Excessive Trimming Research Articles

Preharvest and postharvest factors influencing vitamin C content of horticultural crops

Abstract Vitamin C, including ascorbic acid and dehydroascorbic acid, is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. The content of vitamin C in fruits and vegetables can be influenced by various factors such as genotypic differences, preharvest climatic conditions and cultural practices, maturity and harvesting methods, and postharvest handling procedures. The higher the intensity of light during the growing season, the greater is vitamin C content in plant tissues. Nitrogen fertilizers at high rates tend to decrease the vitamin C content in many fruits and vegetables. Vitamin C content of many crops can be increased with less frequent irrigation. Temperature management after harvest is the most important factor to maintain vitamin C of fruits and vegetables; losses are accelerated at higher temperatures and with longer storage durations. However, some chilling sensitive crops show more losses in vitamin C at lower temperatures. Conditions favorable to water loss after harvest result in a rapid loss of vitamin C especially in leafy vegetables. The retention of vitamin C is lowered by bruising, and other mechanical injuries, and by excessive trimming. Irradiation at low doses (1 kGy or lower) has no significant effects on vitamin C content of fruits and vegetables. The loss of vitamin C after harvest can be reduced by storing fruits and vegetables in reduced O 2 and/or up to 10% CO 2 atmospheres; higher CO 2 levels can accelerate vitamin C loss. Vitamin C of produce is also subject to degradation during processing and cooking. Electromagnetic energy seems to have advantages over conventional heating by reduction of process times, energy, and water usage. Blanching reduces the vitamin C content during processing, but limits further decreases during the frozen-storage of horticultural products.

Origins of Extreme Climate States during the 1982–83 ENSO Winter

Abstract The origin of extreme climate states during the exceptional 1982–83 El Nino event has continued to be a source of controversy and debate. On the one hand, empirical analyses of extratropical climate patterns during past El Nino events suggests the observed anomalies during 1982–83 were consistent with tropical forcing. On the other hand, the large amplitude of those anomalies have not been replicated in atmospheric general circulation model (AGCM) simulations for that period performed as part of the Atmospheric Model Intercomparison Project (AMIP). It has recently become apparent, however, that the sea surface boundary conditions used to drive the multitude of AMIP simulations were deficient, in that at least 30% of available tropical Pacific SST observations were discarded in the analysis cycle due to excessive trimming constraints. It is shown from a reanalysis of the sea surface temperatures that the observed east equatorial Pacific waters were 1.5°C warmer than original estimates. In order to...

Performance, carcass, and palatability traits for cull cows fed high-energy concentrate diets for 0, 14, 28, 42, or 56 days.

Cull cows, thin to moderate in initial condition scores, were randomly assigned within breed to slaughter groups and fed a high-concentrate diet for 0, 14, 28, 42 or 56 d (n = 40). Carcass data were collected, and one side of each carcass was fabricated into boneless subprimals, lean trimmings, fat, and bone. Live and carcass weights, ADG, and dressing percentage increased through 28 d of feeding (P < .05), and lean firmness increased (P < .05) through 42 d of feeding. Adjusted preliminary yield grades and final yield grades increased (P < .05) with feeding, but not to levels requiring knife trimming of fat. Fat color became whiter (P < .05) but marbling was not affected (P > .05) by feeding. Weights of fat-free lean, fat, and bone and percentages of fat in soft tissues of cow carcasses increased (P < .05) by 28 d on feed. Overall steak tenderness was higher (P < .05) for cows fed 56 d than for cows fed 0 or 14 d. Warner-Bratzler shear force was not affected by feeding. Amounts of soluble collagen increased (P < .05) in the longissimus muscle between 0 and 28 d on feed, and total collagen decreased (P < .05) in the biceps femoris muscle between 0 and 42 d on feed. Continental European cow carcasses yielded more fat-free lean and less fat (P < .05) and dairy cows generally provided the most tender product across all slaughter periods. In general, sensory tenderness and yields of cow carcass components increased without requiring excessive trimming of fat by feeding cull beef and dairy cows for periods up to 56 d.

