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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.
The Foot and Mouth Disease (FMD) epidemic of 2001 clearly illustrated the fragility of the UK's farm animal genetic resources. In particular, millions of sheep were killed by the disease and by the ‘stamping out’ policy chosen for disease control. Loss of genetic resources was not evenly spread throughout the UK, nor throughout the many different sheep breeds that are native to the UK and for which the UK has a formal responsibility for protection to the United Nations. In fact, the FMD epidemic demonstrated for the first time that sheep breeds comprising large numbers of individuals which are commercially farmed, can nevertheless be at considerable risk of extinction. The breeds most affected were those restricted to geographical regions of the UK into which the FMD spread. These regionally important breeds are adapted to their particular regional environments, represent an important living heritage for the UK and are a key component in sustaining the rural economies of sheep farming communities.
The events of 2001 provided clear proof that there are two components of the UK's farm animal genetic resources demanding protection. One component is already recognised as a priority and is composed of the numerically rare breeds of all domesticated species: these are already under the protection of the Rare Breeds Survival Trust (RBST). The second component has not previously been recognised as a priority for protection. The FMD crisis proved that sheep breeds could exist as large numbers of individuals, but nevertheless face extinction due to their regional location. Urgent attention must be focussed on our Heritage Breeds of sheep. The UK has one of the greatest number of native sheep breeds of any country in the world. The Heritage Breeds provide potentially valuable genetic resources for environmental, low-input farming systems.
Heritage GeneBank was founded during the FMD epidemic specifically to protect sheep breeds at threat of extinction from the disease. A group of academic research scientists established a genetic salvage programme: collecting semen and embryos for protection in a gene bank. Germplasm from seven breeds is in long-term storage. Following the crisis, the scientists involved in the gene bank made a commitment to continue their conservation work in recognition that the Heritage Breeds of sheep in the UK continue to require protection.
This paper describes: (1) the work of Heritage GeneBank (HGB); (2) the threefold mission of The Sheep Trust, the new national charity that evolved from HGB (http://www.thesheeptrust.org); and (3) the ongoing urgent need for conservation of the UK's Heritage Breeds of sheep threatened by genetic erosion.
Developing countries are experiencing an increase in total demand for livestock commodities, as populations and per capita demands increase. Increased production is therefore required to meet this demand and maintain food security. Production increases will lead to proportionate increases in greenhouse gas (GHG) emissions unless offset by reductions in the emissions intensity (Ei) (i.e. the amount of GHG emitted per kg of commodity produced) of livestock production. It is therefore important to identify measures that can increase production whilst reducing Ei cost-effectively. This paper seeks to do this for smallholder agro-pastoral cattle systems in Senegal; ranging from low input to semi-intensified, they are representative of a large proportion of the national cattle production. Specifically, it identifies a shortlist of mitigation measures with potential for application to the various herd systems and estimates their GHG emissions abatement potential (using the Global Livestock Environmental Assessment Model) and cost-effectiveness. Limitations and future requirements are identified and discussed. This paper demonstrates that the Ei of meat and milk from livestock systems in a developing region can be reduced through measures that would also benefit food security, many of which are likely to be cost-beneficial. The ability to make such quantification can assist future sustainable development efforts.
The ice-sheet margin at Russell Glacier, West Greenland, advanced ∼7 m a−1 between 1968 and 1999. As the ice advanced over moraine ridges, small changes in position caused major changes in the routing of proglacial water and sediment. These included changes in the distribution of ice-marginal lakes, in the periodic drainage of ice-dammed lakes, in the routing and sediment content of meltwater draining into the proglacial zone, and in the release of sediment from the moraines by erosion and mass movements. Proglacial hydrology and sediment flux appear to be controlled not simply by glacier mass balance, but by evolving ice-marginal geomorphology, which must be accounted for in palaeoenvironmental interpretation of proglacial sediments.
Sediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12–45 m3 m−1 a−1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glaciofluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.
The livestock sector is one of the fastest growing subsectors of the agricultural economy and, while it makes a major contribution to global food supply and economic development, it also consumes significant amounts of natural resources and alters the environment. In order to improve our understanding of the global environmental impact of livestock supply chains, the Food and Agriculture Organization of the United Nations has developed the Global Livestock Environmental Assessment Model (GLEAM). The purpose of this paper is to provide a review of GLEAM. Specifically, it explains the model architecture, methods and functionality, that is the types of analysis that the model can perform. The model focuses primarily on the quantification of greenhouse gases emissions arising from the production of the 11 main livestock commodities. The model inputs and outputs are managed and produced as raster data sets, with spatial resolution of 0.05 decimal degrees. The Global Livestock Environmental Assessment Model v1.0 consists of five distinct modules: (a) the Herd Module; (b) the Manure Module; (c) the Feed Module; (d) the System Module; (e) the Allocation Module. In terms of the modelling approach, GLEAM has several advantages. For example spatial information on livestock distributions and crops yields enables rations to be derived that reflect the local availability of feed resources in developing countries. The Global Livestock Environmental Assessment Model also contains a herd model that enables livestock statistics to be disaggregated and variation in livestock performance and management to be captured. Priorities for future development of GLEAM include: improving data quality and the methods used to perform emissions calculations; extending the scope of the model to include selected additional environmental impacts and to enable predictive modelling; and improving the utility of GLEAM output.
