Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Biol Lett ; 10(3): 20130974, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24598107

RESUMEN

Facial expressions have long been proposed to be important agents in forming and maintaining cooperative interactions in social groups. Human beings are inordinately cooperative when compared with their closest-living relatives, the great apes, and hence one might expect species differences in facial expressivity in contexts in which cooperation could be advantageous. Here, human children and chimpanzees were given an identical task designed to induce an element of frustration (it was impossible to solve). In children, but not chimpanzees, facial expressions associated with effort and determination positively correlated with persistence at the task. By contrast, bodily indicators of stress (self-directed behaviour) negatively correlated with task persistence in chimpanzees. Thus, children exhibited more behaviour as they persisted, and chimpanzees exhibited less. The facial expressions produced by children, could, therefore, function to solicit prosocial assistance from others.


Asunto(s)
Ira , Animales de Zoológico/psicología , Expresión Facial , Pan troglodytes/psicología , Animales , Niño , Preescolar , Femenino , Humanos , Masculino , Recompensa
2.
Biosens Bioelectron ; 16(9-12): 857-63, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11679264

RESUMEN

Technologies enabling specific recognition of medically relevant nucleic acid sequences will play a pivotal role in future medical diagnosis. Whereas many approaches to molecular diagnosis systems include DNA microarrays on chips and fluorometric detection, the basis of our approach is the use of inexpensive components like plastic or metal thin film electrodes with low multiplexing and an electrochemical detection unit. To increase the sensitivity, PCR can be used as an intermediate step. For selective enrichment, specific nucleic acid probes were covalently attached at their 5'-ends to conducting polycarbonate/carbon fiber electrodes. Complementary oligonucleotides were enriched at the electrodes by cyclic inversion of an electrochemical potential, transferred into a PCR vial and thermally or electrochemically desorbed. The analysis of the PCR product shows the efficiency and selectivity of the electrochemical enrichment. Hybridization of DNA was shown by electrochemical methods, in this work especially by differential pulse voltammetry (DPV) using the single strand specific hybridization redox indicator osmium(VIII)-tetroxide, and potentiometric stripping analysis (PSA). This combination of experimental methods is the basis for a molecular diagnosis system including a disposable nucleic acid modified working electrode for specific enrichment, detection and quantification, and an optional capillary PCR module for fast amplification.


Asunto(s)
Técnicas Biosensibles/métodos , ADN/genética , ADN/aislamiento & purificación , Electrónica Médica , Reacción en Cadena de la Polimerasa , Técnicas y Procedimientos Diagnósticos , Electroquímica , Electrodos , Humanos , Microscopía Electrónica de Rastreo , Hibridación de Ácido Nucleico , Plásticos
3.
World Watch ; 4(4): 37-8, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-12343751

RESUMEN

PIP: Cholera, identified by violent diarrhea, cramps, vomiting, and dehydration, is spreading through Peru into Colombia, Ecuador, Child, and Brazil. Water contaminated with Vibrio cholerae is used for washing food and/or drinking thereby transmitting the disease. PAHO estimates 6 million people in South America may get cholera within the next 3 years. This cholera epidemic is the result of unsanitary conditions in which the urban poor in South America live. In fact, in Lima, Peru, 40% of the people do not have potable, piped water available. These individuals fetch their water from far away taps and private vendors both of which are not necessarily safe. In addition, 40% do not have access to a sewage system. Further, 80% of sick people in developing countries have a water related illness, be it transmitted by contaminated water or by insects and snails that reproduce in the water. Diarrhea is the most deadly of these conditions. Indeed every year 10-20 million children die from the effects of diarrhea which include malnutrition, dehydration, and shock. Yet 940 million people in developing countries have no access to safe water and 1.7 billion do not have a sanitary means of disposing of human wastes, despite the fact that the UN decreed the 1980s the International Drinking Water Supply and Sanitation Decade. Nevertheless UNICEF efforts did bring communal taps, odorless latrines, and/or pour flush toilets to 1.2 billion people. These types of sanitation costs $20-25/person whereas conventional sewers cost $350/person. Low technology supplied water averages $30/person compared to $200/person for piped water. Peru has spent $43 million on emergency medical care for cholera victims which could have provided low cost clean water and sanitation for almost 800,000 poor.^ieng


Asunto(s)
Diarrea , Estudios de Evaluación como Asunto , Organización Panamericana de la Salud , Áreas de Pobreza , Pobreza , Saneamiento , Abastecimiento de Agua , Américas , Brasil , Chile , Colombia , Conservación de los Recursos Naturales , Demografía , Países en Desarrollo , Enfermedad , Economía , Ecuador , Ambiente , Geografía , Salud , Agencias Internacionales , América Latina , Organizaciones , Perú , Población , Salud Pública , Factores Socioeconómicos , América del Sur , Naciones Unidas , Población Urbana , Urbanización , Organización Mundial de la Salud
4.
World Watch ; 3(6): 10-1, 34, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-12283423

RESUMEN

PIP: The Middle East and North Africa constitute the Islamic world. From Morocco to Afghanistan the population is 340 million and growing at a rate of 3% annually and will double in 23 years. Currently food, water, and land resources are being taxed to their limit and continued growth will only cause larger scale problems for the region. To complicate the issue public policies and private practices and attitudes are leading to continued population growth. The rise of Islamic fundamentalism does not recognize the problem of over population. In fact the revision of family law by fundamentalist politicians has done a great deal of damage to the improvements in the status of women throughout the region. The revival of Purdah, the practice of keeping women out of the public eye and confined to home, is just one example or how the rise of Islamic fundamentalism is turning back the clock in terms of women's rights. The primary disadvantage is that since women are being returned to the home, their only source of values is as child bearers. Women cloistered at home are expected to be prolific child bearers, in fact their value as human beings is judged primarily on this basis. It is their ability to bear sons that is coveted. This of course will only compound the population problems being experienced in the region. Few countries have tried to institute state wide family planning programs, namely: Algeria, Egypt, Morocco, Tunisia and Yemen, but none of these programs has been very successful. In Iraq, Kuwait, Oman and Saudi Arabia, population growth is viewed as a positive event because it will help eliminate the need for foreign workers. Even in this region, educated people have a lower fertility rate. For example in Jordan 60% of illiterate males "did not believe in" contraception while only 15% of men educated past the secondary level felt the same way. If women are forced out of the labor force and into the home to have children, the population problem will only grow.^ieng


Asunto(s)
Actitud , Escolaridad , Islamismo , Núcleo Familiar , Crecimiento Demográfico , Sexo , Derechos de la Mujer , África , África del Norte , Argelia , Asia , Asia Occidental , Conducta , Demografía , Países en Desarrollo , Economía , Egipto , Composición Familiar , Relaciones Familiares , Fertilidad , Irak , Jordania , Kuwait , Líbano , Medio Oriente , Marruecos , Omán , Población , Dinámica Poblacional , Psicología , Religión , Arabia Saudita , Clase Social , Valores Sociales , Factores Socioeconómicos , Túnez
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda