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Results for “Environment, Controlled”

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PubMed1966

A system for measuring penetration of radioactive ions across roots of intact plants.

A technique was developed for estimating penetration of P(32) across roots of intact plants (Phaseolus vulgaris) by measuring the level of isotope in the xylem stream. Penetration was defined as movement from the root surface to the xylem sap. The xylem sap measurement for P(32) was made in the stem as the material ascended the plant in the transpiration stream. Stems were held near 0 degrees to arrest metabolic concentration of isotope adjacent to the xylem column. A 3 layer environment control system was constructed to allow stem chilling in a manner that would not interfere with the environments of the roots or foliage. Despite these precautions, some extra-xylary build-up of (32)P occurred in the chilled stem. The mathematical function of the extra-xylary fraction was derived, and the difference between this value and total P(32) in the stem represented xylem sap isotope.

Journal Article↗

PubMed2005

Differential regulation of proopiomelanocortin (POMC) mRNA expression in hypothalamus and anterior pituitary following repeated cyanamide with ethanol administration.

BACKGROUND/AIM: We have investigated proopiomelanocortin (POMC) mRNA expression in the arcuate nucleus of the hypothalamus (ARC) and the anterior lobe of the pituitary (AL) following repeated cyanamide-ethanol reaction (CER). METHODS: Adult male Sprague-Dawley rats (250-290 gr) were housed in a temperature and humidity controlled environment with free access to food and water. Four experimental groups were used as follows: saline (as control), cyanamide alone, ethanol alone and ethanol with cyanamide. The animals recived daily intraperitoneal injections (i.p.) of cyanamide (10 mg/kg, 60 min before ethanol dosing) with or without ethanol (1g/kg) for 5 consecutive days, and were sacrificed 60 min after the last dosing of ethanol. The results were presented as the mean +/- SEM for each group. All groups within each deta set were compared by one-way ANOVA followed by Fisher PLSD test for multiple comparisons. A value of p < 0.05 was considered significant. RESULTS: The POMC mRNA levels in ARC were significantly decreased with cyanamide compared to the control and ethanol alone (p < 0.05 and p < 0.05 respectively), but increased in AL following repeated CER. CONCLUSION: We speculate that this differential regulation of POMC mRNA expression may be partially involved in the preventive effects on alcohol intake in response to CER.

Animals↗

PubMed2006

A risk assessment approach applied to the growth of Erwinia carotovora in vegetable juice for variable temperature conditions.

Risk assessment for food spoilage relies on probabilistic models of microbial growth to predict the likelihood that microbial populations will exceed predefined spoilage levels. To assist in the design and management of industrial food quality systems, predictive microbiological models have to incorporate major risk factors such as the variability in the microbial strain, environment and initial contamination levels. In addition, the application of results measured under laboratory conditions to the less controlled environment of an industrial process usually also involves uncertainty. Extra information regarding this uncertainty must be factored into industrial microbial risk assessment. In this paper, based on our previous analysis of the growth of Erwinia carotovora we show how different factors contribute to the risk of microbial spoilage of vegetable juice and we demonstrate an effective way of including these factors into risk assessment models. The association of risk components with different unavoidable and manageable factors is also valuable for the development of optimal strategies for reducing microbial risk.

Beverages↗

PubMed2003

Fracture of plant tissues and walls as visualized by environmental scanning electron microscopy.

The environmental scanning electron microscope (ESEM) provides a highly relevant and controllable environment in which to study hydrated systems without the artefacts of other highly prepared specimens. The instrument facilitates control of turgor through hydration using different chamber vapour pressures. Deformation of a simple plant tissue-upper epidermal layers in Allium cepa (onion)-was observed at the scale of the two principal failure mechanisms: cell breakage; and cell separation induced by treatment with a chelating agent. Cell rupture and release of contents occurred at cellular junctions ahead of an imposed growing notch, indicating that disruption of cells occurred remotely from the creation of a new surface. Cells that separated usually maintained their turgor and the separation process took place through progressive failure of middle lamellar material seen as strands between separating cells. These mechanisms were compared with the rupture of excised Chara corallina walls that occurred by formation and breakage of strands between separating wall layers. This study provides in situ visual characterization of wall rupture and cell separation at the microscopic level in hydrated plant material.

Cell Wall↗

PubMed2003

Environmental mycological study and respiratory disease investigation in fur-processing workers.

This paper presents the results of an investigation of respiratory symptoms, chest X-ray examinations, and analysis of antibodies to fungi of 138 fur-processing workers and 40 control workers. Industrial hygiene survey and environmental mycological studies were also conducted. The dust concentrations in fur processing workshops (1.8-6.7 mg/m3) were below the national health limit (10 mg/m3). Most dusts in all fur processing workshops contained less than 2.0% silica. Numbers of isolated fungi in fur processing workshops [629-3,681 cfu/m3 (colony forming unit/m3)] were significantly higher than those in control environments (63-503 cfu/m3). The prevalences of respiratory symptoms in fur processing workers were higher than those in control workers, especially among female exposed workers. The prevalences of the symptoms in female exposed workers were 37.9% with chronic cough, 28.4% with chronic phlegm, 10.5% with dyspnea, 22.1% with chest tightness, and 4.2% with fever. Seven cases showed abnormalities in chest X-ray examinations. The OD450nm values for antibodies to fungi in fur processing workers were significantly higher than those in control workers (P<0.05). The prevalences of positive anti-fungi antibodies in fur-processing workers were also significantly higher than those in control workers (p<0.01). The results suggested that fungi might be one of the main allergens in respiratory diseases in fur processing workers.

