Additive energy forward curves in a Heath-Jarrow-Morton framework

One of the peculiarities of power and gas markets is the delivery mechanism of forward contracts. The seller of a futures contract commits to deliver, say, power, over a certain period, while the classical forward is a financial agreement settled on a maturity date. Our purpose is to design a Heath-Jarrow-Morton framework for an additive, mean-reverting, multicommodity market consisting of forward contracts of any delivery period. The main assumption is that forward prices can be represented as affine functions of a universal source of randomness. This allows us to completely characterize the models which prevent arbitrage opportunities: this boils down to finding a density between a risk-neutral measure $\mathbb{Q}$, such that the prices of traded assets like forward contracts are true $\mathbb{Q}$-martingales, and the real world probability measure $\mathbb{P}$, under which forward prices are mean-reverting. The Girsanov kernel for such a transformation turns out to be stochastic and unbounded in the diffusion part, while in the jump part the Girsanov kernel must be deterministic and bounded: thus, in this respect, we prove two results on the martingale property of stochastic exponentials. The first allows to validate measure changes made of two components: an Esscher-type density and a Girsanov transform with stochastic and unbounded kernel. The second uses a different approach and works for the case of continuous density. We apply this framework to two models: a generalized Lucia-Schwartz model and a cross-commodity cointegrated market.Comment: 28 page

Fetal growth, birth size and energetic cost of gestation in southern right whales

The cost of reproduction greatly affects a species’ life history strategy. Baleen whales exhibit some of the fastest offspring growth rates in the animal kingdom. We quantified the energetic cost of gestation for southern right whales (Eubalaena australis) by combining whaling catch records of pregnant females with photogrammetry data on southern right whale mothers and calves from two breeding grounds in Argentina and Australia. The relationship between calf birth size and maternal length was determined from repeated measurements of individual females before and after giving birth. Fetal growth was determined from generalized linear models fitted to fetal length data from whaling operations between 1961 and 1967. Fetal length was converted to volume and mass, using the volume-to-length relationship of newborn southern right whales calves, and published tissue composition and energy content estimates. Fetal maintenance costs (heat of gestation) and the energy content of the placenta were predicted from published relationships and added to the fetal growth cost to calculate the total cost of gestation. Our findings showed that fetal growth rates and birth size increased linearly with maternal length, with calves being born at ∼35% maternal length. Fetal length increased curvilinearly through gestation, which resulted in an exponential increase in fetal volume and mass. Consequently, the cost of gestation was very low during the first (0.1% of total cost) and second trimester (4.9%), but increased rapidly during the last trimester (95.0%). The heat of gestation incurred the highest cost for pregnant females (73.8%), followed by fetal growth (21.2%) and the placental energy content (5.0%)

Fatty acids and stable isotopes (13C, 15N) in southern right whale Eubalaena australis calves in relation toage and mortality at Peninsula Valdes, Argentina

Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whale Eubalaena australis population that calves off Península Valdés, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous studies found that the population’s reproductive success is influenced by prey availability. Mothers unable to build sufficient fat reserves or feeding on prey with different nutritional value may fail to meet the demands of lactation. Milk is the only source of nutrients and energy for calves at Valdés, so their fatty acids (FAs) and stable isotopes should reflect their mother’s diet and feeding-ground locations. Here, we compared FA profiles and C and N stable isotopes of dead calves with those of living calves to evaluate the potential impact of maternal nutrition on calf survival. We found no differences in the FA composition of blubber in dead and living calves, indicating similar maternal diets. Likewise, the isotopic values of living and dead calves imply that their mothers had similar foraging ranges. However, FA composition was greatly affected by calf length, indicating effects of calf age and duration of nursing. These findings suggest that mothers of dead calves did not feed on different diets or feeding grounds compared to mothers of living calves. Future research should further assess the overall health and body condition of the Valdés southern right whale calves.Fil: Marón, Carina Flavia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Conservación de Ballenas; ArgentinaFil: Budge, Suzanne M.. Dalhousie University Halifax; CanadáFil: Ward, Robert E.. Utah State University; Estados UnidosFil: Valenzuela, Luciano Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología. Laboratorio de Ecología Evolutiva Humana (Sede Quequén); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Di Martino, Matías. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Ricciardi, Marcos. Instituto de Conservación de Ballenas; ArgentinaFil: Sironi, Mariano. Instituto de Conservación de Ballenas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Uhart, Marcela. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. University of California; Estados UnidosFil: Seger, Jon. University Of Utah. Department Of Biology; Estados UnidosFil: Rowntree, Victoria J.. University Of Utah. Department Of Biology; Estados Unidos. Instituto de Conservación de Ballenas; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. Whale Conservation Institute/Ocean Alliance; Estados Unido

