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In recent years, the discovery of massive quasars at
has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.
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.
Over the past 25 years, numerous studies of polymers utilizing both X-ray diffraction (XRD) and differential scanning calorimetry (DSC) have been reported in the literature. These studies have suffered because the two techniques must be performed on separate samples and under conditions that are often dissimilar. By combining the two techniques into one instrument, typical problems encountered with variations in sample preparation and thermal and atmospheric environment are eliminated. This is quite important in the study of polymers since one must match not only temperatures between the two techniques, but also heating rates as well. Matched thermal conditions are necessary because polymer properties such as crystallinity and crystallite size depend on both the temperature and thermal history of the sample under study.
Community-acquired pneumonia (CAP) results in substantial numbers of hospitalisations and deaths in older adults. There are known lifestyle and medical risk factors for pneumococcal disease but the magnitude of the additional risk is not well quantified in Australia. We used a large population-based prospective cohort study of older adults in the state of New South Wales (45 and Up Study) linked to cause-specific hospitalisations, disease notifications and death registrations from 2006 to 2015. We estimated the age-specific incidence of CAP hospitalisation (ICD-10 J12-18), invasive pneumococcal disease (IPD) notification and presumptive non-invasive pneumococcal CAP hospitalisation (J13 + J18.1, excluding IPD), comparing those with at least one risk factor to those with no risk factors. The hospitalised case-fatality rate (CFR) included deaths in a 30-day window after hospitalisation. Among 266 951 participants followed for 1 850 000 person-years there were 8747 first hospitalisations for CAP, 157 IPD notifications and 305 non-invasive pneumococcal CAP hospitalisations. In persons 65–84 years, 54.7% had at least one identified risk factor, increasing to 57.0% in those ⩾85 years. The incidence of CAP hospitalisation in those ⩾65 years with at least one risk factor was twofold higher than in those without risk factors, 1091/100 000 (95% confidence interval (CI) 1060–1122) compared with 522/100 000 (95% CI 501–545) and IPD in equivalent groups was almost threefold higher (18.40/100 000 (95% CI 14.61–22.87) vs. 6.82/100 000 (95% CI 4.56–9.79)). The CFR increased with age but there were limited difference by risk status, except in those aged 45 to 64 years. Adults ⩾65 years with at least one risk factor have much higher rates of CAP and IPD suggesting that additional risk factor-based vaccination strategies may be cost-effective.
Elevated levels of pro-inflammatory cytokines are consistently reported in schizophrenia (SZ) and bipolar-I disorder (BD), as well as among individuals who have been exposed to childhood trauma. However, higher levels of inflammatory markers in these disorders are yet to be investigated with respect to levels of exposure to different types of childhood trauma.
Participants were 68 cases with a diagnosis of schizophrenia/schizoaffective disorder (SZ), 69 cases with a diagnosis of psychotic BD and 72 healthy controls (HC). Serum levels of interleukin 6 (IL-6), tumour necrosis factor-α (TNF-α) and C-reactive protein (CRP) were quantified, and childhood trauma exposure was assessed with the Childhood Trauma Questionnaire.
The SZ group had significantly higher levels of IL-6, TNF-α and CRP when compared with the HC group (all p < 0.05, d = 0.41–0.63), as well as higher levels of TNF-α when compared with the BD group (p = 0.014, d = 0.50); there were no differences between the BD and HC groups for any markers. Exposure to sexual abuse was positively associated (standardised β = 0.326, t = 2.459, p = 0.018) with levels of CRP in the SZ group, but there were no significant associations between any form of trauma exposure and cytokine levels in the HC or BD groups.
These results contribute to the evidence for a chronic state of inflammation in SZ but not BD cases. Differential associations between trauma exposure and levels of pro-inflammatory cytokines across the diagnostic categories suggest that trauma may impact biological (stress and immune) systems differently in these patient groups.
