bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of oxytocin release during repeated milking in unfamiliar surroundings: the importance of opioids and adrenal cortex sensitivity
Authors: MAČUHOVÁ JULIANA , TANČIN VLADIMIR , KRAETZL WOLF-DIETER , MEYER HEINRICH H. D. , BRUCKMAIER RUPERT M. 
Published: July 2002

The aim of this study was to test if the opioid antagonist naloxone has a beneficial effect on normalization of oxytocin (OT) release during repeated milking of cows in unfamiliar surroundings. One control milking without naloxone treatment in all cows was performed in the familiar parlour. For four successive evening milkings, cows were transported to, and milked in, the operating theatre of the research station without (control group) or with naloxone administration (1 mg/kg BW) (naloxone group) before milking. After cessation of spontaneous milk flow, but not before 3 min of milking, vaginal stimulation was applied for 2 min. After milk flow ceased again, 10 IU of OT was injected intravenously to remove the remaining milk including residual milk. Milk flow was recorded continuously and blood samples were collected via a jugular vein cannula at 1-min intervals from 1 min before the start of milking until i.v. injection of OT. The inhibition of milk ejection and its normalization during repeated milking in unfamiliar surroundings was not influenced by naloxone treatment. Concentrations of cortisol and β-endorphin during control milking and all relocations were similar in the naloxone and control groups, although their concentrations were higher after relocations than in the control. Therefore, a role of endogenous opioids in the inhibition of milk ejection in unfamiliar surroundings could not be demonstrated. In addition, the effect of exogenous ACTH1–24 (8 IU, i.v.) on the release of cortisol related to the response of cows milked in unfamiliar surroundings was studied. Cows with totally inhibited milk ejection in response to vaginal stimulation during milking after first relocation had numerically, but not significantly lower cortisol levels (8·8±3·4 ng/ml; AUC/min) in response to ACTH than did cows with at least partial milk ejection (38·7±12·9 ng/ml). Thus animals with a higher adrenal response to ACTH seemed to have less severe inhibition of milk ejection.
On the distortion of turbulence by a progressive surface wave
Authors: TEIXEIRA M. A. C. , BELCHER S. E. 
Published: July 2002

A rapid-distortion model is developed to investigate the interaction of weak turbulence
with a monochromatic irrotational surface water wave. The model is applicable when
the orbital velocity of the wave is larger than the turbulence intensity, and when
the slope of the wave is sufficiently high that the straining of the turbulence by the
wave dominates over the straining of the turbulence by itself. The turbulence suffers
two distortions. Firstly, vorticity in the turbulence is modulated by the wave orbital
motions, which leads to the streamwise Reynolds stress attaining maxima at the wave
crests and minima at the wave troughs; the Reynolds stress normal to the free surface
develops minima at the wave crests and maxima at the troughs. Secondly, over several
wave cycles the Stokes drift associated with the wave tilts vertical vorticity into the
horizontal direction, subsequently stretching it into elongated streamwise vortices,
which come to dominate the flow. These results are shown to be strikingly different
from turbulence distorted by a mean shear flow, when ‘streaky structures’ of high and
low streamwise velocity fluctuations develop. It is shown that, in the case of distortion
by a mean shear flow, the tendency for the mean shear to produce streamwise vortices
by distortion of the turbulent vorticity is largely cancelled by a distortion of the mean
vorticity by the turbulent fluctuations. This latter process is absent in distortion by
Stokes drift, since there is then no mean vorticity.The components of the Reynolds stress and the integral length scales computed
from turbulence distorted by Stokes drift show the same behaviour as in the simulations
of Langmuir turbulence reported by McWilliams, Sullivan & Moeng (1997).
Hence we suggest that turbulent vorticity in the upper ocean, such as produced
by breaking waves, may help to provide the initial seeds for Langmuir circulations,
thereby complementing the shear-flow instability mechanism developed by Craik &
Leibovich (1976).The tilting of the vertical vorticity into the horizontal by the Stokes drift tends
also to produce a shear stress that does work against the mean straining associated
with the wave orbital motions. The turbulent kinetic energy then increases at the
expense of energy in the wave. Hence the wave decays. An expression for the wave
attenuation rate is obtained by scaling the equation for the wave energy, and is found
to be broadly consistent with available laboratory data.
Deterministic and stochastic behaviour of
non-Brownian spheres in sheared suspensions
Authors: DRAZER GERMAN , KOPLIK JOEL , KHUSID BORIS , ACRIVOS ANDREAS 
Published: July 2002

