bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal variations of temperature and ozone profiles observed by MIPAS during the Antarctic stratosphere sudden warming of 2002
Authors: Wang D. Y. , von Clarmann T. , Fischer H. , Funke B. , García‐Comas M. , Gil‐López S. , Glatthor N. , Grabowski U. , Höpfner M. , Kellmann S. , Kiefer M. , Koukouli M. E. , Lin G. , Linden A. , López‐Puertas M. , Mengistu Tsidu G. , Milz M. , Steck T. , Stiller G. P.
Published: October 2005

The temperature and ozone volume mixing ratio (VMR) profiles measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on ENVISAT are used to study the unusual Antarctic major stratospheric warming of 2002. The observed zonal mean temperatures show rapid poleward increase and remarkable reversal of the latitudinal gradients at 35 km or below in several days. The highest temperature increase is of 50 K or more. The zonal mean ozone VMRs also increase poleward and have maximum values of 7 ppmv in a wide region between 20 and 40 km at latitudes south of 40°S. Temperature amplitudes of zonal wave number 1 to 3 exhibit a double‐peaked structure with peaks near 25 km and 35 km. The ozone waves in the lower stratosphere are generally in phase with the corresponding temperature waves. At the onset of the warming, the wave 1 amplitudes drastically increase at 60°S–80°S, reaching maxima of ∼20 K for the temperature and ∼2 ppmv for the ozone VMR. Significant wave 3 amplitudes are also observed with maximum of 14–18 K and 1–1.5 ppmv for temperature and ozone VMR, respectively. The wave 3 amplitudes are larger than those of wave 2 by nearly a factor of 2 immediately before and after the polar vortex split. The large‐amplitude wave 1 and 3 disturbances break down in 1 or 2 days, and the wave 2 variations are enhanced and attain amplitudes comparable to those of wave 1 and 3, resulting in an apparent wave 2 warming event. These results are consistent with other observations and suggest the importance of wave 3 forcing in the major warming.
Deriving the tropospheric integrated water vapor from tipping curve–derived opacity near 22 GHz
Authors: Deuber Beat , Morland June , Martin Lorenz , Kämpfer Niklaus
Published: October 2005

In this study we present a simple relation between the tropospheric opacity τ near 22.235 GHz and the integrated water vapor (IWV) content of the troposphere. The opacity is measured at Bern, Switzerland, by the radiometer Middle Atmospheric Water Vapour Radiometer (MIAWARA), designed for middle atmospheric water vapor profile measurements. In contrast to typical radiometers for tropospheric monitoring, this middle atmospheric water vapor radiometer only measures in the vicinity of the 22.235 GHz water vapor line with a bandwidth of 1 GHz. With this study we show that it is even possible to derive the integrated tropospheric water vapor (IWV) content of the atmosphere using this limited frequency range if the liquid water content of the atmosphere is negligible. IWV measurements of the tropospheric monitoring instruments Tropospheric Water Vapour Radiometer (TROWARA, two‐channel radiometer), All‐Sky Multi Wavelength Radiometer (ASMUWARA, multichannel radiometer), and GPS, which are operated next to MIAWARA, are used to derive a linear relation between the opacity and the water vapor content of the troposphere. In a second step, the mean tropospheric temperature is taken into account and a slight improvement of the linear relation is achieved. All instruments involved in this study are contributing to the Studies in Atmospheric Radiative Transfer and Water Vapour Effects (STARTWAVE) project of the Climate program of the National Competence Center in Research. The MIAWARA measurements in the subarctic winter in northern Finland during the Lapbiat Upper Tropospheric Lower Stratospheric Water Vapor Validation Project (LAUTLOS/WAVVAP) campaign in 2004 are compared to radiosonde measurements by the Finnish Meteorological Institute using the same algorithm that was derived for Bern. The agreement of MIAWARA IWV and radiosonde IWV is of the same order as for Bern. Finally, Payerne radiosonde measurements and model simulation using the Atmospheric Radiative Transfer Simulator (ARTS) software and the continuum absorption models of Rosenkranz (1998) and Liebe (MPM87/MPM93) confirm the derived opacity‐IWV relation. This study shows that the integrated water vapor content of the troposphere can be measured by a radiometer operating near the 22.235 GHz water vapor line using a bandwidth of 1 GHz, if the liquid water content of the atmosphere is negligible.
Virus fate and transport during artificial recharge with recycled water
Authors: Anders Robert , Chrysikopoulos C. V.
Published: October 2005

A field‐scale experiment was conducted at a research site using bacterial viruses (bacteriophage) MS2 and PRD1 as surrogates for human viruses, bromide as a conservative tracer, and tertiary‐treated municipal wastewater (recycled water) to investigate the fate and transport of viruses during artificial recharge. Observed virus concentrations were fitted using a mathematical model that simulates virus transport in one‐dimensional, homogeneous, water‐saturated porous media accounting for virus sorption (or filtration), virus inactivation, and time‐dependent source concentration. The fitted time‐dependent clogging rate constants were used to estimate the collision efficiencies for bacteriophage MS2 and PRD1 during vertical fully saturated flow. Furthermore, the corresponding time‐dependent collision efficiencies for both bacteriophage asymptotically reached similar values at the various sampling locations. These results can be used to develop an optimal management scenario to maximize the amount of recycled water that can be applied to the spreading grounds while still maintaining favorable attachment conditions for virus removal.
Particle acceleration by elliptically and linearly polarized waves in the vicinity of quasi‐parallel shocks
Authors: Kuramitsu Y. , Krasnoselskikh V.
Published: October 2005

