bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the
Pseudomonas pseudoalcaligenes
CECT5344 Cyanase, an Enzyme That Is Not Essential for Cyanide Assimilation
Authors: Luque-Almagro Víctor M. , Huertas María-J. , Sáez Lara P. , Luque-Romero Manuel Martínez , Moreno-Vivián Conrado , Castillo Francisco , Roldán M. Dolores , Blasco Rafael
Published: August 2008

Cyanase catalyzes the decomposition of cyanate into CO
2
and ammonium, with carbamate as an unstable intermediate. The cyanase of
Pseudomonas pseudoalcaligenes
CECT5344 was negatively regulated by ammonium and positively regulated by cyanate, cyanide, and some cyanometallic complexes. Cyanase activity was not detected in cell extracts from cells grown with ammonium, even in the presence of cyanate. Nevertheless, a low level of cyanase activity was detected in nitrogen-starved cells. The
cyn
gene cluster of
P. pseudoalcaligenes
CECT5344 was cloned and analyzed. The
cynA, cynB
, and
cynD
genes encode an ABC-type transporter, the
cynS
gene codes for the cyanase, and the
cynF
gene encodes a novel σ
54
-dependent transcriptional regulator which is not present in other bacterial
cyn
gene clusters. The CynS protein was expressed in
Escherichia coli
and purified by following a simple and rapid protocol. The
P. pseudoalcaligenes
cyanase showed an optimal pH of 8.5°C and a temperature of 65°C. An insertion mutation was generated in the
cynS
gene. The resulting mutant was unable to use cyanate as the sole nitrogen source but showed the same resistance to cyanate as the wild-type strain. These results, in conjunction with the induction pattern of the enzymatic activity, suggest that the enzyme has an assimilatory function. Although the induction of cyanase activity in cyanide-degrading cells suggests that some cyanate may be generated from cyanide, the
cynS
mutant was not affected in its ability to degrade cyanide, which unambiguously indicates that cyanate is not a central metabolite in cyanide assimilation.
CcpA Mediates the Catabolite Repression of
tst
in
Staphylococcus aureus
Authors: Seidl Kati , Bischoff Markus , Berger-Bächi Brigitte
Published: August 2008

Some clinical isolates of
Staphylococcus aureus
produce the superantigenic toxic shock syndrome toxin 1 (TSST-1), encoded by
tst
, located on pathogenicity islands. The expression of
tst
is complex and is influenced by environmental conditions such as pH, CO
2
, and glucose. We identified a putative catabolite-responsive element (
cre
) in the promoter regions of all known
tst
genes, indicating that
tst
transcription may be regulated by the catabolite control protein CcpA. By introducing
tst
genes under the control of their native promoters or
tst
promoter-reporter gene fusions in wild-type strain Newman, we showed that glucose was able to repress
tst
transcription and TSST-1 production, whereas glucose repression was abolished in the corresponding Δ
ccpA
mutant. Stabilizing the pH ruled out a pH effect due to acid production during glucose catabolism. CcpA thus directly regulates
tst
transcription, linking carbohydrate utilization to virulence gene expression in
S. aureus
.
Environmental Modulation of Annual and Daily Rhythms Associated with Reproduction in Teleost Fishes
Authors: Crim L. W.
Published: August 2008

Both temperate and the cold water teleosts are seasonal breeders and production of young fish occurs at an optimal time of the year thereby maximizing survival. Teleost reproductive activity can be divided into annual periods of prespawning, spawning, and postspawning gonadal events which correlate with wave-like endocrine fluctuations. Long-term (circannual) endocrine patterns in the hypothalamo-pituitary-gonad axis (HPG) are observed with maximum hormone levels occurring with spawning and minimal values relating to gonad regression during the postspawning period. Recently, short-term (circadian) endocrine rhythms have also been described. During the period of gonadal recrudescence the basal gonadotropin (GtH) level rises and daily variations of GtH are maximal. Light and temperature variations primarily cue seasonal gonad development in teleosts although the relative importance of these and other environmental triggers differs among various fish species. Clearly HPG activity is influenced by environmental conditions. Temperature has a direct effect upon circulating GtH levels but other physiological mechanisms are implicated as well. Endocrine organ sensitivity undergoes annual variations and cyclic hormone release may respond accordingly. But, daily fluctuations in gonadal responsivity to GtH treatment suggests that phasing of endocrine variations may play an important role and should be considered in future studies of environmental regulation of fish reproductive cycles.Key words: teleost fishes, hormone rhythms, environmental modulation, reproduction
Hormonal Control of Fish Reproductive Behavior: Brain–Gonadal Steroid Interactions
Authors: Demski L. S. , Hornby P. J.
Published: August 2008

A number of hormones are known to influence reproductive behavior in teleosts. The best studied in this regard are the sex steroids estradiol and testosterone. Sufficient evidence is available to permit the outlining of possible modes of action of these hormones on mechanisms controlling reproductive responses in fishes. Autoradiographic studies using tritium-labeled steroids have revealed several brain areas with neurons that concentrate testosterone and estradiol in both males and females. An area near the anterior commissure (preoptic region and parts of the area ventralis telencephali) is of primary interest for behavioral systems. Electrophysiological experiments in goldfish (Carassius auratus) have demonstrated that both hormones strongly influence olfactory mechanisms. These effects may be mediated by steroid feedback on brain areas involved in centrifugal control of the olfactory bulbs. The neurological substrates for several behaviors which are thought to be androgen dependent have been studied using classical neurobehavioral methods. These include: spawning and sperm release in goldfish and sunfish (Lepomis sp.) and courtship and nestbuilding in sunfish. As of yet, a direct action of sex steroids on these systems has not been demonstrated; however, they all relate to the steroid-concentrating area mentioned above. Some of the systems are incorporated into a tentative model of the neural–hormonal mechanisms controlling reproductive behavior in male goldfish.Key words: reproductive behavior, fishes, brain, hormones, sex steroids, olfaction
Aquaculture in North America: An Assessment of Future Prospects
Authors: Larkin P. A.
Published: August 2008

