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Few studies have investigated the patterns of posttraumatic stress disorder (PTSD) symptom change in prolonged exposure (PE) therapy. In this study, we aimed to understand the patterns of PTSD symptom change in both PE and present-centered therapy (PCT).
Participants were active duty military personnel (N = 326, 89.3% male, 61.2% white, 32.5 years old) randomized to spaced-PE (S-PE; 10 sessions over 8 weeks), PCT (10 sessions over 8 weeks), or massed-PE (M-PE; 10 sessions over 2 weeks). Using latent profile analysis, we determined the optimal number of PTSD symptom change classes over time and analyzed whether baseline and follow-up variables were associated with class membership.
Five classes, namely rapid responder (7–17%), steep linear responder (14–22%), gradual responder (30–34%), non-responder (27–33%), and symptom exacerbation (7–13%) classes, characterized each treatment. No baseline clinical characteristics predicted class membership for S-PE and M-PE; in PCT, more negative baseline trauma cognitions predicted membership in the non-responder v. gradual responder class. Class membership was robustly associated with PTSD, trauma cognitions, and depression up to 6 months after treatment for both S-PE and M-PE but not for PCT.
Distinct profiles of treatment response emerged that were similar across interventions. By and large, no baseline variables predicted responder class. Responder status was a strong predictor of future symptom severity for PE, whereas response to PCT was not as strongly associated with future symptoms.
Radiometric and AMS radiocarbon dating of a 6-m sediment core from Loch Ness, Scotland, indicates that it represents perhaps the very end of the Late Pleistocene, and the first ca. 7500 yr of the Holocene. Counts of laminations observed in the Holocene section of the core suggest that they are present in sufficient number to constitute annual laminations (varves), an hypothesis consistent with the pollen record, which contains a sequence of zones representative of the Early, Middle and part of the Late Holocene regional vegetation history. On the basis of BSEM and X-ray studies of sediments, and modern seston trap data, the laminations are believed to be produced by winter floods, which introduce increased silt loading into the Loch. Sediment for the rest of the year is mostly composed of clay-sized material. This hypothesis is being further tested, however, by continuing sedimentological and microfossil studies.
Time-depth relations for the core based on calibrated 14C dates and lamination counts, respectively, illustrate the close correspondence between the two sets of data. The latter are therefore now being used to develop a varve chronology for the Holocene for Loch Ness. This will then in turn be used for further chronological studies, and for investigations of palaeoclimatic variations over the eastern North Atlantic, to which the signal of lamination thickness in the sediments is thought to be particularly sensitive. They may also eventually be used for calibration studies, employing 14C dating of specific carbon compounds, or groups of compounds extracted from the sediment using modern organic geochemical methods.
Delayed feed and water access is known to impair growth performance of day old broiler chickens. Although effects of feed access on growth performance and immune function of broilers have been examined before, effects of dietary composition and its potential interaction with feed access are hardly investigated. This experiment aimed to determine whether moment of first feed and water access after hatch and pre-starter composition (0 to 7 days) affect growth rate and humoral immune function in broiler chickens. Direct fed chickens received feed and water directly after placement in the grow-out facility, whilst delayed fed chickens only after 48 h. Direct and delayed fed chickens received a control pre-starter diet, or a diet containing medium chain fatty acids (MCFA) or fish oil. At 21 days, chickens were immunized by injection of sheep red blood cells. The mortality rate depended on an interaction between feed access and pre-starter composition (P=0.014). Chickens with direct feed access fed the control pre-starter diet had a higher risk for mortality than chickens with delayed feed access fed the control pre-starter diet (16.4% v. 4.2%) whereas the other treatment groups were in-between. BW gain and feed intake till 25 days in direct fed chickens were higher compared with delayed fed chickens, whilst gain to feed ratio was lower. Within the direct fed chickens, the control pre-starter diet resulted in the highest BW at 28 days and the MCFA pre-starter diet the lowest (Δ=2.4%), whereas this was opposite for delayed fed chickens (Δ=3.0%; P=0.033). Provision of MCFA resulted in a 4.6% higher BW gain and a higher gain to feed ratio compared with other pre-starter diets, but only during the period it was provided (2 to 7 days). Minor treatment effects were found for humoral immune response by measuring immunoglobulins, agglutination titers, interferon gamma (IFN-γ), and complement activity. Concluding, current inclusion levels of fish oil (5 g/kg) and MCFA (30 g/kg) in the pre-starter diet appear to have limited (carryover) effects on growth and development, as well as on humoral immune function.