We discuss an acceleration mechanism of charged particles in the presence of elliptically or linearly polarized electromagnetic waves at parallel shocks. Such waves are often detected by spacecraft observations in the deep foreshock region of the Earth's bow shock. Under the influence of a circularly polarized electromagnetic wave and an electrostatic shock potential, particles can be accelerated efficiently by gyroresonant surfing, a perpendicular acceleration mechanism due to a combined effect of trapping by the wave and dragging by the electrostatic field. We describe the elliptically or linearly polarized waves as a superposition of two circularly polarized waves with the same phase speed and wavelength, but with the opposite wave polarization. In the presence of such waves, particles are pitch angle diffused, and this leads to smearing of the perpendicular acceleration. However, the particles are efficiently accelerated in the parallel direction owing to exchange of the parallel and the perpendicular kinetic energies, and/or owing to the shock potential. Furthermore, as the wave ellipticity becomes large, because of the strong pitch angle scattering, the particles can be repeatedly accelerated by the gyroresonant surfing. The efficient diffusion both in the pitch angle and in the energy space produces the particle distribution function similar to the so‐called diffuse ions associated with the elliptically and linearly polarized waves observed in the foreshock.
Solar extreme‐ultraviolet irradiance for general circulation models
Authors: Solomon Stanley C. , Qian Liying
Published: October 2005

Recent measurements of the solar extreme‐ultraviolet spectrum provide high‐resolution spectral irradiance that can be used for calculating ionization and dissociation rates in the upper atmosphere and for providing improved proxy‐based models of the solar spectrum. These are crucial inputs for global time‐dependent general circulation models of the thermosphere and ionosphere, but computational economies require that a lower‐resolution spectrum be used in the calculations without excessive loss of accuracy. The problem is compounded by the photoelectrons generated by ionization, which cause further ionization and dissociation of atmospheric gases. We describe a method for using solar spectral measurements or models to calculate ionization and dissociation rates throughout the upper atmosphere, including photoelectron effects, that is more accurate and more efficient than its predecessors. Examples of use with measurements from the Solar EUV Experiment on the TIMED satellite and with the EUVAC model are given, and an example calculation using the National Center for Atmospheric Research thermosphere‐ionosphere‐electrodynamics general circulation model is shown.
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island
Authors: Lu Hailong , Moudrakovski Igor , Riedel Michael , Spence George , Dutrisac Regent , Ripmeester John , Wright Fred , Dallimore Scott
Published: October 2005

Gas hydrate samples recovered from a cold vent field offshore Vancouver Island were studied in detail both by macroscopic observations and instrumental methods (powder X‐ray diffraction method (PXRD), nuclear magnetic resonance (NMR), and Raman spectroscopy). It was found that gas hydrates were massive from 2.64 to 2.94 m below seafloor (mbsf), elongated, nodular and tabular from 4.60 to 4.81 mbsf, and vein‐like from 5.48 to 5.68 mbsf, showing a trend of decreasing hydrate content with increasing depth. All samples were determined to be structure I hydrate from PXRD, NMR, and Raman spectroscopies. The hydration numbers were estimated to be 6.1 ± 0.2 on average as determined from the methane distribution over the cage sites from NMR and Raman analytical results. Estimates of conversion levels indicated that ∼78% of the water in the massive samples was hydrate, down to a low value of ∼0.4% for the pore hydrate samples. The results are compared with measurements on synthetic hydrates and samples recovered from below the permafrost on the Mallik site. Differences in methane content and lattice parameters for synthetic and natural samples are relatively minor. Additional work is needed to address the presence of minor gas components and the heterogeneity of natural hydrate samples.
Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current System: A modeling approach
Authors: Penven P. , Echevin V. , Pasapera J. , Colas F. , Tam J.
Published: October 2005

The Humboldt Current System is the most productive of the eastern boundary currents. In the northern part, the Peru Current System (PCS) is located between 5°S and 20°S. Along the Peruvian coast, an equatorward wind forces a strong coastal upwelling. A high resolution model is designed to investigate the mean circulation, the seasonal cycle, and the mesoscale dynamics for the PCS. The model is able to reproduce the equatorward Peru Coastal Current (PCC), the Peru Chile Under‐Current (PCUC) which follows the shelf break towards the pole, and the Peru‐Chile Counter‐Current (PCCC) which flows directly towards the south and veers to the west around 15°S. While the upper part of the PCUC is close to the surface and might even outcrop as a counter current, the bottom part follows isolines. The PCCC appears to be directly forced by the cyclonic wind stress curl. The model is able to produce the upwelling front, the cold water tongue which extends toward the equator and the equatorial front as described in the literature. Model seasonal changes in SST and SSH are compared to measurements. For the central PCS, model EKE is 10% to 30% lower than the observations. The model eddy diameters follow a strong equatorward increase. The injection length scales, derived from the energy spectra, strongly correlate to the Rossby radius of deformation, confirming the predominant role of baroclinic instability. At 3°S, the model solution appears to switch from a turbulent oceanic regime to an equatorial regime dominated by zonal currents.
Increased Phosphorylation of Protein Kinase B and Related Substrates after Traumatic Brain Injury in Humans and Rats
Authors: Zhang Xiaopeng , Chen Yarning , Ikonomovic Milos D , Nathaniel Paula D , Kochanek Patrick M , Marion Donald W , DeKosky Steven T , Jenkins Larry W , Clark Robert SB
Published: October 2005

