wheat and sugar beet leaves, and with the aid of C14O2was shown to be only weakly reversible. No evidence was obtained for the presence in leaf extracts of an enzyme, or mixture of enzymes, capable of decarboxylating phosphoglyceric acid in vitro.
LES ZONES BIOLOGIQUES DE LA PÉNINSULE QUÉBEC–LABRADOR ET L'HÉMIARCTIQUE
Authors: Rousseau Par Jacques
Published: August 2008

In order to place phytogeographical regions on a world basis, it is necessary to invoke the zone concept. For example, a botanist who studies the flora of some parts of the USSR, Alaska, Quebec, and Scandinavia recognizes many similarities, if not analogous floras: before considering the local differentiations which distinguish regional floras, he recognizes on first sight the "arctic" aspect. The tendency of phytogeographers, foresters, and biologists in general is to overlook the zonal division of the world from the arctic zone to the tropical zone and consider the regional aspects only. In a zonal division of Quebec, there are the temperate zone, grossly south of the 50° lat. N.; the subarctic zone, between the 50° and the 55° approximately; the hemiarctic zone, between the 55° and the absolute limit of trees; and finally the arctic zone, north of the 58°. The hemiarctic zone, described herein, and consisting principally of the habitat commonly called forest–tundra, is not formed of transitional habitats between those of the subarctic zone and those of the arctic zone, but made up of purely arctic patches (from 60 to 90% of the surface) imprisoned in a net of subarctic forest strips. The hemiarctic zone instead of being merely a mixture of arctic and subarctic plants, may be compared then to an "emulsion" of arctic and subarctic habitats. This "mixed" zone, highly convenient for phytogeographical purposes, finds its justification in biological and ciimatological data. For the distinction of the zones, we must not consider only the arborescent flora but all other expressions of life as well. From tentative studies, it is quite evident that a distinction of the zones based on limited floristic aspects,—the aquatic flora for example,—will lead to the same conclusion.
STUDIES ON THE LEGUME ROOT NODULE BACTERIA: III. GROWTH FACTOR REQUIREMENTS FOR EFFECTIVE, INEFFECTIVE, AND PARASITIC STRAINS
Authors: Jordan D. C.
Published: August 2008

Under the experimental conditions used, amino acids played a very important part in the growth initiation of washed cells of alfalfa – sweet clover rhizobia. There were, however, distinct differences in utilization, both among genetically related mutants, and among other cultures when compared before and after plant passage. None of 15 vitamins, purines, and pyrimidines was able to initiate growth and hence these rhizobia are able to synthesize these compounds when a readily utilizable nitrogen source is present. Because of this fact, the stimulation of these bacteria by yeast extract is probably due, primarily, to the amino acid content. No strain was found able to concentrate free amino acids intracellularly or, when grown in lysine or tyrosine media, to excrete additional amino acids. No differences were found among effective, ineffective, or parasitic rhizobia in biochemical requirements.
APHANOMYCES CLADOGAMUS DRECH., A CAUSE OF DAMPING-OFF IN PEPPERS AND CERTAIN OTHER VEGETABLES
Authors: McKeen C. D.
Published: August 2008

A species of Aphanomyces was isolated from damped-off pepper seedlings which had been grown in a sandy loam compost soil under glass. This fungus was obtained from up to 8% of the damped-off pepper seedlings. The morphological characteristics of this fungus corresponded so closely with the descriptions of Aphanomyces cladogamus Drech., which Drechsler isolated from diseased tomato rootlets, that the two fungi are considered to be the same. Reduction in stands of pepper seedlings resulted from both pre-emergence and post-emergence damping-off, when seeds were planted in soil inoculated with isolates of the fungus. Characteristic symptoms of postemergence attacks consisted of black lesions on the hypocotyl frequently extending into the bases of the cotyledons, and death of affected seedlings usually occurred. A. cladogamus was found to cause a considerable amount of damping-off in tomato, eggplant, radish, and spinach as well as in pepper. It attacked Spanish onions only slightly, but lettuce, pea, and muskmelon not at all. Except in spinach, A. cladogamus showed little tendency to colonize root tissues, whereas hypocotyl and cotyledonary tissues were highly vulnerable.
STUDIES ON THE WITCHES'-BROOM VIRUS DISEASE OF POTATOES IN BRITISH COLUMBIA
Authors: Wright N. S.
Published: August 2008