Resistant starch (RS) has been suggested to prolong satiety in adult pigs. The present study investigated RS-induced changes in behaviour, satiety-related hormones and metabolites in catheterized growing pigs to explore possible underlying mechanisms for RS-induced satiety. In a cross-over design with two 14-day periods, 10 pigs (initial BW: 58 kg) were assigned to two treatments comprising diets containing either 35% pregelatinized starch (PS) or 34% retrograded starch (RS). Diets were isoenergetic on gross energy. Pigs were fed at 2.8× maintenance. Postprandial plasma response of satiety-related hormones and metabolites was measured at the end of each period using frequent blood sampling. Faecal and urinary energy losses were measured at the end of each period. Behaviour was scored 24 h from video recordings using scan sampling. Energy digestibility and metabolizability were ~6% lower in RS compared with PS diet (P<0.001), and metabolizable energy (ME) intake was ~3% lower in RS-fed than in PS-fed pigs (P<0.001). RS-fed pigs showed less feeder-directed (P=0.001) and drinking (P=0.10) behaviours than PS-fed pigs throughout the day. Postprandial peripheral short-chain fatty acid (SCFA) levels were higher in RS-fed than in PS-fed pigs (P<0.001). Postprandial glucose and insulin responses were lower in RS-fed than in PS-fed pigs (P<0.001). Triglyceride levels were higher in RS-fed than in PS-fed pigs (P<0.01), and non-esterified fatty acid levels did not differ between diets (P=0.90). Glucagon-like peptide-1 (GLP-1) levels were lower in RS-fed than in PS-fed pigs (P<0.001), and peptide tyrosine tyrosine (PYY) levels did not differ between diets (P=0.90). Blood serotonin levels were lower (P<0.001), whereas monoamine oxidase activity (P<0.05) and tryptophan (P<0.01) levels were higher in RS-fed than in PS-fed pigs. Despite a lower ME intake, RS seemed to prolong satiety, based on behavioural observations. Possible underlying mechanisms for RS-induced satiety include increased 24 h plasma SCFA levels, and decreased postprandial glucose and insulin responses. GLP-1 and PYY seemed not to play a role in RS-induced satiety. Low blood serotonin levels in RS-fed pigs suggested a difference in intestinal serotonin release between treatments. Increased postprandial plasma triglyceride levels corresponded with increased SCFA levels, but it is unclear whether triglycerides may have signalled satiety in RS-fed pigs.
The Management Board of the UK Actuarial Profession is undertaking a thought leadership cross-practice research project on the use of discount rates by UK actuaries. The timing for this research is particularly appropriate as there is a convergence of interest in discount rates from within and outside of the Profession. Discount rates are at the heart of most actuarial calculations and are of significant public interest. As part of this project the Management Board wants a full and open debate on the significant issues and this paper is the next step in stimulating that debate, giving another opportunity to influence the future direction of the project.
The Management Board set up a small cross-practice steering committee to drive the project. The Discount Rate Steering Committee identified five areas of work that would be needed to achieve the project's overall objectives:
(1)A survey of current practices.
(2)A survey of existing research and debate.
(3)Developing a common language for communicating discount rates and risk.
(4)Developing a common framework for the future where appropriate.
(5)Considering the impact of any changes.
