Calculation of the electromagnetic field behind a building, based on the equivalence principle

The electromagnetic field behind buildings is calculated by making use of the equivalence principle in two-dimensional environments. We derive equivalent currents on the building walls and other boundaries. The electromagnetic field at a receiver behind the building is calculated from those currents. We also visualize the Poynting vector field strength behind the building, which makes clear how the field is reflected or diffracted around the top of the building. We compare our result with a knife-edge model and a ray-tracing model, and we confirm that the equivalence principle provides predictions of the fields accurately. The calculation method is applied to multiple buildings by using it consecutively to obtain the field behind the last building.     

Tumor cells cultured in vivo in diffusion chambers induce hematological alterations

We have studied in BALB/c mice the hematological alterations of the host induced by the growth of tumor cells in diffusion chambers (DC) In this model, host-tumor interactions are only mediated by soluble factors. Tumor cells proliferate and grow in DC up to 15 days after implant. Our results show a reversal of the granulocyte-lymphocyte ratio in peripheral blood, with lymphopenia and a relative increase of myeloid progenitors in the bone marrow of mice bearing DC with M3 tumor cells (M3TC).     

Evolution of the statistical properties of photons passed through atraveling-wave laser amplifier

The authors determine the evolution of the photon statistics of a light beam as it passes through a traveling-wave laser amplifier, modeled as a birth-death immigration (BDI) medium. The relationship between the input and output probability distributions and probability generating functions with given (but possibly varying) birth, death, and immigration rates for arbitrary input statistics is obtained. The case of constant birth, death, and immigration rates is considered in particular detail. The photon statistics at the output of a general BDI traveling-wave amplifier are always broader than those at the input, and they can take many forms. The most general solution can be applied when the input distribution to the amplifier takes the form of a negative-binomial transform     

Oral glucose ingestion increases endurance capacity in normal and diabetic (type I) humans

The effects of an oral glucose administration (1 g/kg) 30 min before exercise on endurance capacity and metabolic responses were studied in 21 type I diabetic patients [insulin-dependent diabetes mellitus (IDDM)] and 23 normal controls (Con). Cycle ergometer exercise (55-60% of maximal O2 uptake) was performed until exhaustion. Glucose administration significantly increased endurance capacity in Con (112 +/- 7 vs. 125 +/- 6 min, P < 0.05) but only in IDDM patients whose blood glucose decreased during exercise (70.8 +/- 8.2 vs. 82.8 +/- 9.4 min, P < 0.05). Hyperglycemia was normalized at 15 min of exercise in Con (7.4 +/- 0.2 vs. 4.8 +/- 0.2 mM) but not in IDDM patients (12.4 +/- 0.7 vs. 15.6 +/- 0.9 mM). In Con, insulin and C-peptide levels were normalized during exercise. Glucose administration decreased growth hormone levels in both groups. In conclusion, oral glucose ingestion 30 min before exercise increases endurance capacity in Con and in some IDDM patients. In IDDM patients, in contrast with Con, exercise to exhaustion attenuates hyperglycemia but does not bring blood glucose levels to preglucose levels.     

Power flow between adjacent electric dipoles

The Poynting vector field is shown for two adjacent electric dipoles, when there is a phase difference between them. There is a boundary around the two dipoles, inside which the time-averaged Poynting-vector field flows from one dipole to the other, and outside which it flows outwards. It is shown that in spite of the behavior of the Poynting-vector field, in which the time-averaged power leaves one dipole and enters the other, it complies with Poynting's theorem for harmonic fields, and maintains the constancy of the net radiated power. It is also shown that the total time-averaged power radiated from the two-dipole system comes from the small area between the axis along which the two dipoles are aligned and the boundary or separatrix at one of the dipoles. This two-dipole model also helps us understand the behavior of the Poynting-vector field near the edge of a semi-infinite current sheet.     

Neurologic evolution of children of low birth weight

The prematurity is still an important problem for either pediatricians and neuropediatricinas. All the mechanisms that can produce lowbirth weight, are not known, although many of them are related to genetics and environmental intra-uterine factors. Having in mind tha study of the development of such type of children, a group of investigators has been working for 9 years now, envolving aspects related to the Pediatry, Social Pediatry, Neuropediatry, Psychiatry, Otorhynolaringology, Ophtalmology and Odontology. In this study they are trying to envolve all the possible aspects on growth and development of children with lowbirth weight. In 189 children, 129 were followed during several years. Most of them were observed up to 5 years of age and few of them up to 9 years of age. The children were divided into three groups as follow: Group I-Children with weights under 1.750 g; Group II-Children with weights between 1.751 and 2.000 g; Group III-Children with weights over 2.001 g and under 2.500 g. The neurol-gical tests were done according to the used system at the Neurologic Clinic of the Faculty of Medicine (University of S?o Paulo). The present work starts with a general revision on the most important existent papers on the prematures neurological evolution. After presenting his own results, the authors make a correlaction of the neurologic evolution with the developmental quotient (DQ), which were gotten through Gesell's tests and its variations, in order to verify the existence of what is known as "continuum of lesion" of Knobloch and col.     

Expectation biases in observational evaluation of therapeutic change.

Investigated systematic biases of observational recordings of behavior as a function of experimental hypotheses. Predictions of decrease and of no change in level of recorded behavior as a function of "treatment" were given, respectively, to 2 groups of 5 pairs of Os (high school students). Both groups viewed the same videotapes, selected to show no change from "baseline" to "treatment." Global evaluations of treatment effects were significantly affected by predicted results, but behavioral recordings were not. Observational recordings were increased by knowledge by Os that reliability was being assessed, computation of reliability within (vs between) O pairs, and computation of reliability by the Os (vs the E). (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design of a phased-array driver with controllable phases and magnitudes

This paper describes the design of a phased-array driver module that provides controllable phases and magnitudes. A single driver is designed and its architecture is applied to the design of a 16-channel computer-controlled 1-GHz phased-array driver. This device is capable of varying and controlling the magnitudes and phases of its output RF signals and may be used to feed a 4/spl times/4 phased-array antenna. The outputs are computer controlled and accuracy is maintained by comparing feedback phase and magnitude values with pre-calibrated ones. Any desired relative phase shift may be obtained at the outputs with up to 30 dB of magnitude variation, having an accuracy of /spl plusmn/5/spl deg/ and /spl plusmn/0.5dB, respectively. This architecture may be applied to the design of larger arrays. Its feedback control techniques may be used to improve beam-steering accuracy.