Size constancy in bat biosonar?

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed "size constancy". It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the 'sonar aperture', i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats

Long-term results of radiotherapy for periarthritis of the shoulder: a retrospective evaluation

<p>Abstract</p> <p>Background</p> <p>To evaluate retrospectively the results of radiotherapy for periarthritis of the shoulder</p> <p>Methods</p> <p>In 1983–2004, 141 patients were treated, all had attended at least one follow-up examination. 19% had had pain for several weeks, 66% for months and 14% for years. Shoulder motility was impaired in 137/140 patients. Nearly all patients had taken oral analgesics, 81% had undergone physiotherapy, five patients had been operated on, and six had been irradiated. Radiotherapy was applied using regular anterior-posterior opposing portals and Co-60 gamma rays or 4 MV photons. 89% of the patients received a total dose of 6 Gy (dose/fraction of 1 Gy twice weekly, the others had total doses ranging from 4 to 8 Gy. The patients and the referring doctors were given written questionnaires in order to obtain long-term results. The mean duration of follow-up was 6.9 years [0–20 years].</p> <p>Results</p> <p>During the first follow-up examination at the end of radiotherapy 56% of the patients reported pain relief and improvement of motility. After in median 4.5 months the values were 69 and 89%, after 3.9 years 73% and 73%, respectively. There were virtually no side effects. In the questionnaires, 69% of the patients reported pain relief directly after radiotherapy, 31% up to 12 weeks after radiotherapy. 56% of the patients stated that pain relief had lasted for "years", in further 12% at least for "months".</p> <p>Conclusion</p> <p>Low-dose radiotherapy for periarthropathy of the shoulder was highly effective and yielded long-lasting improvement of pain and motility without side effects.</p

5. Zittau fuzzy colloquium Proceeding

The 5&quot;t&quot;h Fuzzy Colloquium at the University of Applied Sciences Zittau/Goerlitz, organized by the Institute of Process Technique, Process Automation and Measuring Technique, is the continuation of activities in the field of modern methods in automatic control. The colloquium was application-oriented with the aim to exchange experiences between science and practice. About 50 scientists and research engineers discussed about the topics of the colloquium during the sessions. The colloquium was also a platform for continuation and establishment of contacts for collaboration in teaching and research. (orig./RHM)Available from TIB Hannover: RA 5226(1589-1607) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Optisch gefuehrte Feuerungssysteme Schlussbericht

The flame pyrometer is an efficient, low-cost sensor for detecting local and temporal variations in the local fuel/air ratio; it provides the basis for optically controlled industrial combustion systems. In spite of the increasing cost pressure caused by deregulation of the energy market, there are good prospects for receiving industrial funds for the following projects: Monitoring and control of individual burners in multi-flame systems; Furnace monitoring and control in plants for thermal waste treatment; Furnace monitoring and control in district heating systems.Im Rahmen des Projektes wurde mit der Auswahl des Flammenpyrometers als industrietauglichen und preiswerten Sensor, der es ermoeglicht, zeitliche Aenderungen bzw. oertliche Unterschiede des lokalen Brennstoff/Luft-Verhaeltnisses zu erkennen und der praktischen Realisierung einer optisch gefuehrten Feuerungsregelung an der Versuchsanlage die Basis fuer die Bearbeitung einschlaegiger Industrieauftraege geschaffen. Aufgrund der Liberalisierung des Energiemarktes stehen die Anlagenbetreiber derzeit unter besonderem Kostendruck. Ungeachtet dessen bestehen auf der Grundlage der Ergebnisse der Projektbearbeitung, der umfangreichen Industriekontakte des IPM und der interdisziplinaeren Zusammenarbeit auf den Gebieten der Feuerungstechnik, Messtechnik und Prozessautomatisierung gute Aussichten Drittmittel von Industriepartnern zur Realisierung folgender Projekte einzuwerben: - Einzelbrennerueberwachung und -regelung in Mehrflammensystemen -Feuerungsueberwachung und -regelung in Anlagen zur thermischen Abproduktbehandlung - Feuerungsueberwachung und -regelung von Anlagen zur Fernwaermeversorgung. (orig.)SIGLEAvailable from TIB Hannover: F01B1149 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

