Evaluation of options portfolios for exchange rate hedges

<p><span>In this paper evaluate six exchange rate hedging strategies with financial options from the OTC market in Colombia. Three hedging strategies for importers and three for exporters were raised. The coverage for importers was carried out with the traditional strategy of long call, bull call spread and bull put spread, the last two correspond to options portfolios. the coverage for importers was carried out with the traditional strategy of long put, bear call spread and bear put spread, the last two correspond to options portfolios. to determine the best hedging strategy, the currency price was modeled with a Wiener process and the VaR for the six covered scenarios was calculated and compared with the VaR of the uncovered scenario. The results shown by the six hedging strategies manage to mitigate the exchange risk, but the most efficient strategies are the traditional ones for both importers and exporters.</span></p>

Two New Frog Species of the Genus Copiula Mehely, 1901 (Anura, Microhylidae, Asterophryinae) from Southern Papua New Guinea

We describe two new species in the microhylid frog genus Copiula from Western Province, Southern Highlands Province, and Gulf Province in southern Papua New Guinea based on morphological and acoustic data. Both species are medium-sized (between 27 – 30 mm SVL), terrestrial frogs with a predominantly beige-colored dorsum and a yellow ventrum. They can be distinguished from each other and from all congeners by their distinct advertisement calls. In the first species calls are short bursts of 3 – 7 rapidly repeated yapping notes lasting 30 – 44 msec at a repetition rate of 11.6 – 16.5 notes/sec, and in the second species calls consist almost exclusively of two notes (occasionally one or three notes) lasting 50 – 91 msec and produced at a repetition rate of 7.1 – 11.3 notes/sec. Calls of the second species are usually uttered in long call series that may start with one or more, one-note calls before increasing to two notes, and occasionally to three notes/call late in the series. Descriptions of these two species brings the number of Copiula known from the New Guinea region to at least 12.

3. The Effect of Audio Recording for Playback Experiment to the Alteration of Orangutan’s Territorial Behavior

The aim of this study was to find an alternative method to prevent the conflict between the orangutan and human with the utilization of audio recording as biofence. The location of this study was in Leuser National Park on Bukit Lawang, Langkat, North Sumatra using 16 orangutans as the subject of this study. The method used in this study was a simulation and playback experiment which were using long call, spontaneous call, predator voice, and siren sound in the audio recording of non-alpha orangutans. The respond was observed using binocular and recorded using camera recorder. The data obtained were analyzed using Krustal Wallist test. The result showed that 87% of orangutan showed an interest in the attractor, on the other hand, 13% showed disinterest to the attractor. The facial expression shown by orangutan was fear, submission, aggression, and worry. The statistical analyzing result showed that long call and the spontaneous call was very significant (P0.01), while the predator and siren voice were insignificant (P0.05). The result can be concluded that long call and spontaneous calls showing the effective result to the alteration of territorial behavior on orangutan and have a potential as a biofence that is used as an alternative method to prevent the conflict between orangutan and human.

Orangutan Night-Time Long Call Behavior: Sleep Quality Costs Associated with Vocalizations in Captive Pongo

Researchers have suggested that the ability of male primates to emit long-distance vocalizations is energetically costly and potentially incurring important adaptive consequences upon the calling individuals. Here, we present the first preliminary data on captive orangutan (Pongo spp.) nocturnal long calls, generated at the Indianapolis Zoo. We used videography to characterize long calls with observed behavioral contexts for 48 nights (816 observed hours totaling 83 long calls). We generated somnographic data for a subset of the long calls. Overall measures of sleep quality generated by infrared videography were then compared to the somnographic, nocturnal long call data. We tested hypotheses related to the proximate mechanisms involved in the initialization of vocalization and the potential costs of emitting long calls to overall sleep quality. We found that (1) performed long calls were conscious and premeditated in nature and (2) greater number of night-time long calls shared a positive relationship with arousability and sleep fragmentation and a negative relationship with total sleep time and sleep quality. These findings strongly suggest that only several minutes of total time invested in long calls throughout the night disproportionately cost the caller by negatively impacting overall sleep quality.

Efficient Front-End Cache for XEN Virtual Block Device

Xen’s VBD (virtual-block-device) driver is proved to be an efficient solution for block device virtualization, which can achieve nearly 90% performance of bare mode. However, long call path, heavy involvement of hypervisor and redundant context-switches are still obstacles preventing current frontend-backend virtual disk driver from reaching a more efficient level. In this paper we proposed a cache-based method to improve the performance of Xen’s VBD driver. By implementing a cache which buffers recent frontend disk requests, guest is given the opportunity to complete read virtual disk independently without any involvement of Dom0 and XEN hypervisor. Result shows that our cache can brings great improvement of performance to Xen’s VBD driver.