bluuebunny/crossref_metadata_2025_split huggingface dataset:
Going wild: what a global small-animal tracking system could do for experimental biologists
Authors: Wikelski Martin , Kays Roland W. , Kasdin N. Jeremy , Thorup Kasper , Smith James A. , Swenson George W. 
Published: January 2007

SUMMARYTracking animals over large temporal and spatial scales has revealed invaluable and spectacular biological information, particularly when the paths and fates of individuals can be monitored on a global scale. However, only large animals (greater than ∼300 g) currently can be followed globally because of power and size constraints on the tracking devices. And yet the vast majority of animals is small. Tracking small animals is important because they are often part of evolutionary and ecological experiments, they provide important ecosystem services and they are of conservation concern or pose harm to human health. Here, we propose a small-animal satellite tracking system that would enable the global monitoring of animals down to the size of the smallest birds, mammals (bats), marine life and eventually large insects. To create the scientific framework necessary for such a global project, we formed the ICARUS initiative(www.IcarusInitiative.org),the International Cooperation for Animal Research Using Space. ICARUS also highlights how small-animal tracking could address some of the `Grand Challenges in Environmental Sciences' identified by the US National Academy of Sciences, such as the spread of infectious diseases or the relationship between biological diversity and ecosystem functioning. Small-animal tracking would allow the quantitative assessment of dispersal and migration in natural populations and thus help solve enigmas regarding population dynamics,extinctions and invasions. Experimental biologists may find a global small-animal tracking system helpful in testing, validating and expanding laboratory-derived discoveries in wild, natural populations. We suggest that the relatively modest investment into a global small-animal tracking system will pay off by providing unprecedented insights into both basic and applied nature.Tracking small animals over large spatial and temporal scales could prove to be one of the most powerful techniques of the early 21st century, offering potential solutions to a wide range of biological and societal questions that date back two millennia to the Greek philosopher Aristotle's enigma about songbird migration. Several of the more recent Grand Challenges in Environmental Sciences, such as the regulation and functional consequences of biological diversity or the surveillance of the population ecology of zoonotic hosts, pathogens or vectors, could also be addressed by a global small-animal tracking system.Our discussion is intended to contribute to an emerging groundswell of scientific support to make such a new technological system happen.
Growing out of a caste - reproduction and the making of the queen mole-rat
Authors: Henry Erin C. , Dengler-Crish Christine M. , Catania Kenneth C. 
Published: January 2007

SUMMARY
Naked mole-rats have a eusocial colony structure consisting of non-reproductive workers and a reproductively active caste where a single,dominant queen and 1-3 males produce all of the offspring. Well-established queens have elongated bodies that characterize their caste. Worker females retain the ability to transform into queens, however the trigger and time course for this physical transformation remain a mystery. Here, we show a direct link between periods of pregnancy and vertebral lengthening in nascent queens. Adult female mole-rats were paired with a male and radiographed weekly for two and a half years to track the growth of the lumbar vertebrae as the mole-rats became sexually mature and experienced pregnancies. The lumbar vertebrae of breeding females grew at an increased rate during each pregnancy but growth rates returned to normal between pregnancies and during extended periods without reproduction. The rate of lumbar lengthening was reduced to normal rates in older, established queens experiencing pregnancies. Our results imply that the length of a new queen mole-rat is proportional to the number of pregnancies experienced and suggest that hormones related to pregnancy may play the critical role in bone growth associated with caste transformation.
Quantitative analysis of tethered and free-swimming copepodid flow fields
Authors: Catton Kimberly B. , Webster Donald R. , Brown Jason , Yen Jeannette 
Published: January 2007