Although the Profession does not set standards for technical work it still has a significant role for undertaking research in the public interest which supports the competence of its members and the furtherance of actuarial science.
Chinu Patel and Chris Daykin were commissioned to undertake the first part of this work and they presented their preliminary output at a forum of thought leaders across the Profession and externally on 23 March 2010. Their report “Actuaries and Discount Rates” was subsequently published in May 2010 and presented the results of their initial research into past and current practice in the setting of discount rates in the UK, and a survey of existing research and debate. A summary of that report is included in Section 2 of this paper.
Following consultation both within and outside the Actuarial Profession, this interim paper now takes forward the ideas and initial steps developed by Patel & Daykin and looks at developing a common language and framework for using discount rates in actuarial work. The Discount Rate Steering Committee is making a number of recommendations to the Profession which are intended to help actuaries speak clearly and with authority in future debates about discount rates and to support actuaries in communicating impartially and effectively. The recommendations are set out in Section 6 of the report following the development of the framework in Sections 3–5. As part of further developing the recommendations to the Profession, the Discount Rate Steering Committee is seeking views from stakeholders from inside and outside of the Profession. This will be undertaken throughout January and February 2011 and, as part of this process, the report will be presented at sessional research events in Edinburgh (17 January 2011) and London (31 January 2011). The Discount Rate Steering Committee is committed to seeking feedback on the recommendations and hopes this paper will give those inside and outside the Profession an opportunity to add to the dialogue so that as wide a range of potential views as possible is heard.
In this paper, the steering committee has concentrated on the more technical aspects of developing a framework for communicating discount rates and associated risks and the report is aimed primarily at actuaries. But the committee is mindful of the need to help actuaries communicate more clearly with those outside the Profession. During the first half of 2011, the steering committee will therefore concentrate on producing a document in less technical language to help non-actuaries understand the issues around the selection and use of discount rates and to help actuaries in their communication with stakeholders.
A model for the early Palaeozoic metamorphic history of the Midland Valley and adjacent areas to the S in Scotland, England and Ireland is based on the results of new field mapping, thin section petrography, electron probe microanalysis, X-ray diffractometry, conodont and palynomorph colouration and graptolite reflectance measurement.
The oldest metamorphic rocks of the Midland Valley of Scotland, excluding xenoliths in post-Silurian lavas, are possibly the blueschist occurrences in the melange unit of the Ballantrae complex. These may be tectonised remnants of (?)pre-Arenig ocean-floor subducted during closure of the Iapetus Ocean. In the early Ordovician, the melange terrane was dynamothermally metamorphosed during obduction of newly-formed ocean crust. The obduction process piled up a thick sequence of various ocean-floor types such that burial metamorphism in parts reached pumpellyite-actinolite facies; elsewhere prehnite-pumpellyite and zeolite facies was attained.
Whilst the Midland Valley acted as an inter- or fore-arc basin during the Late Ordovician and Silurian and experienced burial metamorphism, an accretionary prism was formed to the S. Accretion, tectonic burial and metamorphism of ocean-floor and trench sediment was continuous in the Southern Uplands and the Longford-Down massif of Ireland through Late Ordovician to Late Silurian times. Rocks at the present-day surface vary from zeolite facies to prehnitepumpellyite facies. Silurian trench-slope basin sediments can be recognised in part by their lower grade of burial metamorphism. Greenschist facies rocks of the prism probably lie close to the surface.
The Lake District island-arc terrane of Northern England has an early Ordovician history of burial metamorphism up to prehnite-pumpellyite facies. The Late Ordovician and Silurian metamorphic history is one of sedimentary burial complicated by tectonism and intrusion of granite plutons to a relatively high level. The Iapetus suture is marked by a weak contrast in metamorphic grade.