The dynamics of macroscopically homogeneous sheared suspensions of neutrally
buoyant, non-Brownian spheres is investigated in the limit of vanishingly small
Reynolds numbers using Stokesian dynamics. We show that the complex dynamics
of sheared suspensions can be characterized as a chaotic motion in phase space and
determine the dependence of the largest Lyapunov exponent on the volume fraction ϕ.
We also offer evidence that the chaotic motion is responsible for the loss of memory in
the evolution of the system and demonstrate this loss of correlation in phase space. The
loss of memory at the microscopic level of individual particles is also shown in terms
of the autocorrelation functions for the two transverse velocity components. Moreover,
a negative correlation in the transverse particle velocities is seen to exist at the lower
concentrations, an effect which we explain on the basis of the dynamics of two isolated
spheres undergoing simple shear. In addition, we calculate the probability distribution
function of the transverse velocity fluctuations and observe, with increasing ϕ, a
transition from exponential to Gaussian distributions.The simulations include a non-hydrodynamic repulsive interaction between the
spheres which qualitatively models the effects of surface roughness and other irreversible
effects, such as residual Brownian displacements, that become particularly
important whenever pairs of spheres are nearly touching. We investigate, for very
dilute suspensions, the effects of such a non-hydrodynamic interparticle force on the
scaling of the particle tracer diffusion coefficients Dy and Dz, respectively, along and
normal to the plane of shear, and show that, when this force is very short-ranged,
both are proportional to ϕ2 as ϕ → 0. In contrast, when the range of the non-hydrodynamic
interaction is increased, we observe a crossover in the dependence of
Dy on ϕ, from ϕ2 to ϕ as ϕ → 0. We also estimate that a similar crossover exists for
Dz but at a value of ϕ one order of magnitude lower than that which we were able
to reach in our simulations.
Finding Distance – The Haecke Rangefinder
Authors: Ifland Peter 
Published: July 2002

This article is the second in a series dealing with the hand-held instruments and
techniques navigators have used to find distance.Warships frequently steam in tight formation in order to concentrate defensive
gunfire. It is the Conning Officer's responsibility to keep his ship on station at an
assigned range and bearing from the guide ship, usually the flagship of the Senior
Officer Present Afloat. This can be an easy task when the fleet is steaming along
peacefully, but it becomes a particularly challenging responsibility when the formation
is changing course frequently under battle conditions. In such difficult situations, the
Conning Officer needs all the help he can get.In the days before radar, and even now when radar and laser are blacked-out, the
Conning Officer had to rely on optical instruments to determine range and bearing.
Bearing always has been easy – a pelorus mounted on the wings of the bridge gives
bearing quickly and accurately. Measuring range is more difficult. Many ingenious
instruments relying on prisms or the doubly reflecting principles of the sextant have
been produced to simplify the task of finding distance (Ifland, 2002).
Differences in alarm vocalizations of sympatric populations of the whistling rats, Parotomys brantsii and P. littledalei (Rodentia: Muridae)
Authors: le Roux A. , Jackson T. P. , Cherry M. I. 
Published: July 2002