SUMMARY
We quantified the flow field generated by tethered and free-swimming Euchaeta antarctica using the particle image velocimetry (PIV)technique. The streamlines around the free-swimming specimens were generally parallel to the body axis, whereas the streamlines around all of the tethered copepodids demonstrated increased curvature. Differences noted in the streamline pattern, and hence the vorticity, dissipation rate and strain rate fields, are explained by considering the forces on the free-swimming specimen compared to the tethered specimen. Viscous flow theory demonstrates that the force on the fluid due to the presence of the tether irrevocably modifies the flow field in a manner that is consistent with the measurements. Hence,analysis of the flow field and all associated calculations differ for tethered versus free-swimming conditions. Consideration of the flow field of the free-swimming predatory copepodid shows the intensity of the biologically generated flow and the extent of the mechanoreceptive signal quantified in terms of shear strain rate. The area in the dorso-ventral view surrounded by the 0.5 s-1 contour of exy, which is a likely threshold to induce an escape response, is 11 times the area of the exoskeletal form for the free-swimming case. Thus, mechanoreceptive predators will perceive a more spatially extended signal than the body size.
The energetic consequence of specific dynamic action in southern bluefin tunaThunnus maccoyii
Authors: Fitzgibbon Q. P. , Seymour R. S. , Ellis D. , Buchanan J. 
Published: January 2007

SUMMARYThe effect of feeding on the rate of oxygen consumption(ṀO2) of four groups of three southern bluefin tuna Thunnus maccoyii (SBT) was examined in a large static respirometer at water temperatures of 18.2-20.3°C. Six feeding events of rations between 2.1-8.5% body mass(%Mb) of Australian sardines (Sardinops neopilchardus) were recorded (two of the groups were fed twice). Before feeding, fish swam between 0.71 and 1.4 body lengths s-1(BL s-1) and the routine metabolic rate (RMR) was 366±32.5 mg kg-1 h-1 (mean ± s.e.m.). For all trials, ṀO2was elevated post feeding, presumably as a result of specific dynamic action(SDA). Swimming velocity was also elevated post feeding for periods similar to that of ṀO2(between 20-45 h, longest for the largest rations). Post feeding swimming velocity increased to between 0.87-2.6 BL s-1 and was also dependent on ration consumed. It is suggested that the purpose of increased post-feeding swimming velocity was to increase ventilation volume as a response to the enhanced metabolic demand associated with SDA. Peak post-prandial ṀO2increased linearly with ration size to a maximum of 1290 mg kg-1h-1, corresponding to 2.8 times the RMR. When converted to its energy equivalent, total magnitude of SDA was linearly correlated with ration size to a maximum of 192 kJ kg-1 h-1, and as a proportion of gross energy ingested (SDA coefficient), it averaged 35±2.2%. These results demonstrate that, although the factorial increase of SDA in SBT is similar to that of other fish species, the absolute energetic cost of SDA is much higher. These results support the contention that tuna are energy speculators, gambling high rates of energy expenditure for potentially higher rates of energy returns. The ration that southern bluefin tuna require to equal the combined metabolic costs of SDA and RMR is estimated in this study to be 3.5%Mb of Australian sardines per day.
Ground forces applied by galloping dogs
Authors: Walter Rebecca M. , Carrier David R. 
Published: January 2007

SUMMARYThe gallop differs from most other quadrupedal gaits in that each limb plays a unique role. This study compares the ground forces applied by the four limbs and uses force differences between limbs to address the question of why the gallop is the fastest quadrupedal gait. Individual ground forces were recorded from each of the four limbs as six dogs galloped down a runway at constant speed. Trials were videotaped at high speed using a camera positioned perpendicular to the runway, and velocity was measured using photosensors. The trailing forelimb applied greater peak vertical forces than the lead forelimb,however the vertical impulses from the two forelimbs were similar because the lead forelimb had a longer contact interval. The trailing forelimb and lead hindlimb applied greater peak accelerating forces and accelerating force impulses than their contralateral limbs despite their tendency to have shorter contact intervals. The accelerating impulse of both forelimbs combined did not differ significantly from that of both hindlimbs. The forelimbs applied a greater decelerating impulse than the hindlimbs, such that their net fore-aft impulse was decelerating whereas that of the hindlimbs was accelerating. The greater accelerating impulse applied by the trailing forelimb and greater decelerating impulse applied by the lead forelimb are consistent with the forelimbs acting as elastic struts rather than being actively retracted. In contrast, greater accelerating forces were produced by the lead hindlimb while the center of mass was lifted, suggesting that the hindlimbs are more actively extended or retracted during stance. The differences in ground forces measured between paired limbs suggest that the lead forelimb and trailing hindlimb are limited in their ability to apply forces by their positions in the stride cycle rather than by their muscular capacity. Although a bound or half-bound would allow more limbs to produce their maximal forces, a gallop may generate higher speeds because it is more efficient. Galloping could be more efficient than other gaits involving sagittal bending if the increased number of ground contact intervals decreased either the decelerating forces applied at the onset of ground contact or the vertical motion of the center of mass.
The kinematics of multifunctionality: comparisons of biting and swallowing inAplysia californica
Authors: Neustadter David M. , Herman Robert L. , Drushel Richard F. , Chestek David W. , Chiel Hillel J. 
Published: January 2007

