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The Roman period sees the introduction of many new plants and animals into Britain, with a profound impact on people's experience of their environment. Sweet chestnut is considered to be one such introduction, for which records of sweet chestnut wood and charcoal from archaeological excavations of Romano-British period contexts have been used as evidence. This paper reviews the records for sweet chestnut in Britain pre-a.d. 650, by critically evaluating original excavation reports and examining archived specimens. This review re-assesses the original identifications of sweet chestnut and/or their dating and concludes that most of the evidence that justified sweet chestnut's status as a Roman archaeophyte is untenable. The review emphasises the importance of securely identifying and directly dating plant material and of long-term curation by museums and archives. The Supplementary Material online (https://doi.org/10.1017/S0068113X19000011) contains details of all published records of finds of sweet chesnut.
Optical parametric chirped-pulse amplification (OPCPA) [Dubietis et al., Opt. Commun. 88, 437 (1992)] implemented by multikilojoule Nd:glass pump lasers is a promising approach to produce ultraintense pulses (
). Technologies are being developed to upgrade the OMEGA EP Laser System with the goal to pump an optical parametric amplifier line (EP OPAL) with two of the OMEGA EP beamlines. The resulting ultraintense pulses (1.5 kJ, 20 fs,
) would be used jointly with picosecond and nanosecond pulses produced by the other two beamlines. A midscale OPAL pumped by the Multi-Terawatt (MTW) laser is being constructed to produce 7.5-J, 15-fs pulses and demonstrate scalable technologies suitable for the upgrade. MTW OPAL will share a target area with the MTW laser (50 J, 1 to 100 ps), enabling several joint-shot configurations. We report on the status of the MTW OPAL system, and the technology development required for this class of all-OPCPA laser system for ultraintense pulses.
An effective method for enhancing milk production efficiency in dairy cows is to increase milk yield and significant progress has been achieved through intense selection, assisted by the application of new reproductive techniques. However this increased milk yield has been accompanied by a slow but steady decline in dairy cow fertility. The two main reasons for this reducing level of fertility appear to be selection for increased milk yield and large herd sizes, although the affect of the introduction of Holstein genes needs to be investigated. In addition, other negative consequences such as an increase in the incidence of metabolic diseases and lameness have been observed. This has given rise to public concern that the high-yielding dairy cow may be under a state of metabolic stress during peak lactation and therefore the welfare and performance of other body functions are compromised.
The reason for this decline in fertility is not well understood, although a nutritional influence on the initiation of oestrous cycles, follicular growth, oocyte quality and early embryonic development has been implicated. In early lactation dietary intake is unable to meet the demands of milk production and most cows enter a period of negative energy balance. Negative energy balance has a broadly similar effect to undernutrition leading to a mobilization of body reserves. Furthermore diets high in rumen degradable protein lead to an excess of rumen ammonia, which before it is converted to urea by the liver and excreted in the urine, may cause an alteration in the reproductive tract environment reducing embryo survival. Such major changes in the metabolic and endocrine systems can therefore influence fertility at a number of key points.
Possible reproductive sites where inadequate nutrition may have detrimental effects include: (i) the hypothalamic/pituitary gland where gonadotropin release may be impaired; (ii) a direct effect on the ovaries, where both follicular growth patterns and corpus luteum function may be directly influenced; (iii) the quality of the oocyte prior to ovulation may be reduced and coupled with an inadequate uterine environment will result in reduced embryo survival and (iv) there may be effects on subsequent embryo development. The initiation of normal oestrous cycles post partum is usually delayed in dairy cows with a higher genetic merit for milk production, confirming that intense selection towards high milk yield can compromise reproductive function. In addition, the effects of increased milk yield may include changes in circulating GH and insulin concentrations, which in turn alter both insulin-like growth factor (IGF) and IGF binding protein production. Nutrition has recently been shown to have a direct effect at the level of both the ovaries and the uterus to alter the expression of these growth factors.
In conclusion, further knowledge is required to determine how the metabolic changes associated with high milk output reduce fertility. Identification and understanding of the mechanisms involved and the key sites of action responsible for compromised reproductive function, will enable the identification of possible indices for future multiple-trait selection programmes.