Observations made with the Infrared Astronomical Satellite (IRAS) showed the existence of a set of K stars with excess emission at 60 μ. The brightest star in the group is δ And (K3 III). Spectra of δ And have been obtained with the International Ultraviolet Explorer (IUE) in both the long and short wavelength regions. These spectra show several features unusual in a K giant as cool as δ And, in particular, emission from CIV, MgII h and k lines with blue wings stronger than the red and MgII absorption blue shifted to up to 300 km s−1. Overall δ And is similar to the known hybrid bright giant α TrA (K4 II). We have discovered the first ‘hybrid’ giant star. The IRAS observations are interpreted in terms of a cool (∼100 K) dust cloud surrounding δ And - a spectroscopic binary system- and a third component at 1200 A.U.
Hippocampal dysfunction is considered central to many neurobiological models of schizophrenia, yet there are few longitudinal in vivo neuroimaging studies that have investigated the relationship between antipsychotic treatment and morphologic changes within specific hippocampal subregions among patients with psychosis.
A total of 29 patients experiencing a first episode of psychosis with little or no prior antipsychotic exposure received structural neuroimaging examinations at illness onset and then following 12 weeks of treatment with either risperidone or aripiprazole in a double-blind randomized clinical trial. In addition, 29 healthy volunteers received structural neuroimaging examinations at baseline and 12-week time points. We manually delineated six hippocampal subregions [i.e. anterior cornu ammonis (CA) 1–3, posterior CA1–3, subiculum, dentate gyrus/CA4, entorhinal cortex, and fimbria] from 3T magnetic resonance images using an established method with high inter- and intra-rater reliability.
Following antipsychotic treatment patients demonstrated significant reductions in dentate gyrus/CA4 volume and increases in subiculum volume. Healthy volunteers demonstrated non-significant volumetric changes in these subregions across the two time points. We observed a significant quadratic (i.e. inverted U) association between changes in dentate gyrus/CA4 volume and cumulative antipsychotic dosage between the scans.
This study provides the first evidence to our knowledge regarding longitudinal in vivo volumetric changes within specific hippocampal subregions in patients with psychosis following antipsychotic treatment. The finding of a non-linear relationship between changes in dentate gyrus/CA4 subregion volume and antipsychotic exposure may provide new avenues into understanding dosing strategies for therapeutic interventions relevant to neurobiological models of hippocampal dysfunction in psychosis.
Sediments from the Antarctic continental margin may provide detailed palaeoenvironmental records for Antarctic shelf waters during the late Quaternary. Here we present results from a palaeoenvironmental study of two sediment cores recovered from the continental shelf off Mac. Robertson Land, East Antarctica. These gravity cores were collected approximately 90 km apart from locations on the inner and outer shelf. Both cores are apparently undisturbed sequences of diatom ooze mixed with fine, quartz-rich sand. Core stratigraphies have been established from radiocarbon analyses of bulk organic carbon. Down-core geochemical determinations include the lithogenic components AÍ and Fe, biogenic components opal and organic carbon, and palaco-redox proxies Mn, Mo and U. We use the geochemical data to infer past variations in the deposition of biogenic and lithogenic materials, and the radiocarbon dates to estimate average sediment accumulation rates. The Holocene record of the outer-shelf core suggests three episodes of enhanced diatom export production at about 1.8, 3.8 and 5.5 ka BP, as well as less pronounced bloom episodes which occurred over a shorter period. Average sediment accumulation rates at this location range from 13.7 cm ka−1 in the late Pleistocene early Holocene to 82 cm ka−1 in the late Holocene, and suggest that the inferred episodes of enhanced biogenic production lasted 100-1000 years. in contrast, data for the inner-shelf core suggest that there has been a roughly constant proportion of biogenic and lithogenic material accumulating during the middle to late Holocene, with a greater proportion of biogenic material relative to the outer shelf. Notably, there is an approximately 7-fold increase in average sediment accumulation rate (from 24.5 to 179 cm ka−1) at this inner-shelf location between the middle and late Holocene, with roughly comparable increases in the mass accumulation rates of both biogenic and lithogenic material. This may represent changes in sediment transport processes, or reflect real increases in pelagic sedimentation in this region during the Holocene. Our results suggest quite different sedimentation regimes in these two shelf locations during the middle to late Holocene.
