A PHASE TRANSITION FOR COMPETITION INTERFACES

We study the competition interface between two growing clusters in a growth model associated to last-passage percolation. When the initial unoccupied set is approximately a cone, we show that this interface has an asymptotic direction with probability 1. The behavior of this direction depends on the angle theta of the cone: for theta >= 180 degrees, the direction is deterministic, while for theta < 180 degrees, it is random, and its distribution can be given explicitly in certain cases. We also obtain partial results on the fluctuations of the interface around its asymptotic direction. The evolution of the competition interface in the growth model can be mapped onto the path of a second-class particle in the totally asymmetric simple exclusion process; from the existence of the limiting direction for the interface, we obtain a new and rather natural proof of the strong law of large numbers (with perhaps a random limit) for the position of the second-class particle at large times.

Psychogenetics of Turner syndrome: an investigation of 28 subjects and respective controls using the Bender test and Piagetian scales

Piagetian scales and the Bender visual motor gestalt test (BT) were applied to 28 subjects with universal 45, X Turner syndrome (TS), and their respective controls, in order to investigate their cognitive performance. Dermatoglyphics were also analyzed to obtain clues concerning embryological changes that may have appeared during development of the nervous system and could be associated with cognitive performance of TS patients. Dermatoglyphic pattern distribution was similar to that reported in previous studies of TS individuals: ulnar loops in the digital patterns and finger ridge, a-b, and A'-d counts were more frequent, while arch and whorl patterns were less frequent compared to controls. However, we did not find higher frequencies of hypothenar pattern, maximum atd angle, and ulnarity index in our TS subjects, unlike other investigations. Furthermore, we found significant differences between TS and control T line index values. The BT scores were also lower in probands, as has been previously reported, revealing a neurocognitive deficit of visual motor perception in TS individuals, which could be due to an absence of, or deficiency in, cerebral hemispheric lateralization. However, TS subjects seemed to improve their performance on BT with age. Cognitive performance of the TS subjects was not significantly different from that of controls, confirming a previous study in which TS performance was found to be similar to that of the normal Brazilian population. There were significant correlations between BT scores and Piagetian scale levels with dermatoglyphic parameters. This association could be explained by changes in the common ectodermal origin of the epidermis and the central nervous system. TS subjects seem to succeed in compensating their spatial impairments in adapting their cognitive and social contacts. We concluded that genetic counseling should consider cognitive and psychosocial difficulties presented by TS subjects, providing appropriate treatment and orientation for them and their families.

Toxicity of High-Dose Intravitreal Adalimumab (Humira) in the Rabbit

Purpose: To evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira (R)) in the rabbit eye. Methods: Thirty New Zealand albino rabbits received intravitreous injections of 0.5mg (6 eyes), 1.0mg (6 eyes), 2.5mg (6 eyes), 5mg (6 eyes), and 10mg (6 eyes) adalimumab. Slit lamp biomicroscopy and fundoscopy were carried out at baseline, day 7, and day 14 after intravitreous injection, whereas electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14, and histopathological examination of the eyes was performed. Results: Slit lamp biomicroscopy and fundoscopy were normal in all eyes receiving doses up to 5mg. In the 10mg group, 3 of 6 eyes showed mild anterior chamber inflammatory reaction on day 7. Similarly, scotopic and photopic a- and b-wave ERG amplitudes at baseline and day 14 were similar in all groups up to 5mg, but there was a significant decrease in the photopic-wave ERG response in the 10mg group (P = 0.046). Finally, histopathology demonstrated no differences among eyes receiving balanced salt solution, 0.5, 1.0, 2.5, 5.0, or 10mg of adalimumab. Conclusions: Intravitreous adalimumab exhibited no associated ocular short-term toxicity in rabbit eyes up to the 5mg dose. In the 10mg group mild clinical findings and ERG amplitude reduction could reflect early toxicity.

4-Methyl-3-(2-phenoxyacetyl)-5-phenyl-1,3,4-oxadiazinan-2-one

The 1,3,4-oxadiazinane ring in the title compound, C(18)H(18)N(2)O(4), is in a twisted boat conformation. The two carbonyl groups are orientated towards the same side of the molecule. The dihedral angle between the planes of the benzene rings is 76.6 (3)degrees. Molecules are sustained in the three-dimensional structure by a combination of C-H center dot center dot center dot O, C-H center dot center dot center dot pi and pi-pi [shortest centroid-centroid distance = 3.672 (6) angstrom] interactions.