Plants of the White Rose and Netted Gem potato varieties naturally or artificially inoculated with the witches'-broom of potato virus expressed symptoms only after the progeny of inoculated plants was grown, but symptoms occurred on the foliage of the X virus-immune potato seedling 41956 within eight weeks after grafting. Tomato and tree tomato served as indicator plants on which two apparent strains of the virus could be distinguished. The first strain caused the symptoms on tomato usually associated with the disease on this suscept, but the second strain caused a disease similar to tomato big bud. Attempts to transmit the virus by means of dodder and insects were unsuccessful. An abrupt cessation of cambial activity and consequent underdevelopment of secondary conductive tissue precede the appearance of disease symptoms on potato.
Phosphorus, Nitrogen, and Carbon Dynamics of Experimental Lake 303 during Recovery from Eutrophication
Authors: Levine S. N. , Schindler D. W.
Published: August 2008

Little is known about the recovery of lakes from eutrophication, especially as it effects the cycling of nutrients other than phosphorus. We fertilized a naturally oligotrophic lake (Lake 303) in the Experimental Lakes Area, northwestern Ontario, with nitrogen and phosphorus over two summers and examined the subsequent recovery using mass balance and large in situ mesocosms. While large amounts of ammonium and smaller amounts of dissolved inorganic carbon (DIC) were released from the lake's aerobic sediments during the first year of recovery, phosphorus input from the sediments was not detectable during the same period. Chlorophyll a concentration closely tracked total phosphorus concentration, and both returned to prefertilization levels within 1 yr. In contrast, ammonium, nitrate, DIC, and dissolved organic carbon (DOC) needed almost 2 yr to reach baseline levels, and dissolved organic nitrogen (DON) even longer. The results show that different elements may recover at different rates and that the release of stored pools of nitrogen and carbon in the sediments plays a major role in delaying the recovery of these elements.
Effects of Oceanic Variations and the West Greenland Fishery on Age at Maturity of Icelandic West Coast Stocks of Atlantic Salmon (Salmo salar)
Authors: Scarnecchia Dennis L. , Ísaksson Árni , White S. E.
Published: August 2008

Investigations were conducted on the effects of oceanic variations (as measured by sea temperatures) and catches by the West Greenland salmon fishery on the sea age composition of Atlantic salmon (Salmo salar) stocks from 21 Icelandic west coast rivers. Annual ratios of grilse to two-sea-winter (2SW) salmon were strongly correlated among the 21 rivers. All eight rivers with time series extending back before the expansion of the West Greenland fishery showed lower ratios during the earlier period. Only 2 of the 21 rivers, however, had significantly declining ratios over their time series. In addition, for only one river was West Greenland catch significantly related to the ratios (P < 0.05), and for only one river did ratios increase when the expanded West Greenland fishery was active. Overall, the effects of the fishery on stock composition are evidently minimal. The mean April–May temperature when the smolts were to migrate out of rivers was significantly and positively related to subsequent ratios for five of the rivers, which, along with correlations among the ratios, indicated that more rapid growth of smolts in their first summer may have increased the ratios of grilse to 2SW salmon on several rivers.
Groundwater–Surface Water Relationships in Boreal Forest Watersheds: Dissolved Organic Carbon and Inorganic Nutrient Dynamics
Authors: Ford T. E. , Naiman Robert J.
Published: August 2008