The farming of aquatic environments is already a large-scale world enterprise involving relatively simple technology, but aquacultural production in North America is only a small part of the world total. Aquaculture is only economically rewarding where high rates of production over a long growing period can be coupled with close proximity to large markets in which there are few cheap alternative sources of protein. Much of North American aquaculture is aimed at meeting demands of recreational fishermen rather than as a way of producing food. There are many opportunities for development of aquaculture in North America and it seems reasonable to project substantial increases in production in the next two decades.Key words: aquaculture, geographical location, North America, future prospects, economics
Metal Accumulation by the Polychaete Capitella capitata: Influences of Metal Content and Nutritional Quality of Detritus
Authors: Windom H. L. , Tenore K. T. , Rice D. L.
Published: August 2008

Experimental chambers were used to evaluate the influence of nitrogen and metal concentration of detritus on metal accumulation by the marine polychaete Capitella capitata. During the 90-d experiments worms were fed diets of detritus derived from natural seaweeds, nitrogen supplemented seaweeds, and metal contaminated phytoplankton–zooplankton debris. Metal concentrations in Capitella grown on 19 detrital stocks derived from natural seaweeds were similar. Metal accumulation from a single seaweed detritus supplemented with varying amounts of nitrogen suggests that nutritional quality of the food source influences metal uptake. Metal accumulation in Capitella is significantly increased when fed detritus containing metal concentrations significantly elevated above natural levels.Key words: metal, accumulation, benthos, detritus, polychaetes
Algorithms for Solving the Catch Equation Forward and Backward in Time
Authors: Sims S. E.
Published: August 2008

Approximate solutions to the catch equation for the fishing mortality rate both forward and backward in time are obtained with an application of the diagonal Padé approximation of degree four to the exponential function. In either case the resulting approximation as well as Pope's estimate are shown to serve quite well as starting values for Newton's Method which is used to obtain a numerical solution of the catch equation. Convergence criteria for Newton's Method are discussed in each setting.Key words: catch equation, Newton's method, Padé approximation, Pope's estimate
Effect of Preservation on the Weight of Marine Benthic Invertebrates
Authors: Mills Eric L. , Pittman Karin , Munroe Brent
Published: August 2008

It would be convenient if preserved animals could be used to determine fresh-weight biomass. However, marine annelids, nematodes, bivalves, amphipods, and isopods all lost weight when preserved and stored in 70% isopropanol. In 10% formalin only bivalves lost weight significantly; the other groups showed evidence of small increases or decreases. Many animals preserved in alcohol decreased sharply in weight within a few minutes, probably due to dehydration. In formalin most increased at first, then slowly decreased. The response to preservatives is complex, involving short-term changes of water content and long-term changes of tissue composition. Precision, though not accuracy, of preserved wet weights can only be achieved after specimens have been in preservatives for a month or more, especially in the case of isopropanol. For these reasons, wet and dry weight biomass figures should be determined from fresh, unpreserved animals.Key words: fixation, preservation (organisms), biomass determination, benthos
Isolation of Infectious Pancreatic Necrosis Virus from the Blood and Blood Components of Experimentally Infected Trout
Authors: Swanson Robert N. , Gillespie James H.
Published: August 2008

Experimental infection with infectious pancreatic necrosis virus (IPNV) was achieved in yearling rainbow trout (Salmo gairdneri) and 7-mo-old brook trout (Salvelinus fontinalis) by intraperitoneal inoculation and by water contact, respectively. Blood removed periodically from both groups of fish was fractionated and various blood components examined for virus. IPNV was recovered consistently from the plasma and mononuclear-enriched blood fractions of the rainbow trout from 1 to 19 d postinoculation (DPI) and also was detected in the mononuclear fraction on 33 DPI. In the brook trout virus was recovered from 3 to 40 DPI in the plasma and from 7 to 40 DPI in the mononuclear fraction. Thus a viremia appeared to be important in the early stages of experimental IPNV infection and infectious virus was found both free in the plasma and in association with an undetermined cell population present in the mononuclear component of blood.Key words: infectious pancreatic necrosis, blood, fish disease, Salmo gairdneri, Salvelinus fontinalis
A SIMPLE ULTRAMICROMETHOD FOR THE QUANTITATIVE ESTIMATION OF AMINO ACIDS BY PAPER PARTITION CHROMATOGRAPHY
Authors: Auclair Jacques L. , Dubreuil Robert
Published: August 2008

A new ultramicromethod for the quantitative estimation of amino acids by paper partition chromatography is described. The material required and the procedure adopted are detailed. As an application of this new method, a quantitative estimation of the free amino acids present in the blood of the last larval instar of Galleria mellonella (L.) is presented. The results obtained, when converted into total amino nitrogen, compare favorably with total amino nitrogen results already published in the literature.
ENERGY METABOLISM OF THE WHITE-FOOTED MOUSE, PEROMYSCUS LEUCOPUS NOVEBORACENSIS, AFTER ACCLIMATION AT VARIOUS ENVIRONMENTAL TEMPERATURES
Authors: Hart J. Sanford
Published: August 2008

