Visual Adaptations and Behavioural Strategies to Detect and Catch Small Targets

Predatory behaviours are ideal for studying the limits of performance and control within animals. Predation naturally creates a competition between the sensors and physiology of predator and prey. Aerial predation demonstrates the greatest feats of physical performance, demanding the highest speeds and accelerations whilst both predator and prey are free to pitch, yaw, and roll. These high speeds and degrees of rotational freedom make control a complex problem. However, from the perspective of the researcher attempting to decipher the control laws that underpin predator guidance, the question is made more soluble by the predator’s fixation on its target. The goal of the pursuer is clear, to contact the target, and thus their systems are focused on the optimization of that action. This is as opposed to more mundane activities, where conflicting interests compete for the attention and behavioural response of the animal. In order to study the necessary trade-offs that underpin aerial predation, this thesis will focus on the hunting behaviour of two fly species. The first is a robber fly, Holcocephala fusca, on which the majority of the first two chapters focus. Secondarily, work with the killer fly Coenosia attenuata will be included in the latter two chapters as a direct contrast to results from Holcocephala. Both are miniature dipteran predators, but not closely related. The structure of this thesis is broken into six chapters, summarised in the following list: 1. Thecompoundeyeofinsectsgenerallyhasmuchpoorerresolutionthanthatofcameratype eyes. Poor resolution is exacerbated in smaller insects that cannot commit the resources required for eyes with large lenses that facilitate high spatial resolution. Holcocephala has developed a small number of facets into a forward-facing acute zone where the spatial acuity is reduced to ~0.28°, rivalling the very best resolution of any compound eye. The only compound eyes with a comparable spatial resolution belong to dragonflies, in excess of an order of magnitude larger than Holcocephala. 2. Numerous potential targets may be airborne within the visual range of a predator. Not all of these may be suitable. Chasing unsuitable targets may waste energy or result in direct harm should they turn out to be larger than the predator can overcome. It is thus a strong imperative for a predator to filter the targets it takes after. Targets silhouetted against the sky display a paucity of cues that a predator could use to determine their size. Holcocephala displays acute size selectivity towards smaller targets. This selectivity goes beyond heuristic rules and size/speed ratios. Instead, Holcocephala appears able to determine absolute size and distance of targets. 3. Both Holcocephala and Coenosia intercept targets, heading for where the target is going to be in the future rather than its current location. Both species plot trajectories in keeping with the guidance law of proportional navigation, an algorithm derived for modern guided missiles. There are key differences evident in the internal physiological constants applied to the control system between the species. These differences are likely linked to the specific environmental conditions and visual physiologies of the flies, especially the range at which targets are attacked. 4. Stemming from the use of the proportional navigational framework, this chapter dives into the intricacies of gain and the weighting of the navigational constant, and the geometric factors that underpin the control effort and eventual success of the control system. 5. “Falcon-diving” can be found in killer flies dropping from their enclosure ceiling, in which they miss targets after diving towards them. Through proportional navigation, it can be demonstrated that the navigational system combined with excessive speed results in acceleration demands the body cannot match. 6. Holcocephala is capable of evading static obstacle whilst intercepting targets. Application of proportional navigation and a secondary obstacle-evasive controller can demonstrate where the fly is combining multiple inputs to guide its heading.This work was funded by the United States Airforce Office of Scientific Research

Peran Conservation International (CI) Terhadap Konservasi Perairan di Bali (Studi Kasus: Desa Tulamben, Bali)