A method is described for the production of collagen constructs formed from densely packed, native-banded collagen fibrils. This “Dense Fibrillar Collagen” is formed by concentrating collagen in situ prior to self assembly of the collagen into fibrils. The effect of altering the pH, ionic strength, and osmolarity of the concentrating solution was measured. Increasing the ionic strength and osmolarity of the concentrating solution increased the burst strength of the constructs; increasing the pH from 3.8 to 7.1 reduced the surface fibrillarity, degree of platelet uptake and “short term in vivo thrombogenicity. This construct is being considered as the basis of a small-caliber vascular prosthesis to support guided tissue regeneration.
A comparison of F2 and F6/7 inter-cross lines of mice, derived from CBA and SWR parental strains, has provided strong evidence for several previously undetected quantitative trait loci (QTL) for resistance to Heligmosomoides bakeri. Five QTL affecting average faecal egg counts and/or worm burdens in week 6 were detected on mouse chromosomes 5 (Hbnr9 and Hbnr10), 8 (Hbnr11) and 11 (Hbnr13 and Hbnr14). Three QTL for faecal egg counts in weeks 4 and 6 were found on both chromosomes 5 (Hbnr9) and 11 (Hbnr13 and Hbnr14). Two QTL for the mucosal mast cell protease 1 (MCPT1) response were located on chromosomes 8 (Hbnr11) and 11 (Hbnr13), two for the IgG1 antibody response to adult worms on chromosomes 5 (Hbnr10) and 8 (Hbnr11), two for PCV in week 6 on chromosomes 5 (Hbnr9) and 11 (Hbnr13), and two for the granulomatous response on chromosome 8 (Hbnr12) and 11 (Hbnr15). Our data emphasize that the control of resistance to H. bakeri is multigenic, and regulated by genes within QTL regions that have a complex range of hierarchical relationships.
Twenty-two reference isolates and 30 local isolates of group A Streptococci were classified into 36 electrophoretic types (ET) on the basis of allozyme variation at 27 enzyme loci. Local isolates were characterized by a high frequency of M-non typable strains. M-type and ET were more closely associated in local isolates from an endemically-infected population; nevertheless, amongst the local isolates there were also strains of the same ET type with different M-types. A possible explanation is that genetic exchange between strains may introduce different M-types into strains of defined ET when these are exposed to strong selection in the presence of heavy loads of infection.
In contrast to the reported clustering of strains associated with toxic shock-like syndrome into two closely related ET clones, we found no relationship of ET phenotype to acute poststreptococcal glomerulonephritis or rheumatic fever.
Ribotyping with the restriction enzyme XbaI was used to study the dynamics of carriage of non-encapsulated Haemophilus influenzae (NCHi) in Aboriginal infants at risk of otitis media. Carriage rates of NCHi in the infants in the community were very high; the median age for detection was 50 days and colonization was virtually 100% by 120 days of age and persisted at a high level throughout the first year of life . Eighteen different ribotypes of NCHi were identified from 34 positive swabs taken from 3 infants over a period of 9 months. The same ribotypes were recovered for up to 3 months from consecutive swabs of individual infants, and 12 of 27 swabs (44·4%) yielded two ribotypes from four colonies typed. Statistical analysis suggested that most swabs would have been positive for two ribotypes if enough colonies had been typed although the second most frequent ribotype was detected on average in only 13% of strains. Early colonization and carriage of multiple ribotypes of NCHi may help to explain the chronicity of carriage and thus the persistence of otitis media in Aboriginal infants.
Between 1966 and 1991, melioidosis, a disease caused by Pseudomonas pseudomallei that is mostly confined to tropical regions, occurred in farm animals and a farmer in temperate south-west Western Australia. Using an Escherichia coli probe containing a ribosomal RNA operon, P. pseudomallei DNA from isolates from 8 animals, a soil sample and the human case showed an identical ribotype on Southern blotting. The ribotype was different from the 3 commonest ribotypes seen in tropical Australia. This molecular typing supports the theory of clonal introduction of P. pseudomallei into a non-endemic region, with environmental contamination, local dissemination and persistence over 25 years. As melioidosis is often fatal in humans, such persistence in a temperate region is cause for concern.
