To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
In this paper, we revisit our previous work in which we derive an effective macroscale description suitable to describe the growth of biological tissue within a porous tissue-engineering scaffold. The underlying tissue dynamics is described as a multiphase mixture, thereby naturally accommodating features such as interstitial growth and active cell motion. Via a linearization of the underlying multiphase model (whose nonlinearity poses a significant challenge for such analyses), we obtain, by means of multiple-scale homogenization, a simplified macroscale model that nevertheless retains explicit dependence on both the microscale scaffold structure and the tissue dynamics, via so-called unit-cell problems that provide permeability tensors to parameterize the macroscale description. In our previous work, the cell problems retain macroscale dependence, posing significant challenges for computational implementation of the eventual macroscopic model; here, we obtain a decoupled system whereby the quasi-steady cell problems may be solved separately from the macroscale description. Moreover, we indicate how the formulation is influenced by a set of alternative microscale boundary conditions.
Objectives: Research has shown that analyzing intrusion errors generated on verbal learning and memory measures is helpful for distinguishing between the memory disorders associated with Alzheimer’s disease (AD) and other neurological disorders, including Huntington’s disease (HD). Moreover, preliminary evidence suggests that certain clinical populations may be prone to exhibit different types of intrusion errors. Methods: We examined the prevalence of two new California Verbal Learning Test-3 (CVLT-3) intrusion subtypes – across-trial novel intrusions and across/within trial repeated intrusions – in individuals with AD or HD. We hypothesized that the encoding/storage impairment associated with medial-temporal involvement in AD would result in a greater number of novel intrusions on the delayed recall trials of the CVLT-3, whereas the executive dysfunction associated with subcortical-frontal involvement in HD would result in a greater number of repeated intrusions across trials. Results: The AD group generated significantly more across-trial novel intrusions than across/within trial repeated intrusions on the delayed cued-recall trials, whereas the HD group showed the opposite pattern on the delayed free-recall trials. Conclusions: These new intrusion subtypes, combined with traditional memory analyses (e.g., recall versus recognition performance), promise to enhance our ability to distinguish between the memory disorders associated with primarily medial-temporal versus subcortical-frontal involvement.
A requirement exists in the aeronautical industry for measuring temperature non-invasively in critical components, such as the turbine disc in an operating engine. Neutron diffraction, unique among nuclear techniques, offers the possibility of measuring both temperature and strain within an operating engine by virtue of the high penetration of neutrons through industrial materials. Static diffraction experiments on Waspaloy and Ti6A14V showed, by comparison with thermocouples, that both the diffraction peak position and the peak intensity can measure the tempeiaturc to within ±6 K aL 800 K. Measurements on a rotating Waspaloy disc, heated from its rim, showed that temperature gradients could be determined accurately by lattice parameter measurements. The large grain size in Waspaloy prevented accurate peak intensity measurements in this dynamic test. Finally, the structures within a small Pratt & Whitney engine in its equatorial plane were mapped by mounting the engine on an X-Y translator on the diffractometer and moving it through a grid of positions. Possible future directions in the field will be discussed.
Sleeve coldworking (SCW) is a mechanical process used in the aircraft industry to strengthen fastener holes of structural parts. By cold-expanding the holes, compressive residual stresses and a high dislocation density are introduced around the holes, the effect of which is to counteract the initiation and propagation of fatigue cracks and thus increase the fatigue life of the parts. The knowledge of residual stress due to SCW is therefore crucial for assessing the fatigue properties of a treated part. In this study, residual stresses were investigated, by employing neutron and X-ray diffraction methods, in a lug specimen that was sleeve coldworked and fatigued.
The specimen had been used for testing the influence of the SCW process on fatigue life and crack propagation behaviour under constant amplitude or variable amplitude cyclic loading.
Mini-sabbaticals are formal short-term training and educational experiences away from an investigator’s home research unit. These may include rotations with other research units and externships at government research or regulatory agencies, industry and non-profit programs, and training and/or intensive educational programs. The National Institutes of Health have been encouraging training institutions to consider offering mini-sabbaticals, but given the newness of the concept, limited data are available to guide the implementation of mini-sabbatical programs. In this paper, we review the history of sabbaticals and mini-sabbaticals, report the results of surveys we performed to ascertain the use of mini-sabbaticals at Clinical and Translational Science Award hubs, and consider best practice recommendations for institutions seeking to establish formal mini-sabbatical programs.