This study aims to determine Conservation International's strategy for Aquatic Conservation in Tulamben, Bali and the impact resulting from Conservation International on Aquatic Conservation in Tulamben, Bali. The research method used in the preparation of this thesis is descriptive method, with data collection techniques in the form of reviewing books, journals, articles, official internet sites, as well as reports or documents related to this research. The results of this study found two things. First, Conservation International's strategy for Marine Conservation in Tulamben, Bali, which is to play a role in managing policies and regulations with the Tulamben Village government and participating with the community in the context of integrating the Marine Protected Area (KKP) program. Second, the impact of Conservation International on Marine Conservation in Tulamben, Bali is divided into three dimensions, namely social, environmental and economic. The social impact is the active role of the community in the Conservation International program. Environmentally, there is growth of fish varieties in the conservation area of ​​Tulamben Village. And the economic impact is the increase in hotel accommodation in Tulamben and local workers.     Penelitian ini bertujuan untuk mengetahui strategi Conservation International terhadap Konservasi Perairan di Tulamben, Bali dan dampak yang dihasilkan dari Conservation International terhadap Konservasi Perairan di Tulamben, Bali. Metode penelitian yang digunakan dalam penyusunan skripsi ini adalah metode deskriptif, dengan teknik pengumpulan data berupa telaah buku, jurnal, artikel, situs internet resmi, serta laporan atau dokumen yang berkaitan dengan penelitian ini. Hasil penelitian ini menemukan dua hal. Pertama, strategi Conservation International terhadap Konservasi Perairan di Tulamben, Bali yaitu berperan dalam pengelolaan kebijakan dan regulasi bersama pemerintah Desa Tulamben serta partisipasi bersama masyarakat dalam konteks integrasi program Kawasan Konservasi Perairan (KKP). Kedua, dampak Conservation International  terhadap Konservasi Perairan di Tulamben,Bali terbagi atas tiga  dimensi, yaitu sosial,  lingkungan, dan ekonomi. Adapun dampaknya secara sosial yaitu peran aktif masyarakat dalam program Conservation International. Secara lingkungan, adanya pertumbuhan varietas ikan di areal kawasan konservasi Desa Tulamben. Dan dampaknya secara ekonomi yaitu meningkatnya akomodasi perhotelan di Tulamben serta tenaga kerja lokal

Fast optical layer mesh protection using pre-cross-connected trails

Conventional optical networks are based on SONET rings, but since rings are known to use bandwidth inefficiently, there has been much research into shared mesh protection, which promises significant bandwidth savings. Unfortunately, most shared mesh protection schemes cannot guarantee that failed traffic will be restored within the 50 ms timeframe that SONET standards specify. A notable exception is the p-cycle scheme of Grover and Stamatelakis. We argue, however, that p-cycles have certain limitations, e.g., there is no easy way to adapt p-cycles to a path-based protection scheme, and p-cycles seem more suited to static traffic than to dynamic traffic. In this paper we show that the key to fast restoration times is not a ring-like topology per se, but rather the ability to pre-cross-connect protection paths. This leads to the concept of a pre-cross-connected trail or PXT, which is a structure that is more flexible than rings and that adapts readily to both path-based and link-based schemes and to both static and dynamic traffic. The PXT protection scheme achieves fast restoration speeds, and our simulations, which have been carefully chosen using ideas from experimental design theory, show that the bandwidth efficiency of the PXT protection scheme is comparable to that of conventional shared mesh protection schemes.Comment: Article has appeared in IEEE/ACM Trans. Networkin

Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

[Image: see text] Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing a plethora of opportunities to synthetic organic chemists. However, performing a photochemical transformation can be quite a challenge because of various issues related to the delivery of photons. These challenges have barred the widespread adoption of photochemical steps in the chemical industry. However, in the past decade, several technological innovations have led to more reproducible, selective, and scalable photoinduced reactions. Herein, we provide a comprehensive overview of these exciting technological advances, including flow chemistry, high-throughput experimentation, reactor design and scale-up, and the combination of photo- and electro-chemistry

Modeling Correlation in Vehicle Routing Problems with Makespan Objectives and Stochastic Travel Times

The majority of stochastic vehicle routing models consider travel times to be independent. However, in reality, travel times are often stochastic and correlated, such as in urban areas. We examine a vehicle routing problem with a makespan objective incorporating both stochastic and correlated travel times. We develop an approach based on extreme-value theory to estimate the expected makespan (and standard deviation) and embed this within a routing heuristic. We present results that demonstrate the impact of different correlation patterns and levels of correlation on route planning

Different Patterns of HIV Expansion Between High-income and Non-rich Countries and the Potential Drivers during the 1980s

Disease dynamics theory predicts that after the introduction of an infected individual into a susceptible population, the number of infected individuals will grow exponentially until a point at which the depletion of the susceptible class starts to affect the rate of increase of the infectious class. The disease then starts to self-limit its own rate of increase towards an equilibrium with the size of the infectious population. Here, we explored whether the HIV dynamics described exponential growth as theoretically predicted during the 1980s decade for 64 countries.  We focused on the HIV population rate of change per infectious individual ( RHIV ) of the infectious class. We used nonlinear regression between HIV infectious class size and RHIV to determine the dynamic behavior of HIV. The prevalence of HIV increased exponentially in most countries, except for high-income countries. The world during the 1980s could be separated into two groups based on HIV dynamics at the country scale. We performed a multivariate analysis with variables mentioned in the HIV literature to explore the preexisting scenarios that could influence this global separation with regard to HIV dynamics. Poverty levels, malaria burden, the prevalence of men who have sex with men, the prevalence of sex workers, the modes of transmission (HIV subtypes) and the urbanization process could interact to explain the differences among countries with regard to HIV dynamics. The results suggest that during the 1980s, we could divide the world into two groups based on the HIV exponential (non-rich countries) and logistic growth patterns (high-income countries)

