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1.
Ergonomics ; 65(12): 1639-1658, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35243968

ABSTRACT

Humans have developed a prolonged and special relationship with their tools, which themselves exhibit the propensity to become ever more intelligent across the years. A 'smart tool' is defined as to representing any entity, machine, or device that can complete an informational, mechanical, or electronic work. This work explains the development of the Smart Tool Proneness Questionnaire (STP-Q), which is designed to measure an individual's propensity to use smart tools. Data collection was designed to (1) identify the psychological dimensions underlying smart tool use (2) establish the questionnaire's reliability (3) validity, (4) propose a normalisation, and (5) provide an English translation of the French original. The work therefore implements a reliable and valid questionnaire, sensitive to inter-individual differences regarding the propensity to use smart tools. Statistical analysis reveals that the individual self-reported propensity for smart tool use rests on three factors (1) utilitarian use, (2) hedonic and social use, and (3) proneness to delegate. From a theoretical perspective, this individual propensity to use smart tools might be considered key to our species development. In practical terms, measuring an individual's propensity to use smart tools can be of considerable benefit to the design of future smart tools in both professional and non-professional settings. Practitioner summary: The STP-Q, a self-reported measure of an individual's propensity to use smart tools, was developed. STP-Q offers practitioners a measure of individual propensity to use smart tools along three dimensions: utilitarian use, hedonic and social use, and proneness to task delegate. Individual results can easily be interpreted from normalizations that STP-Q provides. Abbreviations: CFI: comparative fit index; GFI: goodness of fit index; IFI: incremental fit index; ISO: International Standardization Organization; IRB: institutional review board of the university of central Florida; IT: information technology; MATB: multi-attribute task battery; NMP-Q: no more phone phobia; RMSEA: root mean square error of approximation; STP-Q: smart tools proneness questionnaire; TAM: technology acceptance model; TRI: technology readiness index; UTAUT: unified theory of acceptance and use of technology; WAIS IV: Wechsler adult intelligence scale.


Subject(s)
Intelligence , Adult , Humans , Reproducibility of Results , Surveys and Questionnaires , Psychometrics
2.
Behav Res Methods ; 52(5): 1980-1990, 2020 10.
Article in English | MEDLINE | ID: mdl-32140999

ABSTRACT

OpenMATB is an open-source variant of the Multi-Attribute Task Battery (MATB) and is available under a free software license. MATB consists of a set of tasks representative of those performed in aircraft piloting. It is used, in particular, to study the effect of automation on decision-making, mental workload, and vigilance. Since the publication of MATB 20 years ago, the subject of automation has grown considerably in importance. After introducing the task battery, this article highlights three main requirements for an up-to-date implementation of MATB. First, there is a need for task customization, to make it possible to change the values, appearance or integrated components (such as rating scales) of the tasks. Second, researchers need software extensibility to enable them to integrate specific features, such as synchronization with psychophysiological devices. Third, to achieve experiment replicability, it is necessary that the source code and the scenario files are easily available and auditable. In the present paper, we explain how these aspects are implemented in OpenMATB by presenting the software architecture and features, while placing special emphasis on the crucial role of the plugin system and the simplicity of the format used in the script files. Finally, we present a number of general trends for the future study of automation in human factors research and ergonomics.


Subject(s)
Aircraft , Automation , Software , Task Performance and Analysis , Workload , Humans , Psychophysiology
3.
Neurochirurgie ; 59(4-5): 142-8, 2013.
Article in English | MEDLINE | ID: mdl-23953035

ABSTRACT

The operating room (OR) is a high-risk complex setting, where patient safety relies on the coordinated efforts of multiple team members. However, little attention has been paid to evaluating the strategies employed by OR practitioners to prevent and correct incidents that inevitably occur during surgery. Therefore, we were prompted to investigate human factor (HF) engineering methods that have been used in an innovative way in order to systematically observe and analyze the management of incidents in the neurosurgical OR of a French university hospital. A technical case report illustrates our approach that associates the following procedures: the recording of OR team member activities and behaviour by video cameras and direct observation of a HF researcher, with the description and the explicit demonstration of safety related procedures in self- and cross-confrontation interviews of OR team members. This technical report emphasizes complementary aspects of clinical performance related to safety skills. Moreover, individual and team performances rely on complementary abilities that associate practical knowledge, skills, and attitudes, which are engaged at various degrees to prevent and manage incidents. This report also enlightens new quality-improvement opportunities as well as further objectives for future studies.