Activation of protein kinase B (PKB, also known as Akt) by phosphorylation at serine-473 and threonine-308 promotes cell survival in multiple in vitro and in vivo models where neuronal death is seen, including traumatic brain injury (TBI); however, whether PKB is activated in humans after TBI was heretofore unknown. Activated PKB inhibits apoptogenic factors and is involved in the regulation of several transcription factors. Accordingly, we examined phosphorylation of the PKB signaling pathway in humans as well as rats after TBI using phosphospecific antibodies. Increased phosphorylation of PKB and PKB substrates was detected in injured brain from both humans and rats. In humans, increased phosphorylation of the PKB signaling pathway-related proteins Bad and forkhead transcription factor (FKHR) was detected in patients with TBI versus controls. In rats, increased phosphorylation of FKHR, inhibitor of κB α, and cyclic adenosine monophosphate responsive element binding protein (CREB) was detected after TBI versus controls. The deoxyribonucleic acid-binding activity of CREB was also enhanced after TBI in rats. Increased phosphorylation of PKB and PKB substrates was identified in neurons and other cell types by immunohistochemistry in both humans and rats. These data show increased phosphorylation of PKB, PKB substrates, and related proteins after both experimental and clinical TBI, suggesting either activation of the PKB signaling pathway or reduced phosphatase activity in both species.
Terahertz studies of the dielectric response and second-order phonons in a GaSe crystal
Authors: Yu B. L. , Zeng F. , Kartazayev V. , Alfano R. R. , Mandal Krishna C.
Published: October 2005

The dielectric function and momentum relaxation time of carriers for a single-crystal GaSe were investigated using terahertz time-domain spectroscopy over the frequency range from 0.4to2.4THz. The key parameters determined from THz data using the Drude model are: the plasma frequency ωp=2.6±0.2THz, the average momentum relaxation time ⟨τ⟩=56±2fs, and the mobility μ=89cm2∕Vs for electrons. The THz absorption spectrum showed resonance structures attributed to the difference frequency combinations associated with acoustical and optical phonons.
Dielectrophoresis of nanoscale double-stranded DNA and humidity effects on its electrical conductivity
Authors: Tuukkanen S. , Kuzyk A. , Toppari J. J. , Hytönen V. P. , Ihalainen T. , Törmä P.
Published: October 2005

The dielectrophoresis method for trapping and attaching nanoscale double-stranded DNA between nanoelectrodes was developed. The method gives a high yield of trapping single or a few molecules only which enables transport measurements at the single molecule level. Electrical conductivity of individual 140-nm-long DNA molecules was measured, showing insulating behavior in dry conditions. In contrast, clear enhancement of conductivity was observed in moist conditions, relating to the interplay between the conformation of DNA molecules and their conductivity.
Monodisperse spherical core-shell-structured phosphors obtained by functionalization of silica spheres with Y2O3:Eu3+ layers for field emission displays
Authors: Wang H. , Lin C. K. , Liu X. M. , Lin J. , Yu M.
Published: October 2005

Spherical SiO2 particles have been coated with Y2O3:Eu3+ phosphor layers (SiO2@Y2O3:Eu3+) by a Pechini sol-gel process. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, and cathodoluminescence spectra were utilized to characterize the SiO2@Y2O3:Eu3+ core-shell-structured phosphor particles. The obtained core-shell phosphors consist of well dispersed submicron spherical particles with narrow size distribution. The thickness of Y2O3:Eu3+ shell could be easily controlled by changing the number of deposition cycles (60nm for three deposition cycles). The SiO2@Y2O3:Eu3+ core-shell particles show a strong red emission corresponding to D05-F27 (611nm) of Eu3+ under the excitation of ultraviolet (250nm) and low-voltage electron beams (2–6kV), which have potential application for field emission displays.
Spatial Modulation of Tactile Temporal-Order Judgments
Authors: Shore David I , Gray Kellie , Spry Emily , Spence Charles
Published: October 2005

We report a series of three experiments designed to examine the effect of posture on tactile temporal processing. Observers reported which of two tactile stimuli, presented to the left and right index fingers (experiments 1 – 3; or thumb, experiment 3), was perceived first while adopting one of two postures—hands-close (adjacent, but not touching) or hands-far (1 m apart)—in the dark. Just-noticeable differences were significantly smaller in the hands-far posture across all three experiments. In the first two experiments we compared hand versus foot responses and found equivalent advantages for the hands-far posture. In the final experiment the stimuli were presented to either the same or different digit on each hand (index finger or thumb) and we found that only when the same digit on each hand was stimulated was there an advantage for the hands-far posture. The finding that temporal precision was better with greater distance contradicts predictions based on attention-switching models of temporal-order judgments, and also contrasts with results from similar experimental manipulations in other modalities (eg vision). These results provide support for a rapid and automatic process that transforms the representation of a tactile stimulus from a skin-centred reference frame to a more external (eg body-centred or allocentric) one.
Human Spatial Navigation via a Visuo-Tactile Sensory Substitution System
Authors: Segond Hervé , Weiss Déborah , Sampaio Eliana
Published: October 2005