AbstractThe alarm vocalizations of the whistling rats Parotomys brantsii and P. littledalei were investigated at the Goegap Nature Reserve in the Northern Cape, South Africa, where they occur sympatrically. Parotomys brantsii's call is a single note vocalization, characterized by an upward frequency sweep and high frequency plateau with a dominant frequency of 10.0 ± 0.3 kHz and duration of 164 ± 11 ms. The alarm whistle of P. littledalei has three overlapping components and is both shorter (53 ± 5 ms) and lower in dominant frequency (7.7 ± 0.1 kHz) than that of P. brantsii. The frequency bandwidth of P. littledalei calls (10.2 ± 0.7 kHz) is significantly higher than that of P. brantsii (6.8 ± 0.4 kHz). These significant distinctions are attributed to habitat preferences of the two species. Our data support the acoustic adaptation hypothesis in that P. littledalei, which inhabits a more closed habitat, has calls which are lower in frequency than P. brantsii calls, but contrary to the hypothesis, P. brantsii calls do not show greater frequency modulation than those of P. littledalei. Despite these differences, the alarm calls of the two species are both high‐pitched, and may have converged in structure to be difficult for predators to locate.
Tusklessness in the elephant population of the Addo Elephant National Park, South Africa
Authors: Whitehouse Anna M. 
Published: July 2002

AbstractThe majority (98%) of the 174 female elephants in South Africa's Addo Elephant National Park are tuskless. Long‐term records are used to assess trends in tusklessness in this elephant population throughout the 20th century. These data are then used to test hypotheses of possible causes of this tusklessness. It is shown that attributes of the region's vegetation (structure and/or nutrient composition) and selective hunting cannot provide adequate explanations for the high frequency of tusklessness among the Addo elephants. Non‐selective genetic changes resulting from the population's isolation, small size and bottlenecks (during the 1800s and 1920s) are suggested to be primarily responsible for the observed tusklessness. The rapid increase in the frequency of tusklessness during the past 70 years provides a phenotypic indicator of underlying genetic drift.
The marginal dentition of the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)
Authors: Kemp A. 
Published: July 2002

AbstractThe dentary, a component of the transient marginal dentition found in the mandible of juveniles of the living Australian lungfish Neoceratodus forsteri, is a tooth plate exactly comparable to the tooth plates with radiating ridges that make up the marginal dentitions of Devonian dipnoans like Andreyevichthys, Orlovichthys and Ichnomylax. In N. forsteri, the dentary consists of two ridges, set almost in line with each other, and growing by the addition of cusps, of increasing sizes, to the extremity of each ridge. It is therefore equivalent to two ridges of a more normal tooth plate with radiating ridges. Despite its appearance, as a long row of sharp cusps ankylosed to a slender bone, and its position, embedded in soft tissue above the anterolabial margin of Meckel's cartilage, it is a tooth plate and is not comparable to the marginal dentitions of other vertebrates. Structure and development of the transient marginal dentition of this lungfish is another indication that dipnoans may not be the sister group of tetrapods.
Reunion vigour: an experimental test of the mate guarding hypothesis in the monogamous sleepy lizard (Tiliqua rugosa)
Authors: How Travis L. , Bull C. Michael 
Published: July 2002

AbstractThe Australian sleepy lizard Tiliqua rugosa forms socially monogamous pair bonds for 6 to 8 weeks each spring before mating occurs. This behaviour could not be explained by any hypothesis involving males helping to rear their young, because pairs split up soon after mating, and males seem to have no contact with the offspring of their partners. Short monogamous associations in other lizard species are often interpreted as mate guarding by the male to assure paternity. The mate guarding hypothesis was tested by experimental separation of pairs at various times during the pairing season. Data from 73 trials indicated that males were more likely to return to females than vice versa, and that the tendency of males to return to females increased as the time of mating approached. Also, reunion was more likely in pairs that had a greater tendency to remain together during the season. These results are consistent with predictions that the monogamous relationship is a form of mate guarding by males. However, the incidence of females re‐uniting with males, and the long duration of pair bonds before mating occurs are not predicted by a mate guarding hypothesis. There may be additional explanations for monogamous pairing in the sleepy lizard.
Cross‐taxon congruence in complementarity and conservation of temperate biodiversity
Authors: Lund Mette Palitzsch , Rahbek Carsten 
Published: July 2002

