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A new transmission electron microscopy (TEM) specimen preparation method that utilizes a combination of focused ion beam (FIB) methods and ultramicrotomy is demonstrated. This combined method retains the benefit of site-specific sampling by FIB but eliminates ion beam-induced damage except at specimen edges and allows recovery of many consecutive sections. It is best applied to porous and/or fine-grained materials that are amenable to ultramicrotomy but are located in bulk samples that are not. The method is ideal for unique samples from which every specimen is precious, and we demonstrate its utility on fine-grained material from the one-of-a-kind Paris meteorite. Compared with a specimen prepared by conventional FIB methods, the final sections are uniformly thin and free from re-deposition and curtaining artifacts common in FIB specimens prepared from porous, heterogeneous samples.
Salmonella enterica serovar Wangata (S. Wangata) is an important cause of endemic salmonellosis in Australia, with human infections occurring from undefined sources. This investigation sought to examine possible environmental and zoonotic sources for human infections with S. Wangata in north-eastern New South Wales (NSW), Australia. The investigation adopted a One Health approach and was comprised of three complimentary components: a case–control study examining human risk factors; environmental and animal sampling; and genomic analysis of human, animal and environmental isolates. Forty-eight human S. Wangata cases were interviewed during a 6-month period from November 2016 to April 2017, together with 55 Salmonella Typhimurium (S. Typhimurium) controls and 130 neighbourhood controls. Indirect contact with bats/flying foxes (S. Typhimurium controls (adjusted odds ratio (aOR) 2.63, 95% confidence interval (CI) 1.06–6.48)) (neighbourhood controls (aOR 8.33, 95% CI 2.58–26.83)), wild frogs (aOR 3.65, 95% CI 1.32–10.07) and wild birds (aOR 6.93, 95% CI 2.29–21.00) were statistically associated with illness in multivariable analyses. S. Wangata was detected in dog faeces, wildlife scats and a compost specimen collected from the outdoor environments of cases’ residences. In addition, S. Wangata was detected in the faeces of wild birds and sea turtles in the investigation area. Genomic analysis revealed that S. Wangata isolates were relatively clonal. Our findings suggest that S. Wangata is present in the environment and may have a reservoir in wildlife populations in north-eastern NSW. Further investigation is required to better understand the occurrence of Salmonella in wildlife groups and to identify possible transmission pathways for human infections.
We investigated whether older adults are more likely than younger adults to violate a foundational property of rational decision making, the axiom of transitive preference. Our experiment consisted of two groups, older (ages 60-75; 21 participants) and younger (ages 18-30; 20 participants) adults. We used Bayesian model selection to investigate whether individuals were better described via (transitive) weak order-based decision strategies or (possibly intransitive) lexicographic semiorder decision strategies. We found weak evidence for the hypothesis that older adults violate transitivity at a higher rate than younger adults. At the same time, a hierarchical Bayesian analysis suggests that, in this study, the distribution of decision strategies across individuals is similar for both older and younger adults.
Although many mental health care systems provide care interventions that are not related to direct health care, little is known about the interfaces between the latter and core health care. ‘Core health care’ refers to services whose explicit aim is direct clinical treatment which is usually provided by health professionals, i.e., physicians, nurses, psychologists. ‘Other care’ is typically provided by other staff and includes accommodation, training, promotion of independence, employment support and social skills. In such a definition, ‘other care’ does not necessarily mean being funded or governed differently. The aims of the study were: (1) using a standard classification system (Description and Evaluation of Services and Directories in Europe for Long Term Care, DESDE-LTC) to identify ‘core health’ and ‘other care’ services provided to adults with mental health problems; and (2) to investigate the balance of care by analysing the types and characteristics of core health and other care services.
The study was conducted in eight selected local areas in eight European countries with different mental health systems. All publicly funded mental health services, regardless of the funding agency, for people over 18 years old were identified and coded. The availability, capacity and the workforce of the local mental health services were described using their functional main activity or ‘Main Types of Care’ (MTC) as the standard for international comparison, following the DESDE-LTC system.