Dissolved organic carbon (DOC) and inorganic nutrients (NH4-N, NO3-N, soluble total N, PO4-P, soluble total P, and Si) were measured in ground and surface waters in the Matamek River drainage network, Quebec, Canada. In general, concentrations of carbon and nitrogen were significantly higher in groundwater than in surface water (up to 340% for DOC and up to 700% for total N). No significant difference was detected for phosphorus whereas considerable variation occurred for silicon, with significantly higher groundwater concentrations at 50% of the study sites. We hypothesize that (1) groundwater is a source of DOC and nitrogen in these systems and (2) nutrients introduced through groundwater seepage are rapidly utilized via oxidative, biotic processes within the hyporheal zone or at the sediment–water interface.
Effect of Carbon Monoxide Exposure on Gas Bubble Disease in Rainbow Trout (Salmo gairdneri)
Authors: Machado J. P. , Bell T. G. , Trapp A. L. , Garling Jr. D. L. , Kevern N. R.
Published: August 2008

Cumulative mortalities of 100, 50, 20, and 0% due to gas bubble disease (GBD) occurred on exposure of rainbow trout (Salmo gairdneri) for 180 min to supersaturated water at 136, 130, 124, and 116% total dissolved gas saturation (TDGS), respectively. At 130% TDGS, a prior exposure to carbon monoxide (CO), which converted 80% of the hemoglobin to carboxyhemoglobin (COHb), significantly prolonged survival time, but cumulative mortality was insignificantly reduced in the same group. Histologically, all supersaturation mortalities had branchial lesions for GBD (characterized by gas displacement of blood from the afferent arterioles of the gill filaments), while 70% had gas emboli in the retinal choroid gland. At a TDGS of 100%, these histological lesions were not observed and the CO 80% COHb conversion did not induce mortality within 120 min. Breathing movements of both control and CO-exposed fish slowed greatly when a TDGS of 130% was imposed; however, the COHb conversion initiated tachypnea and the CO-treated fish maintained a relatively higher respiratory rate when exposed to supersaturation conditions for a period which was proportional to their prolonged survival time. We concluded that the initial formation of gas emboli preceding fatal GBD was delayed as a result of a CO-inhibited function of hemoglobin.
Somatic Growth Effects on the Otolith–Fish Size Relationship in Young Pond-reared Striped Bass, Morone saxatilis
Authors: Secor David H. , Dean John Mark
Published: August 2008

Somatic growth rate of pond-reared larval and juvenile striped bass, Morone saxatilis, influenced the relationship between otolith size and fish size. Slower growing groups of individuals had larger and heavier otoliths, relative to fish length, than did faster growing groups. Within each growth group, otolith and fish size were highly correlated. Daily increment formation was validated from 10 to 51 d after hatch. Significant interaction occurred between age and fish size effects on otolith size. We propose that otolith growth occurs by two interacting processes. Otoliths grow daily in an incremental manner which is independent of somatic growth. Growth also proceeds continuously within each daily cycle of increment deposition, probably in some proportion to daily somatic growth. Corollaries to the hypotheses are (1) somatic growth rate can influence the otolith–fish size relationship, (2) intraspecific variation in otolith scaling might be used to predict past differences in somatic growth rate, and (3) there is a biological rationale for the use of otolith size and fish size as predictors in age estimation.
Cardiac Responses to a Natural Odorant as Evidence of a Sensitive Period for Olfactory Imprinting in Young Atlantic Salmon, Salmo salar
Authors: Morin Pierre-Philippe , Dodson Julian J. , Doré François Y.
Published: August 2008