1-(4-Bromophenyl)-2-ethylsulfinyl-2-(phenylselanyl)ethanone monohydrate

In the title hydrate, C(16)H(15)BrO(2)SSe center dot H(2)O, the sulfinyl O atom lies on the opposite side of the molecule to the Se and carbonyl O atoms. The benzene rings form a dihedral angle of 51.66 (17)degrees and are splayed with respect to each other. The observed conformation allows the water molecules to bridge sulfinyl O atoms via O-H center dot center dot center dot O hydrogen bonds, generating a linear supramolecular chain along the b axis; the chain is further stabilized by C-H center dot center dot center dot O contacts. The chains are held in place in the crystal structure by C center dot center dot center dot H center dot center dot center dot pi and C-Br center dot center dot center dot pi interactions.

Solution structure of the human signaling protein RACK1

Background: The adaptor protein RACK1 (receptor of activated kinase 1) was originally identified as an anchoring protein for protein kinase C. RACK1 is a 36 kDa protein, and is composed of seven WD repeats which mediate its protein-protein interactions. RACK1 is ubiquitously expressed and has been implicated in diverse cellular processes involving: protein translation regulation, neuropathological processes, cellular stress, and tissue development. Results: In this study we performed a biophysical analysis of human RACK1 with the aim of obtaining low resolution structural information. Small angle X-ray scattering (SAXS) experiments demonstrated that human RACK1 is globular and monomeric in solution and its low resolution structure is strikingly similar to that of an homology model previously calculated by us and to the crystallographic structure of RACK1 isoform A from Arabidopsis thaliana. Both sedimentation velocity and sedimentation equilibrium analytical ultracentrifugation techniques showed that RACK1 is predominantly a monomer of around 37 kDa in solution, but also presents small amounts of oligomeric species. Moreover, hydrodynamic data suggested that RACK1 has a slightly asymmetric shape. The interaction of RACK1 and Ki1/57 was tested by sedimentation equilibrium. The results suggested that the association between RACK1 and Ki-1/57(122-413) follows a stoichiometry of 1:1. The binding constant (KB) observed for RACK1-Ki-1/57(122-413) interaction was of around (1.5 +/- 0.2) x 10(6) M(-1) and resulted in a dissociation constant (KD) of (0.7 +/- 0.1) x 10(-6) M. Moreover, the fluorescence data also suggests that the interaction may occur in a cooperative fashion. Conclusion: Our SAXS and analytical ultracentrifugation experiments indicated that RACK1 is predominantly a monomer in solution. RACK1 and Ki-1/57(122-413) interact strongly under the tested conditions.

Imidazolium 4-aminobenzoate

In the title salt, C(3)H(5)N(2)(+) center dot C(7)H(6)NO(2)(-), the carboxylate group of the 4-aminobenzoate anion forms a dihedral angle of 13.23 (17)degrees with respect to the benzene ring. There are N-H center dot center dot center dot O hydrogen-bonding interactions between the anion and cation, and weak intermolecular C-H center dot center dot center dot O contacts with carboxylate O-atom acceptors of the 4-aminobenzoate anion result in extended three-dimensional R(4)(4)(22) and R(5)(6)(30) edge-fused rings along the [100], [010] and [001] directions.

(4-Hydroxy-2,5-dimethylphenyl)phenylmethanone

The title compound, C(15)H(14)O(2), was obtained by Friedel-Crafts acylation between 2,5-dimethylphenol and benzoyl chloride in the presence of aluminium chloride as a catalyst. The dihedral angle between the benzene rings is 61.95 (4)degrees. In the crystal, O-H center dot center dot center dot O hydrogen bonding and C-H center dot center dot center dot O weak interactions lead to polymeric C(6), C(8) and C(11) chains along the a, b and c-axis directions, respectively.

2-Bromo-2-methyl-N-p-tolylpropanamide

In the title molecule, C(11)H(14)BrNO, there is twist between the mean plane of the amide group and the benzene ring [C(=O)-N-C...;C torsion angle = -31.2 (5)degrees]. In the crystal, intermolecular N-H...O and weak C-H...O hydrogen bonds link molecules into chains along [100]. The methyl group H atoms are disordered over two sets of sites with equal occupancy.