SUMMARYWhat are the mechanisms of multifunctionality, i.e. the use of the same peripheral structures for multiple behaviors? We studied this question using the multifunctional feeding apparatus of the marine mollusk Aplysia californica, in which the same muscles mediate biting (an attempt to grasp food) and swallowing (ingestion of food). Biting and swallowing responses were compared using magnetic resonance imaging of intact, behaving animals and a three-dimensional kinematic model. Biting is associated with larger amplitude protractions of the grasper (radula/odontophore) than swallowing, and smaller retractions. Larger biting protractions than in swallowing appear to be due to a more anterior position of the grasper as the behavior begins, a larger amplitude contraction of protractor muscle I2, and contraction of the posterior portion of the I1/I3/jaw complex. The posterior I1/I3/jaw complex may be context-dependent, i.e. its mechanical context changes the direction of the force it exerts. Thus, the posterior of I1/I3 may aid protraction near the peak of biting, whereas the entire I1/I3/jaw complex acts as a retractor during swallowing. In addition, larger amplitude closure of the grasper during swallowing allows an animal to exert more force as it ingests food. These results demonstrate that differential deployment of the periphery can mediate multifunctionality.
The desert ant odometer: a stride integrator that accounts for stride length and walking speed
Authors: Wittlinger Matthias , Wehner Rüdiger , Wolf Harald 
Published: January 2007

SUMMARYDesert ants, Cataglyphis, use path integration as a major means of navigation. Path integration requires measurement of two parameters, namely,direction and distance of travel. Directional information is provided by a celestial compass, whereas distance measurement is accomplished by a stride integrator, or pedometer. Here we examine the recently demonstrated pedometer function in more detail.By manipulating leg lengths in foraging desert ants we could also change their stride lengths. Ants with elongated legs ('stilts') or shortened legs('stumps') take larger or shorter strides, respectively, and misgauge travel distance. Travel distance is overestimated by experimental animals walking on stilts, and underestimated by animals walking on stumps - strongly indicative of stride integrator function in distance measurement.High-speed video analysis was used to examine the actual changes in stride length, stride frequency and walking speed caused by the manipulations of leg length. Unexpectedly, quantitative characteristics of walking behaviour remained almost unaffected by imposed changes in leg length, demonstrating remarkable robustness of leg coordination and walking performance.These data further allowed normalisation of homing distances displayed by manipulated animals with regard to scaling and speed effects. The predicted changes in homing distance are in quantitative agreement with the experimental data, further supporting the pedometer hypothesis.
Hydrodynamic function of dorsal and anal fins in brook trout(Salvelinus fontinalis)
Authors: Standen E. M. , Lauder G. V. 
Published: January 2007