We are in agreement with some of the points made in the recent article by Tregeagle, ‘Weighing up the evidence and local experience of residential care’ (Children Australia, 42(4), 240–247). For example, there can be no dispute about the high costs of residential placements or that achieving a stable residential environment is very challenging. Table 1 provides a three state cost comparison of residential placements (Ainsworth, 2017).
Objectives: The third edition of the California Verbal Learning Test (CVLT-3) includes a new index termed List A versus Novel/Unrelated recognition discriminability (RD) on the Yes/No Recognition trial. Whereas the Total RD index incorporates false positive (FP) errors associated with all distractors (including List B and semantically related items), the new List A versus Novel/Unrelated RD index incorporates only FP errors associated with novel, semantically unrelated distractors. Thus, in minimizing levels of source and semantic interference, the List A versus Novel/Unrelated RD index may yield purer assessments of yes/no recognition memory independent of vulnerability to source memory difficulties or semantic confusion, both of which are often seen in individuals with primarily frontal-system dysfunction (e.g., early Huntington’s disease [HD]). Methods: We compared the performance of individuals with Alzheimer’s disease (AD) and HD in mild and moderate stages of dementia on CVLT-3 indices of Total RD and List A versus Novel/Unrelated RD. Results: Although AD and HD subgroups exhibited deficits on both RD indices relative to healthy comparison groups, those with HD generally outperformed those with AD, and group differences were more robust on List A versus Novel/Unrelated RD than on Total RD. Conclusions: Our findings highlight the clinical utility of the new CVLT-3 List A versus Novel/Unrelated RD index, which (a) maximally assesses yes/no recognition memory independent of source and semantic interference; and (b) provides a greater differentiation between individuals whose memory disorder is primarily at the encoding/storage level (e.g., as in AD) versus at the retrieval level (e.g., as in early HD). (JINS, 2018, 24, 833–841)
We derive an effective macroscale description for the growth of tissue on a porous scaffold. A multiphase model is employed to describe the tissue dynamics; linearisation to facilitate a multiple-scale homogenisation provides an effective macroscale description, which incorporates dependence on the microscale structure and dynamics. In particular, the resulting description admits both interstitial growth and active cell motion. This model comprises Darcy flow, and differential equations for the volume fraction of cells within the scaffold and the concentration of nutrient, required for growth. These are coupled with Stokes-type cell problems on the microscale, incorporating dependence on active cell motion and pore scale structure. The cell problems provide the permeability tensors with which the macroscale flow is parameterised. A subset of solutions is illustrated by numerical simulations.
The Vulnerable fishing cat Prionailurus viverrinus faces a perilous future in South-east Asia. It was last sighted in Cambodia in 2003. We deployed 16 camera traps at four sites in southern Cambodia during January–May 2015 to determine if the fishing cat was still present in the country. Eight photograph/video captures of fishing cats were recorded from the mangroves in Peam Krasop Wildlife Sanctuary and one from Ream National Park, but there were no records from Botum Sakor National Park or Prey Nup. A number of other globally threatened species were also photographed in Peam Krasop Wildlife Sanctuary: the Sunda pangolin Manis javanica, the hog deer Axis porcinus and the large-spotted civet Viverra megaspila. We learnt of the killing of an alleged fishing cat at the Sanctuary in July 2015 in retaliation for raiding fishing nets. Illegal hunting and capture of fishing cats for the wildlife trade were reported by local informants at all sites. We provide photographic and video evidence of the fishing cats and highlight the importance of Cambodia's mangroves for threatened species conservation.
In the context of water use for agricultural production, water footprints (WFs) have become an important sustainability indicator. To understand better the water demand for beef and sheep meat produced on pasture-based systems, a WF of individual farms is required. The main objective of this study was to determine the primary contributors to freshwater consumption up to the farm gate expressed as a volumetric WF and associated impacts for the production of 1 kg of beef and 1 kg of sheep meat from a selection of pasture-based farms for 2 consecutive years, 2014 and 2015. The WF included green water, from the consumption of soil moisture due to evapotranspiration, and blue water, from the consumption of ground and surface waters. The impact of freshwater consumption on global water stress from the production of beef and sheep meat in Ireland was also computed. The average WF of the beef farms was 8391 l/kg carcass weight (CW) of which 8222 l/kg CW was green water and 169 l/kg CW was blue water; water for the production of pasture (including silage and grass) contributed 88% to the WF, concentrate production – 10% and on-farm water use – 1%. The average stress-weighted WF of beef was 91 l H2O eq/kg CW, implying that each kg of beef produced in Ireland contributed to freshwater scarcity equivalent to the consumption of 91 l of freshwater by an average world citizen. The average WF of the sheep farms was 7672 l/kg CW of which 7635 l/kg CW was green water and 37 l/kg CW was blue water; water for the production of pasture contributed 87% to the WF, concentrate production – 12% and on-farm water use – 1%. The average stress-weighted WF was 2 l H2O eq/kg CW for sheep. This study also evaluated the sustainability of recent intensification initiatives in Ireland and found that increases in productivity were supported through an increase in green water use and higher grass yields per hectare on both beef and sheep farms.
