Anisotropy and coherent vortex structures in planetary turbulence

High-resolution numerical simulations were made of unforced, planetary-scale fluid dynamics. In particular, the simulation was based on the quasi-geostrophic equations for a Boussinesq fluid in a uniformly rotating and stably stratified environment, which is an idealization for large regions of either the atmosphere or ocean. The solutions show significant discrepancies from the long-standing theoretical prediction of isotropy. The discrepancies are associated with the self-organization of the flow into a large population of coherent vortices. Their chaotic interactions govern the subsequent evolution of the flow toward a final configuration that is nonturbulent.     

The Activity of Matrix Metalloproteinase-2 and -9 in Serum of Pregnant and Non-Pregnant Bitches

The aim of this study was to investigate, whether the activity of matrix metalloproteinase (MMP)-2 and -9 in the serum of pregnant and non-pregnant bitches differs significantly. For this purpose, 81 blood samples were taken from pregnant bitches at days 5-13, 15-21, 24-31, 34-40 and 41-50 after mating, and 51 samples from non-pregnant animals at corresponding times. Relative enzyme activity, calculated as the percentage of serum enzyme activity on enzyme activity in a control sample, was determined with a commercially available assay after activation of serum MMPs with p-aminophenylmercuric acetate (APMA). In addition, serum oestradiol (E(2)) and progesterone (P(4)) concentrations were measured with an enzymeimmunoassay (EIA). In the pregnant bitches, at days 5-13 and 15-21 after mating, the mean activity of both MMPs was significantly higher than in non-pregnant animals (28.5% vs 24.5% and 27.7% vs 22.6%; p < 0.01). Moreover, in the pregnant bitches, significant correlations were detected between the serum enzyme activity and the serum concentrations of E(2) (-0.900; p < 0.05) and P(4) (+0.667; p < 0.05).     

A Screening for the Occurrence of Autoreactive Antibodies in Sera of Pregnant and Non-pregnant Bitches

Sera of healthy pregnant (group I, n = 11) and non-pregnant (group II, n = 11) bitches were screened for autoantibodies (AAb). In both groups, blood samples were drawn every fifth day between days 5 and 55 after mating. Serum was analysed via indirect immunofluorescence (IIF) with the Canine ANA HEp-2 Screening Kit. In all animals, anticytoplasmic AAb were detected. Utilizing primate-heart substrate slides AAb against contractile proteins of the cytoplasm could be observed. The predominating fluorescence pattern in pregnant animals resembled above all desmin, which was proven via Western blot. The sera were then pre-incubated with tropomyosin, actin, vimentin, vinculin and keratin solutions, and assessed on HEp-2 slides and on human and canine fibroblasts as well. The latter substrate was used to verify whether the detected Ab were in fact AAb. Utilizing tropomyosin, revealed elimination of the cytoplasmic fluorescences on all three substrates. It is therefore assumed, that in sera of healthy dogs, AAb against contractile structure proteins of the cytoplasm are present regularly. The majority of pregnant bitches presented with higher end-point titres (EPT), than to be found in non-pregnant dogs. AAb against desmin played the key role in those patterns. In addition, sera were screened for thyroid specific AAb, namely thyroglobulin, thyroid peroxidase (TPO), T3 and T4, and for AAb against insulin by ELISA or Western blot (TPO). Only in two of the pregnant bitches a weak positive reaction (1:100) for T3-AAb was detected.     

IFN‐τ Acts in a Dose‐Dependent Manner on Prostaglandin Production by Buffalo Endometrial Stromal Cells Cultured in vitro

Interferon‐τ (IFN‐τ) has been recognized as the primary embryonic signal responsible for maternal recognition of pregnancy. Uterine endometrium produces both prostaglandin F_2α (PGF_2α) and prostaglandin E₂ (PGE₂). PGF_2α is responsible for the luteolysis; however, PGE₂ favours establishment of pregnancy by its luteoprotective action. In this study, the dose‐response effect of recombinant bovine IFN‐τ (rbIFN‐τ) on prostaglandin (PG) production by buffalo endometrial stromal cells cultured in vitro was studied. Buffalo endometrial stromal cells were isolated by double enzymatic digestion, initially with trypsin III followed by a cocktail of trypsin III, collagenase type II and DNase I and subsequently cultured till confluence. Further, cells were treated with different doses of rbIFN‐τ (0.001, 0.01, 0.1, 1.0 and 10 μg/ml) and keeping a separate set of control. Culture supernatant was collected after 6, 12 and 24 h of treatment. PG levels in the culture supernatant were measured by enzyme immune assay (EIA) and total cellular protein estimated by Bradford method. Results indicated that buffalo endometrial stromal cells following rbIFN‐τ treatment enhanced the secretion of both PGE₂ and PGF_2α, and also its ratio in a strict dose‐dependent manner with a significant increase (p < 0.01) in PGE₂ production at 1 μg/ml dose of rbIFN‐τ and maximal stimulation for both PG was observed at 10 μg/ml. Further, both PG production and its ratio were increased significantly (p < 0.01) in a time‐dependent fashion in all the groups at 6, 12 and 24 h post‐treatment with highest level achieved at 24 h as compared with control. Absolute levels of PGE₂ remained higher than PGF_2α indicating PGE₂ as the major PG produced by endometrial stromal cells. The dose‐dependent response of rbIFN‐τ signifies the importance of optimum concentration of IFN‐τ for the embryonic development especially during the critical period to establish successful pregnancy.     

