The rolling ball problem on the plane revisited

By a sequence of rollings without slipping or twisting along segments of a straight line of the plane, a spherical ball of unit radius has to be transferred from an initial state to an arbitrary final state taking into account the orientation of the ball. We provide a new proof that with at most 3 moves, we can go from a given initial state to an arbitrary final state. The first proof of this result is due to Hammersley ( 1983). His proof is more algebraic than ours which is more geometric. We also showed that generically no one of the three moves, in any elimination of the spin discrepancy, may have length equal to an integral multiple of 2 pi.

Swimming performance in semiaquatic and terrestrial Oryzomyine rodents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Darboux invariants for planar polynomial differential systems having an invariant conic

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrocatalytic effect of Pb and Sn adatoms on the oxidation of 1-propanol on platinized platinum electrodes: Determination of the apparent activation energy

The electrocatalytic oxidation of 1-propanol was investigated on platinum electrodes modified by submonolayers of Pb and Sn in acid media. An increase of oxidation rates observed for both Pb and Sn, and the influence of theta values was investigated. The values of the apparent activation energy evaluated from the Arrhenius plots concerning the electrochemical oxidation of 1-propanol on modified platinzed platinum electrodes, reveal a significant decrease in the presence of upd Sn and Ph adatoms. A decrease from 56 to 26 U mol(-1) in the presence of Sn. and from 78 to 25 U mol(-1) for Ph adatoms are some illustrative values which reflect the promoting effect of the upd adatoms.

Antitumor and Anti-Inflammatory Effects of Palladium(II) Complexes on Ehrlich Tumour

Palladium(II) complexes are an important class of cyclopalladated compounds that play a pivotal role in various pharmaceutical applications. Here, we investigated the antitumour, anti-infl ammatory, and mutagenic effects of two complexes: [Pd(dmba)(Cl)tu] (1) and [Pd(dmba)(N3)tu] (2) (dmba = N,N-dimethylbenzylamine and tu = thiourea), on Ehrlich ascites tumour (EAT) cells and peritoneal exudate cells (PECs) from mice bearing solid Ehrlich tumour. The cytotoxic effects of the complexes on EAT cells and PECs were assessed using the 3-(4,5-dimethylthiazol-3-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The effects of the complexes on the immune system were assessed based on the production of nitric oxide (NO) (Griess assay) and tumour necrosis factor-Į (TNF-Į), interleukin-12 (IL-12), and interleukin-10 (IL-10) (ELISA). Finally the mutagenic activity was assessed by the Ames test using the Salmonella typhimurium strain TA 98. Cisplatin was used as a standard. The IC50 ranges for the growth inhibition of EAT cells and PECs were found to be (72.8 ± 3.23) µM and (137.65 ± 0.22) µM for 1 and (39.7 ± 0.30) µM and (146.51 ± 2.67) µM for 2, respectively. The production of NO, IL-12, and TNF-Į, but not IL-10, was induced by both complexes and cisplatin. The complexes showed no mutagenicity in vitro, unlike cisplatin, which was mutagenic in the strain. These results indicate that the complexes are not mutagenic and have potential immunological and antitumour activities. These properties make them promising alternatives to cisplatin.

Definição e abordagem de currículo: exame de um curso de formação de professores para a educação não formal em ONGs

This article presents a research aimed to analyze the approach and the definition of guiding curriculum of teacher training for work in the non-formal education in non-governmental organizations (NGOs). We opted for a qualitative approach and case study of Te- acher Training Course for NGOs, developed by Ong São Paulo-SP. The research instruments were: analysis of documents of the cou- rse, interviews with trainers and coordinator and literature review. In this course, curriculum is defined as a path to be followed by students and instructors and the coordinator of the subjects studied. We adopted the so-called Integrated Curriculum, in which teaching occurs by the study of problem situations and integrators of learning projects. At the end, we suggest improving the course and following that information, it is hoped, one will support the production of fur- ther comparative research.