AbstractIdentification of reliable surrogate indicator taxa and effective shortcuts for the preservation of overall biodiversity is a major challenge. Encouragingly, complementarity‐derived priority sets of focal taxa were found highly effective in representing non‐target taxa in a study from Ugandan forests. It has been proposed cross‐taxon congruence in complementarity is less distinct in temperate regions than in the tropics, because temperate regions have fewer species, and hence focal taxa may be less effective as they are less diverse. To test this, we used all available atlas data (10 × 10 km scale) in Denmark (butterflies, birds, amphibians, reptiles, large moths, bats and click beetles, n= 434 species), and looked at whether conservation priority areas based on one taxonomic group represent species richness of other groups in a highly fragmented landscape. We apply a new approach (based on G‐statistics) that enables statistical evaluation of cross‐taxon congruence in complementarity‐derived priority sets. We found indications that the same taxa represented other groups effectively and exhibited cross‐taxon congruence in complementarity‐derived priority sets. Birds performed significantly, but relatively poorly, butterflies somewhat better and bats relatively well in representing species richness of other groups. Large moths performed best and may be an overlooked predictor of diversity in other animal taxa.
Prevention of experimental carotid and coronary artery thrombosis by the glycoprotein IIb/IIIa receptor antagonist CRL42796
Authors: Hennan James K , Hong Ting‐Ting , Willens David E , Driscoll Edward M , Giboulot Thierry A , Lucchesi Benedict R 
Published: July 2002

The antithrombotic effect of the glycoprotein IIb/IIIa receptor antagonist, CRL42796, was examined in canine models of carotid and coronary artery thrombosis.
In the carotid artery thrombosis model, occlusion occurred in all control vessels (time to thrombosis 47.6±8.9 min). After treatment with low dose CRL42796 (15 μg kg−1 loading dose +0.31 μg kg−1 min−1 i.v.), two of five vessels occluded. Time to thrombosis increased significantly to 155.2±23.1 min. When the drug infusion was increased (0.69 μg kg−1 min−1), each of five vessels remained patent.
Ex vivo platelet aggregation in response to arachidonic acid (AA) and ADP was examined in platelet rich plasma (PRP) prepared from citrate or heparin anticoagulated blood. CRL42796 reduced platelet reactivity at low and high doses in PRP from citrate anticoagulated blood. However, in PRP from heparin anticoagulated blood, only the higher infusion dose produced a significant reduction in ex vivo platelet responses.
A combination of oral aspirin (4.6 mg kg−1 −41, −17 h) and the low infusion dose of CRL42796 did not produce an additional benefit beyond that provided by CRL42796 alone.
Coronary artery thrombosis was inhibited in four of five vessels treated with the lower infusion dose of CRL42796 and in five of five vessels treated with the higher infusion. Time to thrombosis increased with both doses (Control, 90.8±10.4 min; low dose, 165.8±14.2 min; high dose, >180.0±0 min).
The results indicate that CRL42796 is an effective in vivo antithrombotic agent against experimentally‐induced carotid and coronary artery thrombosis.

British Journal of Pharmacology (2002) 136, 927–937. doi:10.1038/sj.bjp.0704744
K+‐induced hyperpolarization in rat mesenteric artery: identification, localization and role of Na+/K+‐ATPases
Authors: Weston A H , Richards G R , Burnham M P , Félétou M , Vanhoutte P M , Edwards G 
Published: July 2002