SUMMARYRecent kinematic and hydrodynamic studies on fish median fins have shown that dorsal fins actively produce jets with large lateral forces. Because of the location of dorsal fins above the fish's rolling axis, these lateral forces, if unchecked, would cause fish to roll. In this paper we examine the hydrodynamics of trout anal fin function and hypothesize that anal fins,located below the fish's rolling axis, produce similar jets to the dorsal fin and help balance rolling torques during swimming. We simultaneously quantify the wake generated by dorsal and anal fins in brook trout by swimming fish in two horizontal light sheets filmed by two synchronized high speed cameras during steady swimming and manoeuvring. Six major conclusions emerge from these experiments.First, anal fins produce lateral jets to the same side as dorsal fins,confirming the hypothesis that anal fins produce fluid jets that balance those produced by dorsal fins. Second, in contrast to previous work on sunfish,neither dorsal nor anal fins produce significant thrust during steady swimming; flow leaves the dorsal and anal fins in the form of a shear layer that rolls up into vortices similar to those seen in steady swimming of eels. Third, dorsal and anal fin lateral jets are more coincident in time than would be predicted from simple kinematic expectations; shape, heave and pitch differences between fins, and incident flow conditions may account for the differences in timing of jet shedding. Fourth, relative force and torque magnitudes of the anal fin are larger than those of the dorsal fin; force differences may be due primarily to a larger span and a more squarely shaped trailing edge of the anal fin compared to the dorsal fin; torque differences are also strongly influenced by the location of each fin relative to the fish's centre of mass. Fifth, flow is actively modified by dorsal and anal fins resulting in complex flow patterns surrounding the caudal fin. The caudal fin does not encounter free-stream flow, but rather moves through incident flow greatly altered by the action of dorsal and anal fins. Sixth, trout anal fin function differs from dorsal fin function; although dorsal and anal fins appear to cooperate functionally, there are complex interactions between other fins and free stream perturbations that require independent dorsal and anal fin motion and torque production to maintain control of body position.
Pd-catalyzed Coupling Reaction of Allyl and Propargyl Ethers with Chlorosilanes
Authors: Naitoh Yoshitaka , Bando Fumiaki , Terao Jun , Otsuki Kazutaka , Kuniyasu Hitoshi , Kambe Nobuaki 
Published: January 2007

Abstract
Pd-catalyzed synthesis of allylsilanes from chlorosilanes and allyl ethers is described. The reaction proceeds efficiently at room temperature by the use of phenyl or vinyl Grignard reagent in the presence of palladium catalysts. The present method can also be applied to synthesis of propargylsilanes by the use of propargyl ethers.
Low Dielectric Loss Copolymer Obtained from 2,6-Dimethylphenol and 2-Allyl-6-methylphenol via Cu-catalyzed Oxidative Coupling Polymerization
Authors: Nunoshige Jun , Akahoshi Haruo , Shibasaki Yuji , Ueda Mitsuru 
Published: January 2007

Abstract
A method for synthesizing a novel thermosetting poly(2-allyl-6-methylphenol-co-2,6-dimethylphenol) (Allyl-PPE) with a narrow molecular weight distribution (MWD) has been developed. Allyl-PPE was prepared by a pyridine/copper(I) chloride-catalyzed oxidative coupling polymerization of 2-allyl-6-methylphenol (10 mol %) with 2,6-dimethylphenol (90 mol %), using large amounts of pyridine. Allyl-PPE with a narrow MWD showed a lower dielectric constant (ε′) and dielectric loss tangent (tan δ) than copolymers with a broad MWD.
Photoswitching of Fluorescence Based on Intramolecular Electron Transfer
Authors: Odo Yuka , Fukaminato Tuyoshi , Irie Masahiro 
Published: January 2007

Abstract
A fluorescent diarylethene derivative, which changes fluorescence intensity based on the photocontrol of intramolecular electron transfer, was designed and synthesized. In polar solvents, the fluorescence intensity decreased upon irradiation with UV light and recovered upon irradiation with visible light.
Weekend versus working day: differences in telemetric blood pressure in male Wistar rats
Authors: Schreuder M F , Fodor M , van Wijk J A E , Delemarre-van de Waal H A 
Published: January 2007