Olfactory imprinting was assessed in young Atlantic salmon, Salmo salar, undergoing smoltification (parr–smolt transition) by measuring their cardiac responses to a natural odorant, L-cysteine. Condition factor and body coloration were used for characterizing the degree of smoltification. In Experiment 1, heart rate conditioning to L-cysteine was used to compare olfactory learning between fish from different age groups of smoltification. In Experiments 2 and 3, other fish from the same age groups of smoltification were exposed to L-cysteine and their long-term olfactory memory was assessed by measuring their unconditioned cardiac responses to L-cysteine after smoltification. In Experiment 2, the time from the end of odor exposure to testing for olfactory recognition was kept constant for ail age groups of smoltification whereas in Experiment 3, the age of fish tested for olfactory recognition was kept constant. Greater conditioning (heart rate reduction) to L-cysteine occurred in age-groups 3 (612–619 d since birth) and 6 (642–649 d) as compared with any other age group of smoltification. Fish tested for odor recognition exhibited a greater unconditioned response (cardiac deceleration) to L-cysteine if they belonged to age-group 3 than to any other age group of smoltification. Our results demonstrated the existence of a sensitive period for olfactory imprinting in Atlantic salmon that occurred between 21 and 28 d after the onset of smoltification induced in the laboratory.
Interaction of Temperature and Photoperiod in the Regulation of Spawning by American lobsters (Homarus americanus)
Authors: Aiken D. E. , Waddy S. L.
Published: August 2008

Various studies have yielded conflicting information on the role of photoperiod in the regulation of spawning by the American lobster (Homarus americanus). Some have indicated a requirement for short days followed by long days, while others have suggested that there is no photoperiod requirement. To resolve the question of photoperiod control, we exposed mature female lobsters to various combinations of temperature and photoperiod for 1 yr starting in December and found that there was no requirement for spring photoperiod under local winter seawater temperature (0–5 °C, but when winter seawater temperature was maintained at 10–17 °C, spawning came under the influence of spring photoperiod. It therefore appears that vitellogenesis and spawning of nearshore lobster populations are normally regulated by seasonal seawater temperature but that photoperiod can assume a regulatory role if the winter seawater temperature remains abnormally high.
Disposition and Elimination Routes of 17α-Methyltestosterone in Rainbow Trout (Salmo gairdneri)
Authors: Cravedi J. P. , Delous G. , Rao D.
Published: August 2008

The excretion routes and tissue distribution of [14C] 17α-methyltestosterone (17MT) were investigated in rainbow trout (Salmo gairdneri) after a single intragastric dose (40 μg, 126.8 kBq); about 95% of the ingested 17MT was absorbed. Total excretion 24 h after treatment accounted for 67.4% of the dose and most of this radioactivity was eliminated into the aquarium water, probably through the gills. Fecal and urinary 14C accounted for 22 and 0.5%, respectively, of the excreted radioactivity. Three days after dosing, 23% of the ingested radioactivity was stored in the whole body and part of the residue (about 20%) was bound to tissues. No detectable amounts of unchanged 17MT were found in tissues 48 h after dosing, in liver, 17MT-derived radioactivity was present primarily as glucuronide conjugates whereas in muscle, radioactivity originated essentially from free metabolites. Maximum bile 14C concentrations were from 200 to 2000 times the levels found in other tissues. This radioactivity was associated with glucuronide conjugates only. Excretion of 17MT-derived radioactivity occurred primarily as free metabolites in aquarium water and as glucuronide conjugates in feces. These results demonstrate the extent of biotransformation of 17MT in trout and suggest the occurrence of several metabolic pathways for this steroid in fish.
Catchability Variations of Cod in the Marginal Ice Zone
Authors: Fréchet Alain
Published: August 2008

An analysis of results obtained during the winter groundfish surveys in the Gulf of St. Lawrence since 1978 was undertaken by relating the cod (Gadus morhua) catch to the distance from ice edge while taking temperature and depth variables into account. This analysis was prompted by anecdotal accounts and recently published data on increased abundance of many taxa related to an upwelling phenomenon in the marginal ice zone. Results indicate that large catches of cod occur in the marginal ice zone when depths are suitable. It is hypothesized that a strong thermal gradient close to the bottom would increase the concentration of cod and thus its catchability.
Density-Dependence at Sea for Coho Salmon (Oncorhynchus kisutch)
Authors: Emlen J. M. , Reisenbichler R. R. , McGie A. M. , Nickelson T. E.
Published: August 2008