Acclimation of white-footed mice to successively lower temperatures (30 °C., 20 °C., 10 °C.) had no effect on average initial oxygen consumption levels during exposure to environmental temperatures from 30 °C. to −26 °C., but prolonged the time that the initial levels could be maintained. When the initial oxygen consumption could no longer to maintained, there was a gradual decline to the torpidity level. The duration of this metabolism decline period increased only slightly with increase in total duration of the test. The effect of acclimation on ability to maintain metabolism appears sufficient to account for its influence on resistance to low temperatures in this species.
A SEQUENTIAL SAMPLING TECHNIQUE FOR SPRUCE BUDWORM EGG SURVEYS
Authors: Morris R. F.
Published: August 2008

The object in extensive spruce budworm egg surveys is to classify the infestation as light, moderate, or severe, at a large number of sampling points. The sequential plan, having no fixed sample size, was tested in 1953. It proved very useful, particularly in eliminating superfluous sampling at points where the infestation was definitely light or definitely severe. Curves showing operating characteristics and average sample numbers in relation to population mean permitted an appraisal of the plan in advance of the field test. Field parties were provided with simple tabulations prepared from the acceptance and rejection lines. With an expenditure of 1300 man-days, more than 1000 points were classified in northern New Brunswick.
THE IDENTIFICATION OF ADULT FEMALE AEDES MOSQUITOES (DIPTERA, CULICIDAE) OF THE BLACK-LEGGED GROUP TAKEN IN THE FIELD AT CHURCHILL, MANITOBA
Authors: Beckel W. E.
Published: August 2008

The present status of the taxonomy of the black-legged species complex within the genus Aedes is discussed. The complex in the Churchill region includes Aedes nigripes (Zetterstedt), A. impiger Dyar (equals A. nearcticus Dyar), A. pionips Dyar, A. communis (De Geer), A. punctor (Kirby), A. hexodontus Dyar, A. cinereus Meigen, and may involve A. intrudens Dyar, A. implicatus Vockeroth (equals A. impiger Dyar), and A. sticticus (Meigen). The difficulty of separation of the females with the existing taxonomic characters is pointed out, especially if badly rubbed specimens or specimens preserved in alcohol are to be studied. Characters are then presented to separate all the species in the complex except A. punctor from A. hexodontus and A. intrudens from A. communis. Since, in the Churchill region, the larvae of A. punctor are rarely found, and those of A. intrudens have not yet been found, these exceptions are of minor importance.
A PROVISIONAL LIFE TABLE FOR THE BARREN GROUND CARIBOU
Authors: Banfield A. W. F.
Published: August 2008

A provisional life table for the continental Barren Ground caribou, Rangifer arcticus arcticus (Richardson), has been prepared from a collection of 292 mandibles collected in 1948 and 1949 on the summer and winter ranges of the species in northern Canada. The data include both sexes. The age of the specimens was estimated by the eruption and wear of the teeth. The mean expected life span at birth was found to be 4.09 years. The average mortality rate for the first 10 years of life was 71%. The apparent potential natural longevity was about 13 years.
THE SELECTION BY CERTAIN SMALL MAMMALS OF DEAD, PARASITIZED, AND HEALTHY PREPUPAE OF THE EUROPEAN PINE SAWFLY, NEODIPRION SERTIFER (GEOFF.)
Authors: Holling C. S.
Published: August 2008

Caged Sorex cinereus cinereus Kerr, Blarina brevicauda talpoides Gapper, and Peromyscus maniculatus bairdii Hoy and Kenicott opened more cocoons containing healthy, living sawfly prepupae than ones containing prepupae attacked by fungus. In the field and in the laboratory, S.c.cinereus opened more healthy cocoons than cocoons containing parasites. The reverse appeared to be true for B.b.talpoides. P.m.bairdii opened equal numbers of healthy and parasitized cocoons. The more insectivorous animals exhibited the greatest selective ability. Pretreatment to cocoons of one category affected the selective ability. Pretreating P.m.bairdii to fungus cocoons lowered the ability to select healthy cocoons over fungus cocoons. Pretreating animals to healthy cocoons raised the selective ability. Selection occurred in the digging, removing, opening, and eating phases in the search for cocoons. The closer the phase to the consummatory action, the greater was the degree of selection. The selective ability in the first three phases was acquired with experience. In the final, eating, phase it was innate.
A METHOD FOR THE ASSESSMENT OF THE NUTRITIONAL STATUS OF WILD UNGULATES
Authors: Bandy P. J. , Cowan I. McT. , Kitts W. D. , Wood A. J.
Published: August 2008

A study has been made of the relationship existing between heart girth and body weight and hind foot length and body weight of growing Columbian black-tailed deer (Odocoileus hemionus columbianus). From the results obtained, a method has been proposed for the assessment of the nutritional status of wild ungulates. This method involves a comparison of ratios of body weight estimated from heart girth to body weight estimated from hind foot length.
A MICROSPORIDIAN PARASITE OF THE FOREST TENT CATERPILLAR, MALACOSOMA DISSTRIA HBN.
Authors: Thomson H. M.
Published: August 2008

The life cycle of a microsporidian parasite of the forest tent caterpillar is described. The microsporidian attacks primarily the silk glands and the mid-gut epithelium but other tissues are also infected. Observations are made on the ejection of the polar filament. It is apparent that the microsporidian is a new species and the name Perezia disstriae n. sp. is proposed.
PROTOZOA, INCLUDING AN ENTOZOAN OF GUINEA PIGS, FROM HOUSE FLIES
Authors: Laird Marshall
Published: August 2008