During the summer of 2016, the Hawaii Department of Health responded to the second-largest domestic foodborne hepatitis A virus (HAV) outbreak in the post-vaccine era. The epidemiological investigation included case finding and investigation, sequencing of RNA positive clinical specimens, product trace-back and virologic testing and sequencing of HAV RNA from the product. Additionally, an online survey open to all Hawaii residents was conducted to estimate baseline commercial food consumption. We identified 292 confirmed HAV cases, of whom 11 (4%) were possible secondary cases. Seventy-four (25%) were hospitalised and there were two deaths. Among all cases, 94% reported eating at Oahu or Kauai Island branches of Restaurant Chain A, with 86% of those cases reporting raw scallop consumption. In contrast, a food consumption survey conducted during the outbreak indicated 25% of Oahu residents patronised Restaurant Chain A in the 7 weeks before the survey. Product trace-back revealed a single distributor that supplied scallops imported from the Philippines to Restaurant Chain A. Recovery, amplification and sequence comparison of HAV recovered from scallops revealed viral sequences matching those from case-patients. Removal of product from implicated restaurants and vaccination of those potentially exposed led to the cessation of the outbreak. This outbreak further highlights the need for improved imported food safety.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
Objectives: Although subjective cognitive complaints (SCC) are an integral component of the diagnostic criteria for mild cognitive impairment (MCI), previous findings indicate they may not accurately reflect cognitive ability. Within the Alzheimer’s Disease Neuroimaging Initiative, we investigated longitudinal change in the discrepancy between self- and informant-reported SCC across empirically derived subtypes of MCI and normal control (NC) participants. Methods: Data were obtained for 353 MCI participants and 122 “robust” NC participants. Participants were classified into three subtypes at baseline via cluster analysis: amnestic MCI, mixed MCI, and cluster-derived normal (CDN), a presumptive false-positive group who performed within normal limits on neuropsychological testing. SCC at baseline and two annual follow-up visits were assessed via the Everyday Cognition Questionnaire (ECog), and discrepancy scores between self- and informant-report were calculated. Analysis of change was conducted using analysis of covariance. Results: The amnestic and mixed MCI subtypes demonstrated increasing ECog discrepancy scores over time. This was driven by an increase in informant-reported SCC, which corresponded to participants’ objective cognitive decline, despite stable self-reported SCC. Increasing unawareness was associated with cerebrospinal fluid Alzheimer’s disease biomarker positivity and progression to Alzheimer’s disease. In contrast, CDN and NC groups over-reported cognitive difficulty and demonstrated normal cognition at all time points. Conclusions: MCI participants’ discrepancy scores indicate progressive underappreciation of their evolving cognitive deficits. Consistent over-reporting in the CDN and NC groups despite normal objective cognition suggests that self-reported SCC do not predict impending cognitive decline. Results demonstrate that self-reported SCC become increasingly misleading as objective cognitive impairment becomes more pronounced. (JINS, 2018, 24, 842–853)
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)
Good education requires student experiences that deliver lessons about practice as well as theory and that encourage students to work for the public good—especially in the operation of democratic institutions (Dewey 1923; Dewy 1938). We report on an evaluation of the pedagogical value of a research project involving 23 colleges and universities across the country. Faculty trained and supervised students who observed polling places in the 2016 General Election. Our findings indicate that this was a valuable learning experience in both the short and long terms. Students found their experiences to be valuable and reported learning generally and specifically related to course material. Postelection, they also felt more knowledgeable about election science topics, voting behavior, and research methods. Students reported interest in participating in similar research in the future, would recommend other students to do so, and expressed interest in more learning and research about the topics central to their experience. Our results suggest that participants appreciated the importance of elections and their study. Collectively, the participating students are engaged and efficacious—essential qualities of citizens in a democracy.