Commissural dehiscence of Carpentier-Edwards mitral bioprostheses: Explant analysis and pathogenesis

Manufacturing factors have seldom been implicated as a direct cause of structural deterioration of valvular bioprostheses; this phenomenon has generally been considered to be of a host-dependent origin. We analyzed the clinical and pathologic data from 12 Carpentier-Edwards mitral bioprostheses removed from 12 patients because of severe dysfunction and showing detachment of the porcine aortic wall from the stent in one commissure or more. These 12 prostheses were part of a group of 92 such valves that were explanted and displayed structural deterioration. They belong to a population of 405 Carpentier-Edwards bioprostheses implanted in the mitral position in our institution between May 1978 and November 1988. The patients included three men and nine women with a mean age of 54 ± 13 years. One patient had a history of chronic renal failure, and two had systemic hypertension. Prosthesis sizes were 29, 31, and 33 mm ( n = 4 for each size). The models of the valves were 6625 ( n = 8) and 6650 ( n = 4). Mean duration of implantation of the prostheses was 99 ± 27 months (52 to 136 months) and did not differ depending on the model. There was no significant clustering of commissural detachments depending on valve size, year of implantation, or gender of the patient. No similar phenomenon was observed among 76 explanted aortic Carpentier-Edwards bioprostheses with structural deterioration from a population of 441 valves implanted during the same time frame. Native porcine aortic roots ( n = 5) and aortic Carpentier-Edwards bioprostheses explanted because of structural deterioration ( n = 4) were used as controls for comparison. Macroscopic examination showed single commissural dehiscence in 10 patients and double in two. Radiology disclosed no or mild mineralization in eight valves and no calcium in the area of aortic wall dehiscence, except for heavily calcified valves. Light microscopy evidenced a significant thinning of the aortic wall at the paracommissural level of mitral bioprostheses (351 ± 68 μm) compared with either aortic bioprostheses (526 ± 59 μm; p < 0.01) or control native porcine aortic roots (419 ± 50 μm; p < 0.01). No difference was found in terms of aortic wall thickness between detached (322 ± 42 μm) and intact (366 ± 74 μm) commissures in mitral bioprostheses. It is concluded that the dehiscence of the aortic wall from the Dacron cover of the stent in the commissural area of Carpentier-Edwards bioprostheses in the mitral position is most likely produced by its weakening, as a consequence of excessive trimming with elimination of the outer layers of the aorta, during the manufacturing process. The reason this phenomenon appears in mitral bioprostheses and in a particular commissure seems to be linked to the areas of concentration of mechanical stress. (J T HORAC C ARDIOVASC S URG 95;110:688-96)

Tree Stress and the Bronze Birch Borer

Fast-growing, white-barked birches are more likely to suffer from drought stress, when water demand exceeds water supply, than slow-growing trees. Artificial watering and fertilization may postpone stress, and subsequent attack by the bronze birch borer, for as long as those practices are continued. Branch damage by other insects, as well as excessive trimming, may cause sufficient localized stress to trigger oviposition by the borers.

Corrigendum - Heterosis and breed effect on carcass traits of rams. 1. Carcass weight and component traits

A three-breed diallel mating design was used to generate 632 rams comprising three purebreds (Dorset Horn, Merino and Corriedale) and their six contemporary F1 crossbreds in the CSIRO Sheep Crossbreeding Experiment to provide materials for studying the heterosis and breed effects on carcass traits of intact rams maintained under pasture grazing conditions. The rams were slaughtered at an average age of 21 months, at which time their average (� s.e.) carcass weight was 28.4 � 0.2 kg. This paper, the first of a series, is concerned with estimation of the linear effects due to heterosis (h') and breed-transmitted effect (gI) and breed-maternal effect (gM) on cold carcass weight and weight components (edible meat, bones and excess fat trim) of the carcass. The results showed that, in general, gI was more important than gM. Whether evaluated as a purebred, or as a paternal or maternal breed, the Dorset Horn produced more edible meat per sheep than either the Merino or the Corriedale. In terms of excess fat trim, the Corriedale tended to be the most wasteful. A significant (P &lt; 0.05) heterosis effect was observed on all traits under investigation, but its main impact was on excess fat trim, where the h1 varied with the specific breed combination and ranged from 10% to 30%, but averaged c. 24% for the whole population.