Of 179 examples of Musca domestica L. examined, 7 harbored Octosporea muscae-domesticae Flu (Sporozoa: Microsporidia), 2 Herpetomonas muscarum (Leidy) (Mastigophora: Protomonadina), and 2 Retortamonas caviae (Hegner and Schumaker) (Mastigophora: Retortamonadina). Trophozoites of the last-named species, a common entozoan of guinea pigs, were active in the mid-gut and faeces of the flies concerned, which had presumably ingested the trophozoites from moist, fresh faeces of the normal host.
STUDIES IN THE MODE OF ACTION OF ROYAL JELLY IN HONEYBEE DEVELOPMENT: II. RESPIRATION OF NEWLY EMERGED LARVAE ON VARIOUS SUBSTRATES
Authors: Shuel R. W. , Dixon S. E.
Published: August 2008

Measurements were made of oxygen uptake and carbon dioxide evolution, during the first 24 hours of life, by larvae on substrates of different age and type. These substrates included royal jelly, the pharyngeal secretion fed to larvae destined to become queens, which varied in age from 0 to 96 hours; the pharyngeal secretion fed to young larvae destined to be workers, which varied in age from 0 to 60 hours and which was termed "worker jelly"; and the food supplied to older worker larvae, composed of a pharyngeal secretion modified by an admixture of honey and pollen, and termed "modified jelly". The pattern and magnitude of oxygen uptake was similar on all substrates. Net carbon dioxide evolution by larvae on royal jelly or modified jelly was highly positive; net carbon dioxide evolution by larvae on worker jelly was slightly negative. Microchemical analyses showed that royal jelly differed in composition from worker jelly and modified jelly. The composition of royal jelly remained relatively constant with age. The addition of sugars to worker jelly produced an increase in carbon dioxide output which was nullified by the further addition of an extract of the water-soluble acids of royal jelly. The differences observed in carbon dioxide evolution by young larvae on worker jelly and royal jelly are considered to be an expression of the initiation of female dimorphism. An hypothesis of nutritional balance is advanced to account for this dimorphism.
FURTHER OBSERVATIONS ON WATER ABSORPTION BY THE EGGS OF ACHETA DOMESTICUS (L.)
Authors: McFarlane J. E. , Kennard C. P.
Published: August 2008

Eggs of Acheta domesticus (L.) absorb water during the stage of embryonic development in which the serosa surrounds the embryo and yolk. Water is absorbed over the entire surface of the shell. The egg membranes are more permeable to water, as shown by water loss in an unsaturated atmosphere, during the period of water absorption than either before or after; they are also permeable to dyes during the period of water absorption. The mechanism of water absorption is discussed. A possible explanation is presented for water loss after maximal absorption has occurred.
DEVELOPMENTAL RATES AND DIAPAUSE IN ACHETA PENNSYLVANICUS (BURMEISTER) AND ACHETA VELETIS ALEXANDER AND BIGELOW (ORTHOPTERA:GRYLLIDAE)
Authors: Bigelow R. S.
Published: August 2008

Tendencies to diapause were not observed in nymphs of Acheta pennsylvanicus (Burmeister), but diapause was noted in a high proportion of the nymphs of Acheta veletis Alexander and Bigelow. On the average, nymphal development was more rapid in pennsylvanicus than it was in veletis nymphs. Embryonic diapause always occurred in pennsylvanicus but never in veletis eggs. These differences in developmental physiology are genetically determined and the failure of the two species to produce hybrids may be due to conflicting lethal interactions of the two genotypes in hybrid embryos. Both species die out after several generations of laboratory rearing at continuous high temperatures, and the evolution of cold hardiness has apparently involved a reduction in tolerance to constant high temperatures. Reproductive isolation may have been achieved by these two species without geographical isolation. Nymphal development is more rapid in northern than in southern veletis populations.
EFFECTS OF SOME PURINES ON DEVELOPMENT OF THE BROWN TROUT (SALMO TRUTTA FARIO L.)
Authors: Purko John , Battle Helen I.
Published: August 2008

Recently fertilized eggs of the brown trout (Salmo trutta fario L.) were subjected to each of the purines adenine and hypoxanthine in concentrations ranging from 0.025 to 0.150% for periods up to 21 days at 9.5 °C. Measurements of blastomere diameters during cleavage, of blastoderm diameters during blastulation, and of the lengths of the embryonic axes during and subsequent to gastrulation indicated that over the whole range of concentrations of both purines, these processes were significantly accelerated over those of controls. Adenine and hypoxanthine appear to be equally effective. It is concluded that an exogenous source of the purines adenine or hypoxanthine can exercise a general acceleration of the processes of cleavage, blastulation, gastrulation, and early differentiation in the brown trout embryo.
PARASITES FROM NORTHERN CANADA: II. HAEMATOZOA OF FISHES
Authors: Laird Marshall
Published: August 2008

Parasites were present in thin blood films from only 6 of 188 fishes of 11 species, collected in the Northwest Territories and northern Quebec. The haemoflagellate, Cryptobia gurneyorum (Minchin), is recorded from North America for the first time—from the type host, Esox lucius L., and from two new ones, Coregonus clupeaformis (Mitchill) and Salvelinus namaycush (Walbaum). Haemogregarina irkalukpiki n.sp., characterized by its large size (av., 17.2 by 3.2 μ) and nucleophilic habit, is described from two sea-run arctic char, Salvelinus alpinus (L.).
POLYCHAETA FROM BRITISH COLUMBIA; WITH A NOTE ON SOME WESTERN CANADIAN ARCTIC FORMS
Authors: Berkeley E. , Berkeley C.
Published: August 2008

Nine species of Polychaeta collected off the coast of British Columbia are recorded. Two of these (Micromaldane ornithochaeta and Notomastus lineatus var. balanoglossi) have not been reported previously outside Europe, one (Asychis biceps) is new to the west coast of North America, and four are new to British Columbia. Six species are recorded from the neighborhood of Herschell Island in the western Canadian Arctic. All are new to that region, though known from further western seas, and, in three cases (Melaenis loveni, Antinoella sarsi, and Nephthys malmgreni) from the western Canadian Arctic further east.
HETEROGENEOUS INDUCTIONS IN THE CHICK EMBRYO
Authors: Pasternak L. , McCallion D. J.
Published: August 2008