Population comparison of right whale body condition reveals poor state of the North Atlantic right whale

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Christiansen, F., Dawson, S. M., Durban, J. W., Fearnbach, H., Miller, C. A., Bejder, L., Uhart, M., Sironi, M., Corkeron, P., Rayment, W., Leunissen, E., Haria, E., Ward, R., Warick, H. A., Kerr, I., Lynn, M. S., Pettis, H. M., & Moore, M. J. Population comparison of right whale body condition reveals poor state of the North Atlantic right whale. Marine Ecology Progress Series, 640, (2020): 1-16, doi:10.3354/meps13299.The North Atlantic right whale Eubalaena glacialis (NARW), currently numbering <410 individuals, is on a trajectory to extinction. Although direct mortality from ship strikes and fishing gear entanglements remain the major threats to the population, reproductive failure, resulting from poor body condition and sublethal chronic entanglement stress, is believed to play a crucial role in the population decline. Using photogrammetry from unmanned aerial vehicles, we conducted the largest population assessment of right whale body condition to date, to determine if the condition of NARWs was poorer than 3 seemingly healthy (i.e. growing) populations of southern right whales E. australis (SRWs) in Argentina, Australia and New Zealand. We found that NARW juveniles, adults and lactating females all had lower body condition scores compared to the SRW populations. While some of the difference could be the result of genetic isolation and adaptations to local environmental conditions, the magnitude suggests that NARWs are in poor condition, which could be suppressing their growth, survival, age of sexual maturation and calving rates. NARW calves were found to be in good condition. Their body length, however, was strongly determined by the body condition of their mothers, suggesting that the poor condition of lactating NARW females may cause a reduction in calf growth rates. This could potentially lead to a reduction in calf survival or an increase in female calving intervals. Hence, the poor body condition of individuals within the NARW population is of major concern for its future viability.North Atlantic: NOAA NA14OAR4320158; Australia: US Office of Naval Research Marine Mammals Program (Award No. N00014-17-1-3018), the World Wildlife Fund for Nature Australia and a Murdoch University School of Veterinary and Life Sciences Small Grant Award; New Zealand: New Zealand Antarctic Research institute (NZARI 2016-1-4), Otago University and NZ Whale and Dolphin Trust; Argentina: National Geographic Society (Grant number: NGS-379R-18)

Managing macropods without poisoning ecosystems

A recent review of the management of hyperabundant macropods in Australia proposed that expanded professional shooting is likely to lead to better biodiversity and animal welfare outcomes. While the tenets of this general argument are sound, it overlooks one important issue for biodiversity and animal health and welfare: reliance on toxic lead-based ammunition. Lead poisoning poses a major threat to Australia's wildlife scavengers. Current proposals to expand professional macropod shooting would see tons of an extremely toxic and persistent heavy metal continue to be introduced into Australian environments. This contrasts with trends in many other countries, where lead ammunition is, through legislation or voluntary programs, being phased out. Fortunately, there are alternatives to lead ammunition that could be investigated and adopted for improved macropod management. A transition to lead-free ammunition would allow the broad environmental and animal welfare goals desired from macropod management to be pursued without secondarily and unintentionally poisoning scavengers. Through this article, we hope to increase awareness of this issue and encourage discussion of this potential change.publishedVersio

Avian influenza virus isolated in wild waterfowl in Argentina: Evidence of a potentially unique phylogenetic lineage in South America