History of the Innovation of Damage Control for Management of Trauma Patients: 1902-2016

Objective: To review the history of the innovation of damage control (DC) for management of trauma patients. Background: DC is an important development in trauma care that provides a valuable case study in surgical innovation. Methods: We searched bibliographic databases (1950-2015), conference abstracts (2009-2013), Web sites, textbooks, and bibliographies for articles relating to trauma DC. The innovation of DC was then classified according to the Innovation, Development, Exploration, Assessment, and Long-term study model of surgical innovation. Results: The innovation\u27\u27 of DC originated from the use of therapeutic liver packing, a practice that had previously been abandoned after World War II because of adverse events. It then developed\u27\u27 into abbreviated laparotomy using rapid conservative operative techniques.\u27\u27 Subsequent exploration\u27\u27 resulted in the application of DC to increasingly complex abdominal injuries and thoracic, peripheral vascular, and orthopedic injuries. Increasing use of DC laparotomy was followed by growing reports of postinjury abdominal compartment syndrome and prophylactic use of the open abdomen to prevent intra-abdominal hypertension after DC laparotomy. By the year 2000, DC surgery had been widely adopted and was recommended for use in surgical journals, textbooks, and teaching courses ( assessment\u27\u27 stage of innovation). Long-term study\u27\u27 of DC is raising questions about whether the procedure should be used more selectively in the context of improving resuscitation practices. Conclusions: The history of the innovation of DC illustrates how a previously abandoned surgical technique was adapted and readopted in response to an increased understanding of trauma patient physiology and changing injury patterns and trauma resuscitation practices

Fe XXV and Fe XXVI Diagnostics of the Black Hole and Accretion Disk in Active Galaxies: Chandra Time-Resolved Spectroscopy of NGC 7314

We report the detection of Fe XXV and Fe XXVI $K\alpha$ emission lines from a Chandra HETGS observation of the Seyfert~1 galaxy NGC 7314, made simultaneously with RXTE. The lines are redshifted (cz ~ 1500 km/s) relative to the systemic velocity and unresolved. We argue that the lines originate in a near face-on (<7 degrees) disk having a radial line emissivity flatter than r^-2. Line emission from ionization states of Fe in the range ~Fe I up to Fe XXVI is observed. The ionization balance of Fe responds to continuum variations on timescales less than 12.5 ks, supporting an origin of the lines close to the X-ray source. We present additional, detailed diagnostics from this rich data set. These results identify NGC 7314 as a key source to study in the future if we are to pursue reverberation mapping of space-time near black-hole event horizons. This is because it is first necessary to understand the ionization structure of accretion disks and the relation between the X-ray continuum and Fe K line emission. However, we also describe how our results are suggestive of a means of measuring black-hole spin without a knowledge of the relation between the continuum and line emission. Finally, these data emphasize that one {\it can} study strong gravity with narrow (as opposed to very broad) disk lines. In fact narrow lines offer higher precision, given sufficient energy resolution.Comment: Accepted for publication in the Astrophysical Journal. 30 pages, six figures, five of them color. Abstract is abridge

Amphiphilic Perylene-Calix[4]arene hybrids:synthesis and tunable self-assembly

The first highly water-soluble perylene–calix[4]­arene hybrid with the calixarene scaffold acting as a structure-determining central platform is presented. In this tetrahedrally shaped amphiphilic architecture the hydrophilic and hydrophobic subunits are oriented at the opposite side of the calixarene platform. The hydrophobic part contains the two perylene diimide moieties, which enable strong π–π interactions in self-assembly processes. Two hydrophilic Newkome-type dendrons provide sufficient water solubility at slightly basic conditions. The tetrahedrally shaped amphiphile displays an unprecedented aggregation behavior down to concentrations as low as 10^–7 mol L^–1. The intriguing self-assembly process of the compound in water as well as under changed polarity conditions, achieved by addition of THF, could be monitored by the complemented use of cryogenic transmission electron microscopy (cryo-TEM), UV–vis spectroscopy, and fluorescence spectroscopy. Molecular-dynamics and molecular modeling simulations helped in understanding the interplay of supramolecular and optical behavior