The success of expanded salmon hatchery programs will depend strongly on the degree of density-induced diminishing returns per smolt released. Several authors have addressed the question of density-dependent mortality at sea in coho salmon (Oncorhynchus kisutch), but have come to conflicting conclusions. We believe there are compelling reasons to reinvestigate the data, and have done so for public hatchery fish, using a variety of approaches. The results provide evidence that survival of these public hatchery fish is negatively affected, directly by the number of public hatchery smolts and indirectly by the number of private hatchery smolts. These results are weak, statistically, and should be considered primarily as a caution to those who, on the basis of other published work, believe that density-dependence does not exist. The results reported here also re-emphasize the often overlooked point that inferences drawn from data are strongly biased by investigators' views of how the systems of interest work and by the statistical assumptions they make preparatory to the analysis of those data.
Occurrence, Relative Abundance, and Size of Landlocked Sea Lamprey (Petromyzon marinus) Ammocoetes in Relation to Stream Characteristics in the Great Lakes
Authors: Young R. J. , Kelso J. R. M. , Weise J. G.
Published: August 2008

The effect of 14 environmental variables on the occurrence of sea lamprey (Petromyzon marinus) ammocoetes was examined in 73 tributaries of the Great Lakes. We successfully classified 86% of streams without lamprey and 90.5% of streams with ammocoete populations using discriminant analysis. Eighty percent of streams in a test data set were also successfully classified. The classification success was largely determined by differences in stream substrate characteristics based on the magnitude of canonical coefficients and contribution to the multivariate F-statistic. Streams with ammocoetes had significantly (P < 0.10) higher proportion of sand and a lower proportion of bedrock and clay than streams without ammocoetes. Catch per unit effort (CPUE) of ammocoetes collected with electro-fishing gear was also significantly related (P = 0.004) to the proportion of rubble, gravel, and clay. As well, we observed a significant (P < 0.01) positive relationship between conductivity and temperature with size of 2+ ammocoetes. Results indicate that it should be possible to develop predictions for the number of metamorphosing ammocoetes based upon differences in stream characteristics.
Interactions between White Perch (Morone amerićana) and Yellow Perch (Perca flavescens) in Lake Erie as Determined from Feeding and Growth
Authors: Parrish Donna L. , Margraf F. Joseph
Published: August 2008

Since the mid-1970's, white perch Morone americana have expanded rapidly, resulting in possible major interactions with the native yellow perch Perca flavescens. We compared the food consumption rates, diet overlap, and growth of white perch and yellow perch from field data collected during 1983–85 and 1987. Food consumption rates were as much as 27% greater in white perch than in yellow perch, and were higher for both species in the central basin than in the western basin. Seasonal diet composition was most alike in summer and less so in spring and fall, when yellow perch ate more benthos or fish than did white perch. Of 48 Schoener index comparisons of diet overlap during a 3-yr period, 52% were significant (> 0.6). Although yellow perch grew faster in the central basin, reflecting the greater consumption rates, white perch did not show the similar large interbasin growth differences.
Occurrence, Size, and Sexual Maturity of Long-Finned Squid (Loligo pealei) at Nova Scotia and Newfoundland, Canada
Authors: Dawe E. G. , Shears J. C. , Balch N. E. , O'Dor R. K.
Published: August 2008

