Determination of the Optimum Fattening Period and Fattening Performance Slaughter and Carcass Characteristics of Hair Goat and Saanen × Hair Goat (G1) Crossbred Kids Fattened in Different Systems

This research was carried out to investigate the fattening performance and slaughter and carcass characteristics of Hair goat and Saanen × Hair goat (G1) crossbred kids in different fattening systems. Thirty Hair goats and 30 Saanen × Hair goat (G1) crossbred singleton male kids 2.5-3 months old and weaned were used. The kids were fattened in three different systems: intensive, semi-intensive, and extensive. Marginal value analysis was applied to determine the optimum feeding periods of the kids. In order to determine the slaughter and carcass characteristics, all the kids fattened were taken to slaughter after determining their live weight at the end of the fattening. Live weight gains after the intensive, semi-intensive, and extensive fattening were 17.83 kg, 19.39 kg, and 18.29 kg in the Hair goat kids and 17.88 kg, 18.24 kg, and 17.32 kg in the Saanen × Hair goat (G1) crossbred kids, respectively. In the same order, the average concentrate feed consumed by kids for 1 kg live weight gain was 7.55 kg, 7.28 kg, 7.00 kg and 7.07 kg. Hot carcass weights after the intensive, semi-intensive, and extensive fattening were 13.58, 14.06, and 13.02 kg in the Hair goat kids and 14.21, 15.03, and 14.06 kg in the Saanen × Hair goat (G1) crossbred kids. The Saanen × Hair goat (G1) crossbred goats increased more in live weight than the Hair goat kids and the semi-intensive fattened goats increased more in live weight than the intensive and extensive fed goats. Moreover, the optimum fattening times generally varied between the groups, but not between genotypes within the group.

Can Parfit’s Appeal to Incommensurabilities Block the Continuum Argument for the Repugnant Conclusion?

Blocking the Continuum Argument for the Repugnant Conclusion by an appeal to incommensurabilities in value, as suggested in Parfit (2016), is an attractive option. But incommensurabilities (‘imprecise equalities’ in Parfit’s terminology) that need to be posited to achieve this result have to be very thoroughgoing – ‘persistent’ in the sense to be explained. While this persistency is highly atypical, it can be explained if incommensurability is interpreted on the lines of the fitting-attitudes analysis of value, as permissibility of divergent attitudes towards the items that are being compared. More precisely, it can be interpreted as parity – as the permissibility of opposing preferences with respect to the compared items. This account makes room for the persistency phenomena. Nevertheless, some of Parfit’s substantive value assumptions must be given up, to avoid implausible implications. In particular, his Simple View regarding the marginal value of added lives cannot be retained.

Alternation emerges as a multi-modal strategy for turbulent odor navigation

Foraging mammals exhibit a familiar yet poorly characterized phenomenon, "alternation", a momentary pause to sniff in the air often preceded by the animal rearing on its hind legs or raising its head. Intriguingly, rodents executing an olfactory search task spontaneously exhibit alternation in the presence of airflow, suggesting that alternation may serve an important role during turbulent plume-tracking. To test this hypothesis, we combine fully-resolved numerical simulations of turbulent odor transport and Bellman optimization methods for decision-making under partial observability. We show that an agent trained to minimize search time in a realistic odor plume exhibits extensive alternation together with the characteristic cast-and-surge behavior commonly observed in flying insects. Alternation is tightly linked with casting and occurs more frequently when the agent is far downwind of the source, where the likelihood of detecting airborne cues is higher relative to cues close to the ground. Casting and alternation emerge as complementary tools for effective exploration when cues are sparse. We develop a model based on marginal value theory to capture the interplay between casting, surging and alternation. More generally, we show how multiple sensorimotor modalities can be fruitfully integrated during complex goal-directed behavior.