Prior studies have suggested a relationship between atopy and mental health, although methodological barriers have limited the generalizability of these findings. The objective of this study was to investigate the relationship between early-life atopy and vulnerability to mental health problems among youth in the community.
Data were drawn from the Raine Study (N = 2868), a population-based birth cohort study in Western Australia. Logistic regression and generalized estimating equations were used to examine the relationship between atopy at ages 1–5 years [using parent report and objective biological confirmation (sera IgE)], and the range of internalizing and externalizing mental health problems at ages 5–17 years.
Atopy appears to be associated with increased vulnerability to affective and anxiety problems, compared to youth without atopy. These associations remained significant after adjusting for a range of potential confounders. No relationship was evident between atopy and attention deficit hyperactivity disorder or externalizing problems.
Findings are the first linking atopy (measured by both parent report and objective verification) with increased vulnerability to affective and anxiety problems. Therefore, replication is required. If replicated, future research aimed at understanding the possible biological and/or social and environmental pathways underlying these links is needed. Such information could shed light on shared pathways that could lead to more effective treatments for both atopy and internalizing mental health problems.
Two studies consisting of six field experiments each were conducted at three locations in southwestern Ontario, Canada, in 2014 and 2015 to evaluate the possible antagonism when dicamba was added to quizalofop-p-ethyl or clethodim for the control of volunteer glyphosate-resistant (GR) corn. At 4 wk after application (WAA), quizalofop-p-ethyl at 24, 30, or 36 g ai ha−1 provided 88, 94, and 95% control of volunteer GR corn, respectively. The addition of dicamba at 300 or 600 g ae ha−1 to quizalofop-p-ethyl (24 g ha−1) reduced the activity of quizalofop-p-ethyl on volunteer GR corn by 12 and 20%. At 4 WAA, clethodim at 30, 37.5, and 45 g ai ha−1 provided 85, 91, and 95% control of volunteer GR corn, respectively. The addition of dicamba at 300 or 600 g ha−1 to clethodim (30 g ha−1) resulted in antagonism, causing a reduction in volunteer GR corn by 12 and 11%, respectively. In general, there was greater antagonism when the high rate of dicamba was tank-mixed with the lower rate of the graminicide. There was no antagonistic effect on soybean yield by tank-mixing dicamba with either graminicide at all rates evaluated. Based on these results, volunteer GR corn can be controlled effectively by increasing the rate of the graminicide when tankmixed with dicamba.
Current calibration methods for single and replicate 14C dates are compared. Various forms of tabular and graphic output are discussed. Results from all the methods show reasonable agreement but further methodological development and improvements in computer output are required. Comparison of existing techniques for a series of non-contemporaneous dates showed less agreement amongst participants on this issue. We recommend that calibrated dates should be presented as a combination of graphs and ranges, in preference to mean and standard deviation.
A significant proportion of people with learning difficulties have social problems, which are often considered to be the product of school failure. However, a number of studies have suggested that these social skill problems may relate to the inability to decode subtle visual cues of body language and facial expression. The majority of studies of facial expression, however, have viewed learning disability as a unitary condition, without taking account of specific sub‐types which may have more difficulty in processing visual cues, especially for facial emotion. This study investigated children aged 8 to 12 years who were divided into three learning disability sub‐groups: 1) a visual‐perceptual sub‐type called Irlen Syndrome (n=41); 2) a group with learning disabilities, but no indications of Irlen Syndrome (n=30); and 3) a normally achieving control group (n=31). The Irlen Syndrome sub‐group had significantly lower scores for interpreting emotion from facial expression than the two other groups. The learning disabled non‐lrlen sub‐group also had significantly lower scores than the control group, but with much smaller levels of significance than those between the Irlen and control groups.
We examine the roles of actuaries in UK life offices, along with trends, challenges to and opportunities for actuaries. We carry out an analysis of senior roles in life offices, a questionnaire survey and interviews with relevant senior personnel. We find that actuaries occupy many important roles in life offices and are regarded as having good industry knowledge and technical skills, especially in financial modelling. There are fewer executive directors and more non-executive directors of life offices who are actuaries compared with the position in 1990. A higher proportion of reserved roles is outsourced to consultants than was the case in 1990. Only a small number of Actuarial Function Holders are directors. Actuaries are more siloed than was the case in the past, although actuaries are well represented in the finance and risk functions of many offices. Although actuarial work in connection with the preparation for Solvency II will decline, there will be important ongoing requirements for actuaries following Solvency II implementation. We also see opportunities for actuaries in four areas: in risk management, in financial analysis and management based on Solvency II and international financial reporting standards, in connection with “big data”, and in product development and the customer proposition. There are implications for the examination syllabus, continuing professional development and research.