Past improvement programmes in pigs have concentrated on lean growth, and have relied on direct comparisons of contemporaries in a common environment. The new mixed model technology now allows comparisons across environments and generations, and, by utilizing all possible genetic relationships, more accurate prediction of genetic merit for traits of low heritability. In addition, breeding programme design will benefit from more precise estimation of genetic parameters. Principal benefits of the new technology are greater flexibility of structure of breeding programmes, and faster improvement of litter size. The consequence will be larger populations under selection with lower costs per unit of genetic improvement. For national improvement schemes using a high proportion of AI matings, central testing stations could become unnecessary. Main research priorities are the optimum family structure to balance selection and inbreeding, more efficient computing strategies for large numbers of traits, and the incorporation of single genes into predictions of merit. The new technology will be important for the exploitation of biological advances in manipulation of both reproduction and the genome.
A combination of better management and genetic selection for good health and fertility would provide a more effective long term solution for economic loss due to diseases and poor fertility. This would also help to address public concerns about the use of medical treatment in milk production. A balance in the genetic improvement of health and fertility together with milk production could be achieved through their inclusion in national genetic selection indices, for which genetic parameters are needed. One of the main objectives of this study was to estimate genetic parameters for various disease and fertility traits in the UK dairy cattle population, using records from a national recording scheme run by Livestock Services UK Ltd. Genetic analysis of traits recorded as present or absent (binary traits; e.g. diseases) requires the use of non-linear threshold models, because linear models require normality assumptions (e.g., Gianola 1982). The other objective of this study was to estimate genetic parameters for binary disease and fertility traits based on threshold animal models and to compare results with those from linear animal models.
Identifying genetic relationships between complex traits in emerging adulthood can provide useful etiological insights into risk for psychopathology. College-age individuals are under-represented in genomic analyses thus far, and the majority of work has focused on the clinical disorder or cognitive abilities rather than normal-range behavioral outcomes.
This study examined a sample of emerging adults 18–22 years of age (N = 5947) to construct an atlas of polygenic risk for 33 traits predicting relevant phenotypic outcomes. Twenty-eight hypotheses were tested based on the previous literature on samples of European ancestry, and the availability of rich assessment data allowed for polygenic predictions across 55 psychological and medical phenotypes.
Polygenic risk for schizophrenia (SZ) in emerging adults predicted anxiety, depression, nicotine use, trauma, and family history of psychological disorders. Polygenic risk for neuroticism predicted anxiety, depression, phobia, panic, neuroticism, and was correlated with polygenic risk for cardiovascular disease.
These results demonstrate the extensive impact of genetic risk for SZ, neuroticism, and major depression on a range of health outcomes in early adulthood. Minimal cross-ancestry replication of these phenomic patterns of polygenic influence underscores the need for more genome-wide association studies of non-European populations.
Competition resulting in high social status and maintenance of that status within farmed pigs may have both welfare and economic consequences. Aggressive behaviours, associated with the establishment and maintenance of a dominance hierarchy, may cause poor welfare and skin damage reducing the value of pigs at slaughter. In order to investigate the impact of social status on welfare we first need to establish the status of individuals relative to their peers. In this paper we compare two alternative indicators of pig rank, namely: (i) aggressive interactions between individuals - the occurrence of aggressive behaviour from pig A to pig B is often assumed to imply social dominance of pig A over pig B; and (ii) the order in which pigs stand at the feeder - an advantage of attaining high social status in many populations is priority of access to food. Social rank of individuals based on observed aggressive behaviour can only be assigned once evidence for a linear or quasi-linear hierarchy has been established (Langbein and Puppe, 2004). In a population with a purely hierarchical structure we expect all triads of individuals to be transitive, that is A→B, B→C implies A→C. For observational studies it is unlikely that interactions between all individuals will be observed. Here we present a novel methodology by which we can assess the linearity of the dominance structure that is not affected by missing or null interactions between individuals. By conducting a census of all types of triad in a social network we can assess whether the subset of interactions observed provide evidence of a linear or quasi-linear hierarchy. Transitive triads provide evidence of linear hierarchy whilst intransitive triads, such as A→B, B→C, C→A, contradict the presence of a linear hierarchy.
Reproductive failure is a source of major economic loss to the UK pig industry, accounting for 0.5 of all first parity gilt cullings (MLC Pig Year Book, 1995). Previous research (Cameron et al, 1999) has shown that rearing gilts on a diet formulated to support maximal protein deposition has beneficial effects on ovulation rate at 3rd oestrus. The aim of the current experiment was to develop further the previous model to assess long and short-term effects of protein nutrition on reproductive performance, body composition and metabolic status.