Achieving adequate fertility is essential in any dairy unit, but is compromised by genetic selection for increased yield. Selection has altered the somatotrophic axis and resulted in cows which mobilise more body tissue for milk production in early lactation, thus prolonging both the depth and duration of the post partum negative energy balance. Poor energy status is reflected in altered metabolic parameters including raised urea and decreased insulin-like growth factor-I (IGF-I) and insulin concentrations, which adversely affect ovarian cyclicity and early embryo survival. Attempts to optimise the diet in terms of energy and protein content have generally been aimed at increasing milk production further rather than improving fertility. Advances in biosensor technology now provide us with the opportunity to monitor production, fertility and health parameters of each cow. Integration of this information should improve the timing for inseminations and could assist in selecting diets more suited to the needs of the individual cow. Genetic selection may in future be used to produce cows optimised for a particular type of management system. In both cases we need a greater understanding of the rules governing nutrient partitioning at different stages of the cows' life cycle to ensure that diets selected are cost effective and achieve an appropriate balance in promoting production, reproduction and health.
The pre-requisites for nutritional management of dairy cows are information about how much feed is being consumed as well as the nutrients that are being derived from that feed. Studies of feed intake and nutrient supply have been limited by difficult experimental techniques, particularly with grazing animals. The models derived from much earlier work are of only general applicability and there is a need for more site-specific information in order to benefit further from conceptual advances.
We have adopted a different approach to studying herbage intake and nutrient supply, using less-invasive approaches as well as techniques that monitor more accessible aspects of these processes, such as jaw movements. These techniques have a major advantage, in addition to their value as research tools, because they could translate directly into commercial applications in on-farm monitoring. The use of diagnostics and behavioural recording is well explored in relation to health monitoring; here we argue for its potential to advance the application of knowledge about grazing and nutrition. We will illustrate this approach using our experiences in measuring grazing behaviour, using IGER behaviour recorders and assessing rumen function, using a series of non-invasive techniques.
The IGER grazing behaviour recorder allows us to record jaw movements and hence grazing and ruminating time and bite dynamics. It also allows the recording of steps and is now being developed to incorporate non-invasive rumen state sensors. It has made a major contribution to our understanding of the foraging strategies of grazing animals and their effect on herbage intake. This technology has the potential to be developed for on-farm monitoring of foraging behaviour providing valuable inputs to the prediction of herbage intake, in decision support systems for grazing.
The introduction of concept of protein degradation and microbial synthesis in the rumen are significant advances in protein rationing schemes. However, real progress has been limited because the lack of consistent experimental results means that models have little relevance to specific farm situations. We foresee considerable opportunities to monitor products of rumen degradation and synthesis that appear in milk (e.g. odd-chain fatty acids) or breath (e.g. sulphides).
Taken together these technologies open the possibilities of an entirely new approach to nutritional management of dairy cows, with site-specific recommendations based on information gathered using new sensors that are incorporated into computerised feeding equipment and milking parlours.
Scientists have long known that certain pesticides, industrial chemicals and heavy metals have a detrimental impact on the reproductive health of a wide range of species (including humans) by disrupting the endocrine system. As exposure to, and the effects of, ‘endocrine disrupters’ are likely to be more pronounced in wild species with a short gestation period and life-cycle we have chosen to develop non-invasive tools based upon faecal steroid analysis to monitor the reproductive status of the short-tailed field vole (Microtus agrestis). This approach is hoped to eventually provide a sensitive means of detecting environmental disturbances that could adversely affect humans, livestock and wildlife by establishing the the field vole as a terrestrial biomarker. Faecal steroid hormone analysis has already been demonstrated as being a convenient and reliable means of diagnosing reproductive state in a large range of mammalian species (including gazelle, rhino, macaque and mice), however, as of yet little is known regarding the hormonal changes that occur during pregnancy in M. agrestis.