In these European study areas, 822 MTCs were identified as providing core health care and 448 provided other types of care. Even though one-third of mental health services in the selected study areas provided interventions that were coded as ‘other care’, significant variation was found in the typology and characteristics of these services across the eight study areas.
The functional distinction between core health and other care overcomes the traditional division between ‘health’ and ‘social’ sectors based on governance and funding. The overall balance between core health and other care services varied significantly across the European sites. Mental health systems cannot be understood or planned without taking into account the availability and capacity of all services specifically available for this target population, including those outside the health sector.
During May 2015, an increase in Salmonella Agona cases was reported from western Sydney, Australia. We examine the public health actions used to investigate and control this increase. A descriptive case-series investigation was conducted. Six outbreak cases were identified; all had consumed cooked tuna sushi rolls purchased within a western Sydney shopping complex. Onset of illness for outbreak cases occurred between 7 April and 24 May 2015. Salmonella was isolated from food samples collected from the implicated premise and a prohibition order issued. No further cases were identified following this action. Whole genome sequence (WGS) analysis was performed on isolates recovered during this investigation, with additional S. Agona isolates from sporadic-clinical cases and routine food sampling in New South Wales, January to July 2015. Clinical isolates of outbreak cases were indistinguishable from food isolates collected from the implicated sushi outlet. Five additional clinical isolates not originally considered to be linked to the outbreak were genomically similar to outbreak isolates, indicating the point-source contamination may have started before routine surveillance identified an increase. This investigation demonstrated the value of genomics-guided public health action, where near real-time WGS enhanced the resolution of the epidemiological investigation.
Monitoring infections and risk in people who inject drugs (PWID) is important for informing public health responses. In 2011, a novel hepatitis C antibody (anti-HCV) avidity-testing algorithm to identify samples compatible with recent primary infection was introduced into a national surveillance survey. PWID are recruited annually, through >60 needle-and-syringe programmes and prescribing services. Of the 980 individuals that could have been at risk of HCV infection, there were 20 (2%) samples that were compatible with recent primary infection. These were more common among: those imprisoned ⩾5 times [8/213; adjusted odds ratio (aOR) 8·7, 95% confidence interval (CI) 2·04–37·03]; women (8/230; aOR 3·8, 95% CI 1·41–10·38); and those ever-infected with hepatitis B (5/56; aOR 6·25, 95% CI 2·12–18·43). This study is the first to apply this algorithm and to examine the risk factors associated with recently acquired HCV infection in a national sample of PWID in the UK. These findings highlight underlying risks and suggest targeted interventions are needed.
Sandy (sdy) is a mouse mutant with diluted pigmentation which recently arose in the DBA/2J strain. Genetic tests indicate it is caused by an autosomal recessive mutation on mouse Chromosome 13 near the cr and Xt genetic loci. This mutation is different genetically and hematologically from previously described mouse pigment mutations with storage pool deficiency (SPD). The sandy mutant has diluted pigmentation in both eyes and fur, is fully viable and has prolonged bleeding times. Platelet serotonin levels are extremely low although ATP dependent acidification activity of platelet organelles appears normal. Also, platelet dense granules are extremely reduced in number when analysed by electron microscopy of unfixed platelets. Platelets have abnormal uptake and flashing of the fluorescent dye mepacrine. Secretion of lysosomal enzymes from kidney and from thrombin-stimulated platelets is depressed 2- and 3-fold, and ceroid pigment is present in kidney. Sandy platelets have a reduced rate of aggregation induced by collagen. The sandy mutant has an unusually severe dense granule defect and thus may be an appropriate model for cases of human Hermansky-Pudlak syndrome with similarly extreme types of SPD. It represents the tenth example of a mouse mutant with simultaneous defects in melanosomes, lysosomes and/or platelet dense granules.