Subject(s)
Brain Neoplasms/surgery , Operating Rooms , Video Recording , Aged , Female , Hospitals, University , Humans , Patient Care Team , Prospective Studies , Video Recording/methods
4.
J Hazard Mater ; 165(1-3): 1119-23, 2009 Jun 15.
Article in English | MEDLINE | ID: mdl-19070426

ABSTRACT

Olive-mill wastes represent a significant environmental problem in Mediterranean areas due to their important production during a short period of time. Their high polyphenol, lipid and organic acid concentrations turn them into phytotoxic wastes. This work examined the evolution of polyphenolic compounds during the composting of an olive-mill waste-wheat straw mixture by using quantitative (Folin-Ciocalteu) and qualitative (High Pressure Liquid Chromatography, HPLC) analyses. The polyphenol content decreased strongly by 93% while the significant correlations obtained between polyphenol content and different humification indices and lignin losses suggested that polyphenols contribute to the synthesis of humic substances. In addition, the significant correlation found between germination index, polyphenols and humification indices must be related to the progressive substrate detoxification as humification process progressed, leading to a non-phytotoxic and partially humified end-product. Nine polyphenolic compounds were identified by HPLC, most of which had disappeared by the end of composting, when only traces of hydroxytyrosol, caffeic and syringic acids and oleuropein were detected.


Subject(s)
Flavonoids/analysis , Industrial Waste/analysis , Olea/chemistry , Phenols/analysis , Soil/analysis , Triticum/chemistry , Chromatography, High Pressure Liquid , Humic Substances , Polyphenols
5.
Waste Manag ; 28(8): 1423-31, 2008.
Article in English | MEDLINE | ID: mdl-17624755

ABSTRACT

Water-soluble extracts from compost may represent an alternative nutrient and organic matter source for crop production under drip irrigation. Dissolved organic matter (DOM), extracted from composted "alperujo", the main by-product from the Spanish olive oil industry, was applied to soil alone or in combination with either Glomus intraradices Schenck and Smith or a mixture of G. intraradices, Glomus deserticola (Trappe, Bloss. and Menge) and Glomus mosseae (Nicol and Gerd.) Gerd. and Trappe. Response measurements included mycorrhizal colonisation, nutrient uptake and growth of Medicago sativa and microbiological and physical properties in the rhizosphere. Dissolved organic matter was added to soil at concentrations of 0, 50, 100 or 300mgCkg(-1) substrate. During the four months of the experiment, the plants were harvested three times. Both mycorrhizal inoculation treatments significantly increased soil aggregate stability. Only the mycorrhizal inoculations increased microbial biomass C and protease and phosphatase activities and decreased water-soluble C, particularly the mixture of arbuscular mycorrhizal fungi. At the third harvest, the greatest increase in growth of M. sativa was observed in the inoculated plants with shoot biomass being 38% greater than for plants grown in the soil amended with the highest dose of DOM and 57% greater than for control plants. The addition of DOM was not sufficient to restore soil structure and microbial activity and did not affect the mycorrhizal development of introduced populations of arbuscular mycorrhizal fungi, but, depending on the dose, its fertiliser efficiency for improving plant growth was apparent.


