Quantum fluctuations create intermolecular forces that pervade macroscopic bodies. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces. ...However, as recognized in the theories of Casimir, Polder and Lifshitz, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies. Here we show experimentally that, in accord with theoretical prediction, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction.
Fifty years ago, inoculation with bovine papillomavirus (BPV) was found to cause mesenchymal tumors of the skin in cattle and horses, as well as tumors of the bladder in cattle. Subsequent to these ...studies of BPVs, human papillomaviruses (HPVs) were found to cause cervical cancer resulting in intense research into papillomaviruses. During the past 50 years, the ways that HPVs and BPVs cause disease have been investigated, and both HPVs and BPVs have been associated with an increasingly diverse range of diseases. Herein, the biology, oncogenic mechanisms, and diseases associated with BPVs are compared with those of HPVs. As reviewed, there are currently significant differences between BPVs and HPVs. However, research 50 years ago into BPVs formed a prologue for the recognition that papillomaviruses have a significant role in human disease, and it is possible that future research may similarly reveal that BPVs are less different from HPVs than is currently recognized.
An approximately 10-year-old, castrated male domestic short-haired cat developed swelling and ulceration of the second digit of the right front paw. Radiographs revealed a spherical soft tissue ...swelling with irregular distal margins that contained multiple lacy mineral opacities. The digit was amputated and submitted for histology. No recurrence has been observed 7 months after amputation.
Histology revealed a moderately well-circumscribed proliferation of well-differentiated squamous cells arranged in trabeculae and nests. Numerous thin spicules of osseous metaplasia were visible throughout the neoplasm. Around 70% of the neoplastic cells contained papillomavirus-induced cell changes including large amphophilic cytoplasmic bodies and cells with shrunken nuclei surrounded by a clear halo. Intense p16
CDKN2A
protein immunostaining was visible within the neoplastic cells, suggesting papillomavirus-induced changes in cell regulation. A DNA sequence from a putative novel Taupapillomavirus type was amplified from the neoplasm.
Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus type.
The findings in this case increase the number of papillomavirus types known to infect cats, and the squamous cell carcinoma had histological features that have not been previously reported. The neoplasm was not as invasive as is typical for a squamous cell carcinoma and excision appeared curative. This is the first report of an osteoinductive squamous cell carcinoma of the skin of cats and the neoplasm had a unique radiographic appearance.
To determine the gross and histological changes developing in the liver of sheep 8 months after a single period of exposure to sporidesmin and to examine associations between the severity of gross ...and histological changes to the liver and the activity of gamma-glutamyltransferase (GGT) measured in serum in the sheep at the time of intoxication.
A group of 50 Romney ewes grazing a mixed ryegrass/white clover pasture were accidentally exposed to sporidesmin for up to 5 weeks. Seventeen sheep showed photosensitisation and four were subject to euthanasia. The remaining sheep were moved to safer pasture and a blood sample collected and analysed for serum GGT activity. The sheep were slaughtered 8 months later. Livers were classified into grossly normal, moderately affected, or severely affected and histology performed to assess portal fibrosis, biliary hyperplasia, portal inflammation, and hepatocellular necrosis.
Serum GGT activity ranged from 59 to 1571 IU/L (reference range 32-70 IU/L). Thirteen of the 46 sheep developed clinical signs of facial eczema. However, at slaughter all except four sheep had grossly detectable changes to the shape of the liver including atrophy of the left lobe and the lateral part of the right lobe. Hypertrophy was typically limited to the medial part of the right lobe. In severely affected sheep the liver hypertrophy formed a nodular bulging mass. Changes in the liver shape were classified as severe in 25 and moderate in 17 sheep. Severely affected livers contained significantly more fibrosis than moderately affected livers (p = 0.001, Cliff's delta (d) = 0.68). While there was significantly greater fibrosis and biliary hyperplasia in the left than right lobes, histological changes were present throughout all samples taken of affected livers. Serum GGT activity taken during acute intoxication were correlated to subsequent fibrosis and biliary hyperplasia.
Hepatic fibrosis develops in sheep after a single episode of sporidesmin intoxication, even in sheep with only mildly elevated GGT activity at the time of intoxication. Furthermore, the severity of the subsequent hepatic fibrosis was predicted by the degree of elevation of serum GGT activity during intoxication.
More research is required to determine how the presence and severity of hepatic fibrosis affect animal production. However, if hepatic fibrosis does decrease production, the consistent development of fibrosis after sporidesmin ingestion reinforces the importance of avoiding exposure of livestock to sporidesmin.
GGT: Gamma-glutamyltransferase; d: Cliff's delta
A 6-year-old Thoroughbred mare developed multiple flat plaques, < 1 cm in diameter, on the left front fetlock. These were treated topically using 5-fluorouracil and resolved after 4 weeks. However, ...additional similar plaques developed on the left front pastern 5 months later. These lesions resolved within 3 months without treatment.