High-pressure studies have been performed on heavy rare earth metals Terbium (Tb) to 155 GPa and Holmium (Ho) to 134 GPa in a diamond anvil cell at room temperature. The following crystal structure sequence was observed in both metals hcp ⟶ Sm-type ⟶ dhcp ⟶ distorted fcc (hR-24) ⟶ monoclinic (C2/m) with increasing pressure. The last transformation to a low symmetry monoclinic phase is accompanied by a volume collapse of 5 % for Tb at 51 GPa and a volume collapse of 3 % for Ho at 103 GPa. This volume collapse under high pressure is reminiscent of f-shell delocalization in light rare earth metal Cerium (Ce), Praseodymium (Pr), and heavy actinide metals Americium (Am) and Curium (Cm). The orthorhombic Pnma phase that has been reported in Am and Cm after f-shell delocalization is not observed in heavy rare earth metals under high pressures.
Photodynamic therapy (PDT) offers potential as a non-invasive treatment of periodontal disease. In this study, microcosm biofilms were grown in vitro under conditions designed to mimic subgingival plaques typically found in patients with periodontitis. To investigate potential PDT modalities, biofilms were exposed to light from a helium/neon laser in conjunction with a photosensitizer, toluidine blue O (TBO), at varying output and concentration, respectively. To determine cytotoxic effects, viability profiling was undertaken on whole biofilms using standard plating methods, and on horizontal cross-sections of biofilms using confocal laser-scanning microscopy (CLSM) in conjunction with a differential viability stain. A light energy dose of 94.5 J in combination with 81.7 μM TBO was found to be optimal, achieving significant kills of over 97%. CLSM enabled visualization of the effects of PDT in three dimensions. Viability profiling of the CLSM images revealed that lethal photosensitization was most effective in the upper layers of biofilm. PDT was found to reduce the viability of subgingivally modelled plaques in vitro by a magnitude similar to that of chlorhexidine digluconate, which is commonly used to treat periodontal disease. The findings of this study indicate that PDT may be an effective alternative to conventional modalities in the treatment of periodontal disease.
Nematode assemblages were studied from four sublittoral sites at 50–56 m depth in the Gulf of Maine, north-eastern coast of the USA, within the context of an open ocean aquaculture experimental site. All four sites, two potential impact and two control sites, had a similar muddy–sand bottom and low organic content. Seventy genera in 27 families were recorded from a total of 1072 individuals. All but one taxa could be related to known genera. Family Comesomatidae was the most dominant with close to a third (27·6%) of the total individuals. At the genus level Sabatieria and Setosabatieria were most dominant with a quarter of the total number of individuals. Composition of dominant families from the Gulf of Maine differed from all hitherto reported sublittoral or deep-sea communities from both sides of the Atlantic, and most similar with European estuaries.
Nematode diversity at the genus-level was reasonably high and was comparable with Mediterranean samples. Most diversity indices ordered the four sites similarly with Site 2 as the most diverse followed by Site 5 and then Site 6. By contrast the relative diversity of Site 4 depended on the index employed and its k-dominance curve crossed that of the others. Furthermore based on clustering the community at Site 4 was least similar to the others. Although these observations could be related to the fact that Site 4 is within the expected impact zone of the fish cage, the low number of fish introduced by the time of sampling and the lack of any difference in the maturity index among all the sites argue that these results can be considered before-impact data for further monitoring of the open ocean aquaculture experiment.
A new paradigm where morphological information is documented and communicated using digital multifocal images is introduced. Each video image is comparable with visualization of a specimen under a microscope where the movie can be played back and forth to mimic focusing through a specimen. Web-based and openly accessible digital multifocal images were used to document and effectively communicate the morphology of all the identified genera in this study. This approach for documenting and communicating survey results is proposed as a benchmark for future similar studies that would enhance standardization and quality control of meiofaunal taxonomy, ecology and biodiversity studies.
New high-pressure x-ray diffraction data on uranium metal (99.9 %) in a diamond anvil cell is presented to 100 GPa (Volume compression V/Vo = 0.700) at room temperature using a variety of pressure markers like ruby, copper, and platinum. The diffraction patterns are carefully indexed allowing for reversal of peak positions based on anisotropic compression. We report anisotropic compression of the orthorhombic unit cell with the axial ratio b/a increasing initially to 40 GPa followed by a rapid decrease at higher pressure. On the other hand, axial ratio c/a shows a rapid increase with increasing pressure followed by saturation at megabar pressures. The most recent full potential electronic structure calculations reproduce the increasing tend of axial ratio c/a to 100 GPa but do not explain the variation in the b/a ratio. Our detailed analysis of all available experimental data also indicates that the observed anisotropic effects are intrinsic to Uranium and are independent of the pressure medium used in the high-pressure experiments.