Spatial navigation within a real 3-D maze was investigated to study space perception on the sole basis of tactile information transmitted by means of a ‘tactile vision substitution system' (TVSS) allowing the conversion of optical images—collected by a micro camera—into ‘tactile images’ via a matrix in contact with the skin. The development of such a device is based on concepts of cerebral and functional plasticity, enabling subjective reproduction of visual images from tactile data processing. Blindfolded sighted subjects had to remotely control the movements of a robot on which the TVSS camera was mounted. Once familiarised with the cues in the maze, the subjects were given two exploration sessions. Performance was analysed according to an objective point of view (exploration time, discrimination capacity), as well as a subjective one (speech). The task was successfully carried out from the very first session. As the subjects took a different path during each navigation, a gradual improvement in performance (discrimination and exploration time) was noted, generating a phenomenon of learning. Moreover, subjective analysis revealed an evolution of the spatialisation process towards distal attribution. Finally, some emotional expressions seemed to reflect the genesis of ‘qualia’ (emotional qualities of stimulation).
Colour, Polarity, Disparity, and Texture Contributions to Motion Segregation
Authors: Poom Leo , Börjesson Erik
Published: October 2005

We measured how different cues are combined in motion-segregation processes by using motion stimuli where randomly distributed target dots were organised in global revolving motion while the remaining noise dots performed random motion. Target dots were cued with a different colour, polarity, disparity depth, or texture orientation than the noise dots, or they were the same as the noise dots. The stimuli were presented with a prolonged static cue preview which provided position cues to target dots or, briefly with static pre-target and post-target noise frames, which provided false position cues (no preview). All cues efficiently facilitated global motion segregation in cued-preview conditions. Colour completely failed to facilitate global motion segregation in no-preview conditions. Polarity and disparity facilitated segregation in no-preview conditions, although sensitivities were lower than in the preview conditions. Remarkably, texture orientation largely facilitated motion segregation by the same amount in both cued-preview and no-preview conditions. So, colour provides only position cues to the motion-segregation task whereas texture orientation, disparity, and to a lesser extent polarity are integrated with the segregation process.
The Perception of Emotion from Body Movement in Point-Light Displays of Interpersonal Dialogue
Authors: Clarke Tanya J , Bradshaw Mark F , Field David T , Hampson Sarah E , Rose David
Published: October 2005

We examined whether it is possible to identify the emotional content of behaviour from point-light displays where pairs of actors are engaged in interpersonal communication. These actors displayed a series of emotions, which included sadness, anger, joy, disgust, fear, and romantic love. In experiment 1, subjects viewed brief clips of these point-light displays presented the right way up and upside down. In experiment 2, the importance of the interaction between the two figures in the recognition of emotion was examined. Subjects were shown upright versions of (i) the original pairs (dyads), (ii) a single actor (monad), and (iii) a dyad comprising a single actor and his/her mirror image (reflected dyad). In each experiment, the subjects rated the emotional content of the displays by moving a slider along a horizontal scale. All of the emotions received a rating for every clip. In experiment 1, when the displays were upright, the correct emotions were identified in each case except disgust; but, when the displays were inverted, performance was significantly diminished for some emotions. In experiment 2, the recognition of love and joy was impaired by the absence of the acting partner, and the recognition of sadness, joy, and fear was impaired in the non-veridical (mirror image) displays. These findings both support and extend previous research by showing that biological motion is sufficient for the perception of emotion, although inversion affects performance. Moreover, emotion perception from biological motion can be affected by the veridical or non-veridical social context within the displays.
Depth and Motion in Historical Descriptions of Motion Parallax
Authors: Ono Hiroshi , Wade Nicholas J
Published: October 2005

Motion parallax was described as a cue to depth over 300 years ago and as producing apparent motion over 150 years ago. In recent years, experimental interest in motion parallax has increased, following the rediscovery of the idea that stimulus motion can be yoked to head movement. We compare the historical descriptions with some contemporary research, which indicates how depth and motion perception are dependent on the conditions of stimulation.
Temporal Properties of Disparity Processing Revealed by Dynamic Random-Dot Stereograms
Authors: Gheorghiu Elena , Erkelens Casper J
Published: October 2005

In studies of the temporal flexibility of the stereoscopic system, it has been suggested that two different processes of binocular depth perception could be responsible for the flexibility: tolerance for interocular delays and temporal integration of correlation. None has investigated the relationship between tolerance for delays and temporal integration mechanisms and none has revealed which mechanism is responsible for depth perception in dynamic random-dot stereograms. We address these questions in the present study. Across five experiments, we investigated the temporal properties of stereopsis by varying interocular correlation as a function of time in controlled ways. We presented different types of dynamic random-dot stereograms, each consisting of two pairs of alternating random-dot patterns. Our experimental results demonstrate that (i) disparities from simultaneous monocular inputs dominate those from interocular delayed inputs; (ii) stereopsis is limited by temporal properties of monocular luminance mechanisms; and (iii) depth perception in dynamic random-dot stereograms results from cross-correlation-like operation on two simultaneous monocular inputs that represent the retinal images after having been subjected to a process of monocular temporal integration of luminance.
Addition of steroids to embryo-uterine monolayer co-culture enhances embryo survival and implantation in vitro
Authors: Lavranos TC , Seamark RF
Published: October 2005