Chick embryos at stages three and four were explanted to a saline–albumen– agar medium and incubated for a further 30 hours at 38° C. All were reasonably normal embryos and had reached stages of development comparable to in ovo standards. Chick embryos at the same stages of development and containing a small Fragment of coagulated liver, kidney, or Hensen's node or live Hensen's node in contact with the under side of the epiblast were similarly explanted and cultivated. A large number of successful inductions of secondary neural axes was obtained with liver, kidney, and Heusen's node as inductor. No inductions were obtained with killed Hensen's node as inductor.Rectangles of epiblast taken outside of the presumptive neural area of stage three–four embryos were isolated and cultured on the same medium. These showed no neural differentiation tendencies. Similar areas of epiblast, cultured with fragments of coagulated liver or kidney, developed a large number of neural inductions.
THE COMPARATIVE BIOLOGY AND MORPHOLOGY OF TAENIA OVIS AND TAENIA KRABBEI, WITH OBSERVATIONS ON THE DEVELOPMENT OF T. OVIS IN DOMESTIC SHEEP
Authors: Sweatman G. K. , Henshall T. C.
Published: August 2008

The geographic distribution of infections of skeletal muscle and cardiac cysticerci, possibly T. krabbei, in North American Cervidae is related where pertinent to the geographic distribution of T. ovis in domestic sheep. Experiments show that T. krabbei and T. ovis are biologically distinct but morphologically indistinguishable.The T. ovis embryo migrates through the muscle tissue forming a streak when only a few days old. Where the host response is not inhibitory, complete differentiation and rostellar hook development occur about 56 days after exposure. Many parasites are destroyed by the host as differentiating embryos, before rostellar hooks have begun to develop, during hook development, but only rarely after the cyst is differentiated completely. Viable cysts are surrounded by only a thin fibrous wall. Dead and viable cysts occur non-systematically and show no relationship to any particular muscles, body area, or body system.
ADULT ABDOMINAL CHARACTERS IN THE LYGAEOID–COREOID COMPLEX OF THE HETEROPTERA, AND THE CLASSIFICATION OF THE GROUP
Authors: Scudder G. G. E.
Published: August 2008

The characters used in the classification of the logaoedic–coreoid complex of the Heteroptera vary and no simple classification into superfamilies is apparent. The abdomen provides a number of additional characters which are useful and can be used with previous ones, in the assessment of phenetic affinity. The Coreoidea can be considered as containing families with 75% affinity with the Coreidae, whilst the Lygaeoidea contains families with less than a 75% affinity with this family. Since many of the families in the complex are defined on rather subjective characters, a key based on objective abdominal characters seems more satisfactory.
A SIMPLE ELECTROLYTIC RESPIROMETER FOR SMALL ANIMALS
Authors: Hayward J. S. , Nordan H. C. , Wood A. J.
Published: August 2008

A simple electrolytic respirometer is described. Its design embodies several features advantageous for the accurate measurement of oxygen consumption. Representative results using two species of mice are presented.
A COMPARISON OF FOUR TYPES OF TRAPS USED FOR CAPTURING FLYING INSECTS
Authors: Juillet J. A.
Published: August 2008

The captures of Hymenoptera, Diptera, Lepidoptera, Coleoptera, and Homoptera–Hemiptera were compared during simultaneous operation of glass-barrier, Malaise, rotary, and sticky traps. The results show that the rotary is by far the most reliable and versatile for most groups of insects, then the Malaise, glass-barrier, and sticky traps in a decreasing order of reliability but increasing order of versatility.
AN EFFECT OF DILUTIONS OF SEAWATER ON THE LETHAL TEMPERATURE OF THE GUPPY
Authors: Arai Mary Needler , Cox E. T. , Fry F. E. J.
Published: August 2008

Two phases of resistance times with decreasing upper lethal temperatures are shown for guppies acclimated to 25 °C, with a more marked increase in resistance between 37° and 36 °C than for the same increment at higher or lower temperatures in fresh water. Increased salinity has little effect at high (39 °C) and low (34°) lethal temperatures. At 38° and 37 °C thermal resistance is increased by ⅛ seawater and still more so by ¼ seawater, as might be expected since the latter is approximately isosmotic. However, at 36° the least resistance is obtained in ¼ seawater.
POLAR BEAR MILK: I. GROSS COMPOSITION AND FAT CONSTITUTION
Authors: Baker B. E. , Harington C. R. , Symes A. L.
Published: August 2008

A sample of milk was obtained from a young polar bear which was killed near the north coast of Lowther Island. The gross composition of the milk was found to be as follows: total solids, 44.1%; ash, 1.17%; fat, 31.0%; solids not fat, 13.0%; lactose, 0.49%; total protein, 10.2%. Gas chromatographic analysis of the milk fat showed that the milk contained at least 14 fatty acids including butyric acid (13.9%), palmitoleic acid (22.6%), oleic acid (33.4%).
GLUTAMIC AND ASPARTIC ACIDS AND SUCROSE IN THE DIET OF THE FLOUR BEETLE, TRIBOLIUM CONFUSUM (TENEBRIONIDAE)
Authors: Naylor Alfred F.
Published: August 2008