Subject(s)
Medicago sativa/metabolism , Mycorrhizae/metabolism , Soil , Agriculture , Biochemistry/methods , Biomass , Electric Conductivity , Fertilizers , Hydrogen-Ion Concentration , Industrial Waste , Industry , Models, Statistical , Olive Oil , Organic Chemicals , Plant Oils
6.
J Hazard Mater ; 154(1-3): 682-7, 2008 Jun 15.
Article in English | MEDLINE | ID: mdl-18054430

ABSTRACT

The co-composting of olive oil mill wastes and household refuse was followed for 5 months. During the thermophilic phase of composting, the aerobic heterotrophic bacteria (AHB) count, showed a significant rise with a slight regression of fungal biomass. In the same way, phospholipid fatty acids PLFAs common in bacteria, showed a significant increase of hydroxyl and branched PLFAs. The evaluation of the ratio of octadecenoic PLFAs to stearic acid (C18:1omega/C18:0) revealed a significant reduction while a significant rise in the length of aliphatic chains evaluated by the stearic acid to palmitic acid ratio (C18:0/C16:0) was noted during the stabilization phase. The follow-up of PLFAs, indicates the degree of biodegradation that occurs during composting, it can be regarded an indicator of the stability and maturity of the end product.


Subject(s)
Fatty Acids/analysis , Plant Oils , Refuse Disposal/methods , Soil , Bacteria/growth & development , Bacteria/metabolism , Biomass , Colony Count, Microbial , Food Industry , Fungi/growth & development , Fungi/metabolism , Olive Oil , Waste Products
7.
Bioresour Technol ; 98(4): 940-5, 2007 Mar.
Article in English | MEDLINE | ID: mdl-16762544

ABSTRACT

A pot experiment was conducted on a low-fertility calcareous soil in order to evaluate the effect on ryegrass growth and nutrient uptake of an organic fertiliser obtained by composting "alperujo" and cotton gin waste. Compost, alone and combined with nitrogen fertilisation, was added to the soil at three rates and three harvests were obtained. The compost application enhanced plant growth in the first and third harvest. However, the additional nitrogen fertilisation clearly improved soil productivity due to the scarce availability of this nutrient in the compost. Also, a general increase in the plant contents of phosphorus and potassium in the first two harvests was recorded, whereas treatments with the maximum compost rate showed the highest plant content of copper in the last two harvests. Decreases in calcium in the last two harvests, in magnesium in all of them and in iron and manganese in the last harvest were also observed.


Subject(s)
Centrifugation/instrumentation , Industrial Waste , Lolium/metabolism , Plant Oils/isolation & purification , Lolium/growth & development , Olive Oil
8.
Rev. fitoter ; 6(2): 155-159, oct. 2006. ilus, tab
Article in Es | IBECS | ID: ibc-051364

ABSTRACT

Las especies medicinales y tóxicas del género Lepechinia Willd. en Venezuela son Lepechinia bullata (Kunth) Epling y Lepechinia schiedeana (Schleghtd) Vatke, las dos viven en alta montaña. Se han encontrado diferencias en la composición del aceite esencial y en el indumento de la hoja


Lepechinia bullata (Kunth) Epling and Lepechinia schideana (Schleghtd) Watke are the medicinal and toxic species of genus WiIld in Venezuela, both live in high mountain and they have some differences in the composition of the essential oil and some differences in the indument of leaves


Subject(s)
Humans , Lamiaceae/classification , Lamiaceae/chemistry , Plant Oils/chemistry , Oils, Volatile/chemistry , Plant Oils/toxicity , Plant Oils/therapeutic use , Oils, Volatile/toxicity , Oils, Volatile/therapeutic use , Lamiaceae/toxicity , Venezuela
9.
Waste Manag ; 26(12): 1377-83, 2006.
Article in English | MEDLINE | ID: mdl-16426834

ABSTRACT

The evaluation of the most suitable aeration technology for olive-mill by-product "alperujo" (AL) composting was carried out by using two identical piles prepared by mixing AL with a bulking agent (fresh cow bedding) and a mature compost (as inoculant). Forced ventilation was employed in conjunction with mechanical turning in one of the piles, whereas only mechanical turning was used in the other pile. These two treatment methods were evaluated by assessing process efficiency and end-product quality. The results show that the composting process was completed in less time when forced ventilation was coupled with mechanical turning. A slight delay in the evolution of pH, C/N ratio, and biodegradation of fats and organic matter was observed when only turning was employed. However, the recommended method for composting AL was mechanical turning without forced ventilation since the composition of the end-product in this case was comparable to the composted AL using forced ventilation coupled with mechanical turning. Furthermore, there were substantial economic savings by selecting mechanical turning alone, which included capital costs for equipment.