A major extension of the geographic range of Loligo pealei, in quantitative as well as spatial aspects, is described. The species' range is extended northward and eastward to approximately 47°30′N: 53°06′W, based on its occurrence in Newfoundland inshore trap samples in the autumn of 1986. Biological data from these samples, as well as from collections from Nova Scotian inshore traps from 1974 to 1986, indicate that L. pealei becomes sexually mature and spawns in Nova Scotian waters but not at Newfoundland. Loligo pealei appears to be prevalent in Canadian waters at times when its sympatric competitor, the short-finned squid Illex illecehrosus, is not abundant. The reported catch of L. pealei in Atlantic Canada for 1986 was 67 t, which suggests that this species could possibly support a small Canadian fishery in some years.
Estimating Salmon Spawning Escapement Using Capture–Recapture Methods
Authors: Schwarz Carl J. , Bailey Richard E. , Irvine James R. , Dalziel Frank C.
Published: August 2008

We describe a method of estimating the spawning escapement of coho salmon (Oncorhynchus kisutch) from capture–recapture data. Traditional capture–recapture analyses do not directly provide estimates of escapements; however, we show how simple modifications to the Jolly–Seber method can estimate the total number of fish returning to a river including those that enter and die between sampling occasions. Spawning runs of Pacific salmon were simulated and their escapements estimated using capture–recapture. The performance of the maximum likelihood estimators (MLEs), the censored MLEs, the constrained MLEs, and less-biased estimators in estimating the run sizes and providing estimates of precision were evaluated. Simulation results indicated that constrained MLEs provided the most appropriate estimates of escapement and that standard errors be computed using the large-sample variance formulae evaluated at these estimates. These methods were used to estimate the escapements of coho salmon to a small river on Vancouver Island in 1989 and 1990.
Downstream and Early Marine Migratory Behaviour of Sockeye Salmon (Oncorhynchus nerka) Smolts Entering Barkley Sound, Vancouver Island
Authors: Wood Chris C. , Hargreaves N. Brent , Rutherford Dennis T. , Emmett Brian T.
Published: August 2008

Behaviour of sockeye salmon (Oncorhynchus nerka) smolts was studied during their migration down the Stamp and Somass rivers and through Alberni Inlet and Barkley Sound, Vancouver Island. Emigration from Great Central Lake was typical of other sockeye lakes: smolt abundance peaked in early May and most smolts left the lake at dusk. Migration down the rivers occurred only during twilight or darkness and most smolts made the 25-km journey to tidal waters within a single night. Those that did not held position in tight schools in the surface waters of deep pools during daylight. During downstream migration, ground speed averaged about 2.5 km/h, and smolts did not appear to be especially vulnerable to predation owing to their short residence time, with few smolts remaining in the river during daylight. Catch rates at purse-seine sampling sites throughout Alberni Inlet and Barkley Sound indicated that sockeye smolts migrated more slowly in tidal waters and were sometimes highly vulnerable to predaceous fish (especially Pacific hake, Merluccius productus). Estimated migration speeds through Alberni inlet were 1.9 km/d for smolts entering tidal waters during April and May, and 1.3 km/d for those during June and July; speed through Barkley Sound was 1.6 km/d throughout May–July.
Factors Related to the Variation in Mixing Depth among Meromictic Lakes
Authors: McGuire Shawn , Currie David J.
Published: August 2008

Although the factors that influence the mixing depth of holomictic lakes have been well investigated, meromictic lakes, which never mix completely, have received little attention in this regard. The purpose of the present study was to determine if the geographic variation in mixing depth of the mixolimnion is related to the same factors as is the epilimnion depth. Data on the lake morphometry, elevation, latitude, salinity in the mixo- and monimolimnia, and the depths of the epi- and mixolimnia were obtained for 56 meromictic lakes worldwide. The depth of the mixolimnion was most closely related to the maximum depth of the lake (r2 = 0.69); no other variables were significant after accounting for depth. In the same data set, epilimnetic depth was also most closely related to maximum depth, rather than fetch, as earlier studies had found. Our results suggest that wind-induced turbulence has much less effect on the depth to which both the epilimnion and the mixolimnion circulate in meromictic lakes than does morphometry.
Reactions of 6-aminouracils — A novel and highly efficient procedure for preparation of some new spiro pyridodipyrimidines under classical or microwave-assisted solvent-free conditions
Authors: Mohammadizadeh Mohammad R , Azizian Javad , Teimouri Fatemeh , Mohammadi Ali A , Karimi Ali R , Tamari Esmail
Published: August 2008