Adult↗

PubMed1989

"Back" to basics.

Most back-related injuries can be tied to poor posture, lack of physical conditioning, stress, and other environmental factors. Many back-injury prevention strategies focus on improving these areas, plus instructing on proper posture, body mechanics, and lifting techniques. For these techniques to be practical and useful, they must be taught through demonstration and practice in a controlled environment. The benefits of a back-injury prevention program include feeling more physically fit, balanced, and in control. Training will improve performance at work and home, and can also be used to protect family members from these common, devastating injuries.

Allied Health Personnel↗

PubMed1992

Environmental control.

Environmental control measures help eliminate triggers that initiate the allergic reaction and reduce the conditions that sustain it. The most frequent offenders are the ubiquitous dust mites, which are ideally suited to living in the home environment. Control measures consist of minimizing their reservoirs in the patient's bedding, carpets, and upholstered furniture; decreasing humidity; and using acaricides. Cats are the source of another important indoor allergen that becomes and stays airborne as small particles. Removal of the animal (or washing it weekly) and the use of high-efficiency particulate air filters for air ducts and vacuum cleaners are useful in reducing dust mite and cat allergens. Dogs and rodents also produce allergens offensive to the sensitized patient and should be removed or relegated outdoors. Cockroaches have become an increasingly prevalent source of allergens responsible for asthma and rhinitis. Their removal is the focus of research, because current control measures are usually inadequate. Molds, which thrive in any moist environment, produce allergens. Closed windows prevent further influx of outdoor molds and pollens, whereas those harbored indoors, including those residing on plants, should be eliminated.

Allergens↗

PubMed2004

[Dental offices and environment quality].

AIM: The aim of this study was to survey, from a microbiological point of view, dental unit water, air and surface quality in public dental offices and in control environments in Milan. METHODS: We studied tap and dental unit water (from fountain, air-water syringe, turbine), at the beginning and at the end of monday and thursday morning activity; air quality with surface air system (SAS) in dental and control offices; handpieces holder, fountain block, arm of the light, dental trolley, inner and outer walls surfaces quality. RESULTS: Water from the dental unit waterline shows average exceeding the law limits 2-3 fold for total bacteriological counts at 37 degrees and 22 degrees, in all examined points, at the beginning of the working day. There is an improvement in the water contamination at the end of the activity. Pseudomonas aeruginosa is frequently found, total and fecal coliforms are absent, while Legionella pneumophila was found only in one control. Air and surfaces quality is quite good, especially in places with ventilation systems in function. CONCLUSION: Dental unit water is the most critical point among those monitored. Water quality has to be improved with specific projects.

Air Microbiology↗

PubMed1982

Incidence of Salmonella in fresh dressed turkeys raised under Salmonella-controlled and uncontrolled environments.

The incidence of salmonella in turkeys from experimental salmonella-controlled and uncontrolled, or normal, flocks processed at three turkey slaughter plants were compared. The results indicate that processing salmonella-controlled turkeys in a plant that routinely kills normal birds may result in the contamination of the salmonella-controlled birds, probably due to salmonella in the plant environment. The salmonella-controlled turkeys studied tended to have a lower incidence of salmonella than normal birds. These observation indicate that salmonella control practices in turkey raising can result in a salmonella reduction in market birds even under existing commercial slaughter, evisceration, and cooling procedures.

Abattoirs↗

PubMed1991

Phenotypic changes in T-cyt-transformed potato plants are consistent with enhanced sensitivity of specific cell types to normal regulation by root-derived cytokinin.

From over forty independently isolated potato lines transformed with wild-type and promoter-mutated T-cyt genes, a number of lines were selected for examination of phenotypic changes in growth and development for plants grown in soil in a controlled environment. The three lines chosen for most detailed examination showed a wide spectrum of phenotypic changes. In comparisons with control potato cv. Désirée, the plants of one line had a two- to three-fold increase in biomass production during early vegetative growth, advanced senescence and a shortened plant life-span. Another line showed abnormal cellulytic senescence. In two lines there were increases in tuber numbers and more skewed tuber size distributions which correlated with reduced shoot apical dominance and shortened dormancy of the stored tubers. None of the lines showed altered timing of onset of tuberization or flowering, although tuberization was consistently delayed when expressed as a function of increasing total plant weight. A hypothesis is proposed to explain the diverse phenotypes which postulates that (1) T-cyt transformation causes enhanced sensitivity to cytokinins in specific types of shoot cells which are already targets for regulation by normal root-derived cytokinins; (2) two distinct types of shoot target cells are present, one in shoot meristems and one in leaves; (3) the two types can acquire enhanced sensitivity, either separately or in combination depending on the particular T-cyt transformation event. The scope for using the transformed plants in subsequent physiological, biochemical and molecular studies, aimed at examining the molecular basis of the model or selected consequences of T-cyt transformation in altering regulation of potato plant growth and development, is discussed. The attention is drawn to the possible involvement at the subcellular level of sucrose phosphate synthase in mediating the phenotypic effects caused by T-cyt transformation.