Co-culture with a mixed cell monolayer established from trypsinized uterine tissue increased the numbers of embryos developing in a minimum essential medium beyond the hatching blastocyst stage in the 5-day period of culture to 56.0% (343/613) compared with 30.2% (93/308) for embryos cultured in medium alone. The inclusion of progesterone (3.2 x 10(-6), 3.2 x 10(-5), or 3.2 x 10(-4) M) or oestradiol (3.7 x 10(-5) M) to the co-cultures increased the mean percentage of embryos developing to the advanced stages to 72.7-78.4%. The addition of progesterone (3.2 x 10(-6) M) together with oestradiol (3.7 x 10(-5) M) resulted in additional improvement to a mean of 86.5% (787/910, P less than 0.001) but the combination was without significant effect on embryos cultured in media alone. Blastocyst viability was not impaired by co-culture as assessed in embryo survival following surgical transfer to pseudopregnant recipients. This study confirms the feasibility of establishing co-culture systems to facilitate investigation of pre-implantation events in vitro and highlights a role of steroid hormones in enhancing the capacity of uterine cells to support pre-implantation-stage embryos.
Effects of macromolecules recovered from uterine luminal fluid on the metabolism of
Authors: Khurana NK , Wales RG
Published: October 2005

Day-4 mouse embryos grew well in culture media supplemented with macromolecular components of uterine fluids recovered on day 3, 4 or 5 of pregnancy and pseudopregnancy. Addition of these components to media during a 2-h pulse culture had no significant effect on the incorporation of glucose carbon by morulae/early blastocysts. However, various fractions of uterine luminal macro-molecules significantly increased the turnover of glucose carbon incorporated into acid-soluble and acid-insoluble glycogen, into nucleic acids and into proteins during a 24-h chase culture. These effects were due mainly to components with a molecular weight between 1000 and 10,000 Da and the activity was most marked in fluids collected on day 5 of pregnancy or pseudopregnancy. Oxidation of glucose during a 4-h incubation was inhibited in the presence of certain uterine macromolecules but most consistently by the large molecular weight component (greater than 300,000 Da). Some differences were noted in the inhibitory activity of macromolecules obtained from pregnant and pseudopregnant sources. There was little evidence of an effect of uterine-fluid components on lactate production from glucose.
Delayed response of the mouse uterus to progesterone and oestradiol
Authors: Murray CM , Stone GM
Published: October 2005

The delayed response of the uterus of the ovariectomized mouse to progesterone (P) required the presence of a low dose of oestradiol-17 beta (E2) and was associated with a maintained level of uterine DNA, an increase in RNA:DNA ratio and in total tissue protein and a decreased level of uterine P. This last parameter was associated with an increased level of in vitro metabolism of P by the uterus. Changes in the level of receptors for P and E2 were temporally unrelated to the delayed response. Omission of oestradiol every second, third or fourth day inhibited development of the delayed response, which could also be obtained with the long acting progestogen, medroxy progesterone acetate, and E2 or oestradiol benzoate.
Lupins and energy-yielding nutrients in ewes. II. Responses in ovulation rate in ewes to increased availability of glucose, acetate and amino acids
Authors: Teleni E , Rowe JB , Croker KP , Murray PJ , King WR
Published: October 2005

An experiment, using a total of 320 Merino ewes, over two successive breeding seasons was conducted to investigate the separate effects of energy-yielding and protein-yielding nutrients on ovulation rate in sheep. The available energy-yielding or protein-yielding nutrients in the blood of sheep fed a maintenance pelleted ration were increased by either intravenous infusions of metabolites (acetate, glucose or acetate + glucose), feeding lupin grain, modification of the pattern of rumen fermentation to increase propionate production using the ionophore, lasalocid, or by feeding of ruminally undegradable protein (formaldehyde-treated casein). All treatments were given for 9 days prior to and including expected time of ovulation. Ovulation rates were measured by laparoscopy. In the first season (the 1984 experiment) when the effects of lupin grain, glucose + acetate and formaldehyde-treated casein were compared, ovulation rates were increased significantly in the group fed lupin (29%, P less than 0.001) and the group infused with glucose + acetate (24%, P less than 0.01). There was an apparent (17%) but statistically non-significant increase in the group fed casein. In comparisons between lupin grain, glucose, acetate, glucose + acetate, formaldehyde-treated casein and lasalocid in the 1985 experiment there were similar significant increases in ovulation rates in the groups fed lupin, and those infused with glucose or glucose + acetate (approximately 25%, P less than 0.001). The increase in the group infused with acetate was lower at 14% (P less than 0.05) and the increases of 7% in the groups fed casein or lasalocid were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Some biological activities of cronolone and medroxyprogesterone acetate in the uterus of the sheep, mouse and rabbit
Authors: Zhang X , Miller BG
Published: October 2005