East West Fuzzy colloquium 2002. 10th Zittau Fuzzy colloquium Proceedings

SIGLEAvailable from TIB Hannover: RA 5226(1929-1977) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

East West Fuzzy colloquium 2000. 8. Zittau Fuzzy colloquium Proceedings

The Zittau Colloquium is organized annually with the objective to stimulate contacts between scientists in academic research, industrial development and university teaching from Eastern and Western European countries and from other parts of the world. A further aim of the colloquium is the exchange of information about the state-of-the-art in the field of Fuzzy Logic basic investigation and application in connection with other theories, for example Neuronal Networks. Therefore, we want to stimulate the discussion about proposals for common national, bilateral and international supported projects to incite research, teaching, as well as mobility of students and teachers. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Data from: Trophic niche flexibility in Glossophaga soricina: how a nectar seeker sneaks an insect snack

Omnivory enables animals to fill more than one trophic niche, providing access to a wider variety of food resources with potentially higher nutrient value, particularly when resources become scarce. Animals can achieve omnivory using different strategies, for example opportunistic foraging, or switching between multiple trophic niches. The Neotropical bat Glossophaga soricina (Pallas, 1766) is a common and widespread species known for nectar-feeding, but it also eats fruit and insects. Approaching stationary objects (flowers and fruits) or moving objects (insects) pose different sensory tasks and should require different echolocation behaviours. Here we tested the contrasting hypothesis that G. soricina can approach both stationary and moving objects using the same echolocation behaviour, thus feeding at different trophic levels by a single sensory mechanism. Using DNA barcoding, we demonstrate that G. soricina eats beetles (Coleoptera), flies (Diptera), and noctuid moths with bat-detecting ears. Lab observations show that G. soricina actively hunts for prey so insect consumption does not appear to be opportunistic. After capture, individuals consumed prey while perched and manipulated them with jaw, thumb, wrist and wing movements, but food handling was longer and chewing rate slower than in obligate insectivores. In contrast to most insectivorous bats, the echolocation calls of G. soricina are of high frequency and low intensity, and G. soricina did not produce feeding buzzes when approaching insects. An acoustic model of detection distances shows that its low intensity calls fail to trigger the auditory neurons of eared moths, allowing G. soricina to overcome auditory prey defences. Individuals achieved niche flexibility using a unique but generalist behavioural approach rather than employing two different specialist methods. Our findings provide a novel insight into the functional mechanisms of insect capture in G. soricina and highlight the importance of considering niche flexibility in classifying trophic links in ecological communities

Data from: Trophic niche flexibility in Glossophaga soricina: how a nectar seeker sneaks an insect snack

Omnivory enables animals to fill more than one trophic niche, providing access to a wider variety of food resources with potentially higher nutrient value, particularly when resources become scarce. Animals can achieve omnivory using different strategies, for example opportunistic foraging, or switching between multiple trophic niches. The Neotropical bat Glossophaga soricina (Pallas, 1766) is a common and widespread species known for nectar-feeding, but it also eats fruit and insects. Approaching stationary objects (flowers and fruits) or moving objects (insects) pose different sensory tasks and should require different echolocation behaviours. Here we tested the contrasting hypothesis that G. soricina can approach both stationary and moving objects using the same echolocation behaviour, thus feeding at different trophic levels by a single sensory mechanism. Using DNA barcoding, we demonstrate that G. soricina eats beetles (Coleoptera), flies (Diptera), and noctuid moths with bat-detecting ears. Lab observations show that G. soricina actively hunts for prey so insect consumption does not appear to be opportunistic. After capture, individuals consumed prey while perched and manipulated them with jaw, thumb, wrist and wing movements, but food handling was longer and chewing rate slower than in obligate insectivores. In contrast to most insectivorous bats, the echolocation calls of G. soricina are of high frequency and low intensity, and G. soricina did not produce feeding buzzes when approaching insects. An acoustic model of detection distances shows that its low intensity calls fail to trigger the auditory neurons of eared moths, allowing G. soricina to overcome auditory prey defences. Individuals achieved niche flexibility using a unique but generalist behavioural approach rather than employing two different specialist methods. Our findings provide a novel insight into the functional mechanisms of insect capture in G. soricina and highlight the importance of considering niche flexibility in classifying trophic links in ecological communities

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