138 research outputs found
Investigation of the role of selenium in the nutrition and physiology of neural tissues of chickens and turkeys
Endogenous selenium concentrations in selected tissue of chickens, turkeys, and coturni
Human performance in adverse environments
Human performance testing of astronaut capabilities during prolonged space fligh
Grit blasting nozzle fabricated from mild tool steel proves satisfactory
Dry blasting with glass beads through a nozzle assembly descales both the outside and inside surfaces of tubes of Inconel 718 used for the distribution of gaseous oxygen. The inside of the nozzle is coated with polyurethane and the deflector with a commercially available liquid urethane rubber
Sex ratio and maternal rank in wild spider monkeys: when daughters disperse
Data from a long-term field study of the spider monkey, Ateles paniscus , in Peru indicate that a strongly female-biased sex ratio exists from birth in this population. Of 46 infants born between July 1981 and June 1986, 12 were male, 32 were female and 2 were of undetermined sex. This effect is consistent between years as well, with more females than males born in each year of the study (Table 1). This bias is driven by the fact that low-ranking females produce daughters almost exclusively, while high-ranking females bias their investment somewhat less strongly towards sons (Table 2). The unusual pattern of female-biased maternal investment observed in this population of Ateles probably occurs for a combination of the following reasons: (1) maternal investment in individual male offspring is somewhat greater than in individual female offspring; (2) males remain with their natal groups, and the sons of high-ranking females are likely to be competitively superior to the sons of low-ranking females; (3) males compete for mates, and only the one or two most dominant males within a community are likely to achieve significant reproductive success. Two possible mechanisms of sex-ratio adjustment and the evidence for each are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46880/1/265_2004_Article_BF00302985.pd
Research on a one-inch-square linear d-c plasma accelerator
One-inch-square linear d-c plasma accelerator using cesium seeded nitroge
A Heat Transfer Investigation of Ejector Systems with 90 Deg Turns. NERVA Program
Heat transfer characteristics of ejector systems for turning rocket exhaust gases through 90 de
Astro-WISE: Chaining to the Universe
The recent explosion of recorded digital data and its processed derivatives
threatens to overwhelm researchers when analysing their experimental data or
when looking up data items in archives and file systems. While current hardware
developments allow to acquire, process and store 100s of terabytes of data at
the cost of a modern sports car, the software systems to handle these data are
lagging behind. This general problem is recognized and addressed by various
scientific communities, e.g., DATAGRID/EGEE federates compute and storage power
over the high-energy physical community, while the astronomical community is
building an Internet geared Virtual Observatory, connecting archival data.
These large projects either focus on a specific distribution aspect or aim to
connect many sub-communities and have a relatively long trajectory for setting
standards and a common layer. Here, we report "first light" of a very different
solution to the problem initiated by a smaller astronomical IT community. It
provides the abstract "scientific information layer" which integrates
distributed scientific analysis with distributed processing and federated
archiving and publishing. By designing new abstractions and mixing in old ones,
a Science Information System with fully scalable cornerstones has been
achieved, transforming data systems into knowledge systems. This break-through
is facilitated by the full end-to-end linking of all dependent data items,
which allows full backward chaining from the observer/researcher to the
experiment. Key is the notion that information is intrinsic in nature and thus
is the data acquired by a scientific experiment. The new abstraction is that
software systems guide the user to that intrinsic information by forcing full
backward and forward chaining in the data modelling.Comment: To be published in ADASS XVI ASP Conference Series, 2006, R. Shaw, F.
Hill and D. Bell, ed
Prevalencia de sífilis y características del comportamiento de los jóvenes indígenas del Paraguay, 2016
El objetivo fue determinar la prevalencia de sífilis y características de comportamiento de los jóvenes indígenas del Paraguay en el 2016. Se realizó un estudio observacional, descriptivo de corte transversal con muestro probabilístico estratificado bietapico, que incluyó a jóvenes indígenas de 15 a 18 años de cinco familias lingüísticas de Paraguay. Se utilizó un cuestionario estructurado y para el tamizaje de sífilis se utilizó una test rápido treponémico y para confirmar los resultados reactivos se realizó VDRL, considerando como resultado positivo si el test rápido era positivo + VDRL positivo a una dilución de 1:4 o mayor y si la VDRL era menor a 1:4 con TPHA positivo. Los resultados se expresan como medidas de tendencia central, dispersión y proporciones. Ingresaron al estudio 546 jóvenes de 15 a 18 años, el 67,03% era del sexo femenino. Se identificaron 36 casos de sífilis, que representa una prevalencia de 6,6% [IC95%: 4,7-9,0]. Mayor prevalencia de sífilis se observó en los jóvenes que consumieron alcohol en la última relación sexual 20,6% (14/68) (p<0,001), sexo transaccional 40% (2/5) (p=0,010) y no utilización de condón 20,6% (14/68) (p<0,001). Se encontró una alta prevalencia de sífilis en la población juvenil indígena, relacionada al consumo de alcohol en la última relación, práctica de sexo transaccional y no utilización de preservativos. Se recomienda la implementación de estrategias específicas con abordaje intercultural apropiadas para una población joven, orientadas a disminuir las prácticas de riesgo y promocionar la utilización de preservativos
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