Subject(s)
Industrial Waste/analysis , Plant Oils/chemistry , Refuse Disposal/methods , Ventilation , Carbon/analysis , Food Industry/methods , Hydrogen-Ion Concentration , Nitrogen/analysis , Olive Oil , Refuse Disposal/economics
10.
Waste Manag ; 26(6): 620-6, 2006.
Article in English | MEDLINE | ID: mdl-16005202

ABSTRACT

A pollutant solid material called "alperujo" (AL), which is the main by-product from the Spanish olive oil industry, was composted with a cotton waste as bulking agent, and the compost obtained (ALC) was compared with a cattle manure (CM) and a sewage sludge compost (SSC) for use as organic amendment on a calcareous soil. The experiment was conducted with a commercial pepper crop in a greenhouse using fertigation. Composting AL involved a relatively low level of organic matter biodegradation, an increase in pH and clear decreases in the C/N and the fat, water-soluble organic carbon and phenol contents. The resulting compost, which was rich in organic matter and free of phytotoxicity, had a high potassium and organic nitrogen content but was low in phosphorus and micronutrients. The marketable yields of pepper obtained with all three organic amendments were similar, thus confirming the composting performance of the raw AL. When CM and SSC were used for soil amendment, the soil organic matter content was significantly reduced after cultivation, while it remained almost unchanged in the ALC-amended plots.


Subject(s)
Agriculture/methods , Fertilizers , Industrial Waste/analysis , Olea , Refuse Disposal/methods , Biodegradation, Environmental , Carbon/analysis , Hydrogen-Ion Concentration , Manure , Micronutrients/analysis , Minerals/analysis , Nitrogen/analysis , Olea/metabolism , Sewage , Time Factors
11.
Environ Int ; 31(2): 305-12, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15661299

ABSTRACT

The suitability of olive mill wastewater (OMW) for composting was studied by the addition of this liquid waste to a mixture of cotton gin waste and sewage sludge, and its composting was compared with that of another pile of similar composition, but without olive mill wastewater. Both piles were composted by the Rutgers static pile system in a pilot plant. To study the effects of both composts on plant yield and soil properties, a plot experiment was carried out with Swiss chard (Beta vulgaris L. var. cicla). Five treatments were applied: mineral fertiliser and two doses (30 and 60 tons ha(-1)) of both composts. The olive mill wastewater addition produced a compost with lower organic matter and nitrate concentrations, higher electrical conductivity, and a stabilised and humified organic matter similar to that of the compost produced without olive mill wastewater. The olive mill wastewater compost application to soil did not injure plants, producing a similar plant yield to both compost without olive mill wastewater and inorganic fertiliser. Also, the accumulation of potentially toxic heavy metals in plants cultivated with organic or mineral fertilisers did not reveal significant differences. The olive mill wastewater compost application to soil also improved the chemical and physicochemical properties of the soil.


Subject(s)
Beta vulgaris/growth & development , Fertilizers , Plant Oils , Waste Disposal, Fluid , Agriculture , Conservation of Natural Resources , Electrochemistry , Olive Oil , Sewage , Soil
12.
Surg Endosc ; 18(7): 1058-62, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15156379

ABSTRACT

BACKGROUND: Rigor mortis can be a problem when laparoscopy is performed in embalmed cadavers for surgical training. METHODS: To improve the laparoscopic view, a new technique for managing the abdominal wall with a cutaneous-subcutaneous flap, pneumoperitoneum (14-15 mmHg), and a progressive (step-by-step) bilateral section of the lateral muscles of the abdomen was attempted in 10 embalmed cadavers. The degree of abdominal wall increase was calculated by measuring changes in the size of the abdominal wall after each step. Improvement in the peritoneal laparoscopic view was also assessed. RESULTS: For abdominal wall size, no constant relationship was observed between initial (after creation of the pneumoperitoneum) and final increment (after each muscular layer section). Cumulative degrees of increase in the dimensions of the abdominal wall were the only parameters that showed a significant difference among the four groups of cadavers. Bilateral sectioning of both oblique muscles was sufficient to obtain an adequate view of the abdominopelvic cavity; thus, the risk of an unexpected peritoneal opening during sectioning of the transversum abdominis muscle was obviated. CONCLUSIONS: In embalmed cadavers, the laparoscopic view in the presence of a pneumoperitoneum can be facilitated by a section of the lateral muscles of the abdomen, with a previous cutaneous-subcutaneous flap. To obviate an incidental opening of the peritoneum, resulting in air leakage, preservation of the deep muscular layer is advisable.