Avian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from a wild bird in Bolivia in 2001. Extensive surveillance in wild birds was carried out in Argentina during 2006-2007. Using RRT-PCR, 12 AI positive detections were made from cloacal swabs. One of those positive samples yielded an AI virus isolated from a wild kelp gull (Larus dominicanus) captured in the South Atlantic coastline of Argentina. Further characterization by nucleotide sequencing reveals that it belongs to the H13N9 subtype. Phylogenetic analysis of the 8 viral genes suggests that the 6 internal genes are related to the isolates from Chile and Bolivia. The analysis also indicates that a cluster of phylogenetically related AI viruses from South America may have evolved independently, with minimal gene exchange, from influenza viruses in other latitudes. The data produced from our investigations are valuable contributions to the study of AI viruses in South America.Centro de Estudios Parasitológicos y de Vectore

Best practice guidelines for cetacean tagging

Animal-borne electronic instruments (tags) are valuable tools for collecting information on cetacean physiology, behaviour and ecology, and for enhancing conservation and management policies for cetacean populations. Tags allow researchers to track the movement patterns, habitat use andother aspects of the behaviour of animals that are otherwise difficult to observe. They can even be used to monitor the physiology of a tagged animal within its changing environment. Such tags are ideal for identifying and predicting responses to anthropogenic threats, thus facilitating the development of robust mitigation measures. With the increasing need for data best provided by tagging and the increasing availability of tags, such research is becoming more common. Tagging can, however, pose risks to the health and welfare of cetaceans and to personnel involved in tagging operations. Here we provide ‘best practice’ recommendations for cetacean tag design, deployment and follow-up assessment of tagged individuals, compiled by biologists and veterinarians with significant experience in cetacean tagging. This paper is intended to serve as a resource to assist tag users, veterinarians, ethics committees and regulatory agency staff in the implementation of high standards of practice, and to promote the training of specialists in this area. Standardised terminology for describing tag design and illustrations of tag types and attachment sites are provided, along with protocols for tag testing and deployment (both remote and through capture-release), including training of operators. The recommendations emphasise the importance of ensuring that tagging is ethically and scientifically justified for a particular project and that tagging only be used to address bona fide research or conservation questions that are best addressed with tagging, as supported by an exploration of alternative methods. Recommendations are provided for minimising effects on individual animals (e.g. through careful selection of the individual, tag design and implant sterilisation) and for improving knowledge of tagging effects on cetaceans through increased post-tagging monitoring.Publisher PDFPeer reviewe

Gene expression patterns in four brain areas associate with quantitative measure of estrous behavior in dairy cows

<p>Abstract</p> <p>Background</p> <p>The decline noticed in several fertility traits of dairy cattle over the past few decades is of major concern. Understanding of the genomic factors underlying fertility, which could have potential applications to improve fertility, is very limited. Here, we aimed to identify and study those genes that associated with a key fertility trait namely estrous behavior, among genes expressed in four bovine brain areas (hippocampus, amygdala, dorsal hypothalamus and ventral hypothalamus), either at the start of estrous cycle, or at mid cycle, or regardless of the phase of cycle.</p> <p>Results</p> <p>An average heat score was calculated for each of 28 primiparous cows in which estrous behavior was recorded for at least two consecutive estrous cycles starting from 30 days post-partum. Gene expression was then measured in brain tissue samples collected from these cows, 14 of which were sacrificed at the start of estrus and 14 around mid cycle. For each brain area, gene expression was modeled as a function of the orthogonally transformed average heat score values using a Bayesian hierarchical mixed model. Genes whose expression patterns showed significant linear or quadratic relationships with heat scores were identified. These included genes expected to be related to estrous behavior as they influence states like socio-sexual behavior, anxiety, stress and feeding motivation (<it>OXT, AVP, POMC, MCHR1</it>), but also genes whose association with estrous behavior is novel and warrants further investigation.</p> <p>Conclusions</p> <p>Several genes were identified whose expression levels in the bovine brain associated with the level of expression of estrous behavior. The genes <it>OXT </it>and <it>AVP </it>play major roles in regulating estrous behavior in dairy cows. Genes related to neurotransmission and neuronal plasticity are also involved in estrous regulation, with several genes and processes expressed in mid-cycle probably contributing to proper expression of estrous behavior in the next estrus. Studying these genes and the processes they control improves our understanding of the genomic regulation of estrous behavior expression.</p