This review considers the likely impact of changing consumer requirements, political pressure, economics and technological advances on the dairy production industry of the future. The vision is one of diverse strategies of production, the majority of milk being produced from cows managed technologically with much greater regard for welfare, with a number of ‘romantic’ strategies such as organic, extensive or dual-purpose production supplying niche markets. The important novel feature of the technological strategy will be an escape from the intensive twelve-month lactation cycle to extended lactations of, say, eighteen months, since this will reduce the number of times the cow is exposed to metabolic and other stresses associated with parturition, peak lactation and rebreeding.
The application of modern process control techniques to poultry production is outlined. Compact dynamic data-based models are proposed to describe and control the metabolic responses of broiler chickens to variations in the micro-environment. The dynamic response of heat production to step changes in air temperature and light intensity could be modelled with a , on average, of 0.83 and 0.93 respectively. Using recursive parameter estimation techniques, the time-variant response of animal growth to food supply could be predicted on-line with a prediction error of a maximum of 5%, three to seven days ahead depending on the type of feeding schedule. We argue that the potential conflicts between the environmental, financial and biological pressures on sustainable poultry production can be resolved through the development of integrated management systems using process control techniques.
Livestock systems are comprised of sets of complex interconnected processes each with their own outputs eg growth, yield, animal health, welfare and environmental emissions. Livestock management decisions are currently based almost entirely on the judgement and experience of the stockman who has to estimate or guess the likely effects of any control action.
An integrated management system for a livestock production enterprise would be one which controlled all relevant processes. For example if the purpose of the system was to regulate nutritional input in order to control animal growth and pollutant emissions, the controller would calculate input values which would enable growth and emissions criteria to be satisfied simultaneously.
The essential components of an integrated management system are sensors and models. Developments in sensor technology will make available increasing amounts of information relevant to monitoring animals and their environment. Model-based control systems are particularly appropriate for accommodating the variability of most livestock production processes. Models exist for most of the economically important and scientifically interesting processes in livestock production. However the requirements of a process model that is to be incorporated into a controller are different from those of a model which is aimed at demonstrating understanding of the process. Areas where process models are lacking include those involving interactions between production and environmental factors.
Current commercial poultry production in the UK faces many challenges which make it difficult to confidently predict the future. Changing legislation, responding largely to welfare pressures, is one such challenge. Additionally, consumer demands are widening. Eggs and meat from stock which is organically produced, or fed on rations containing no genetically modified ingredients, or free range produced, or corn fed are some of the assurances sought by the purchaser and consumer. Although the market place already offers such produce it is difficult to predict the extent to which they will penetrate a market which developed largely through the use of intensive production systems. The alternatives to intensively produced eggs and meat are more expensive to produce and therefore purchase and consequently are susceptible to changes in standards of living and the affluence of the consumer.
This paper briefly describes current commercial practices and some of the specific challenges arising from new legislation.
A description of some specific requirements of birds highlights areas where improvements, in terms of performance, production efficiency, and welfare might be gained. Since the overwhelming majority of eggs and meat is produced in intensive, highly automated systems, there is an obvious need for an integrated approach featuring engineers and the poultry industry to refine and further develop technology which better serves the birds, and ultimately, the consumer.
It is concluded that the UK cannot compete in production costs with some other areas of the world and as retailers increasingly source their goods worldwide, the UK poultry producer may have to resort to the production of products which satisfy niche demands.
This paper concentrates on livestock production systems by introducing sustainable housing characteristics, and the type of information required to make an informed choice on environmentally sound materials and systems. It then compares energy use in two contrasting beef cattle systems, one a conventional straw-bedded court and roofed silo, with feed delivered by a side-delivery wagon, and the other a roofless woodchip corral and earth-bank silo, with feed delivered by fore-end loader. The woodchip corral system requires 70% less energy than the conventional bedded court, when the total energy inputs are analysed for preparation of the building materials, construction of the livestock accommodation with associated feed and waste storage, and manufacture and operation of machinery. However, when energy used in feed production is included this dominates the energy budget, accounting for 60% of all energy used in the conventional bedded court, and 85% of energy used in the woodchip corral system.