The concept of using immunological strategies to boost reproductive performance in sheep and cattle is far from new, with products such as Fecundin®, which involved active immunisation against the weak androgen, androstenedione, having been released nearly 20 years ago. However, whilst effective in sheep, immunisation against androgens was not effective in inducing multiple ovulation in cattle (unpublished observations), in which the natural rate of twinning is low (<4%). The purification of inhibin in the late 1980’s and the subsequent elucidation of its role in controlling follicle stimulating hormone (FSH) release from the pituitary represented an alternative means to increase prolificacy in domestic ruminants. Intense research effort throughout the 1990’s utilising active inhibin immunisation showed that while this approach was quite successful in sheep, results in cattle were less promising due to the extreme variability of the response obtained both between animals and within a single animals across successive cycles. Further, while numerous studies have shown that with correct identification and management production of twins in cattle can lead to significant economic gains, the possibility of more than two young clearly raised welfare concerns for both sheep and cattle in terms of dystocia and post-natal welfare of both the mother and her offspring. Over recent years, however, continued research into the control of ovarian follicle development in ruminants has suggested alternate immunological strategies that could be used to modulate prolificacy in a more reliable and controllable manner.
Leptin is involved in the regulation of food intake, energy expenditure and whole body energy balance. In livestock species these processes are important for optimisation of growth, reproduction, lactation and overall health and well-being. Condition score is a useful indicator of energy balance and is highly correlated (-0.84) genetically to commencement of luteal activity (CLA), an endocrine measurement of fertility in dairy cattle (Royal et al., submitted). Circulating leptin levels drop post-partum reflecting changes in energy balance and fat mobilisation. The interval to first ovulation post-partum is phenotypically correlated (0.83) to the interval from parturition to the leptin nadir (Kadokawa et al. 2000), suggesting that a delay in the recovery of leptin secretion postpartum increases the delay to first ovulation. The heritability of circulating leptin concentrations in humans and pigs is high (0.39-0.61; Cameron et al., 2000; Rotimi et al., 1997). If this were also the case in cattle, and postpartum changes were related to concentrations at an early age, then it would be of immense value to the genetic improvement of traits associated with fertility.
Recent studies have reported a substantial increase in the incidence of reproductive cycle problems in modern dairy cows (Opsomer et al., 1998; Royal et al., 1999). This increase is often attributed to the ever-increasing metabolic demands placed upon these cows by continually increasing milk yields. In this study we have monitored a variety of metabolic parameters in lactating dairy cows and related these to reproductive function in an attempt to establish metabolic predictors of impending reproductive failure.
Fertility of UK dairy cows is at an all time low (Royal et al., 2000). Genetic improvements through direct selection is minimal since parameters can only be measured in the mature female and generally have low heritability (h2 < 0.1). It may be possible to overcome these genetic limitations with the use of an indirect selection criterion. Whilst commencement of luteal activity might prove a valuable genetic indicator of female fertility (Darwash et al., 1997), a major step forward would be the identification of a highly heritable trait in the male that is measurable in early life and genetically correlated to a measurement of female fertility. The physiological control of reproduction is by the same gonadotrophic hormones in both sexes (Land, 1973), and Haley et al. (1989) reported that the underlying variation in gonadotrophin response to GnRH is controlled by the same genes in both sexes. High heritabilities (0.4–0.55) for the response to GnRH have been reported in ram lambs (Haley et al., 1989) and beef bulls (Mackinnon et al., 1991). The objective of this study was to estimate the genetic variation in a number of parameters associated with the LH response to a GnRH challenge in pre-pubertal Holstein-Friesian (H/F) heifers.
Recent MLC survey data (Pig Year Book, 1995) reports that approximately 0.5 of annual first parity gilt cullings are due to reproductive failure. This high culling rate may be attributed to recent genetic selection for increased lean tissue accretion rates, and as a result a greater mature body weight. However, the gilt attains puberty and is thus mated at a lower age and as a consequence has not reached the target threshold of 35kg body protein mass at farrowing, suggested by Everts (1994),to be necessary for optimal reproductive performance. This, confounded with excessive tissue catabolism over lactation results in the attenuation of the gilt's potential protein accretion curve and hence reproductive failure (Foxcroft et al. 1995). The aim of this experiment was to study the effect of two protein accretion rates (maximum and 0.8 of maximum) on reproductive function in the gilt from 50kg liveweight to 3rd oestrus.
