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H Tyson

Publications and source records attributed to H Tyson.

25 records · Page 2Linked to original sources
PubMed1982

A BASIC program for orthogonal polynomials and retrieval of regression coefficients for original model.

A fast, short method for calculating orthogonal polynomials has been programmed in BASIC. This is combined with the retrieval of b coefficients for the original, non-orthogonal model in, for example, a curvilinear regression. The program may be used alone, or in conjunction with a package of BASIC programs for weighted least-squares solutions, to which it forms an update. Transformation of the columns of an X, or design matrix, to orthogonal vectors can detect linear dependence among the columns, as well as supplying orthogonal polynomials for regression situations with unequal increments in x values, the values of the independent variable. Retrieval of the b coefficients for the original X matrix prior to transformation allows the user to insert any x value to obtain the corresponding predicted y (dependent variable) values.

Computers↗
PubMed1982

A BASIC program package for weighted least squares solutions using a microprocessor with disc memory.

The fitting of linear additive models to data by weighted least squares methods has been programmed in BASIC. By splitting up the matrix solution into several steps, the RAM memory space needed in a microprocessor by the corresponding programs was reduced, allowing room for larger matrices. Storage of intermediate products, and of subsequent programs in the sequence , was on a mini floppy dual-disc drive. Using an extended BASIC interpreter permitting several files to be open during a program, the program package compromised between computing time and problem size. Problems involving 1600 element matrices were run on a micro having 32000 bytes of memory, allowing for example, the fitting of a model with 22 parameters to 72 observations.

Computers↗
PubMedDate not supplied

Family dysfunction and Native American women who do not seek prenatal care.

OBJECTIVE: To test the hypotheses that, in a health system with few external barriers to care, women with no prenatal care (NPC) have higher rates of nuclear family dysfunction and disproportionate amounts of adverse neonatal outcomes compared with women with prenatal care. DESIGN: Case-control study. SETTING: Indian Health Service system. PATIENTS: Nuclear families of women not seeking prenatal care compared with those who did seek prenatal care. MAIN OUTCOME MEASURES: Dysfunctional outcome measures in nuclear families were children adopted, placed, or under protective surveillance; mothers denying pregnancy, being abused, or attempting suicide; and parents with alcoholism. Neonatal outcome measures were low birth weight and neonatal intensive care days. RESULTS: Dysfunctional markers occurred significantly more frequently in families of women with NPC than in families of women with prenatal care (57% of NPC and 12% of control families; McNemar odds ratio, 14; 95% confidence interval, 4.7-41.6). Neonatal outcome in this Native American population showed that women with NPC had only 2.6% (58/2222) of the total births but accounted for 11% of the low-birth-weight infants (< 2500 g), 18% of the very-low-birth-weight infants (< 1500 g), and 24% of the level II and 41% of the level III newborn intensive care days. CONCLUSIONS: Women not seeking prenatal care in a system with few external barriers to care have significantly more family dysfunction (P < .001) than women seeking prenatal care. Infants of women with NPC generated a disproportionate amount of adverse neonatal outcome. The combination of NPC and family dysfunction was more predictive of adverse neonatal outcome than was NPC alone.

Adolescent↗