The effects of three factors on larval development were studied in synthetic media based on a mixture of the 10 essential amino acids. Replacement of one third of the cornstarch with sucrose as carbohydrate source increased time to pupation and decreased larval survival. Including glutamic acid, even as partial replacement for essential amino acids, accelerated larval development and increased survivorship. Aspartic acid also decreased time to pupation and is apparently equivalent to glutamic acid in this respect. However, no evidence for mortality decrease through aspartic acid addition was observed; in fact, statistical analysis resulted in computation of a non-significant semilethal effect of this factor.
POSSIBLE VALUE OF CASEIN, GLUTEN, EGG ALBUMIN, OR FIBRIN AS WHOLE PROTEINS IN THE DIET OF TWO STRAINS OF THE FLOUR BEETLE, TRIBOLIUM CONFUSUM (TENEBRIONIDAE)
Authors: Naylor Alfred F.
Published: August 2008

The confused flour beetle was grown on various diets, all simulating one with 15% whole casein protein. Development rate and survival were higher when any of four proteins supplied one-third of available amino acids than when all or nearly all amino acids were present in crystalline form. The experimental design and incidental aspects of the final results are consistent with the inference that peptide-bound amino acids are nutritively more usable than the free amino acids.
THE NUTRITIONAL REQUIREMENTS OF GRASSHOPPERS: I. REARING OF THE GRASSHOPPER, MELANOPLUS BIVITTATUS (SAY), ON A COMPLETELY DEFINED SYNTHETIC DIET AND SOME EFFECTS OF DIFFERENT CONCENTRATIONS OF B-VITAMIN MIXTURE, LINOLEIC ACID, AND β-CAROTENE
Authors: Nayar J. K.
Published: August 2008

Melanoplus bivittatus (Say) can be reared From the first-instar nymphal stage to the adult stage on an amorphous diet consisting of essential chemical feeding requirements such as carbohydrates (sucrose, glucose, and soluble starch), protein (casein), salt mixture, cholesterol, ascorbic acid, and B-vitamin mixture. This suggests that the chemical feeding requirements of M. bivittatus are essentially similar to those of other phytophagous insects. The physical requirements for feeding, especially alphacel, which provides the necessary bulk to the diet, and the effect of available moisture in the container used for rearing the nymphs under laboratory conditions are demonstrated, in addition, effects of different concentrations of B-vitamin mixture, linoleic acid, and β-carotene on growth and development of these nymphs have been shown. Lower concentrations of B-vitamin mixture do not support optimal growth and higher concentrations do not further improve growth appreciably. β-Carotene is required for normal pigmentation of the nymphs, but is not required for growth and development. Linoleic acid is not required for growth of the nymphs, but is necessary for normal molting to the adult stage.
INTERACTION BETWEEN TWO SPECIES OF CRICKETS REARED TOGETHER
Authors: McFarlane J. E.
Published: August 2008

When larvae of Acheta domesticus (L.) and Gryllodes sigillatus (Walk.) are reared together from hatching onwards, the growth of G. sigillatus is delayed, and the percentage survival of both species is reduced. These results are discussed from the point of view of the physiological mechanisms involved.
EFFECTS OF DIETETIC NUCLEIC ACIDS AND COMPONENTS ON GROWTH OF AGRIA AFFINIS (FALLÉN) (DIPTERA: SARCOPHAGIDAE)
Authors: House H. L.
Published: August 2008

Feeding tests on chemically defined diets; showed that dietary nucleic acids are needed for optimal growth rates of the parasitoid Agria affinis (Fallén) reared axenically. Both ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) met this requirement qualitatively and were almost equal quantitatively. The nucleotides adenylic acid, guanylic acid, cytidylic acid, and uridylic acid were the only derivatives of RNA used by the insect larvae to promote growth rates. These nucleotides were equally well utilized regardless of whether their base was purine or pyrimidine. No evidence was found for the utilization of single nucleosides or purine and pyrimidine bases. Phosphorylation of the molecule seemed to be the primary need that decided the utilization of dietary nucleic acid components in this species of Diptera. This augments evidence that various species of Diptera utilize nucleic acids and their derivatives differently. Moreover, it supports an attractive hypothesis of other workers that differences in utilization derive from ecological adaptations of the respective species and more greatly concern the needs for non-essential nutrients than for the essential ones.
COMPARATIVE STUDIES ON THE EFFECTS OF TEMPERATURE ON FREE-LIVING STAGES OF PLACOCONUS LOTORIS, DOCHMOIDES STENOCEPHALA, AND ANCYLOSTOMA CANINUM
Authors: Balasingam E.
Published: August 2008

The effects of temperature on free-living stages of Placoconus lotoris, Dochmoides stenocephala, and Ancylostoma caninum have been studied under identical conditions. Differences in temperature requirements for free-living development as well as tolerance of ova and infective larvae to freezing temperatures have been observed. These are discussed in relation to the ecology and geographical distribution of the parasites and their hosts.
HOST PLANT RELATIONSHIPS OF RHOPALOSIPHUM FITCHII (SAND.) AND R. PADI (L.) IN MANITOBA (HOMOPTERA: APHIDIDAE)
Authors: Sun Rou-Yun , Robinson A. G.
Published: August 2008

Experimental transfers between hosts showed that Rhopalosiphum padi (L.) overwinters in Manitoba on some Prunus spp. and hybrids, and R. fitchii (Sand.) on species or hybrids of Cotoneaster, Malus, Crataegus, and Sorbus, and that both species of aphids can be reared in the laboratory on wheat, oats, and barley.
BREEDING SEASONS OF WHITE-TAILED DEER IN MANITOBA
Authors: Ransom A. Brian
Published: August 2008

White-tailed deer (Odocoileus virginianus) in Manitoba breed from late October to December, but unexpected regional differences in timing were found that could not be explained by latitudinal climatic factors. Nutritional and genetic factors may have been involved.
SEASONAL VARIATIONS IN HEMOGLOBIN AND HEMATOCRIT VALUES IN THE NORTHERN RED-BACKED MOUSE, CLETHRIONOMYS RUTILUS DAWSONI (MERRIAM), IN INTERIOR ALASKA
Authors: Sealander J. A.
Published: August 2008