Redetermination of 3-methylbenzoic acid

The asymmetric unit of the title compound, C(8)H(8)O(2), contains two crystallographically independent molecules, which form dimers linked by O center dot center dot center dot H-O hydrogen bonds. The benzene rings in the dimers are inclined at a dihedral angle of 7.30 (8)degrees and both methyl groups display rotational disorder. This redetermination results in a crystal structure with significantly higher precision than the original determination [Ellas & Garcia-Blanco (1963). Acta Cryst. 16, 434], in which the authors reported only the unit-cell parameters and space group, without any detailed information on the atomic arrangement. In the crystal, dimers are connected by weak C-H center dot center dot center dot O interactions, forming R(2)(2)(10) and R(4)(4)(18) rings along [110] and an infinite zigzag chain of dimers along the [001] direction also occurs.

2-Bromo-2-methyl-N-(4-nitrophenyl)propanamide

The title compound, C(10)H(11)BrN(2)O(3), exhibits a small twist between the amide residue and benzene ring [the C-N-C-C torsion angle = 12.7 (4)degrees]. The crystal structure is stabilized by weak N-H center dot center dot center dot O, C-H center dot center dot center dot Br and C-H center dot center dot center dot O interactions. These lead to supramolecular layers in the bc plane.

2-(2-Nitroanilino)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbonitrile

The title compound, C(16)H(15)N(3)O(2)S, was synthesized by the reaction of 2-amino-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbonitrile and o-fluoronitrobenzene. The thiophene and nitrophenyl rings and amino and carbonitrile groups are coplanar with a maximum deviation of 0.046 (2) angstrom and a dihedral angle of 0.92 (6)degrees between the rings. The cyclohepta ring adopts a chair conformation. Intramolecular N-H center dot center dot center dot O and C-H center dot center dot center dot S interactions occur. In the crystal, the molecules form layers that are linked by pi-pi stacking interactions between the thiophene and benzene rings [centroid-centroid distances = 3.7089 (12) and 3.6170 (12) angstrom].

2-(4-Methylphenyl)-1H-anthraceno-[1,2-d]imidazole-6,11-dione: a fluorescent chemosensor

In the title compound, C(22)H(14)N(2)O(2), the five rings of the molecule are not coplanar. There is a significant twist between the four fused rings, which have a slightly arched conformation, and the pendant aromatic ring, as seen in the dihedral angle of 13.16 (8)degrees between the anthraquinonic ring system and the pendant aromatic ring plane.

TOPOGRAPHIC REGISTERS OF PALEO-VALLEYS ON THE SOUTHEASTERN BRAZILIAN CONTINENTAL SHELF

The evolution of paleo-incised-valleys in the Sao Paulo State region of the southeastern Brazilian continental shelf is presented in this study in relation to the post Last Glacial Maximum (LGM) sea-level rises based on the submarine topography modeled by a detailed Digital Elevation Model and evidences noted in high resolution seismic profiles. The hypothesis that has guided this study is that the set of paleo-valley characteristics (i.e. the fluvial parameters of modern coastal drainage systems, the topographical shape and dimensions of the valleys and of the subsurface channels) may indicate aspects of the relation between the influence of the fluvial and the eustatic variation regime in geomorphological-stratigraphic registers. Models described in the literature sustain the view that faster marine transgressions tend to increase erosion in estuaries, which may explain the lack of registers of paleo-drainage both in topography and the sub-surface in areas with wider shelves. On the other hand, on narrower shelves, with a higher slope angle, the transgression process can preserve, or even enhance, the incised valley registers during shoreface retreat. In the area studied, we observed that the dimensions and form of the continental shelf varies from the northern to the southern part of the area, affecting aspects of the geomorphological registers of the submerged incised valleys.

Comparison of three-dimensional lower extremity running kinematics of young adult and elderly runners

The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67-73 years) and 17 young adults (age 26-36 years) ran at 3.1ms-1 on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23m; P=0.01), an increase in stride frequency (1.58 vs. 1.37Hz; P=0.002), less knee flexion/extension range of motion (26 vs. 33; P=0.002), less tibial internal/external rotation range of motion (9 vs. 12; P0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (-5.8 vs. -1.0; P=0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.