In lambs, the rapid increase in heat production after birth is due to initiation of nonshivering thermogenesis in brown adipose tissue (BAT). This occurs in conjunction with an increase in amount and activity of BAT specific uncoupling protein 1 (UCP1) (Clarke et al. 1997). UCP1 abundance and activity is low in fetal life but, within twelve hours of birth, there is an increase in the thermogenic activity of BAT and mRNA for UCP1. This ontogeny of UCP1 mRNA in BAT is very similar that of leptin, which is first detectable in the sheep fetus at 90 days gestation in fetal adipose tissue, its expression then increases up to term at 147 days (Yuen et al 1999). Leptin is a hormone which is thought to play a physiological role is in energy balance, it is primarily produced by white adipose tissue although there is evidence for its production in both brown adipose tissue and the placenta. Lambs born in the autumn are known to be smaller than those born in the spring (McCoard et al. 1997). It is not known if moderate changes in date of mating can influence birth weight or adipose tissue development. The present study aimed to determine whether date of mating could influence lamb birth weight, the abundance of BAT, UCP1, plasma leptin.
Previous studies have demonstrated that several major psychiatric disorders are influenced by shared genetic factors. This shared liability may influence clinical features of a given disorder (e.g. severity, age at onset). However, findings have largely been limited to European samples; little is known about the consistency of shared genetic liability across ethnicities.
The relationship between polygenic risk for several major psychiatric diagnoses and major depressive disorder (MDD) was examined in a sample of unrelated Han Chinese women. Polygenic risk scores (PRSs) were generated using European discovery samples and tested in the China, Oxford, and VCU Experimental Research on Genetic Epidemiology [CONVERGE (maximum N = 10 502)], a sample ascertained for recurrent MDD. Genetic correlations between discovery phenotypes and MDD were also assessed. In addition, within-case characteristics were examined.
European-based polygenic risk for several major psychiatric disorder phenotypes was significantly associated with the MDD case status in CONVERGE. Risk for clinically significant indicators (neuroticism and subjective well-being) was also associated with case–control status. The variance accounted for by PRS for both psychopathology and for well-being was similar to estimates reported for within-ethnicity comparisons in European samples. However, European-based PRS were largely unassociated with CONVERGE family history, clinical characteristics, or comorbidity.
The shared genetic liability across severe forms of psychopathology is largely consistent across European and Han Chinese ethnicities, with little attenuation of genetic signal relative to within-ethnicity analyses. The overall absence of associations between PRS for other disorders and within-MDD variation suggests that clinical characteristics of MDD may arise due to contributions from ethnicity-specific factors and/or pathoplasticity.
Subjective reports of insomnia and hypersomnia are common in bipolar disorder (BD). It is unclear to what extent these relate to underlying circadian rhythm disturbance (CRD). In this study we aimed to objectively assess sleep and circadian rhythm in a cohort of patients with BD compared to matched controls.
Forty-six patients with BD and 42 controls had comprehensive sleep/circadian rhythm assessment with respiratory sleep studies, prolonged accelerometry over 3 weeks, sleep questionnaires and diaries, melatonin levels, alongside mood, psychosocial functioning and quality of life (QoL) questionnaires.
Twenty-three (50%) patients with BD had abnormal sleep, of whom 12 (52%) had CRD and 29% had obstructive sleep apnoea. Patients with abnormal sleep had lower 24-h melatonin secretion compared to controls and patients with normal sleep. Abnormal sleep/CRD in BD was associated with impaired functioning and worse QoL.
BD is associated with high rates of abnormal sleep and CRD. The association between these disorders, mood and functioning, and the direction of causality, warrants further investigation.
Little is known about the precursors of suicide risk among primary-care patients. This study aimed to examine suicide risk in relation to patterns of clinical consultation, psychotropic drug prescribing, and psychiatric diagnoses.
Nested case-control study in the Clinical Practice Research Datalink (CPRD), England. Patients aged ⩾16 years who died by suicide during 2002–2011 (N = 2384) were matched on gender, age and practice with up to 20 living control patients (N = 46 899).
Risk was raised among non-consulting patients, and increased sharply with rising number of consultations in the preceding year [⩾12 consultations v. 1: unadjusted odds ratio (OR) 6.0, 95% confidence interval (CI) 4.9–7.3]. Markedly elevated risk was also associated with the prescribing of multiple psychotropic medication types (⩾5 types v. 0: OR 62.6, CI 44.3–88.4) and with having several psychiatric diagnoses (⩾4 diagnoses v. 0: OR 31.1, CI 19.3–50.1). Risk was also raised among patients living in more socially deprived localities. The confounding effect of multiple psychotropic drug types largely accounted for the rising risk gradient observed with increasing consultation frequency.
A greater proportion of patients with several psychiatric diagnoses, those prescribed multiple psychotropic medication types, and those who consult at very high frequency might be considered for referral to mental health services by their general practitioners. Non-consulters are also at increased risk, which suggests that conventional models of primary care may not be effective in meeting the needs of all people in the community experiencing major psychosocial difficulties.