Use of an androgenized mare as an aid in detection of estrus in mares

A study was conducted over a 2-mo period to compare estrus detection results obtained using an androgenized teaser mare with those obtained with a stallion, using the same group of 10 normally cyclic mares. The teaser mare was androgenized by administration of boldenone undecylenate (500 mg i.m. every 1 to 2 wk), and allowed to run loose with the mare group. Estrus was determined by observation of the group for a 30-min period daily. In the second month of the experiment, a marking harness was used on the androgenized mare to help detect mares mounted when in estrus. Estrous periods detected by each teasing method were 1) first month: stallion, 18; androgenized mare, 5; 2) second month: stallion, 16; androgenized mare, 9. There were no estrous periods detected by the androgenized mare that were not also detected by the stallion. Under these conditions, the androgenized mare was not an adequate estrus detection aid. Also discussed are the successful results of an independent trial on a breeding farm using an androgenized mare as an estrus detection aid.     

Crystal structure of a soluble form of human monoglyceride lipase in complex with an inhibitor at 1.35 Å resolution

A high-resolution structure of a ligand-bound, soluble form of human monoglyceride lipase (MGL) is presented. The structure highlights a novel conformation of the regulatory lid-domain present in the lipase family as well as the binding mode of a pharmaceutically relevant reversible inhibitor. Analysis of the structure lacking the inhibitor indicates that the closed conformation can accommodate the native substrate 2-arachidonoyl glycerol. A model is proposed in which MGL undergoes conformational and electrostatic changes during the catalytic cycle ultimately resulting in its dissociation from the membrane upon completion of the cycle. In addition, the study outlines a successful approach to transform membrane associated proteins, which tend to aggregate upon purification, into a monomeric and soluble form.     

Mechanism of Sporicidal Activity for the Synergistic Combination of Peracetic Acid and Hydrogen Peroxide

There is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H₂O₂) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H₂O₂ against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H₂O₂ to PAA formation. This study confirmed the synergistic activity of the combination of H₂O₂ and PAA. However, we observed that the sporicidal activity of the combination is largely due to PAA and not H₂O₂. Furthermore, we observed that the synergistic combination was based on H₂O₂ compromising the spore coat, which was the main spore resistance factor, likely allowing better penetration of PAA and resulting in the increased sporicidal activity.     

Adelphocorisella Miyamoto and Yasunaga newly recorded from Australia, with the description of a new species (Heteroptera: Miridae: Mirinae)

Adelphocorisella australis sp. n. is described from north Queensland. This, the first representative of the genus known from Australia, is compared with the two previously described species, both from Japan.     

Pathological effects of the microsporidium Nosema ceranae on honey bee queen physiology (Apis mellifera)

Nosema ceranae, a microsporidian parasite originally described in the Asian honey bee Apis cerana, has recently been found to be cross-infective and to also parasitize the European honey bee Apis mellifera. Since this discovery, many studies have attempted to characterize the impact of this parasite in A. mellifera honey bees. Nosema species can infect all colony members, workers, drones and queens, but the pathological effects of this microsporidium has been mainly investigated in workers, despite the prime importance of the queen, who monopolizes the reproduction and regulates the cohesion of the society via pheromones. We therefore analyzed the impact of N. ceranae on queen physiology. We found that infection by N. ceranae did not affect the fat body content (an indicator of energy stores) but did alter the vitellogenin titer (an indicator of fertility and longevity), the total antioxidant capacity and the queen mandibular pheromones, which surprisingly were all significantly increased in Nosema-infected queens. Thus, such physiological changes may impact queen health, leading to changes in pheromone production, that could explain Nosema-induced supersedure (queen replacement).     

Three major mesoplanktonic communities resolved by in situ imaging in the upper 500 m of the global ocean

Aim

The distribution of mesoplankton communities has been poorly studied at global scale, especially from in situ instruments. This study aims to (1) describe the global distribution of mesoplankton communities in relation to their environment and (2) assess the ability of various environmental-based ocean regionalizations to explain the distribution of these communities.

Location

Global ocean, 0–500 m depth.

Time Period

2008–2019.

Major Taxa Studied

Twenty-eight groups of large mesoplanktonic and macroplanktonic organisms, covering Metazoa, Rhizaria and Cyanobacteria.

Methods

From a global data set of 2500 vertical profiles making use of the Underwater Vision Profiler 5 (UVP5), an in situ imaging instrument, we studied the global distribution of large (>600 μm) mesoplanktonic organisms. Among the 6.8 million imaged objects, 330,000 were large zooplanktonic organisms and phytoplankton colonies, the rest consisting of marine snow particles. Multivariate ordination (PCA) and clustering were used to describe patterns in community composition, while comparison with existing regionalizations was performed with regression methods (RDA).