Mechanisms underlying K+‐induced hyperpolarizations in the presence and absence of phenylephrine were investigated in endothelium‐denuded rat mesenteric arteries (for all mean values,n=4).Myocyte resting membrane potential (m.p.) was −58.8±0.8 mV. Application of 5 mMKCl produced similar hyperpolarizations in the absence (17.6±0.7 mV) or presence (15.8±1.0 mV) of 500 nMouabain. In the presence of ouabain +30 μMbarium, hyperpolarization to 5 mMKCl was essentially abolished.In the presence of 10 μMphenylephrine (m.p. −33.7±3 mV), repolarization to 5 mMKCl did not occur in the presence or absence of 4‐aminopyridine but was restored (−26.9±1.8 mV) on addition of iberiotoxin (100 nM). Under these conditions the K+‐induced repolarization was insensitive to barium (30 μM) but abolished by 500 nMouabain alone.In the presence of phenylephrine + iberiotoxin the hyperpolarization to 5 mMK+was inhibited in the additional presence of 300 nMlevcromakalim, an action which was reversed by 10 μMglibenclamide.RT–PCR, Western blotting and immunohistochemical techniques collectively showed the presence of α1‐, α2‐ and α3‐subunits of Na+/K+‐ATPase in the myocytes.In K+‐free solution, re‐introduction of K+(to 4.6 mM) hyperpolarized myocytes by 20.9±0.5 mV, an effect unchanged by 500 nMouabain but abolished by 500 μMouabain.We conclude that under basal conditions, Na+/K+‐ATPases containing α2‐ and/or α3‐subunits are partially responsible for the observed K+‐induced effects. The opening of myocyte K+channels (by levcromakalim or phenylephrine) creates a ‘K+cloud’ around the cells which fully activates Na+/K+‐ATPase and thereby abolishes further responses to [K+]oelevation.British Journal of Pharmacology(2002)136, 918–926. doi:10.1038/sj.bjp.0704787
Pharmacological evidence for putative CCK1 receptor heterogeneity in human colon smooth muscle
Authors: Morton M F , Harper E A , Tavares I A , Shankley N P 
Published: July 2002

The pharmacology of the cholecystokinin CCK1 receptors endogenously expressed in human gallbladder and human ascending colon smooth muscle tissue was compared using radioligand binding assays.
Saturation analysis of the interaction between the radiolabelled, selective CCK1‐receptor antagonist, [3H]‐L‐364,718, and enriched gastrointestinal tissue membranes suggested the presence of multiple binding sites in human colon but not human gallbladder.
Competition studies, using a range of structurally diverse, CCK‐receptor selective ligands provided further evidence for CCK1 receptor heterogeneity in human colon tissue (nH values significantly less than unity for SR27897=0.77±0.07, 2‐NAP=0.73±0.03, YM220=0.70±0.09 and PD‐134,308=0.83±0.01). Moreover, the competition data for SR27897, 2‐NAP and YM220 were consistent with the interaction of these compounds at two binding sites. In contrast, in the human gallbladder assay, a single binding site model provided a good fit of the competition curve data obtained with all the CCK receptor selective compounds.
The data obtained are consistent with the presence of a single CCK1 receptor binding site in the gallbladder but not in the colon. A two‐site analysis of the colon data, indicated that one of the two sites was indistinguishable from that characterized in the gallbladder. The molecular basis of the apparent receptor heterogeneity in the colon remains to be established.

British Journal of Pharmacology (2002) 136, 873–882. doi:10.1038/sj.bjp.0704794
Quantitation of CMV by real‐time PCR in transfusable RBC units
Authors: Greenlee Deborah J. , Fan Hongxin , Lawless Kathleen , Harrison Chantal R. , Gulley Margaret L. 
Published: July 2002

BACKGROUND: CMV is one of the most significant pathogens infecting immunocompromised individuals. CMV is transmissible through transfusion of blood components. The goal of this study was to measure CMV levels in RBC units using a sensitive and quantitative DNA amplification assay. STUDY DESIGN AND METHODS: An assay to measure CMV load was developed by using real‐time PCR to target the major immediate early viral gene. A probe (TaqMan, Applied Biosystems) was used to confirm product specificity and to permit quantitation of CMV in blood samples on a sequence detection system (ABI Prism 7700, Applied Biosystems). RESULTS: The assay was shown to be accurate, linear, and sensitive to as few as five copies of CMV DNA per PCR. The assay was applied to aliquots of RBC units from 203 healthy donors, 110 of whom were seropositive for CMV. CMV DNA was not detected in any of the 203 RBC samples. CONCLUSION: The findings statistically imply that at least 98.5 percent of RBC units have a CMV load of less than 250 copies per mL. Future clinical studies on larger numbers of units are required to determine the utility of real‐time PCR in evaluating the risk of CMV transmission and in confirming the efficacy of WBC reduction.