A versatile and highly efficient procedure has been introduced for preparation of spiro pyridodipyrimidines during the investigation of the reaction of 1,3-dimethyl-6- aminouracil with isatin derivatives, ninhydrin, and acenaphthoquinone under classical or microwave-assisted solvent-free conditions.Key words: isatin, ninhydrin, acenaphtoquinone, 1,3-dimethyl-6-aminouracil, solvent-free.
Ytterbium(III) triflate catalyzed synthesis of calix[4]pyrroles in ionic liquids
Authors: Kumar Anil , Ahmad Israr , Rao M Sudershan
Published: August 2008

Ytterbium(III) triflate has been utilized as a mild Lewis-acid catalyst for the synthesis of various calix[4]pyrroles by the condensation of pyrrole with different ketones in ionic liquids. The calix[4]pyrroles were obtained in high yield under ecofriendly, economical, and noncorrosive conditions, and the catalyst was recovered and recycled.Key words: calix[4]pyrrole, ionic liquid, ytterbium triflate.
A comparative study of surface preparations of the organ of Corti of the harp seal (Pagophilus groenlandicus Erxleben 1777) and the ringed seal (Pusa hispida). 1. Sensory cell population and density
Authors: Ramprashad F. , Ronald K. , Geraci J. , Smith T. G.
Published: August 2008

The surface preparation technique was used to estimate the sensory cell population and density in the organ of Corti of seven harp seals and four ringed seals. The average total of inner hair cells for the harp seal was 3654 (3078–263) as compared with an average total of 3232 (3120–3354) in the ringed seal. The average total number of outer hair cells in the harp seal was 14 318 (12 173 – 15 709) as compared with an average total of 13 497 (12 903 – 14 894).The distribution of outer and inner hair cells showed an increase in density from base to apex. An increase in density of about 21% and 29% was observed in the inner hair cells of the ringed and harp seal. The increase in density for each row of outer hair cells was 21% in the harp seal and 17% in the ringed seal. The density of outer hair cells per unit surface area decreased from a maximum value at the base to about half its value at the apex.The average total sensory cells of seals exceeded the average total sensory cells of both man and dolphin but were within the range of variation of the human.
New Onychiuridae (Collembola) from Vancouver Island
Authors: Rusek J.
Published: August 2008

Three new genera and six new species from Vancouver Island, British Columbia, are described: Sensiphorura marshalli gen. et sp.nov. (Pachytullbergiinae), Granuliphorura obtusochaeta gen. et sp.nov., Chaetophorura vancouverica gen. et sp.nov., Mesaphorura pacifica sp.nov., Mesaphorura macrochaeta sp.nov. (Tullbergiinae), and Onychiurus eisi sp.nov. (Onychiurinae). The status of the subfamily Pachytullbergiinae is discussed and all described species are briefly synecologically characterized.
Seasonal changes in body composition of the arctic ground squirrel, Citellus undulatus
Authors: Galster William , Morrison Peter
Published: August 2008

The depletion or accumulation of body reserves is followed in terms of the weight and proportion of lipid, protein, water, and minerals in arctic ground squirrels during the entry, deep, and emergent phases of the hibernation season and after the reproductive phase of the active season. Average weight increased slowly through the summer, from a minimum of 346 g, until mid-August when 190 g accumulated in 3 weeks to be used subsequently during the 220-day hibernation season beginning in mid-September. During hibernation, the 325-g loss in weight represents 62% lipid, 26% water, 9% protein, and 2% mineral. Fat in lipid provides most of the energy but insufficient amounts of carbon for glucose synthesis during hibernation. However, protein provides an adequate gluconeogenic reserve. Significant loss of mineral indicates that skeletal reserves of calcium are important during hibernation. After hibernation, continued loss of weight by females indicates further utilization of reserves during gestation and nursing.
Fine structure of the rostral pars distalis follicle cells in homotransplanted pituitaries of rainbow trout, Salmo gairdneri
Authors: Leatherland J. F. , Lin L.
Published: August 2008