This paper presents the first successful methods for accelerator mass spectrometry (AMS) dating of asphalt-impregnated insect chitin from the Rancho La Brea Tar Pits in southern California. A persistent problem with stratigraphic correlation at this site is that asphalt flows are characteristically intermittent and are really discontinuous, which can result in mixing fossils of quite different ages. Direct 14C dating of specimens circumvents this difficulty but requires a pretreatment method that can produce dates from relatively small samples (<10 mg) of insect cuticle, while successfully removing residual asphalt and sample preparation solvents as well as soil carbon contamination. 14C dating accuracy was verified by comparing dates on insect chitin with ages for seeds and twigs compacted during a rapid entrapment event within a separately dated skull of the Western Camel, Camelops hesternus Leidy. All dates fell within a relatively narrow range of ~40,000–44,000 14C yr BP, suggesting that such methods can be used with confidence on other insect material from this site. Insects are often superior paleoenvironmental indicators for establishing precise data points for climate fluctuations. This is because their lifecycles and present-day climate-restricted geographic distributions are well documented, and unlike migrating mammals and birds, insects offer crucial information about the local environment. Our results are therefore potentially significant for studies of paleoecological and paleoclimatic change within the Los Angeles Basin and coastal southern California, as well as reconstruction of entrapment events at Rancho La Brea.
There is little empirical evidence to indicate that dairy cow live weight affects the extent of soil damage at the hoof-soil interface during grazing on poorly drained permanent grassland. In the present study the impact of Holstein-Friesian (HF) dairy cows with a mean (±standard deviation) live weight of 570 (±61) kg were compared with Jersey × Holstein-Friesian (JX) with a mean live weight of 499 (±52) kg each at two stocking densities: mean 2·42 ± (0·062) and 2·66 (±0·079) cows/ha. Soil physical properties (bulk density, macroporosity, gravimetric water content, air-filled porosity, penetration resistance and shear strength), poaching damage (post-grazing soil surface deformation and hoof-print depth), herbage yield and milk production were measured throughout 2011 and 2012. Soil physical properties, post-grazing soil surface deformation and herbage production were not affected by dairy cow breed or by interactions between breed and stocking density. Hoof-print depth was higher in the HF treatments (39 v. 37 mm, s.e. 0·5 mm). Loading pressure imposed at the soil surface was the same for both breeds due to a direct correlation between live weight and hoof size. Poaching damage was greater at higher stocking density. Using the lighter JX cow offered little advantage in terms of lowering the negative impact of treading on soil physical properties or reducing poaching damage and no advantage in terms of herbage or milk production compared with the heavier HF cow.
Canine obesity is a prevalent disease, but many owners are unaware of it, partly due to misperception of their dog's body shape. Body condition scoring (BCS) is a simple method of assessing body composition, but whether it can reduce owner misperception is unclear. Our aim was to determine the effect of a BCS system on owners' ability to estimate the body condition of their dog. Information from 110 dog owners attending three UK veterinary practices was gathered, by interview, between March and April 2013. First, owners were asked to determine their dog's body condition without guidance, and then reassess it using a five-point BCS chart. Most owners (85/110, 77 %) believed the chart to have improved their ability to estimate the condition of their dog correctly. However, only a weak agreement existed between owner estimates and those of the primary investigator, both with (kappa (κ) = 0·28; P < 0·001) and without (κ = 0·32; P < 0·001) the BCS chart. Furthermore, most owners incorrectly estimated their dog's body condition, both with (71/110; 64 %) and without (72/110; 65 %) the chart (P = 1·00), with underestimation being most common (with = 63/71, 89 %; without = 66/72, 92 %; P = 0·57). Owners of overweight dogs more commonly misperceived their dog's body condition, both with (BCS 1–3: 5/35, 14 %; BCS 4–5: 64/75, 85 %; P < 0·001) and without (BCS 1–3: 10/35, 28 %; BCS 4–5: 61/75, 81 %; P < 0·001) the BCS chart. Thus, use of a five-point BCS chart does not improve accuracy of owners' perception of their dog's body shape, despite the accompanying perception that it does.