One plaque that developed initially and one plaque that developed later were examined histologically. Both consisted of well-demarcated foci of moderate epidermal hyperplasia. Scattered throughout both plaques were cells showing evidence of papillomavirus-induced cell changes and the same papillomaviral DNA sequence was amplified from both lesions using PCR. As the novel sequence had 79.1% similarity to a partial sequence previously amplified from an equine cutaneous wart and 67.9% similarity to Equus caballus papillomavirus type 1, these results indicate detection of a putative novel papillomavirus type.
Multiple cutaneous plaques due to infection by a novel papillomavirus type.
Unlike more typical equine cutaneous warts which generally appear as pedunculated and filiform masses, the lesions in this horse appeared as raised plaques. With the exception of aural plaques that are confined to the ears, localised clusters of papillomaviral plaques have not been previously described in horses. The lesions contained subtle histological evidence of papillomavirus infection and careful examination is required to differentiate these plaques from pre-neoplastic lesions. The plaques contained a putative novel papillomavirus type. These results increase the spectrum of papillomavirus-induced skin disease in horses.
Studies the results of biopsies taken from dogs in New Zealand between 2012 and 2016 to evaluate canine mammary gland samples for their neoplasticity, whether lesions were malignant or benign, and ...whether age, reproductive status or breed of dog, or size of the mammary mass were associated with the histological diagnosis. Notes the current review is a preliminary investigation of canine mammary gland diseases in the country. Source: National Library of New Zealand Te Puna Matauranga o Aotearoa, licensed by the Department of Internal Affairs for re-use under the Creative Commons Attribution 3.0 New Zealand Licence.
The 14 essays that make up this 2003 volume are written by leading international scholars to provide an authoritative survey of the state of comparative legal studies. Representing such varied ...disciplines as the law, political science, sociology, history and anthropology, the contributors review the intellectual traditions that have evolved within the discipline of comparative legal studies, explore the strengths and failings of the various methodologies that comparatists adopt and, significantly, explore the directions that the subject is likely to take in the future. No previous work had examined so comprehensively the philosophical and methodological foundations of comparative law. This is quite simply a book with which anyone embarking on comparative legal studies will have to engage.
For humans, strong evidence indicates that some mucosal papillomavirus (PV) types cause genital and oral neoplasia, and weaker evidence suggests that some cutaneous PVs may cause cutaneous squamous ...cell carcinomas (SCC). For nonhuman species, strong evidence supports a causal role of PVs in the development of feline and equine sarcoids. Likewise, PVs are believed to cause cutaneous SCCs in rabbits, western barred bandicoots, and some rodents. Furthermore, some evidence suggests that PVs may influence the development of both feline and canine cutaneous SCCs. This review discusses the evidence that PVs cause human cutaneous SCCs and the proposed mechanisms for this action. It then reviews preneoplastic and neoplastic skin diseases that are associated with PV infection in nonhuman mammals.
We report the discovery of the first hot subdwarf B (sdB) star with a massive compact companion in a wide (
P
= 892.5 ± 60.2 d) binary system. It was discovered based on an astrometric binary ...solution provided by the
Gaia
mission Data Release 3. We performed detailed analyses of the spectral energy distribution (SED) as well as spectroscopic follow-up observations and confirm the nature of the visible component as a sdB star. The companion is invisible despite of its high mass of
M
comp
= 1.50
−0.45
+0.37
M
⊙
. A main sequence star of this mass would significantly contribute to the SED and can be excluded. The companion must be a compact object, either a massive white dwarf or a neutron star. Stable Roche lobe overflow to the companion likely led to the stripping of a red giant and the formation of the sdB, the hot and exposed helium core of the giant. Based on very preliminary data, we estimate that ∼9% of the sdBs might be formed through this new channel. This binary might also be the prototype for a new progenitor class of supernovae type Ia, which has been predicted by theory.
Epichloë endophytes have been used successfully in pastoral systems to reduce the impact of insect pests through the expression of secondary metabolites. The use of endophytes could be extended to ...other plant species, such as cereal crops, where the production of bioactive secondary metabolites would reduce the reliance on pesticides for insect control. The success of this approach is dependent on the selection of an appropriate secondary metabolite target which must not only be effective against insect pests but also be safe for grazing and monogastric animals. The loline alkaloids have been identified as possible target metabolites as they are associated with potent effects on insects and low toxicity to grazing animals. The purpose of the current study was to generate toxicological data on the loline alkaloids in a monogastric system using mice. Male and female mice were fed 415 mg/kg/day total lolines for a 3-week period. The loline treatment caused no statistically significant effect on gross pathology, histology, haematology, blood chemistry, heart rate, blood pressure or motor coordination. Reduced weight gain and food consumption were noted in the loline groups during the initial stages of the experiment. This experiment raises no food safety concerns for the loline alkaloids.
•A short-term toxicity study of lolines was conducted using mice.•No toxicity was observed over 21 days at a dose rate of 415 mg/kg/day total lolines.•Endophytes are used to confer beneficial insect pest protection to their host plants.•A loline-expressing endophyte could be of great benefit in cereal crops.
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