Subject(s)
Abdominal Wall/surgery , Cadaver , Laparoscopy/methods , Anthropometry , Embalming , Female , General Surgery/education , Humans , Male , Pneumoperitoneum, Artificial/methods , Rigor Mortis
13.
Bioresour Technol ; 91(2): 195-200, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14592750

ABSTRACT

Introduction of the two-phase centrifugation system for olive oil extraction during the early nineties in Spain has led to the generation of approximately four million tons per year of a solid olive-mill by-product called "alperujo" (AL). Agrochemical characterisation showed that AL has a high moisture content, slightly acidic pH values and a very high content of organic matter, mainly composed by lignin, hemicellulose and cellulose. It also has a considerable proportion of fats, proteins, water-soluble carbohydrates and a small but active fraction of hydrosoluble phenolic substances. Amongst plant nutrients, AL is rich in potassium, less so in (mainly organic) nitrogen and poor in phosphorus and micronutrients. Some of those properties are not compatible with agricultural requirements, for which reason composting may be considered a suitable alternative for its disposal. AL needs to be characterised before composting, and so an attempt was made to correlate the easily determined ash content with other parameters; the regression models thus obtained are discussed.


Subject(s)
Agriculture/methods , Olea/chemistry , Waste Products/analysis , Centrifugation , Models, Theoretical , Regression Analysis , Spain
14.
Bioresour Technol ; 85(1): 1-8, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12146635

ABSTRACT

The use of maize straw (MS) or cotton waste (CW) as bulking agents in the composting of olive mill wastewater (OMW) sludge was compared by studying the organic matter (OM) mineralisation and humification processes during composting and the characteristics of the end products. Both composts were prepared in a pilot-plant using the Rutgers static-pile system. The use of CW instead of MS to compost OMW sludge extended both the thermophilic and bio-oxidative phases of the process, with higher degradation of polymers (mainly lignin and cellulose), a greater formation of nitrates, higher total nitrogen losses and a lower biological nitrogen fixation. The CW produced a compost with a more stabilised OM and more highly polymerised humic-like substances. In the pile with CW and OMW sludge, OM losses followed a first-order kinetic equation, due to OM degradation being greater at the beginning of the composting and remaining almost constant until the end of the process. However, in the pile with MS and OMW sludge this parameter followed a zero-order kinetic equation, since OM degraded throughout the process. The germination index indicated the reduction of phytotoxicity during composting.


Subject(s)
Agriculture , Industrial Waste/analysis , Plant Oils , Biodegradation, Environmental , Germination/drug effects , Germination/physiology , Gossypium , Humic Substances/analysis , Humic Substances/chemistry , Kinetics , Nitrogen/chemistry , Olea , Oxygen/metabolism , Pilot Projects , Seeds , Temperature , Time Factors , Waste Disposal, Fluid , Waste Management , Zea mays
15.
J Anat ; 198(Pt 1): 117-24, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11215762