Seasonal variations in hemoglobin and hematocrit values were determined in the northern red-backed mouse, Clethrionomys rutilus dawsoni, from July 1963 through August 1964 in the vicinity of College, Alaska. Hemoglobin concentrations and hematocrits did not show any significant seasonal variation. The relative constancy of the blood values was considered to be a reflection of the rather uniform thermal characteristics of the microenvironment inhabited by the mice. Mean corpuscular hemoglobin concentrations followed a cycle which varied inversely with the ambient macroenvironmental temperature, while net body weights followed a seasonal cycle which was directly correlated with the ambient temperature of the macroenvironment.
GROWTH AND DEVELOPMENT OF THE BARREN GROUND CARIBOU: I. HEART GIRTH, HIND FOOT LENGTH, AND BODY WEIGHT RELATIONSHIPS
Authors: McEwan E. H. , Wood A. J.
Published: August 2008

The changes in body weight and body proportions associated with growth in well-nourished captive barren ground caribou (Rangifer tarandus groenlandicus) are described. Corresponding changes in free ranging wild caribou from the same population are compared with those obtained from the captive specimens. Body weight:hind foot length and body weight:heart girth ratios relative to age are examined as possible parameters for expressing the extent of developmental restriction imposed on the wild caribou by their nutritional environment.
THE ECOLOGY AND LIFE HISTORY OF RETUSA OBTUSA (MONTAGU) (GASTROPODA, OPISTHOBRANCHIA)
Authors: Smith S. Tyrell
Published: August 2008

The habitat, diet, life history, and reproductive cycle of Retusa obtusa were investigated over a period of [Formula: see text] years in a population found in the Inner Harbour at Barry, Glamorgan, U.K. A technique was devised for extracting Retusa from the mud of this area. R. obtusa occurs in the topmost 3.5 cm of fine mud covering Barry harbor, which is immersed by the sea for only a short time at each high tide. The principal prey was found to be Hydrobia ulvae.The life cycle was found to be annual, the adults dying in spring, following the natural breeding season. Occasionally, a short extra breeding period occurs in the fall. The life span in no case greatly exceeded one year. Retusa is a protandrous hermaphrodite, and copulates in the fall. The eggs mature through the late fall and the winter, a few at a time, until oviposition occurs in the spring. The average number of eggs produced per individual was 33, deposited in 1–4 egg batches. Development is direct.
ASPECTS OF ORIENTATION BEHAVIOR IN THE AMBROSIA BEETLE TRYPODENDRON LINEATUM (OLIVIER)
Authors: Francia Faustino C. , Graham K.
Published: August 2008

Post-diapause, re productively mature adults of Trypodendron lineatum display various kinds, patterns, and levels of activity in respect to light, temperature, odor, air flow, and gravity. This activity is influenced by the recent flight-history of the beetles, the nature of the factor primarily being examined, its manner of presentation, and its context among the other factors.Photic stimuli are important determinants of spontaneous flight and of olfactory responses to host-tree odor. In turn, the photic response alone and its domination over the olfactory response are modified by temperature, and by the recent flight-history of the individual. Host attractant suppresses photic orientation of the flown beetle, and causes retention in a field of host attractant-bearing air current.The behavior studies reveal that the healthy, living host tree contains neither olfactory attractants nor repellents, but a felled and dying tree of appropriate species contains a primary olfactory attractant for both male and female beetles.The studies provide the foundation for two basically new techniques using the beetles as bioassay instruments in evaluating odors of significance to them.
On delayed social and physical maturation in mountain sheep
Authors: Geist Valerius
Published: August 2008

American mountain sheep are neotenic or paedogenic, depending on their sex. The rams have a juvenile (neotenic) period lasting 5 to 6 years after sexual maturation, during which they develop physically and mature behaviorally. Rams almost double in body weight after sexual maturation, increase their horn mass, grow darker in color, and lose the white fur on belly and legs, grow less gregarious, become more polished in the social behavior by increasing display patterns and reducing aggressive and sexual patterns, and act more "brave" with age. They reach ultimate development and maturation between 7 and 9 years of age. Females are paedogenic since they remain frozen in development at the level of sexually mature yearling rams. Females possess two behavioral states: in estrus they act like young males, but in anestrus they act like sexually immature sheep. Sheep attain strong sexual dimorphism as a consequence of the postpuberal growth of males. The slow behavioral maturation of rams, which is paralleled by physical development, suggests that the quantitative expression of social behavior is a factor of the rams' physical development; the quantitative similarities in behavior between young rams and estrous females suggest that this view is valid.
Bionomics of Androlaelaps casalis (Berlese) (Acarina: Laelapidae) a predator of mite pests of stored cereals
Authors: Barker Philip S.
Published: August 2008

The life history of Androlaelaps casalis (Berlese) was studied at 25.6, 26.7, 30.0, 32.8, and 36.0 °C. Each A. casalis female consumed 2.1 ± 0.6 adult female Glycyphagus domesticus per day; males consumed 0.85 ± 0.2 female G. domesticus per day. An average of 27.4 ± 4.7 G. domesticus protonymphs were consumed during development to adulthood of immature A. casalis males. Other foods included brewer's yeast, Acarus siro (L.), Tyrophagus putrescentiae (Schrank), Aëroglyphus robustus (Banks), the predator Blattisocius keegani (Fox), and the young larvae of Tribolium confusum (Duval).
Pinealectomy procedure for Fundulus heteroclitus L.
Authors: Abbott F. S. , Favreau M. B.
Published: August 2008

