To discover which factors contributed to recovery after surgical intracranial decompression, we reviewed the records of 82 consecutive comatose patients with traumatic acute subdural hematoma (ASDH) who were treated in a single center under a uniform protocol. The delay from injury to operation was the factor of greatest therapeutic importance. Patients who underwent surgery within the first four hours had a 30 per cent mortality rate, as compared with 90 percent in those who had surgery after four hours (P less than 0.0001). Other important prognostic variables included results of the initial neurologic examination, sex, multimodality-evoked potentials, and postoperative intracranial pressure (ICP). If all patients with traumatic ASDH were taken directly to hospitals equipped to diagnose and remove the hematoma within four hours of injury, mortality rates could be reduced considerably.

This study was undertaken to determine phenotypic and genetic correlation coefficients among several agronomic traits in sugarcane (Saccharum spp.) and to analyze their interrelationships through path‐coefficient analyses. Other objectives were to determine broad‐sense heritability and genetic advance under selection for the traits studied. Random selections from two biparental crosses (‘CP 59‐50’ ✕ ‘CP 57‐603’ and ‘CP 62‐374’ ✕ ‘CP 57‐614’) were evaluated in the field for several attributes in plant cane, and first‐ and second‐ratoon crops. Genetic path‐coefficient analyses indicated plant height to be less important than stalk diameter and stalk number as a component of cane yield; but at the phenotypic level, all three components were of equal importance. Sucrose (%) had a large direct positive effect on sugar per ton of cane (S/T) whereas Brix (percent soluble solids) had a small negative direct influence on S/T. The S/T component exerted a greater direct effect on tons per hectare of sugar (THS) than did tons per hectare of cane (THC). Broad‐sense heritability estimates based plot means for various traits ranged from a low of 77% for THS to a high of 94% for stalk diameter. Expected genetic advance for various traits was reasonably high under selection intensities of 2 to 30%. THC estimated from the weight of a 10‐stalk sample per plot was genetically and phenotypically correlated with THC determined by weighing the entire plot (rg = 0.92, rp = 0.64) which suggested that a 10‐stalk sample per plot would be adequate to determine THC.

Sugarcane (Saccharum spp.) is a successful crop in the Florida Everglades Agricultural Area (EAA) that is characterized by high‐N organic and low‐fertility sandy soils, periodic freeze, and flood events. After 50 yr of breeding, the possibility of a yield plateau was investigated in the cooperative Florida sugarcane breeding program via an assessment of yield gains in the industry and an evaluation of the contribution attributed to breeding efforts. Long‐term commercial and selection trial data, covering a 33‐yr period (1968–2000), were used in single‐degree‐of‐freedom regression analyses to determine rates of improvement in sucrose content (SC; kg Mg−1), cane yield (CY; Mg ha−1), and sugar yield (SY; Mg ha−1). Analyses of commercial data reflected yearly increases of 0.80 ± 0.08 kg Mg−1 of cane for SC, 0.31 ± 0.10 Mg ha−1 for CY, and 0.10 ± 0.01 Mg ha−1 for SY. Corresponding gains from selection trial data were 0.74 ± 0.15 kg Mg−1, 1.06 ± 0.40 Mg ha−1, and 0.16 ± 0.05 Mg ha−1, respectively. Improvements were significant for all three traits across plant‐cane, and first‐ and second‐ratoon crops grown on organic soils but not on sandy soils. About 69% of the total gain in SY was attributed to the cooperative Canal Point public breeding program, via a greater allocation of assimilates toward sucrose accumulation, resulting in a contribution of $99 to 203 million as additional profits to the Florida economy across the 33 yr. The genetic potential of the working germplasm has not been exhausted (no evidence of a yield plateau for SC) in this sugarcane breeding program. These gains and future advances are possible because of the use of a diverse gene pool and a breeding strategy that integrates growers’ participation into the program.

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In an observational study in head-injured patients, cerebrovascular pressure transmission was investigated using a systems analysis approach whereby the blood pressure (BP) waveform was used as a measure of an input stimulus to the cerebrovascular bed (CVB) and the intracranial pressure (ICP) waveform as the response to that stimulus. The transfer function is a measure of how much pressure is transmitted through the CVB at a given frequency and is calculated using Fourier analysis of the pressure waveforms. The transfer function allows quantification of the pressure transmission performance of the CVB, thus providing a basis for comparison between normal and abnormal function. Fifteen hundred samples of ICP and BP waveforms were collected from 30 head-injured patients via microcomputer. Off-line spectral analysis of the waveform database revealed four main classes of transfer function: those with an overall flat transfer function (curve type 1); those with an elevated low-frequency response (curve type 2); those with an elevated high-frequency response (curve type 3); and those exhibiting both an elevated low- and high-frequency response (curve type 4). Curve types 2 and 4 were most often associated with raised ICP (greater than 20 mm Hg), whereas curve types 1 and 3 were most often affiliated with ICP less than 15 mm Hg. Studies of this type may provide insight into the pathophysiology of the CVB and ultimately aid in the prediction and treatment of raised ICP.