| cross-section | <physics> Usually refers to the (apparent) area presented by a target particle to an oncoming particle (or electromagnetic wave). This measures the probability of an interaction occuring. For typical interactions between ions and electrons, or between two nuclei, these cross sections are generally measured in barns. <anatomy> A transverse cut through a structure or tissue. The opposite of a cross-section is a longitudinal section. By analogy, a study may be cross-sectional or longitudinal. (12 Dec 1998) |
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| cross-sectional echocardiography | two-dimensional echocardiography |
| cross-sectional method | <epidemiology> The study of the life span involving comparison of groups of individuals at different age levels. Compare: longitudinal method. (05 Mar 2000) |
| cross-sectional study | <epidemiology> A study in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with longitudinal studies which are followed over a period of time. Synonym: horizontal study. (18 Jul 2002) |
| cross-table lateral projection | <radiology> Lateral projection radiography of a supine subject using a horizontal X-ray beam. (05 Mar 2000) |
| cross tolerance | <pharmacology> The resistance to one or several effects of a compound as a result of tolerance developed to a pharmacologically similar compound. (05 Mar 2000) |
| section, cross | A transverse cut through a structure. The opposite is a longitudinal section. (12 Dec 1998) |
| holy cross | The cross as the symbol of Christ's crucifixion. Congregation of the Holy Cross, a community of lay brothers and priests, in France and the United States, engaged chiefly in teaching and manual Labour. Originally called Brethren of St. Joseph. The Sisters of the Holy Cross engage in similar work. Holy-cross day, the fourteenth of September, observed as a church festival, in memory of the exaltation of our Savior's cross. Source: Websters Dictionary (01 Mar 1998) |
| study, cross-sectional | A study done at one time, not over the course of time. A cross-sectional study a disease such as aids might be designed to learn its prevalence and distribution within the population at one point in time. Also known as a synchronic study. (12 Dec 1998) |
| double back cross | A mating that is a back cross at each of two loci of interest; of special value and importance in linkage analysis. (05 Mar 2000) |
| International Committee of the Red Cross | A neutral Swiss organization serving as an intermediary between contending forces in armed conflict, in civil war, or internal strife, to help victims receive protection and other humanitarian assistance under the Geneva Conventions in accordance with the fundamental principles of the Red Cross. (05 Mar 2000) |
| League of Red Cross Societies | The international federation of national Red Cross and similar societies. (05 Mar 2000) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |
| acetone test | A test for ketonuria; the suspected urine is shaken up with a few drops of sodium nitroprusside, and strong ammonia water is then gently poured over the mixture; if acetone is present, a magenta ring forms at the line of contact; tablets containing sodium nitroprusside and alkali are now more commonly used. (05 Mar 2000) |
| achievement test | A standardised test used to measure acquired learning, e.g., competence in a specific subject area such as reading or arithmetic, in contrast to an intelligence test which is a useful index of potential ability or learning. (05 Mar 2000) |