A method for removing the pineal gland of Fundulus heteroclitus L. is described. The method allows 100% survival to the end of the first postoperative day and 65% survival to the end of the sixth day.
A record of Siamese twinning in bats
Authors: Peterson R. L. , Fenion M. Brock
Published: August 2008

Specimens of Siamese twin big brown bats (Eptesicus fuscus) now in the Royal Ontario Museum appear to represent the first reported occurrence among bats.
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). II. Physical blood properties
Authors: Ronald K. , Foster M. E. , Johnson E.
Published: August 2008

The physical properties, including erythrocyte number, leucocyte number and differential ratio, pH, pCO2, pO2, haemoglobin level, haematocrit, are recorded for the harp seal (Pagophilus groenlandicus). Reference is made to various aspects of the seal's biology, including the molt, migration, and parasitism.
Dactylotylenchinae, a new subfamily (Tylenchidae: Nematoda)
Authors: Wu Liang-Yu
Published: August 2008

A new species of Dactylotylenchus, D. filiformis, was described and more information for D. crassacuticulus Wu, 1968 was presented. The thick cuticle and the digitate sclerotized labial framework of this genus provide the unique character for Dactylotylenchus in the family Tylenchidae. A new subfamily Dactylotylenchinae was created to accommodate this genus.
The use of index trap lines to estimate population numbers of deermice (Peromyscus maniculatus) in a forest environment in British Columbia
Authors: Petticrew B. G. , Sadleir R. M. F. S.
Published: August 2008

Monthly live trapping of three 1-hectare grids in differing forest habitats was carried out over an 8-month period. Immediately after 2 nights of trapping on each grid a central index line was trapped for a further 2 nights. The total capture numbers., numbers of males, and numbers of females of deermice (Peromyscus maniculatus) on the index line correlated significantly with the same parameters on the grid. In addition, survival rates and body weights were almost identical and similar representation of other small mammal species was determined by both arrangements of traps. It is suggested that the index line may be a more efficient method of sampling small mammal populations.
Energy metabolism of barren ground caribou (Rangifer tarandus)
Authors: McEwan E. H.
Published: August 2008

The heat production of two caribou, during fasting, 91 kcal and 102 kcal/W0.75 per 24 h, was 20 to 30% higher than the quoted interspecific mean of 70 kcal/W0.75 per 24 h. The mean heat production values of two female caribou at the maintenance level of feeding were 107.0 kcal and 124.5 kcal/W0.75 per 24 h.
Notes on aggregation observed in two species of freshwater Ostracoda
Authors: Nuttall P. M. , Fernando C. H.
Published: August 2008

The term aggregation is discussed and reports of aggregation of freshwater ostracods in ponds described. Aggregations observed in separate laboratory cultures of Cypridopsis vidua Muller and Cyprinotus incongruens Ramdohr are described. Feeding was the main cause of aggregations for both species, although the effect of light appears important in starting the aggregations of C. vidua.
Characters for distinguishing the sex of pupae of the dark-sided cutworm, Euxoa messoria (Harris), (Lepidoptera: Noctuidae)
Authors: Cheng H. H.
Published: August 2008

A reliable method for determining the sex of pupae of the dark-sided cutworm is to observe the structures found on the ventral side of the terminal abdominal segments. Two pairs of rounded tubercles, one pair around the genital opening and the other around the anal opening, are present on the terminal abdominal segments of the male, and one pair around the anal opening only on the female.
Patasson luna (Girault) (Hymenoptera: Mymaridae) and Bathyplectes curculionis (Thomson) (Hymenoptera: Ichneumonidae), two parasites of Hypera postica (Gyllenhal) (Coleoptera: Curculionidae) in Quebec
Authors: Mailloux Gérard , Pilon Jean-Guy
Published: August 2008

Patasson luna (Girault) and Bathyplectes curculionis (Thomson) are two parasites of the alfalfa weevil, Hypera postica (Gyll.), recorded in Québec in 1968. The recovery of these two species of parasites from rearings represents new additions to the fauna of Québec.
Changes in the distribution of Hymenolepis diminuta (Cestoda: Cyclophyllidea) within the rat intestine during prepatent development
Authors: Cannon Christine E. , Mettrick D. F.
Published: August 2008

The changes in the distribution of Hymenolepis diminuta within the rat intestine have been followed over the period 3 to 16 days postinfection using rats, each infected with 10 cysticercoids of H. diminuta, fed ad libitum on Purina Rat Chow.The parameters investigated were distribution of scolex attachment sites in the intestine, and distribution of parasite biomass in the intestine based on strobila length, ex vivo weight distribution, and in vivo weight distribution. Both the scoleces and biomass of 3- and 5-day-old worms are concentrated in the second quarter of the intestine. The mean scolex attachment point for 5-day-old worms was 39% of the total intestinal length behind the pyloric sphincter. Between days 5 and 7 there was a marked anterior migration of the young worms, so that at 7 days the mean scolex attachment site was 15% of the total intestinal length behind the stomach. Over the same period of time the mean in vivo weight distribution moved forward from a point 44% behind the pyloric sphincter to one only 23% along the intestine. After 7 days there was a gradual posteriad spreading of the scolex attachment sites and of the parasite biomass. Hymenolepis diminuta can attach itself anywhere in the anterior 75% of the intestine, including in front of the opening of the bile duct: no worms were found in the small intestine extending back into the caecum.The pattern of migration and the changes in worm distribution in the intestine suggest that H. diminuta selects an appropriate, but changing position, on one or more of the gradients that have been demonstrated or postulated along the length of the small intestine.It is also suggested that the long-term migration during prepatent development is interrelated, but distinct from the daily migrational movements that H. diminuta undergoes within the small intestine.