Is Ecological Birdwatching Tourism a More Effective Way to Transform the Value of Ecosystem Services?—A Case Study of Birdwatching Destinations in Mingxi County, China

Ecological birdwatching tourism is an ecological product and an essential part of ecotourism, and the realization of its recreation value is crucial for improving human well-being, and realization of the local benefits of ecosystem services for areas focused on biodiversity conservation, especially in bird species. In this study, we use travel cost interval analysis, one of the travel cost derived models featuring more easily satisfied assumptions and less limited data, to evaluate the recreation value of the ecological bird-watching tourism destination, and compare it with the general ecotourism, of Mingxi County destination in China. The results show that, firstly, the per capita recreation value of eco-birdwatching is 3.9 times that of general eco-tourism, its per capita social benefit is three times that of general eco-tourism, and its per capita economic benefit is 4.5 times that of general eco-tourism. Secondly, compared with general ecotourists, the per capita travel costs of eco-birdwatchers are higher, and there were significant statistical differences in the expenses for catering, tickets, shopping, opportunity cost, and total travel expenses between these two groups. Thirdly, in comparison with general ecotourists, the marginal cost of an individual eco-birdwatcher is higher, and the travel intention of an eco-birdwatcher is more robust at the same cost level. The price of a single eco-birdwatcher is higher under the same travel intention demand level. In short, the ecological bird-watching industry has a higher marginal value than general eco-tourism and has higher social, economic, and ecological benefits, bringing a higher level of development for the local tourism industry.

Marginal Value of Vehicle-to-Grid Ancillary Service in a Power System with Variable Renewable Energy Penetration and Grid Side Flexibility

Regulating the frequencies of power grids by controlling electric vehicle charging and discharging, known as vehicle-to-grid (V2G) ancillary services, is a promising and profitable means of providing flexibility that integrates variable renewable energy (VRE) into traditional power systems. However, the ancillary services market is a niche, and the scale, saturation, and time-dependency are unclear when assuming future changes in the power system structure. We studied the marginal value of V2G ancillary services as a balancing capacity of the power system operation on the load-frequency control (LFC) timescale and evaluated the reasonable maximum capacity of the LFC provided by V2G. As a case study, we assumed that the Japanese power system would be used under various VRE penetration scenarios and considered the limited availability time of V2G, based on the daily commuter cycle. The power system operation was modeled by considering pumped storage, interconnection lines, and thermal power–partial load operations. The results show that the marginal value of V2G was greater during the daytime than overnight, and the maximum cost saving (USD 705.6/EV/year) occurred during the daytime under the high-VRE scenario. Improving the value and size of V2G ancillary services required coordination with energy storage and excess VRE generation.

A Learning-Based Optimization Approach for Autonomous Ridesharing Platforms with Service-Level Contracts and On-Demand Hiring of Idle Vehicles

Current mobility services cannot compete on equal terms with self-owned mobility products concerning service quality. Because of supply and demand imbalances, ridesharing users invariably experience delays, price surges, and rejections. Traditional approaches often fail to respond to demand fluctuations adequately because service levels are, to some extent, bounded by fleet size. With the emergence of autonomous vehicles, however, the characteristics of mobility services change and new opportunities to overcome the prevailing limitations arise. In this paper, we consider an autonomous ridesharing problem in which idle vehicles are hired on-demand in order to meet the service-level requirements of a heterogeneous user base. In the face of uncertain demand and idle vehicle supply, we propose a learning-based optimization approach that uses the dual variables of the underlying assignment problem to iteratively approximate the marginal value of vehicles at each time and location under different availability settings. These approximations are used in the objective function of the optimization problem to dispatch, rebalance, and occasionally hire idle third-party vehicles in a high-resolution transportation network of Manhattan, New York City. The results show that the proposed policy outperforms a reactive optimization approach in a variety of vehicle availability scenarios while hiring fewer vehicles. Moreover, we demonstrate that mobility services can offer strict service-level contracts to different user groups featuring both delay and rejection penalties.

Comprehensive Strategies to Maximising Value of Late Life Assets: Lessons Learned from Mahakam Block