Pituitary glands from 'donor' rainbow trout were transplanted into the anterior eye compartment of 'recipient' fish to examine the nature of hypothalamic control of the follicle cells in salmonid fishes and to explore the possibility of using the eye as a site of pituitary implantation that permits successful recovery of the grafted gland. After 7 weeks the transplanted prolactin cells appeared less active than in in situ glands and some of the follicle cells appeared to be undergoing degenerative processes. This inhibition of prolactin cell activity was thought to be due to the higher osmotic pressure of the ocular fluid.The follicular formation of the prolactin and non-granulated cells was retained in transplanted glands, although the follicle lumina were smaller than in in situ glands and commonly contained cellular debris. This may suggest that the lumina are sites of cellular degradation and possibly stores of precursor substances.
Studies on the function of the tritosternum in selected Gamasida (Acari)
Authors: Wernz J. G. , Krantz G. W.
Published: August 2008

Observations on the feeding behavior of Parasitus coleoptratorum (L.) and Glyptholaspis americana (Berl.) revealed that the tritosternum functions in concert with the capitular groove of the gnathosoma as a fluid transport and grooming mechanism. Excess prey fluids overflowing into the postcapitular channel are redirected to the prebuccal region between the tritosternal laciniae and the capitular groove, preventing loss of food material.Surgical removal of the tritosternum results in an overflow of fluids from the region behind the tritosternal remnant onto the sternal area. Feeding efficiency studies on normal and tritosternectomized P. coleoptratorum showed that mites which lack a tritosternum feed on significantly more prey than do normal individuals. It is postulated that this increase reflects impairment of feeding efficiency and resultant food loss during each feeding episode.Grooming of the capitular groove is accomplished through the combined raking action of the lacinial pili and the deutosternal denticles. Substantial accumulations of debris were observed only in the capitular grooves of tritosternectomized mites.
Records and range extensions of some northeastern Pacific opisthobranchs (Mollusca: Gastropoda)
Authors: Lambert Philip
Published: August 2008

Thirty-one species of opisthobranchs are recorded from the region of Prince Rupert, British Columbia. Of these, the known ranges of the following nine species are extended north to the border between British Columbia and Alaska: Acanthodoris nanaimoensis, Aldisa sanguinea cooperi, Antiopella fusca, Catriona alpha, Coryphella pricei, Dendronotus albus, Doto columbiana, Pleurobranchus denticulatus, and Tritonia festiva.The known range of Rostanga pulchra is extended north to Dundas Island, British Columbia. The known ranges of Acanthodoris hudsoni, Aegires albopunctatus, Coryphella trilineata, Dendronotus diversicolor, Dirona albolineata, and Discodoris heathi are extended north to Porcher Island, British Columbia, and that of Placida dendritica to Triangle Island at the northern tip of Vancouver Island.
The mineral profile of plumage in captive lesser snow geese
Authors: Kelsall John P. , Pannekoek W. J.
Published: August 2008

This is a contribution to a larger study aimed at development of a technique to determine the origins of waterfowl from their feather chemistry. Results are reported of an experiment designed to show whether there were differences in the mineral profile between primary feathers one-half to two-thirds grown and fully formed feathers, within a population of captive lesser snow geese. Primaries 1 and 10 were used as sample materials and the elements Na, Ca, K, Fe, Cu, Mn, Mg, Zn, and Si were used as variables. Statistically significant differences were shown between stages of growth in respect to all variables except Cu and Zn. The experiment also showed significant differences between different primary feathers in respect to all variables, and some differences attributable to the sex of birds from which samples were taken.