Feline obesity is a prevalent medical disease and the main therapeutic strategy is dietary energy restriction. However, at present there are no data regarding long-term outcome in this species. The purpose of the present study was to investigate if, as in other species, some cats regain weight following successful weight loss, and to identify any influencing factors in a cohort of client-owned cats with naturally occurring obesity. Twenty-six cats were included, all of which had successfully completed a weight management programme. After weight loss, cats were periodically monitored. The median duration of follow-up was 954 d (72–2162 d). Ten cats (39 %) maintained their completion weight (±5 %), four (15 %) lost >5 % additional weight and 12 (46 %) gained >5 % weight. Seven of the rebounding cats (58 %) regained over 50 % of their original weight lost. Older cats were less likely to regain weight than younger cats (P = 0·024); with an approximately linear negative association between the cat's age and the amount of weight regained (Kendall's τ = −0·340, P = 0·016). Furthermore, cats whose energy intake during weight loss was greater were also more likely to regain weight (P = 0·023). When the characteristics of weight regain in cats were compared with those from a similar cohort of dogs, cats that rebounded were more likely to regain >50 % of the weight they had lost. These results suggest that weight regain, after successful weight loss, is common in obese cats, and that young cats (<7 years of age) are most at risk.
Prospective memory (PM) is dependent on executive processes known to be impaired in Huntington's disease (HD); however, no study to the authors’ knowledge has investigated PM in this group. We examined performance-based, semi-naturalistic, and self-reported PM in 20 individuals diagnosed with mild–moderate HD and 20 demographically similar controls. Relative to controls, HD participants demonstrated significantly lower scores in time-based PM, event-based PM (at a trend level), and the semi-naturalistic PM trial, all of which were marked by omission errors. HD participants demonstrated comparable recognition memory for the PM intentions relative to controls. HD and control participants also showed comparable scores in self-reported PM complaints. The results suggest that HD is associated with deficits in the strategic aspects of PM. HD-associated PM deficits also are evident in real-world situations, which may relate to an apparent meta-memory deficit for PM functioning as indicated by HD participants’ overestimation of their PM performance on self-report. (JINS, 2014, 20, 1–8)
Agricultural specialists, particularly animal scientists, tend to use process-based life-cycle assessments (LCA), which describe the production system as a series of processes, to study the environmental impact of milk production based on their experimental data. Another approach called input–output (I–O) based LCA, which uses the economic transaction tables and national environmental accounts to determine the environmental impact triggered by final demand of milk production, is often less used due to data scarcity and higher uncertainty. In the current paper, process-based and I–O-based LCA models were developed to evaluate the greenhouse gas (GHG) and acidifying emissions from pasture-based milk production in Ireland. Process-based LCA found 1338·3 kg CO2 eq and 14·4 kg SO2 eq/t energy-corrected milk (ECM), and revealed details related to the farm management. The I–O based LCA found 1003·1 kg CO2 eq and 12·7 kg SO2 eq/tonne ECM and suggested that the agriculture, forestry and fishery (AFF) sector itself was largely responsible for the environmental impact of AFF products, rather than economic interaction with other sectors. The process-based LCA was found to be suitable for developing farm-scale sustainability strategies if variation of tactics across farms is provided, while the I–O based LCA offered potential sustainability guidance at the national scale. Further work is required to incorporate foreign production into the I–O table to account fully for imported goods and services. A detailed disaggregation within the AFF sector is also needed to gain a better understanding of the environmental sustainability of agricultural commodities. The present paper thus provides interesting results for the dairy industry, dairy researchers and LCA practitioners on further understanding of the environmental impact of milk production.
Free-form deformation (FFD) is a method first introduced within the graphics industry to enable flexible deformation of geometric models. FFD uses an R3 to R3 mapping of a deformable space to the global Cartesian space to produce the geometry deformation. This method has been extensively used within the design optimisation field as a shape parameterisation technique. Typically it has been used to parameterise analysis meshes, where new design geometries are produced by deforming the original mesh. This method allows a concise set of design variables to be used while maintaining a flexible shape representation. However, if a computer aided design (CAD) model of the resulting geometry is required, reverse engineering techniques would need to be utilised to recreate the model from the deformed mesh. This paper extends the use of FFD within an optimisation routine by using FFD to directly parameterise a CAD geometry. Two methods of linking the FFD methods with the CATIA V5 CAD package are presented. Each CAD integration technique is then critiqued with respect to shape optimisation. Finally the set-up and initialisation of a case study is illustrated. The case study chosen is the aerodynamic optimisation of the wing-fuselage junction of a typical passenger aircraft.