Distal aortic aneurysm presumed to be secondary to an infected umbilical artery in a foal

Abstract

CASE HISTORY:?A 3-month-old female Warmblood foal was presented after displaying signs of colic with pyrexia for 5 days.

CLINICAL AND PATHOLOGICAL FINDINGS:?The foal continued to show signs of colic, frequently passed urine, and was pyrexic with an elevated white blood cell count. The umbilical stalk was thickened but there was no evidence of purulent material. Exploratory laparotomy revealed an enlarged left umbilical artery remnant tightly adhered to the bladder wall. The left umbilical artery continued to an aneurysm involving the distal aorta. The foal was subject to euthanasia and post-mortem examination confirmed a spherical aortic aneurysm, in the dorsal midline caudal to the kidneys that contained a large thrombus. Histopathological examination revealed inflammation and necrosis of the tunica intima and tunica media of the left umbilical artery with suppuration and bacterial colonies evident in the periarterial tissues.

DIAGNOSIS:?Infected aortic aneurysm presumably caused by an umbilical artery infection.

CLINICAL RELEVANCE:?A previously undetected umbilical infection appears to have resulted in an unusual delayed complication causing signs of colic in a foal. Veterinarians should be aware of this condition, and the possibility that it may be a cause of signs of colic in foals. Diagnosis based on ultrasonography should be possible, but may require sedation, visceral analgesia and careful examination.     

Southern hemisphere origin of the cretaceous laytonville limestone of california

New paleomagnetic, paleontologic, and stratigraphic data from outcrops of the Laytonville Limestone (101 to 88 million years old) support a Southern Hemisphere origin. A paleomagnetic megaconglomerate test is statistically significant and suggests magnetization at 14 degrees +/- 5 degrees south, predating Late Cretaceous to Eocene (70 to 50 million years ago) accretion. Rapid Kula plate movement or the existence and demise of a now vanished oceanic plate (or both) are required to accommodate the greater than 50 degrees of poleward displacement implied by the paleomagnetic data. This rapid motion brings into question the validity of a "speed limit" for absolute plate velocity based on present-day plate motions.     

An Archean Geomagnetic Reversal in the Kaap Valley Pluton, South Africa

The Kaap Valley pluton in South Africa is a tonalite intrusion associated with the Archean Barberton Greenstone Belt. Antipodal paleomagnetic directions determined from the central and marginal parts of the pluton record a geomagnetic reversal that occurred as the pluton cooled. The age of the reversal is constrained by an 40Ar/39Ar plateau age from hornblende at 3214 +/- 4 million years, making it the oldest known reversal. The data presented here suggest that Earth has had a reversing, perhaps dipolar, magnetic field since at least 3.2 billion years ago.     

The dynamics of zooxanthellae populations: A long-term study in the field

Coral bleaching characterized by the expulsion of symbiotic algae (zooxanthellae) is an increasing problem worldwide. Global warming has been implicated as one cause, but the phenomenon cannot be fully comprehended without an understanding of the variability of zooxanthellae populations in field conditions. Results from a 6-year field study are presented, providing evidence of density regulation but also of large variability in the zooxanthellae population with regular episodes of very low densities. These bleaching events are likely to be part of a constant variability in zooxanthellae density caused by environmental fluctuations superimposed on a strong seasonal cycle in abundance.     

Hot and dry deep crustal xenoliths from tibet

Anhydrous metasedimentary and mafic xenoliths entrained in 3-million-year-old shoshonitic lavas of the central Tibetan Plateau record a thermal gradient reaching about 800 degrees to 1000 degrees C at a depth of 30 to 50 kilometers; just before extraction, these same xenoliths were heated as much as 200 degrees C. Although these rocks show that the central Tibetan crust is hot enough to cause even dehydration melting of mica, the absence of hydrous minerals, and the match of our calculated P-wave speeds and Poisson's ratios with seismological observations, argue against the presence of widespread crustal melting.