Locating control points in aerial images with a multi-scale approach based on terrestrial image patches

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A genomewide association mapping study using ultrasound-scanned information identifies potential genomic regions and candidate genes affecting carcass traits in Nellore cattle

The aim of this study was to identify candidate genes and genomic regions associated with ultrasound-derived measurements of the rib-eye area (REA), backfat thickness (BFT) and rumpfat thickness (RFT) in Nellore cattle. Data from 640 Nellore steers and young bulls with genotypes for 290 863 single nucleotide polymorphisms (SNPs) were used for genomewide association mapping. Significant SNP associations were explored to find possible candidate genes related to physiological processes. Several of the significant markers detected were mapped onto functional candidate genes including ARFGAP3, CLSTN2 and DPYD for REA; OSBPL3 and SUDS3 for BFT; and RARRES1 and VEPH1 for RFT. The physiological pathway related to lipid metabolism (CLSTN2, OSBPL3, RARRES1 and VEPH1) was identified. The significant markers within previously reported QTLs reinforce the importance of the genomic regions, and the other loci offer candidate genes that have not been related to carcass traits in previous investigations.

Antitumour and anti-inflammatory effects of Palladium (II) complexes on Ehrlich Tumour

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de procedimentos e métodos analíticos no campo forense aplicando os princípios da química verde

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da área, da quantidade de habitat e do tipo de matriz sobre dieta de gato-maracajá (Leopardus wiedii)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pinniped Populations at Islas ae Guadalupe, San Benito, Cedros, and Natividad, Baja California, in 1968

In April and June 1968, the Pacific Ocean Biological Survey Program (POBSP) of the Smithsonian Institution conducted surveys on breeding marine birds and pinnipeds on various Mexican islands. Between 18 to 26 April and 21 to 29 June, pinniped populations were surveyed at Islas de Guadalupe, San Benito, Cedros, and Natividad off Baja California. Species observed were the California sea lion, Zalophus californianus, Guadalupe fur seal, Arctocephalus townsendi, harbor seal, Phoca vitulina, and northern elephant seal, Mirounga angustirostris

Monitoring the Prey-Field of Marine Predators: Combining Digital Imaging With Datalogging Tags

There is increasing interest in the diving behavior of marine mammals. However, identifying foraging among recorded dives often requires several assumptions. The simultaneous acquisition of images of the prey encountered, together with records of diving behavior will allow researchers to more fully investigate the nature of subsurface behavior. We tested a novel digital camera linked to a time-depth recorder on Antarctic fur seals (Arctocephalus gazella). During the austral summer 2000-2001, this system was deployed on six lactating female fur seals at Bird Island, South Georgia, each for a single foraging trip. The camera was triggered at depths greater than 10 m. Five deployments recorded still images (640 x 480 pixels) at 3-sec intervals (total 8,288 images), the other recorded movie images at 0.2-sec intervals (total 7,598 frames). Memory limitation (64 MB) restricted sampling to approximately 1.5 d of 5-7 d foraging trips. An average of 8.5% of still pictures (2.4%-11.6%) showed krill (Euphausia superba) distinctly, while at least half the images in each deployment were empty, the remainder containing blurred or indistinct prey. In one deployment krill images were recorded within 2.5 h (16 km, assuming 1.8 m/sec travel speed) of leaving the beach. Five of the six deployments also showed other fur seals foraging in conjunction with the study animal. This system is likely to generate exciting new avenues for interpretation of diving behavior.

Modeling Age-Specific Mortality For Marine Mammal Populations

A method is presented for estimating age-specific mortality based on minimal information: a model life table and an estimate of longevity. This approach uses expected patterns of mammalian survivorship to define a general model of age-specific mortality rates. One such model life table is based on data for northern fur seals (Callorhinus ursinus) using Siler’s (1979) 5-parameter competing risk model. Alternative model life tables are based on historical data for human females and on a published model for Old World monkeys. Survival rates for a marine mammal species are then calculated by scaling these models by the longevity of that species. By using a realistic model (instead of assuming constant mortality), one can see more easily the real biological limits to population growth. The mortality estimation procedure is illustrated with examples of spotted dolphins (Stenella attenuata) and harbor porpoise (Phocoena phocoena).