Heterosis and breed effect on carcass traits of rams. 1. Carcass weight and component traits

A three-breed diallel mating design was used to generate 632 rams comprising three purebreds (Dorset Horn, Merino and Corriedale) and their six contemporary F1 crossbreds in the CSIRO Sheep Crossbreeding Experiment to provide materials for studying the heterosis and breed effects on carcass traits of intact rams maintained under pasture grazing conditions. The rams were slaughtered at an average age of 21 months, at which time their average (� s.e.) carcass weight was 28.4 � 0.2 kg. This paper, the first of a series, is concerned with estimation of the linear effects due to heterosis (h') and breed-transmitted effect (gI) and breed-maternal effect (gM) on cold carcass weight and weight components (edible meat, bones and excess fat trim) of the carcass. The results showed that, in general, gI was more important than gM. Whether evaluated as a purebred, or as a paternal or maternal breed, the Dorset Horn produced more edible meat per sheep than either the Merino or the Corriedale. In terms of excess fat trim, the Corriedale tended to be the most wasteful. A significant (P &lt; 0.05) heterosis effect was observed on all traits under investigation, but its main impact was on excess fat trim, where the h1 varied with the specific breed combination and ranged from 10% to 30%, but averaged c. 24% for the whole population.

Boxing the tongue region in mandibular irreversible hydrocolloid impressions

Alginate (irreversible hydrocolloid) impression material is routinely used for making impressions for diagnostic casts. The resultant diagnostic cast should be neat and esthetically pleasing as it is used to educate the patient. However, it is difficult to box mandibular irreversible hydrocolloid impressions, especially in the tongue region (Fig. 1). Materials such as tissue paper and wet asbestos may result in a rough lingual region requiring excessive trimming. The following method will improve the appearance of the diagnostic cast. 1. Make a thick mix of irreversible hydrocolloid impression material and adapt it to the tongue region. Fig. 2. Irreversible hydrocolloid impression material adapted to tongue region.

A 0-1 Model for Solving the Corrugator Trim Problem

A new method for solving the corrugator trim problem is presented. This problem draws its name from the difficult task facing scheduling personnel in corrugator box plants each day: to determine the least-cost method of combining customer orders on the corrugator, where one of the major costs to avoid is waste or excess trim lost from the materials used. Trim loss, however, is only one of several major concerns. Others include corrugator width utilization, cutting pattern changes, avoidance of split orders, and so on. A full discussion of these factors and associated trade-offs is included in the paper. The solution procedure presented is capable of dealing with these and other trade-offs in a systematic manner. In particular, this approach eliminates the spreading of orders over several stock sizes, a characteristic which has plagued the linear programming-based procedures that have been proposed for solving the problem. This improved material handling characteristic of the solution is obtained through the controlled generation of solution elements. These elements then become potential activities to be scheduled by a 0-1 integer programming algorithm. The algorithm used is well suited to computers of moderate size and speed. In addition to solving the corrugator trim problem, the proposed method has sufficient flexibility to make it a useful vehicle for solving similar problems in other industries which manufacture such products as glass, steel, composition board, and furniture.

Saugspannungsmessungen in der Krone eines Mammutbaumes (Sequoiadendron giganteum)

Summary Scholander’s pressure chamber technique was used for determining suction tensions (= xylem water potentials) in the crown of a giant sequoia, Sequoiadendron giganteum (Lindl.) Buchholz. The influence of repeated cutting on readings was found to be considerable, when 20 minutes had elapsed between detachment of a branch and removal of a piece of stem. Equilibrium pressures became smaller in lateral shoots removed after some time from cut branches, indicating a withdrawal of the water column from the first cutting, probably through water uptake by leaf cells. Excessive trimming of branches and gradual detachment of small twigs from cut branches are not recommended, therefore, unless immediately after the first cutting. Daily fluctuations of suction tension at 7 m above the ground show a good agreement between vapour pressure deficits calculated from meteorological data and tensions in shaded twigs. Xylem tensions in twigs exposed to full sunlight gradually rise over the shadow curve from morning to noon, reaching a maximum difference of ∼ 7 atm. Minimum tensions are observed shortly before sunrise. Tension gradients from the lowest branches (7 m above ground) to the top (24–28 m) show only a slow rise when transpiration is reduced, especially immediately before sunrise. During the day, they are steeper in the shade (e.g. under cloudy sky) than in full sunshine. Measurements of potential osmotic pressures indicate that twigs in the top of the crown are unable to heighten their tensions as much as lower twigs because of osmotic difficulties. These are overcome in winter and early spring, when potential osmotic pressures are high and permit very steep gradients in full sun. A formula originally developed by Huber is further improved and serves as the basis for a discussion of static and dynamic components of xylem tensions.

Airborne Camera Capsule

The universal airborne camera capsule was developed to obtain the photographic coverage needed for better flight-test documentation. The capsule design and modifications, type of camera equipment, timing device and electrical system are described. The capsule has been test flown at speeds up to Mach 1 without need for excessive trim adjustments. Pilots' comments have favorable, and photographic coverage obtained has been good.