Foraminifera and diatoms preserved in salt-marsh sediments have been used to produce high-resolution records of Holocene relative sea-level (RSL) change. To determine which of these microfossil groups is most appropriate for this purpose we investigated their relative utility from salt marshes in North Carolina, USA. Regional-scale transfer functions were developed using foraminifera, diatoms and a combination of both (multi-proxy) from three salt marshes (Oregon Inlet, Currituck Barrier Island and Pea Island). We evaluated each approach on the basis of transfer-function performance. Foraminifera, diatoms and multi-proxy-based transfer functions all demonstrated a strong relationship between observed and predicted elevations (r2jack > 0.74 and RMSEP < 0.05 m), suggesting that they have equal utility. Application of the transfer functions to a fossil core from Salvo to reconstruct former sea levels enabled us to consider relative utility in light of ‘paleo-performance’. Fossil foraminifera had strong modern analogues, whilst diatoms had poor modern analogues making them unreliable. This result reflects the high diversity and site-specific distribution of modern diatoms. Consequently, we used foraminifera to reconstruct RSL change for the period since ∼ AD 1800 using a 210Pb- and 14C-based chronology, and we were able to reconcile this with tide-gauge records.
A panel of microsatellites mapped to the Leishmania genome might make it possible to find associations between specific loci and phenotypic traits. To identify such loci, a Perl programme was written that scans the sequence of a genome and writes all loci containing microsatellites to a MySQL database. The programme was applied to the sequences of the L. braziliensis, L. infantum and L. major genomes. The database is publicly available over the internet: http://www.genomics.liv.ac.uk/tryps/resources.html ‘Microsatellite Locus Extractor’, and allows the selection of mapped microsatellites that meet user-defined criteria from a specified region of the selected genome. The website also incorporates a primer design pipeline that will design primers to amplify the selected loci. Using this pipeline 12 out of 17 primer sets designed against the L. infantum genome generated polymorphic PCR products. A tailed primer protocol was used to label all microsatellite primers with a single set of labelled primers. To avoid the culture of parasites prior to genotyping, sets of nested PCR primers were developed to amplify parasite DNA eluted from microscope slides. The limit of detection was approximately 1·6 parasite equivalents. However, only 6/56 DNA from slides stored at ambient temperature for over 6 months gave positive PCR results.
The relationship between plutonic and volcanic rocks is central to understanding the geochemical evolution of silicic magma systems, but it is clouded by ambiguities associated with unravelling the plutonic record. Here we report an integrated U–Pb, O and Lu–Hf isotope study of zircons from three putative granitic–volcanic rock pairs from the Lachlan Fold Belt, southeastern Australia, to explore the connection between the intrusive and extrusive realms. The data reveal contrasting petrogenetic scenarios for the S- and I-type pairs. The zircon Hf–O isotope systematics in an I-type dacite are very similar to those of their plutonic counterpart, supporting an essentially co-magmatic relationship between these units. The elevated δ18O of zircons in these I-type rocks confirm a significant supracrustal source component. The S-type volcanic rocks are not the simple erupted equivalents of the granites, although the extrusive and plutonic units can be related by open-system magmatic evolution. Zircons in the S-type rocks define covariant εHf–δ18O arrays that attest to mixing or assimilation processes between two components, one being the Ordovician metasedimentary country rocks, the other either an I-type magma or a mantle-derived magma. The data are consistent with models involving incremental melt extraction from relatively juvenile magmas undergoing open-system differentiation at depth, followed by crystal-liquid mixing upon emplacement in shallow magma reservoirs, or upon eruption. The latter juxtaposes crystals with markedly different petrogenetic histories and determines whole-rock geochemical and textural properties. This scenario can explain the puzzling decoupling between the bulk rock isotope and geochemical compositions commonly observed for granite suites.