ABSTRACT

An isolated tracheo-oesophageal fistula could be caused by close proximity of the epithelia of both organs (O'Rahilly & Müller, 1984; Kluth et al. 1987) at certain embryonic stages, the most frequent location being the tracheal bifurcation. Thus the relative position and degree of separation between the digestive and the respiratory tubes throughout their development may be relevant to the origin of this anomaly. The aim of this study was to analyse along the different segments of the tracheo-oesophageal septum (TES) where the closest relationship between both lumina occurred and what degree of separation was present at each segment. Computer imaging techniques were applied on cross sections of a graded series of normal human embryos (Carnegie stages (CS) 13-23). In addition, the differentiation of the primitive TES was also studied (from CS 12) by light microscopy. Between CS 13 and 16 both tubes tended to separate (phase of separation), principally at the proximal segments of the laryngopharyngeal and the tracheo-oesophageal portions of the TES. During this phase the separation between the trachea and oesophagus was wider than between the larynx and pharynx. From CS 17 to CS 23 the digestive and respiratory lumina reached their widest separation at different levels of the laryngopharyngeal portion. Below these levels they tended to come closer together, principally at the proximal segment of the tracheo-oesophageal portion, but also at the distal part of the laryngopharyngeal portion. During this phase of approximation they reached their closest relationship at the proximal (CS 17) and the distal (from CS 18) segments of the tracheo-oesophageal portion. When finally the distal segment of the trachea (which includes the bifurcation) comes closest to the oesophagus, the coats of both organs have already undergone an appreciable differentiation. According to these observations, the origin of the most frequent isolated tracheo-oesophageal fistula at the bifurcation region could not be explained from the normal development of the TES.


Subject(s)
Embryonic and Fetal Development , Esophagus/embryology , Trachea/embryology , Humans , Image Processing, Computer-Assisted , Tracheoesophageal Fistula/embryology
16.
Biodegradation ; 12(4): 225-34, 2001.
Article in English | MEDLINE | ID: mdl-11826905

ABSTRACT

In order to study the suitability of olive mill wastewater (OMW) for composting, this liquid waste was added to two different mixtures of agroindustrial and urban wastes and the composting process was compared with two other piles of similar composition, but without OMW. These four piles were studied in a pilot plant using the Rutgers static pile system. The addition of OMW produced a greater proportion of degradable organic matter or a higher degradation rate, higher electrical conductivity values, greater losses of total N and lower nitrification than in piles without OMW. Its addition also restricted the increase of the cation exchange capacity and provoked the appearance of phytotoxicity or a longer persistence of phytotoxicity. However, in general, all the composts showed increases in the cation exchange capacity, the percentage of humic acid-like carbon, the polymerisation ratio of these humic substances (which revealed that the organic matter had been humified during composting) and the germination index, the latter indicating the reduction of phytotoxicity during the process.


Subject(s)
Agriculture , Food-Processing Industry , Industrial Waste/analysis , Plant Oils , Waste Disposal, Fluid , Citrus/chemistry , Electric Conductivity , Gossypium , Hydrogen-Ion Concentration , Nitrogen/chemistry , Olive Oil , Oxidation-Reduction , Pilot Projects
17.
J Anat ; 194 ( Pt 1): 61-9, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10227667

ABSTRACT

The majority of studies as to whether gastric and nongastric factors are involved in the 'rotation' of the human embryonic stomach around its longitudinal axis have been morphological. The aim of this study was to analyse, with morphometric support, the influence on the angular modifications during gastric rotation of the simultaneous changes of the gastric walls and mesenteric growth, and the volumes of organs adjacent to the stomach (right, left and posterior groups). Computer imaging techniques were applied on cross sections of a graded series of 10 human embryos (from Carnegie stage (CS) 11) and 2 fetuses. A clockwise gastric rotation occurred during the embryonic period. The most rapid angular modifications took place from CS 11 to 16, after the rotation became oscillatory with angular changes in clockwise and anticlockwise directions, reaching the highest value at CS 18 (at the supraomental part of the stomach: 54.37 degrees; at the omental part: 68.03 degrees); after this period the angular values tended to stabilise. The predominant growth of the left gastric wall over the right and the changes in the width of the gastric mesentery were the most persistent factors involved in the modifications of the transverse gastric angle during the embryonic period although without relationship to their direction. During the increasing angular phases, clockwise rotation was promoted by the decrease of the volume of any group of organs adjacent to the stomach. When the volume of the left and posterior groups increased simultaneously, clockwise or anticlockwise angular directional change was related to the respective decrease or increase adjacent organ volume to the right. We conclude that the stomach of the human embryo undergoes heterogeneous and multifactorial rotation as a consequence of the overall increase in gastric wall growth to the left and the increase of gastric mobility produced by the previous mesenteric enlargement, and that the rotational direction results from the forces exerted on the stomach and the gastric mesenteries by the adjacent organs.