Cronolone (9 alpha-fluoro-11 beta-hydroxy-17 alpha-acetoxypregn-4-ene-3,20-dione) is widely employed to regulate breeding activity in the ewe, but its biological activity in the uterus of this and most other species has not been studied. In this study several in vivo uterus-related activities of cronolone have been examined in the sheep, mouse and rabbit. In some experiments the corresponding activities of medroxyprogesterone acetate (6 alpha-methyl-17 alpha-acetoxypregn-4-ene-3,20-dione, MAP) were also examined. Cronolone maintained pregnancy in ovariectomized ewes but not in ovariectomized mice and rabbits; it terminated pregnancy in some mice and in all rabbits that were receiving daily progesterone treatment. Cronolone could not sensitize the mouse uterus for the induction of the decidual-cell reaction or block the induction of such sensitivity by progesterone, but did support limited growth of the oil-stimulated horn after sensitization with progesterone. Cronolone induced uteroglobin secretion by rabbit endometrium. It was concluded that, whereas MAP is a potent progestogen in the sheep, mouse and rabbit, cronolone is a progestogen in the sheep and rabbit only. In the mouse and especially the rabbit, cronolone has other, non-progestational activities, which block pregnancy.
Maternal immune response to pregnancy
Authors: Billington WD
Published: October 2005

The pregnant female is exposed to a variety of potentially immunogenic foreign antigens on her allogenic intra-uterine conceptus. The extent to which maternal antibodies and cell-mediated immune responses to these antigens are relevant to the paradoxical survival of the fetal allograft is not clearly established. The key to the maintenance of pregnancy lies in the trophoblast. This tissue prevents significant entry of maternal lymphocytes to the fetus and is most likely to protected from maternal immune rejection by features of its cell surface molecular structure and/or its synthesis of factors that render it insusceptible to antibody- or cell-mediated immune lysis in vivo. An alternative, or complementary, protective system, involving maternal recognition and immunoregulatory processes that deviate responses away from the expected rejection reactions, may also operate but has not yet been convincingly demonstrated. Such a mechanism is unlikely to involve the classically defined histocompatibility classically defined histocompatibility antigen system, at least in human pregnancy, where there is an absence of Class I antigens from the trophoblast but increasing evidence of trophoblast-associated antigens and related immune responses. It remains to be established whether unexplained recurrent miscarriage in women and spontaneous abortion in animal models is caused by failure of maternal immunoregulatory control or by non-immunological factors. This is relevant to the validity of immunotherapeutic approaches to the prevention of early fetal loss.
Reproduction in the Indian mouse-tailed bat, Rhinopoma hardwickei hardwickei (Chiroptera, Rhinopomatidae)
Authors: Karim KB , Banerjee S
Published: October 2005

At and near Agra, in Uttar Pradesh, India, R. h. hardwickei had a strictly defined annual reproductive cycle. Although many females were inseminated during late February to mid April, ovulation was not recorded until 11 March. Progressively more females ovulated and conceived during the following weeks until the end of April and released one ovum from either of the ovaries with nearly equal frequency. A single conceptus was carried in the ipsilateral uterine cornu during each cycle. The gestation period was 95-100 days. Births occurred between the second week of June and the end of July. Lactation lasted at least 20 days. Females attained sexual maturity at an age of 8.5-9.0 months. Males took at least 16-17 months to attain sexual maturity. Females were segregated during lactation; during the rest of the year, males and females lived together.
Ovarian morphology and function in 12-week-old lambs from breeds with different ovulation rates as adults
Authors: Sonjaya H , Driancourt MA
Published: October 2005

Follicular development and function were compared in 12-16-week-old Romanov and non-prolific (Ile-de-France or Prealpes) lambs. At 12 weeks of age, there was no difference between breeds in the population of antral follicles, their size distribution, their atresia, or the size of the largest follicles. Whatever the breed, intact follicles explanted from 12-week-old lambs actively produced testosterone in an unsupplemented medium. This production increased in a gonadotrophin-supplemented medium. In contrast, basal oestradiol production by Romanov follicles was reduced compared with Ile-de-France and Prealpes follicles. However, in both breeds this production increased about two-fold in an FSH-supplemented medium. At 14-16 weeks of age, lambs of both breeds had LH-sensitive follicles, as evidenced by their ability to ovulate following the injection of hCG. The number of such follicles was related to the prolificacy of the lambs (Romanov 2.8, Ile-de-France 1.6). Hence, at 12-16 weeks of age, the maturation of the ovary is not fully completed in Romanov lambs. Acquisition of a fully functional aromatase system and maturation of the central nervous system are probably required for puberty to proceed. Their relative timings may differ between breeds.
Sex-hormone-binding globulin in human follicular fluid and serum at the time of oocyte recovery
Authors: Campo SM , Rogers PA , Findlay JK
Published: October 2005

Androgen binding activity, indistinguishable from sex-hormone-binding globulin (SHBG) in serum, has been identified in human follicular fluid by binding analyses (saturation and Scatchard analyses and binding specificity), immunoradiometric assay and Con-A Sepharose chromatography. Follicular fluid was obtained at the time of oocyte recovery from either individual follicles (range 2-7) from seven patients, or as a pool obtained from follicles of several patients who had received a Clomid-human menopausal gonadotrophin treatment to stimulate follicular growth as part of an in vitro fertilization program. Concentrations of SHBG in follicular fluid varied between individual follicles (750 +/- 202 fmol mg-1 protein; mean +/- s.d.; n = 14) and ranged above and below concentrations of SHBG in serum (948 +/- 171 fmol mg-1 protein; n = 5) taken 4 h before oocyte recovery and harvest of follicular fluid. There were strong correlations (r = 0.7-0.9) between the steroid and SHBG contents in individual follicular fluids of two patients. However, the concentration of SHBG in follicular fluid was generally 100-fold lower than that of oestradiol or progesterone, suggesting that SHBG may play some role other than determining the concentration of unbound steroid in the follicle.
Changes in milk carbohydrates during lactation in the common brushtail possum, Trichosurus vulpecula (Marsupialia:Phalangeridae)
Authors: Crisp EA , Cowan PE , Messer M
Published: October 2005