Data on injecting anabolic steroid users, within the national Unlinked
Prevalence Monitoring Survey of injecting drug users (IDUs) were analysed
to determine their
risk of acquiring blood borne viruses. One hundred and forty-nine participants
injected anabolic steroids in the previous month were identified from 1991–6,
1·4% of all participation episodes in the survey. Rates
of needle and syringe sharing by steroid
users were low. Three of the 149 (2·0%) had anti-HBc and
none had anti-HIV in their salivary
specimens. The prevalence of anti-HBc in steroid injectors was significantly
lower than in
heroin injectors, 275/1509 (18%) (P<0·001), or in
28/239 (12%) (P<0·001). The risk of blood borne virus
amongst these steroid injectors is low,
probably due to hygienic use of injecting equipment and low levels of sharing.
It is important
to distinguish steroid injectors from other IDUs because they are a distinct
group in terms of
lifestyle and injecting practice.
We have studied the magnetic properties of the Co/Cu(110) system at 300K, using the magneto-optic Kerr effect. After a given deposition of Co in the thickness range 5ML<dCo<40ML, the M-H loop is observed to evolve continuously in time until the magnetic easy axis has switched 90° from the  to [1–10] direction. We attribute this behaviour to the reversal in sign of the effective in-plane uniaxial anisotropy constant, due to the adsorption of submonolayer quantities of a residual gas from the UHV environment. STM images reveal the growth of elongated Co island structures preferentially oriented along the  direction providing ‘step like’ edge sites for gas adsorption. We find the easy axis can be switched back to the  direction by depositing a submonolayer Cu overlayer, and that for relatively thick Co films (>15ML) the Cu overlayer can cause the magnetisation to take up intermediate angles. We analyse this behaviour using a simple model of the effective anisotropy energies.
This paper describes the key aspects of a parser developed at
the University of Pennsylvania
from 1958 to 1959. The parser is essentially a cascade of finite
state transducers. To the best
of our knowledge, this is the first application of finite state
transducers to parsing. This parser
was recently faithfully reconstructed from the original documentation.
Many aspects of this
program have a close relationship to some of the recent work on finite
Robert Perry, Department of Neuropathology, Newcastle General Hospital,Ian McKeith, University of Newcastle upon Tyne,Elaine Perry, MRC Neurochemical Pathology Unit, Newcastle General Hospital
Hallucinations are one of the defining features of the clinical syndrome associated with cortical Lewy body pathology. However, it is not clear whether the time course of hallucinations in Lewy body dementia is different from that in other dementias. We therefore studied the natural history of hallucinations in dementia. Since neuroleptics may be used to treat hallucinations and may have deleterious effects, we also examined the impact of neuroleptic use on cognitive decline. Ninety-eight patients with dementia were assessed every 4 months on a median of eight occasions. Fifty-one patients came to autopsy. Our longitudinal study shows that hallucinations beginning within the first three years of dementia are associated with cortical Lewy body pathology and reduced life expectancy. Patients with cortical Lewy body pathology were more likely to have persistent as opposed to fleeting hallucinations. This information could be incorporated into operational clinical criteria for Lewy body dementia. We did not find an increased mortality amongst those with cortical Lewy body pathology who took neuroleptics. However, men who took neuroleptics had a more rapid rate of cognitive decline than those who did not. This association was not apparent in women. We did not find evidence of increased fluctuation in cognitive ability in the Lewy body group.
The appearance of hallucinations in the context of dementia has implications for diagnosis, prognosis and management. The possibility that hallucinations occur as part of a clinical syndrome is suggested by the findings that hallucinations co-occur more commonly than would be expected with fluctuating cognitive impairment (Ballard et al., 1993) and with extrapyramidal symptoms in patients having a clinical diagnosis of Alzheimer's disease (Mayeux et al., 1985).