Results

Within the observed size range, epipelagic plankton communities were Trichodesmium-enriched in the intertropical Atlantic, Copepoda-enriched at high latitudes and in upwelling areas, and Rhizaria-enriched in oligotrophic areas. In the mesopelagic layer, Copepoda-enriched communities were also found at high latitudes and in the Atlantic Ocean, while Rhizaria-enriched communities prevailed in the Peruvian upwelling system and a few mixed communities were found elsewhere. The comparison between the distribution of these communities and a set of existing regionalizations of the ocean suggested that the structure of plankton communities described above is mostly driven by basin-level environmental conditions.

Main Conclusions

In both layers, three types of plankton communities emerged and seemed to be mostly driven by regional environmental conditions. This work sheds light on the role not only of metazoans, but also of unexpected large protists and cyanobacteria in structuring large mesoplankton communities.     

A technique to continuously measure arteriovenous oxygen content difference and P50 in vivo

In hypoxemic high-altitude polycythemic natives whose arterial O2 saturation (SaO2) normally ranges between 70 and 80%, three polyurethane catheters with both optical and polarographic sensors were inserted into the radial artery to measure SaO2 and O2 tension (PaO2), and three thermodilution fiber-optic balloon-tipped catheters were floated into the pulmonary artery to measure mixed venous O2 saturation (SvO2). Correlation of the in vivo SaO2, PaO2, and SvO2 values with the in vitro measurements was high (r = 0.97, 0.99, and 0.98, respectively). Both catheters were inserted in one polycythemic subject before and 4 days after isovolemic hemodilution. Data from the sensors were used to calculate arteriovenous O2 content difference (CaO2 - CvO2) and the O2 half-saturation pressure of hemoglobin (P50). The mean +/- 1 SD of the in vivo and in vitro P50 calculated with the Hill equation was 27.61 +/- 2.15 Torr and 27.35 +/- 1.60 Torr, respectively. The mean +/- 1 SD of the absolute difference between the in vivo and in vitro measurements was 1.16 +/- 1.21 Torr. The in vivo CaO2 - CvO2 correlated well with the in vitro measurements (r = 0.93), and the mean +/- 1 SD of the error in the catheter CaO2 - CvO2 measurements was 0.47 +/- 0.50 ml/dl. This technique appears to provide a useful measurement of blood gas exchange parameters and should be applicable to the study of exercise physiology and clinical regulation of O2 transport.     

Rapid characterization of protein molecular weights and hydrodynamic structures by quasielastic laser-light scattering

Two methods for the characterization of protein molecular weights from their diffusion coefficients are discussed. These measurements can be made quickly and reliably at low concentrations using quasielastic light-scattering techniques. First, an empirical calibration of the diffusion coefficient at infinite dilution of denatured random coils against molecular weight is reported. The second method combines the measurement of D₀ with the intrinsic viscosity [η]. This D₀–[η] relationship proves to be very insensitive to polymers structure or solvent type. The data indicate that the ratio of the hydrodynamic radius measured by viscosity to the hydrodynamic radius measured by diffusion is about 15% smaller than that predicted by theoretical models. The nature of the molecular-weight average obtained for polydisperse systems is defined for a Schulz distribution. These hydrodynamic methods have also been used to demonstrate the presence of chain branching in the glycoprotein ovomucoid. In addition, a method is proposed by which the effective segment length and an excluded volume parameter for random coils may be evaluated for diffusion measurements.     

The vitamin D receptor: a primitive steroid receptor related to thyroid hormone receptor

We have previously reported the cloning and sequencing of both the chicken and human vitamin D3 receptor cDNAs. A comparison of their deduced amino acid sequence with that of the other classic steroid hormone receptors and the receptor for thyroid hormone indicates that there are two regions of conservation between these molecules. The first is a 70 amino acid, cysteine-rich sequence (C1), the second region (C2) is a 62 amino acid region located towards the carboxyl terminus of the proteins. In other systems the former has been identified as a region responsible for DNA binding activity, whereas the latter represents the NH2-terminal boundary of the hormone binding domain. We present here evidence utilizing eucaryotic expression of cDNA encoding the hVDR C1 domain, followed by a DNA cellulose chromatography assay, which confirms that the DNA binding activity resides in this region of the receptor for vitamin D3. Additionally, the vitamin D3 receptor contains a 60 amino acid portion at its carboxyl terminus (C3) which exhibits homology with the receptor for thyroid hormone. Conservation in this region of the molecule is found only between homologous or closely related receptors. This indicates a relationship between the vitamin D3 receptor and the receptor for thyroid hormone and may suggest that they evolved from a single primordial gene.