Milk samples (186) were obtained at various stages of lactation from 27 common brushtail possums (Trichosurus vulpecula). Qualitative and quantitative changes in the milk carbohydrates during early and mid-lactation were similar to those previously seen in other marsupials; the principal carbohydrate was lactose early in lactation and higher oligosaccharides in mid-lactation, and the hexose concentration reached a peak during mid-lactation. However, the late-lactation milk was unusual in that the carbohydrate was mainly lactose and its concentration remained relatively high (3.5 to 5.5%). In contrast to earlier findings on the milk of the tammar wallaby (Macropus eugenii), little or no nucleotide pyrophosphatase, beta-galactosidase and alkaline phosphatase activities were detected late in lactation.
Intestinal lactase (beta-galactosidase) and other disaccharidase activities of suckling and adult common brushtail possums, Trichosurus vulpecula (Marsupialia:Phalangeridae)
Authors: Crisp EA , Messer M , Cowan PE
Published: October 2005

Small-intestinal disaccharidase activities of eight suckling T. vulpecula, aged from 34 to 150 days, and of two adult animals were investigated. Intestinal maltase, isomaltase and sucrase activities increased with age, whereas lactase activities decreased. Trehalase activities were relatively high in all animals and showed no obvious age-related changes. Three separate beta-galactosidase activities, one neutral and two acid, acted on lactose. The neutral beta-galactosidase activity appeared to be due to a brush border enzyme similar to that of eutherian mammals, whereas the acid beta-galactosidases were soluble and probably of lysosomal origin. One of these, acid beta-galactosidase-1, had similar properties to the sole intestinal beta-galactosidase of macropodid marsupials, whereas the other, acid beta-galactosidase-2, has not previously been described. Galactosyl oligosaccharides isolated from macropodid milk were readily hydrolysed by both acid beta-galactosidases but not by the neutral beta-galactosidase. The total intestinal lactase activity in animals aged up to 125 days was due mainly to acid beta-galactosidase-1, whereas in older animals it was due mostly to the neutral beta-galactosidase; this suggests that late in lactation the young T. vulpecula change from a macropodid mode of digestion of galactosyl oligosaccharides to a eutherian mechanism for the digestion of lactose. These findings may have implications for the hand-rearing of orphaned T. vulpecula.
Increase in ovulation rate in Merino ewes after active immunization with inhibin preparations obtained by immunoaffinity chromatography
Authors: O'Shea T , Bindon BM , Hillard MA , Piper LR , Findlay JK , Miyamoto K
Published: October 2005

Ewes were immunized with four inhibin preparations of increasing purity obtained from bovine follicular fluid by affinity chromatography. The two purest immunogens, which had 69 and 174 ng inhibin micrograms-1 protein (expressed in terms of 32 kDa ovine inhibin), increased ovulation rate by 240 and 320% respectively following two injections, and gave a transient increase in plasma FSH concentration at the same time. Plasma antibodies recognizing native 125I-31 kDa bovine inhibin appeared at the same time, and, together with the increased ovulation rate, persisted after the injections ceased. Ovulation rate and antibody titres were raised by the less pure immunogens, but to a smaller extent, and the increases did not persist. It was concluded that the increased ovulation rate was due to induced inhibin antibodies, acting at least in part through the consequent rise in plasma FSH concentration.
Stage-specific expression of nucleoprotein mRNAs during rat and mouse spermiogenesis
Authors: Mali P , Kaipia A , Kangasniemi M , Toppari J , Sandberg M , Hecht NB , Parvinen M
Published: October 2005

The expression of mRNAs for a transition protein (TP1) and two variants of protamines (P1 and P2) during rat and mouse spermiogenesis was investigated using cDNA hybridization techniques. Slot-blot analyses from 1-mm segments of seminiferous tubules and in situ hybridization from testis sections showed that the levels of mRNA for TP1 increased in step-7 round spermatids at substage VIIb of the seminiferous epithelial cycle, earlier than that of P1 and P2 at substage VIIc. The mRNA levels of all transcripts remained high during steps 8-13 in both species. In the rat, the mRNA of TP1 disappeared during step 14 between substages XIVa and XIVb. The P1 mRNA levels decreased during steps 15-16 (stages I-III) and the P2 mRNA during step 15 (stage I). In the mouse, TP1 mRNA disappeared during step 13 (stage I). The P1 mRNA level decreased before P2 in step 14 (stage II), whereas P2 was detected up to step 15 (stage V). Northern-blot analyses with all three cDNA probes revealed two sizes of mRNA and their stage-specific expression. The shorter transcripts appeared later than the longer ones, at the steps of spermiogenesis where translation is known to begin. The results suggest that transcription of TP1, P1, and P2 mRNAs starts at specifically defined times during spermiogenesis and that the temporal translational regulation of these mRNAs is different.
Human chorionic gonadotrophin raises serum immunoreactive inhibin levels in men with hypogonadotrophic hypogonadism
Authors: Burger HG , Tiu SC , Bangah ML , de Kretser DM
Published: October 2005

