Chimpanzees organize their social relationships like humans

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate species organize their affiliative relationships following the same pattern. We here show that the time chimpanzees devote to grooming other individuals is well described by the same model used for human relationships, supporting the existence of similar social signatures for both humans and chimpanzees. Furthermore, the relationship structure depends on group size as predicted by the model, the proportion of high-intensity connections being larger for smaller groups

Accidente vascular isquémico por disección de la arteria vertebral

El accidente vascular en los niños no es un evento muy raro, motivo por el cual, el pediatra debería pensar en el mismo ante un déficit neurológico de origen inexplicable. Se presenta el caso clínico de un niño de 7 años de edad con antecedente de traumatismos mínimos que inicia el cuadro con déficit motor progresivo en las 4 extremidades, cefalea intensa y posteriormente, hipertensión arterial severa refractaria al tratamiento. La terapéutica fue conservadora por la cantidad de tiempo transcurrido entre el debut del cuadro y el ingreso a la UTI. Recibió megadosis de corticoides por 3 días, antiagregantes plaquetarios y medicación antihipertensiva múltiple hasta el control de la presión arterial con clonidina. Mediante estudios por imágenes y arteriografía, se diagnosticó: disección de la arteria vertebral derecha y lesión isquémica de la porción superior de la medula e inferior de la protuberancia, descartándose las etiologías cardiaca, vascular, renal, autoinmune, hematológica, e infecciosa, entre otras. El niño egresó del hospital a los 19 días en proceso de recuperación neurológica y a los 30 días ya no presentaba ningún déficit motor. En el presente trabajo se discute la importancia del diagnóstico precoz para instituir la terapéutica adecuada, así como los factores pronósticos

Bioethanol production using high density Eucalyptus crops in Uruguay [Research article]

Experimental scale crops for Eucalyptus grandis, Eucalyptus benthamii, Eucalyptus dunnii and Eucalyptus tereticornis, at 2,220, 4,440 and 6,660 trees ha?1 were established in two soil units, at Paysandú and Tacuarembó, Uruguay. Wood samples were taken from twenty-two-months-old trees, and were used to produce bioethanol by pre-hydrolysis simultaneous saccharyfication and fermentation process (PSSF). Cellulose and lignin content was analyzed. Species and planting density affected biomass production at both sites; the highest value was obtained with E. dunnii at 6,660 trees ha?1 at Paysandú. Cellulose content of wood varied between species at both sites, but only between planting densities at Tacuarembó. The site effect showed that the highest amount of cellulose (14.7 Mg ha?1) was produced at Paysandú. E. benthamii and E. tereticornis wood showed higher lignin contents, conversely, the PSSF yields showed no differences, which led to a bioethanol average of 97 L Mg?1. Bioethanol productivity was associated to the biomass productivity. It was possible to obtain 2,650 L ha?1 of bioethanol using wood from E. benthamii, E. dunnii and E. grandis at 4,440 and 6,660 trees ha?1 at Paysandú, and with E. benthamii at 4,440 and 6,660 trees ha?1, and E. dunnii at 6,660 trees ha?1 at Tacuarembó

Near room temperature dielectric transition in the perovskite formate framework [(CH(3))(2)NH(2)][Mg(HCOO)(3)].

We report that the hybrid organic-inorganic compound [(CH(3))(2)NH(2)][Mg(HCOO)(3)] shows a marked dielectric transition around T(t) ∼ 270 K, associated to a structural phase transition from SG R3[combining macron]c (centrosymmetric) to Cc (non-centrosymmetric). This is the highest T(t) reported so far for a perovskite-like formate that is thus a promising candidate to display electric order very close to room temperature

Chimpanzees organize their social relationships like humans

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate species organize their affiliative relationships following the same pattern. We here show that the time chimpanzees devote to grooming other individuals is well described by the same model used for human relationships, supporting the existence of similar social signatures for both humans and chimpanzees. Furthermore, the relationship structure depends on group size as predicted by the model, the proportion of high-intensity connections being larger for smaller groups

A highly sensitive microsystem based on nanomechanical biosensors for genomics applications

Microcantilever-based biosensors are a promising tool to detect biomolecular interactions in a direct way with high accuracy. We show the development of a portable biosensor microsystem able to detect nucleic acid hybridization with high sensitivity. The microsystem comprises an array of 20 micromechanical cantilevers produced in silicon technology, a polymer microfluidic system for delivery of the samples, an array of 20 vertical cavity surface emitting lasers (VCSELs) with collimated beams thanks to an integrated microlens array, an optical coupling element to provide the optical path required, and chips with the photodetectors and the CMOS circuitry for signal acquisition and conditioning, capable of measuring the cantilever deflection with sub-nanometer resolution. Robust immobilization and regeneration procedures have been implemented for the oligonucleotide receptor sequences. In a further innovation, an optical waveguide cantilever transducer has been also developed in order to improve the final performance of the device. This has a number of advantages in terms of a simple optical geometry and improved sensitivity