Blood pressure (BP) is a frequently monitored parameter in research. Various methods are used to obtain BP values in animal models, but telemetry is the method of choice because it allows for continuous monitoring in conscious and freely moving animals. However, factors due to the animal facility, like activities and sound, can still influence measurements. We, therefore, retrospectively compared BP values in adult male Wistar rats during working hours with values from non-working days. Telemetry devices were implanted according to standard protocol. Values were obtained at the age of 6 and 12 months during working hours (Friday 10:00–16:00 h, lights on 06:00–18:00 h) and compared with data from the average of Saturday 10:00–16:00 h and Sunday 10:00–16:00 h, representing non-working days. Data were available from 12 and 7 rats at 6 months and 12 months of age respectively. Relative differences in heart rate, spontaneous locomotor activity, systolic and diastolic BP were 2.2% ( P<0.001), 32.9% ( P<0.05), 3.2% ( P<0.05) and 3.7% ( P<0.05), respectively, with no differences between the age groups. We have shown a significant and important difference between BP values obtained during working hours and non-working days using telemetry in adult male Wistar rats. This phenomenon has implications for the interpretation of BP measurements in animals.
A novel and simple method for endotracheal intubation of mice
Authors: Spoelstra E N , Ince C , Koeman A , Emons V M , Brouwer L A , van Luyn M J A , Westerink B H C , Remie R 
Published: January 2007

Endotracheal intubation in mice is necessary for experiments involving intratracheal instillation of various substances, repeated pulmonary function assessments and mechanical ventilation. Previously described methods for endotracheal intubation in mice require the use of injection anaesthesia to immobilize the animal during the intubation procedure or the use of a volatile anaesthetic prior to intubation for immobilization. With these methods, the control of anaesthetic depth during the intubation procedure is absent. We describe a method for simple and rapid intratracheal intubation in mice for mechanical ventilation, using a self-built plastic support to facilitate the intubation procedure. General anaesthesia is maintained by means of inhalation through a non-rebreathing circuit connected to the plastic support. This set-up gives the operator control of anaesthetic depth and sufficient time to perform the intubation procedure. A purpose-made laryngoscopic blade is used to facilitate the intubation tube entering the trachea. The blade of the purpose-made laryngoscope is constructed as a retraction guide and is curved for easy handling. Under direct vision, the epiglottis is gently lifted by the laryngoscopic blade while the intubation tube is pushed into the trachea. Following this novel intubation technique, we were able to mechanically ventilate mice for at least 2 h without severely disturbing blood gases. Histological evaluation of the lungs and microscopic evaluation of the trachea and larynx showed no signs of trauma related to the intubation technique or mechanical ventilation.
The effect of preweaning and postweaning housing on the behaviour of the laboratory mouse (Mus musculus)
Authors: Marques J M , Olsson I A S 
Published: January 2007

Standard housing for laboratory mice severely restricts natural behaviour and the control that the animal has over its environment. Providing the cage with objects is a method that has been used to both increase environmental complexity, promote the performance of natural behaviour and provide greater controllability for the animal. This method of furnishing cages has mostly been studied in adult animals, and little is known about the influence that the preweaning environment has on the behaviour of mice as adults. This study aimed to investigate the effects on mice behaviour of preweaning and postweaning housing environment. In this experiment, 64 pairs of animals of the strain C57BL/6J were used. Half of the animals were born and reared until weaning in standard cages and the other half in cages twice the size of the standard and furnished with nesting material, a cardboard tube, a PVC nest box and a wooden chewblock. After weaning, half the animals in each group were changed to the other type of cage, whereas the other half remained in the same environment; in both cases they were kept in single-sex pairs of littermates. Behaviour during the dark, active period was studied through video recordings. We found no main effects of preweaning environment on behaviour; however, mice moved from furnished to standard cages at weaning showed a decrease in inactive behaviour at four weeks of age. Mice housed after weaning in standard cages spent less time inactive, and more time engaging in activities like feeding and drinking, self-grooming and allogrooming. A sex difference was also found, in that females showed a greater performance of exploratory behaviour as well as a greater prevalence of stereotypies. The use of different objects and locations within the furnished cage was also analysed at both ages. Results show that at eight weeks of age mice spent more time at the top of the cage, and that the use of the nest box (although not for resting) increased between four and eight weeks. Mice were found to use the nest box as a nesting site/sleeping place only at age four weeks, whereas they always used the nesting material for sleeping.