Inhibin is a gonadal glycoprotein hormone involved in the regulation of FSH. To elucidate the regulation of inhibin production we investigated the acute (daily for 1 week) and chronic (9-10 months of follow-up) changes in immunoreactive inhibin, testosterone, LH and FSH levels in the serum of three hypogonadotrophic hypogonadal patients treated first with hCG alone (for 3-6 months) and then hCG combined with FSH (1-5 months). One patient was unexpectedly resistant to gonadotrophin therapy; in the other two, hCG, with or without FSH, caused a rise in inhibin and testosterone, supporting previous observations that LH, as well as FSH, plays a role in the regulation of inhibin or inhibin-related peptides in men.
Germ cell-Sertoli cell interactions
Authors: de Kretser DM
Published: October 2005

The interactions between the Sertoli cells and germ cells are progressively becoming an important part of testicular physiology. This paper explores the cytological basis for these interactions, detailing the cyclic changes in the Sertoli cells in concert with the stages of the seminiferous cycle and the nature of the blood-testis barrier. These cytological changes are correlated with a number of variations in the function of Sertoli cells. The mechanisms by which germ cells and Sertoli cells interact are explored and can be divided into those using cell-to-cell contact and others utilizing paracrine factors.
Effect of beta-endorphin on steroidogenesis by bovine luteal cells
Authors: Varsano JS , Izhar M , Perk K , Shemesh M
Published: October 2005

To determine if opioid peptides have a local effect on the modulation of progesterone (P4) synthesis, a study was made of the effect of beta-endorphin and leu-enkephalin on P4 production by pure preparations of small luteal cells and dissociated luteal cells comprising both small and large cells from cows 2-3 months pregnant. Corpora lutea were dispersed by collagenase, and the large and small luteal cells were separated using Percoll gradients. Viable luteal cells (5 x 10(5)) were incubated in 0.5 mL of Eagle medium for 2 h at 37 degrees C, in an atmosphere of 5% CO2. Cells were treated with 8-bromoadenosine 3',5'-monophosphate (8Br-cAMP), hCG, beta-endorphin (BE) and leu-enkephalin (LE) alone or in combination. When small luteal cells were used, P4 synthesis was significantly enhanced in the presence of opioid peptides alone (P less than 0.01); there was an additive effect with 8Br-cAMP and with hCG. For dissociated luteal cells, opioid peptides alone had no effect on P4 production but the stimulation of P4 production induced by 8Br-cAMP or hCG was significantly (P less than 0.01) inhibited in the presence of opioid peptides. In contrast, dissociated luteal cells that were preincubated with PGF2 alpha (degranulation) responded to the presence of BE with increased P4 synthesis similar to that seen with the pure preparation of small luteal cells. It is concluded that opioid peptides play an auto/paracrine role in both basal and tropic hormone-induced stimulation of steroidogenesis by the bovine luteal cell.
Maximum survival of frozen goat embryos is attained at the expanded, hatching and hatched blastocyst stages of development
Authors: Li R , Cameron AW , Batt PA , Trounson AO
Published: October 2005

Embryos were collected 5, 6 and 7 days after ovulation to determine their optimum stage of development for cryopreservation. The embryos were frozen using either glycerol or dimethyl sulfoxide (DMSO) as cryoprotectant, and then thawed and cultured to determine their viability. The rate of survival increased as the stage of development of the embryos increased. All hatched blastocysts survived freezing regardless of which cryoprotectant was used, whereas none of the 22 morulae frozen with DMSO survived, and only 12 of the 63 morulae frozen with glycerol survived. At the early blastocyst stage there was a significantly different result between freezing procedures (P less than 0.05) with greater survival rates obtained using DMSO rather than glycerol. The viability of goat embryos obtained at the early to hatched blastocyst stages, when collected 7 days after ovulation, was assessed by transferring half the embryos singly to recipients and freezing the remainder before transfer. When pregnancy was tested at the 7th week of gestation, the survival rate of fresh embryos was 67/111 (60%) compared with 64/109 (59%) for frozen-thawed embryos.
Production of interspecies chimeric calves by aggregation of Bos indicus and Bos taurus demi-embryos
Authors: Williams TJ , Munro RK , Shelton JN
Published: October 2005

Two experiments were conducted to produce interspecific chimeric calves by aggregation of B. indicus and B. taurus demi-embryos. In the first experiment, morulae, compacted morulae, and early blastocysts were collected nonsurgically from Brahman (B. indicus) and Friesian (B. taurus) donors. Embryos were bisected and one demi-embryo from each species was placed in a single zone pellucida. In the second experiment, Brahman (B. indicus) and Hereford-Shorthorn (HS) (B. taurus) demi-embryos were aggregated. The resulting 'chimeric embryos' were transferred nonsurgically to synchronous recipients immediately following microsurgery. Of 112 recipients of 112 chimeric embryos, 29 (26%) were pregnant at 60 days. Of these, 24 (83%) produced full-term calves and 5 (17%) aborted between 2 and 5 months' gestation. From the 24 full-term pregnancies, two sets of twins and 22 singleton calves were born. Of the 22 singletons, 15 were chimeric including six bull calves (one Brahman-Friesian and five Brahman-HS) that were overt chimeras. All the overt chimeras resulted from aggregation of halves of early morulae (precompaction).