Various environmental factors have been associated with the timing of eruption of primary dentition, but the evidence to date comes from small studies with limited information on potential risk factors. We aimed to investigate associations between tooth emergence patterns and pre-conception, pregnancy and postnatal influences. Dentition patterns were recorded at ages 1 and 2 years in 2915 children born to women in the Southampton Women’s Survey from whom information had been collected on maternal factors before conception and during pregnancy. In mutually adjusted regression models we found that: children were more dentally advanced at ages 1 and 2 years if their mothers had smoked during pregnancy or they were longer at birth; mothers of children whose dental development was advanced at age 2 years tended to have poorer socioeconomic circumstances, and to have reported a slower walking speed pre-pregnancy; and children of mothers of Asian ethnicity had later tooth development than those of white mothers. The findings add to the evidence of environmental impacts on the timing of the eruption of primary dentition in indicating that maternal smoking during pregnancy, socio-economic status and physical activity (assessed by reported walking speed) may influence the child’s primary dentition. Early life factors, including size at birth are also associated with dentition patterns, as is maternal ethnicity.
New trait technology incorporating 2,4-dichlorophenoxyacetic acid (2,4-D) resistance in soybean provides an alternative method to control weeds. However, the effect of postemergence treatments of 2,4-D on aryloxyalkanoate dioxygenase-12 (AAD-12) soybean on injury and yield components has not been reported. Our objectives were to characterize the effect of 2,4-D (dimethylamine salt) rates (0, 1,120, and 2,240 g ae ha−1) and soybean growth stage (V5, R2, or V5 followed by R2) on AAD-12 soybean injury and yield components. Less than 3% soybean injury was observed when 2,240 g ha−1 of 2,4-D was applied to R2 soybean, and less than 1% soybean injury was caused by 1,120 g ha−1 of 2,4-D. Seed yield, seed mass, pod number, seed number, seed per pod, reproductive node number, pods per reproductive node, node number, and percent reproductive nodes were not affected by 2,4-D treatments when applied at the V5, R2, or the V5 followed by R2 soybean growth stage. This research demonstrates that soybean transformed with AAD-12 can tolerate foliar applications of 2,4-D at rates up to 2,240 g ha−1 with no effect on soybean grain yield components.
New trait technology incorporating 2,4-D resistance in soybean is dependent upon the ability of the plant to metabolize 2,4-D by the aryloxyalkanoate dioxygenase-12 protein (AAD-12). Our objectives were to determine AAD-12 expression during the daytime, throughout the leaf canopy, and before and after 2,4-D treatment for the events DAS-68416-4 and DAS-21606-3. Field experiments were conducted near Wanatah, IN in 2009 and Fowler, IN in 2009, 2010, and 2011. During the daytime, total AAD-12 expression was lowest between 12:30 and 15:30, averaging 161 ng cm−2, as compared to an average of 245 ng cm−2 in the morning and 243 ng cm−2 in the evening. The youngest fully emerged trifoliate in the DAS-68416-4 event had the highest AAD-12 expression, with means ranging from 369 to 390 ng cm−2, while the older leaves maintained a lower level of expression, 171 to 211 ng cm−2. The youngest leaves of event DAS-21606-3 had the highest level of AAD-12 expression (205 to 225 ng cm−2), while the level of AAD-12 was lower in older leaves (71 to 149 ng cm−2). In general, 2,4-D treatments did not reduce AAD-12 expression at 3, 7, 14, and 21 days after treatment; however, in a few instances AAD-12 expression was increased or decreased by 8 to 11% after 2,4-D treatment. Expression of AAD-12 was between 152 to 390 ng cm−2 for DAS-68416-4 and from 71 to 244 ng cm−2 for DAS-21606-3.
1.1 The background to the production of this paper is somewhat involved, but is necessary for an understanding of why it contains what it does. Readers who are familiar with recent developments in the valuation field may proceed straight to Section 2.
1.2 Statutory valuations of long-term insurance business under the Insurance Companies Act 1982 (“the Act”, which superseded the 1974 and 1981 Acts) and the Insurance Companies Regulations 1981 (“the current Regulations”) have now been prepared by actuaries for some years. Similarly the guidance issued by the profession to Appointed Actuaries, specifically GN1 and GN8, has also remained substantially unchanged over that period. The time was opportune for valuation practice to be reviewed in the light of recent experience.