DE CVn is a relatively unstudied eclipsing binary where one of the components is an M dwarf and the other is a white dwarf. Its brightness makes it an ideal system for a detailed study in the context of common-envelope evolution of a detached white dwarf – red dwarf binary with a relatively short orbital period (∼8.7 hours). We present a detailed study of the basic parameters (e.g. orbital period, components' masses and spectral types) for this system from photometric and spectroscopic studies. The eclipses observed during several photometric observing runs were used to derive the ephemeris. We have used spectroscopic data to derive the radial velocity variations of the emission lines and these are used to determine the components' masses and the orbital separation. The secondary component in DE CVn is an M3 main-sequence star and the primary star, which only contributes to the blue continuum, is a cool white dwarf with a temperature of ∼8000 K. From the photometry and spectroscopy together, we have set a limit on the binary inclination. This system is a post-common-envelope system where the progenitor of the present day white dwarf was a low-mass star (M≤2M⊙). The time before DE CVn becomes a semi-detached system is longer than the Hubble time.
Femtosecond modelocked lasers using new ytterbium-doped borate crystals (Yb:Sr3Y(BO3)3,
Yb:Ca4GdO(BO3)3 and Yb:Ca4YO(BO3)3) are demonstrated. Pulse duration as short as 69 fs
has been obtained. To modelock such lasers, fast saturable absorbers need to be used. Two
different types of fast saturable absorbers have been studied: low-temperature-grown
semiconductor mirrors (SESAM) and high-energy-ion-implanted semiconductor Bragg
reflectors (SBR). We demonstrated, for the first time to our knowledge, that ion-implanted
SBR can be used to modelock oscillators using Yb-doped materials.
Brinrobertsite, an ordered, mixed-layered, dioctahedral pyrophyllite-smectite (P/S), occurs in a metabentonite in the Ordovician Nant Ffrancon Formation near Bangor, N Wales. It comprises ~30% of the metabentonite, in association with quartz (~50%) and chlorite (clinochlore; 20%) which replaced glass shards and fine-grained glass matrix. Transmission electron microscopy (TEM) images show sequences of dominant ~24 Å 001 lattice fringes inferred to correspond to 2:1 layers with alternate pyrophyllite-like (low-charge) and smectite-like (higher-charge) interlayers (i.e. R1 ordering). The hk0 diffraction patterns are mostly hexanets with some spotty circles, implying that layers are largely coherently related, but with some turbostratic stacking. Collective data show that d100 = 5.2, b = 9.1, and d001 = 24–25 Å, assuming monoclinic or pseudomonoclinic symmetry. The composition, as determined by energy dispersive spectral analysis, is (Na0.22K0.07Ca0.06)(Al3.81Mg0.08Fe0.08)(Si7.84 Al0.16)O20(OH)4·3.54H2O, as consistent with the sum of the compositions of pyrophyllite-like and smectite-like units. Water content was determined by DTA/TGA analysis. The powder diffraction patterns have a principal peak with d001 = 24.4 Å. Patterns of air-dried and glycol-saturated brinrobertsite, including Na- and Ca-saturated and untreated samples, were modelled satisfactorily as R1-ordered P/S by the program NEWMOD-for-Windows. The unique composition of brinrobertsite relative to R1 IS, which is ubiquitous in metabentonites, was caused by leaching of alkalis and alkaline-earth elements by hydrothermal fluids associated perhaps with a nearby intrusion, as demonstrated by bulk-chemical analyses of the metabentonite. The crystal structure is modelled as having Al/Si distributions symmetrical by reflection across interlayers. This causes all 2:1 layers to be equivalent in having one tetrahedral sheet with little or no Al, and the other with significant Al substitution, giving rise to alternate high- and low-charge interlayers. Geological evidence suggests that brinrobertsite is a back-reacted product of hydrothermal alteration in the sequence: glass → pyrophyllite → brinrobertsite.