Mahakam Block has been in operation for nearly half a century with cumulative production of approximately 20 trillion cubic feet of gas and 1.5 billion barrels of oil. Mature field challenges have become more evident as portrayed by declining production, more complex surface constraints, more challenging profitability of new projects and decreasing resources of new wells, which are also exacerbated by external factors such as volatility of oil and gas prices. Despite the aforementioned challenges and complexity in terms of operating numerous fields with different characteristics, Mahakam is currently still one of the biggest producing blocks in Indonesia. The success of sustaining production and prolonging the life of Mahakam is the result of continuous innovations, improvements and optimizations on various aspects over the years. Subsurface innovative ideas by restudying and redefining geological concepts has led Pertamina Hulu Mahakam (PHM) to drill step-out wells in Handil, Tunu, South Mahakam and Sisi Nubi fields that deliver positive results and open new opportunities. In the non-subsurface aspect, Indonesia's first Plan of Development that combines higher and lower value projects across fields called OPLL (Optimasi Pengembangan Lapangan-Lapangan) was initiated in order to develop fields with marginal value and to achieve economy of scale. Moreover, Capital Expenditure (CAPEX) optimization through evolution of platform design, well architecture and sand control method is crucial for exploitation of targets with lower resources over time. PHM has also launched CLEOPATRA (Cost Effectiveness and Lean Operations in Mature Asset), later renamed to LOCOMOTIVE-8 (Low Operations Cost of Mahakam to Achieve Effectiveness and Efficiencies), to achieve Operating Expenditure (OPEX) efficiency through various initiatives driven by each entity. Due to cost of money, budget accuracy is as important as expenditures reduction meaning that more detailed and deterministic budget estimation is necessary. In addition to optimizing cost structure, PHM strives to carry out gas commercialization efforts to improve revenue streams. In this rapidly changing era, especially for Mahakam, paradigm shift becomes highly critical. Changes in the structure and size of organization is essential to adjust with business dynamics. Adaptive organization structure is performed through digitalization and competency improvement to reduce repetitive tasks and increase productivity per capita. Cooperation between neighboring companies brings mutual benefit by sharing rig, transportation means, and pipeline network systems. Mutual benefit opportunity is also available between the company and Indonesian government by amendment of fiscal terms with the aim to enable the execution of sub-economic projects. Ultimately, one effort alone may be insignificant, but the combination of all of the efforts will be the key to the continuation of Mahakam story.

Revolution and Protest Online

Revolution and Protest Online is an Alexander Street resource, which provides documents, images and videos on revolutions and resistance, protest, and social movements from the eighteenth to the twenty-first centuries. It can be purchased as a standalone collection with a perpetual access license, or it can be accessed as a Related Collection through a subscription to Global Issues Library, another Alexander Street resource. This database contains original documents and images in PDF format, as well as e-books, monographs, journals, and videos. These are drawn from a variety of national and international sources, and collectively represent several hundred images, almost 200 videos, and nearly 100,000 pages of content.This database is not difficult to navigate, and finding materials there is relatively easy, using either the basic or advanced searches or through browsing. These various search and browse functions can produce useful results, and are easily understandable, though the advanced search is arguably the most flexible and effective (but also the most complex!). Pricing for this database is based on an institution's budget, FTE, and whatever consortia arrangements it and other institutions make with the vendor. As a consequence, its price can vary considerably from one subscriber to another! For a specific price quote, contact Alexander Street. Its licensing agreement is quite average in its length and composition and is apparently the standard one for the vendor. The quality, quantity, and variety of materials in this database is notable. It will certainly be of use to those researching the political, historical, and social aspects of revolution and protest, both in the United States and around the world. However, given its price variability, it may only be of marginal value to institutions with a high purchase/subscription price and a low demand for these kinds of materials.

A model of naturalistic decision making in preference tests

Decisions as to whether to continue with an ongoing activity or to switch to an alternative are a constant in an animal’s natural world, and in particular underlie foraging behavior and performance in food preference tests. Stimuli experienced by the animal both impact the choice and are themselves impacted by the choice, in a dynamic back and forth. Here, we present model neural circuits, based on spiking neurons, in which the choice to switch away from ongoing behavior instantiates this back and forth, arising as a state transition in neural activity. We analyze two classes of circuit, which differ in whether state transitions result from a loss of hedonic input from the stimulus (an “entice to stay” model) or from aversive stimulus-input (a “repel to leave” model). In both classes of model, we find that the mean time spent sampling a stimulus decreases with increasing value of the alternative stimulus, a fact that we linked to the inclusion of depressing synapses in our model. The competitive interaction is much greater in “entice to stay” model networks, which has qualitative features of the marginal value theorem, and thereby provides a framework for optimal foraging behavior. We offer suggestions as to how our models could be discriminatively tested through the analysis of electrophysiological and behavioral data.