Subject(s)
Embryonic and Fetal Development/physiology , Image Processing, Computer-Assisted , Stomach/embryology , Humans , Rotation
18.
J Anat ; 188 ( Pt 2): 395-401, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8621339

ABSTRACT

Morphometric data concerning human embryos and fetuses have become more clinically informative since ultrasound was employed to make prenatal measurements and software preprocessing techniques improved the previous fuzzy ultrasound signals (Mahoney, 1992). The aim of this study was to determine the volume of the human stomach during the embryonic period and to compare its rate of growth with that during the early fetal period. To calculate gastric volume, computer imaging techniques were applied on cross sections of a graded series of human embryos (from Carnegie stage 11) and fetuses. Gastric volume increased progressively, except for a decrease between stages 12 and 13 due principally to the reduction of the right gastric wall. The growth of the left wall of the stomach was predominant over that of the right. Until stage 20 the stomach volume increased due to the predominant growth of the walls, after this stage the gastric cavity volume increased rapidly, and the rate of growth of the gastric volume reached similar values to that of the early fetal period. We concluded that in the beginning the human stomach grows due to the predominant growth of its walls, chiefly of the left, and from stage 20 because of the predominant expansion of its cavity, which may be related to the capacity to swallow amniotic fluid at the end of the embryonic period. The diminution of the right gastric wall volume (stages 12-13) is consistent with an extension of the omental bursa into the mesodermal anlage of the stomach.


Subject(s)
Embryonic and Fetal Development/physiology , Image Processing, Computer-Assisted , Stomach/embryology , Female , Humans , Pregnancy , Pregnancy Trimester, First , Pregnancy Trimester, Second , Stomach/anatomy & histology
19.
Ann Anat ; 176(4): 319-21, 1994 Aug.
Article in English | MEDLINE | ID: mdl-8085653

ABSTRACT

We report a new muscular variation in humans. It consisted of a biceps brachii muscle attached to the extensor carpi radialis brevis muscle by means of an accessory fasciculus. It was a trapezoid tendinous connection band that arose from the terminal tendon of the biceps brachii muscle and ended in the internal margin of the extensor carpi radialis brevis muscle. This intermuscular connection band was the external slip of the insertion tendon of the biceps brachii muscle, which was also attached by means of two other fascicles to the radial tuberosity (intermediate slip) and the flexor digitorum superficialis muscle (internal slip). This variation was observed in only one of the sixty upper limbs examined.


Subject(s)
Muscles/anatomy & histology , Adult , Aged , Arm , Cadaver , Humans , Male , Muscles/abnormalities , Tendons/anatomy & histology
20.
Ann Anat ; 176(3): 223-7, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8059965

ABSTRACT

The purpose of this study is to determine the incidence of the accessory fasciculi of the pronator teres muscle and to evaluate the predispositional role of its morphological characteristics to median nerve entrapment. The accessory fasciculi of the pronator teres muscle have been found in 8.3% of 60 upper extremities which were studied. These fasciculi arose from the tendon of the brachialis muscle (5.0%), from the radial tendon of the biceps brachii muscle (3.3%), from the Gantzer's muscle (1.6%) or from the flexor digitorum superficialis muscle (1.6%). They were slips of origin of the deep head of the pronator teres muscle. They represented the deep head, when there was no other origin slip, or they were additional origin slips when the deep head also had a coronoid origin. Only the accessory fasciculi that represented the deep head and the accessory fasciculi located inside to the coronoid fasciculus were related directly to the median nerve. Three characteristics of these accessory fasciculi adjacent to the median nerve could be considered to be factors that predispose to the nerve entrapment: 1) the location dorsal to the superficial head of the pronator teres muscle, because it increases the area of contact with the median nerve; 2) the location between the superficial head and the coronoid fasciculus, because it reduces the space occupied by the median nerve; and 3) the tendinous nature of considerable segments of short accessory fasciculi because they are less extensible.


Subject(s)
Median Nerve/anatomy & histology , Muscles/anatomy & histology , Tendons/anatomy & histology , Cadaver , Forearm , Humans , Muscles/innervation , Tendons/innervation
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