An Exploration of Rhythm Perception in African Penguins (Spheniscus demersus)

Rhythmic properties in penguin vocalizations may be unique to individuals. Rhythm perception is a cognitive ability previously thought to be exclusive to vocal-learning species who have the neurological complexities required to mimic conspecific and heterospecific vocalizations. Discovering rhythm perception in penguins would provide insight on penguins’ ability to recognize kin using auditory cues, and discount theories constraining rhythm perception to vocal-learning animals. The goal of this study was to learn if African penguins (Spheniscus demersus) could perceive changes in rhythm using a habituation-dishabituation paradigm. Subjects were 32-38 African penguins housed at the Seneca Park Zoo in Rochester, NY. Penguins were presented with four rhythms at 4 kHz and head turns per bird were counted in 24 sessions. Each session was composed of ten familiarization trials followed by six test trials that alternated between the familiar and novel rhythm. The number of head turns per bird did not significantly increase from the last three familiarization trials to the first novel test trial. Results did not provide evidence for auditory rhythm perception in penguins. This may be because subjects met the habituation criterion in only 9 out of 24 sessions or because of other limitations of the method. It is also possible that a habituation-dishabituation methodology was not ideal for discovering rhythm perception in penguins. More research on auditory rhythm perception in penguins is needed

Folding Coarse-Grained Oligomer Models with PyRosetta

Non-biological foldamers are a promising class of macromolecules that share similarities to classical biopolymers such as proteins and nucleic acids. Currently, designing novel foldamers is a non-trivial process, often involving many iterations of trial synthesis and characterization until folded structures are observed. In this work, we aim to tackle these foldamer design challenges using computational modeling techniques. We developed CG PyRosetta, an extension to the popular protein folding python package, PyRosetta, which introduces coarse-grained (CG) residues into PyRosetta, enabling the folding of toy CG foldamer models. Through systematic variation of CG parameters in these models, we can investigate various folding hypotheses and generate folding principles at the CG scale to inform the design process of new foldamer chemistries. We demonstrate CG PyRosetta’s ability to identify minimum energy structures with a diverse structural search over a range of simple models and two hypothesis-driven parameter scans investigating the effects of side-chain size and internal backbone angle on secondary structure. We are able to identify several types of secondary structures from single- and double-helices to sheet-like and knot-like structures. We show how side-chain size and backbone bond angle both play an important role in the structure and energetics of these toy models. Optimal side-chain sizes promote favorable packing of side-chains, while specific backbone bond-angles influence the specific helix type found in folded structures

Organic and inorganic compounds in limestone weathering crusts from cathedrals in Southern and Western Europe

Limestone and weathering crusts have been studied at the major cathedrals of Sevilla, in southwestern Spain, and Mechelen, in northern Belgium. These cities have very different climatic and environmental conditions. The deterioration characteristics of the limestone in both localities have been compared. Detailed petrographical characterization was carried out for the different building stones, including restoration materials. The bulk and trace inorganic composition of the stones and crusts was assessed, and the leachable ions were analyzed, while elemental concentration profiles with depth were studied with electron microprobe analysis. The organic compounds in the black weathering crusts have also been studied and compared. In the different types of limestone, the deterioration is largely influenced by the petrographie characteristics of the stone. Gypsum crusts from Mechelen and Sevilla show variable textures, even on the same stone types. Sulfatation of calcite provides Ca for the gypsum crusts. Except fora part of the Sr and Fe fractions in the crust, all other elements may be of external origin. Concentrations of the various elements are more or less comparable in crusts from Mechelen and Sevilla. External inorganic particles consist of fly ash, quartz, clay, and glauconite. Most of the organic material appeared to be of anthropogenic origin, due to combustion processes, while a minor fraction originated from cuticular waxes of higher plants.This work was supported by the Commission of the European Community, Project STEP-CT90-0107.Peer Reviewe

Cirurgia de osteoma de seio frontal Surgery of frontal sinus osteoma

Os osteomas do seio frontal correspondem a 57% dos osteomas dos seios paranasais, com incidência variando de 0,01% a 3%. A remoção cirúrgica nos osteomas frontais é indicada nos pacientes sintomáticos. Nos pacientes assintomáticos pode-se adotar a conduta conservadora ou cirúrgica em todos os pacientes independente da sua localização ou extensão. Cinco pacientes com diagnóstico de osteoma de seio frontal foram operados entre 1995 e 1999. A idade média foi 38,4 anos (extremos de 12 a 55 anos), sendo 3 homens e 2 mulheres. O período de sintomatologia variou de 6 meses a 3 anos com média de 10,5 meses. Quatro pacientes apresentaram cefaléia. Um paciente apresentou epistaxe. Os exames complementares realizados foram: radiografia simples e tomografia computadorizada de seios paranasais com cortes axiais e coronais. Em dois pacientes o diâmetro do osteoma foi maior que 3 cm, e menor que 3 cm em três. A decisão da técnica cirúrgica entre coronal e supraciliar foi estética, reservando-se a abordagem supraciliar para um paciente com calvície, apesar do tumor ser volumoso com extensão para seio etmoidal. Nenhuma dificuldade técnica intra-operatória foi atribuída à escolha da abordagem. O óstio nasofrontal não foi obstruído no intra-operatório. O seguimento pós-operatório mínimo foi de dois anos. Em todos os casos a remoção foi total sem recidiva ou resíduos tumorais. Os sintomas clínicos, achados radiológicos e abordagens cirúrgicas são discutidos. Não ocorreram complicações pós-operatórias.<br>Frontal sinus osteomas are 57% of all paranasal sinus osteomas, with an incidence of 00.1 to 3%. Surgical removal of the frontal sinus osteomas is done in symptomatic patients. Asymptomatic patients can be managed conservatively or submitted to surgery in spite of its location or extension. Five patients having the diagnosis of frontal sinus osteoma were operated on between 1995 and 1999. Medium age was 38.4 years (from 12 to 55 years), 3 male and 2 female. Symptoms occurred from 6 months to 3 years, average of 10.5 months. Four patients had previous headache and one had epistaxis. All patients had standard radiological exams and computed tomography with coronal and axial studies of paranasal sinus. In two patients the diameter of the osteoma was larger than 3 cm and in three smaller than 3 cm. The choice between coronal and supraciliar approach was made according to esthetics, supraciliar approach was made in only one bald patient even with the tumor being large and extending to ethmoidal sinus. Any intra operative difficulty was related to the choice of the approach. Naso-frontal ostium was not obstructed in intra operative course. Minimal postoperative follow up was of two years. Osteomas were radically removed in all patients with no recurrence or residual tumor. Clinical findings, radiological exams and surgical approaches are discussed. No postoperative complications occurred