Adaptation, Physiological↗

PubMed1985

Seasonal effects on ovarian folliculogenesis in rhesus monkeys.

Reproductive performance is reportedly reduced in some rhesus monkeys during the summer months, even when environmental conditions are controlled. The mechanism(s) underlying this phenomenon remain unknown. We noted that the pattern of folliculogenesis appeared to be altered in rhesus monkeys that continued to exhibit ovulatory menstrual cycles during the "nonbreeding" season. This study was designed to investigate the effect of season on development of the dominant follicle (DF) and upon levels of serum gonadotropins and sex steroids in animals maintained in a controlled environment. Forty-four menstrual cycles were evaluated from October, 1982 to October, 1983. Animals were housed individually in controlled light (12L:12D) and temperature (22-25 degrees C). A DF was identified by laparoscopy on Day 6 of the cycle in only 45% of cycles during the months of May through September, compared with 87.5% the remainder of the year. No effect of season was detected on either the length of the menstrual cycle or luteal phase, mean follicular diameter, or the percentage of ovulatory cycles. During the follicular phase, amounts of follicle-stimulating hormone (FSH) in peripheral sera were depressed, whereas those of luteinizing hormone (LH) were consistently elevated. Amounts of circulating estradiol were similar between groups. However, serum concentrations of progesterone were markedly reduced in the summer. Development of the DF appeared to be delayed in the early follicular phase during the summer months in those rhesus monkeys that had ovulatory menstrual cycles. This delay was accompanied by an alteration in the FSH to LH ratio. Although most cycles were ovulatory, altered follicular development resulted in deficient luteal function.

Animals↗

PubMed1986

Closed-circuit metabolic system with multiple applications.

A closed-circuit metabolic system has been designed and tested for multiple applications. Air pressure within a closed chamber is regulated electronically while allowing for respiratory gas exchange. Compared with a previously reported standard indirect calorimetry system, the new device had by virtue of longer duration of measurement improved precision (coefficient of variation 3% vs. 14%) during studies of O2 consumption both at room temperature and at 5 degrees C. In addition, a more physiological atmospheric environment is maintained. This system has also been utilized for simultaneously labeling groups of up to 20 weanling rats with 18O2 over a 2-day period and for exposure of rats to a hyperoxic (84% O2), normobaric environment for 4-day periods. Potential applications include maintenance of pressure (hypobaric through hyperbaric) and O2 (hypoxic through hyperoxic) controlled environments, exposure to toxic gases, study of diurnal variations in metabolic rate, measurement of metabolic expenditure with activity, and adaptation to other species including humans.

Animals↗

PubMed2003

Embryogenesis and swimming behavior of Medaka fish in JUSTSAP STARS Program (STS-107).

JUSTSAP (Japan-US Science, Technology and Space Application Program) Medaka fish experiment was carried out as a part of STARS (Space Technology and Research for Student) experiment, a space shuttle mission, STS-107 in January 2003. Four eggs laid on earth under artificially controlled environment were put in a closed ecological system, AHAB (Aquatic Habitat), and launched by Space Shuttle Columbia. For the control experiment, four eggs were put in the AHAB and remained on the ground. There was no remarkable difference in the time course of the development. In ground experiment embryos were observed to rotate in the egg membrane, whereas in flight unit they did not rotate. One egg hatched out on L (Launch) +8 days in flight unit. Four eggs hatched out in ground unit. Fry in flight unit was observed to face its back usually to the camera with little swimming movement. Fry in ground unit were observed to move actively and also to control their posture with respect to gravity vector.

Animals↗

PubMed1997

Skin derivative control of thermal environment in a closed incubator.

Defining a thermoneutral environment remains difficult because thermoneutrality depends on both physical and physiological factors. A servocontrolled skin temperature derivative (SCS) heating device has been designed to control the thermal environment in closed incubators without the necessity of setting an air or skin reference temperature. The thermal environment obtained with the SCS program is controlled only by the neonate's skin temperature changes. For each neonate, the program allows the attainment of a specific individual thermal equilibrium (Teq). Although the mean value of the thermal equilibrium level measured on 29 neonates does not differ significantly from the neutral air temperature defined from the charts of other researchers, individual values of Teq differed greatly among neonates of similar birthweight and postnatal age. When compared with on/off heating programs, the SCS system permits greater quiet sleep occurrence and seems to provide an optimal thermal environment. The results suggest that the skin temperature derivative heating program takes into account both the ambient and physiological factors affecting body temperature regulation of each neonate.

Automation↗

PubMed2002

Spatial behaviour is driven by proximal cues even in mildly impaired Parkinson's disease.

This investigation addresses the question whether patients with mild to moderate Parkinson's disease (PD) show spatial deficits in real-life settings. Therefore, a "search through"-locomotor task incorporating basic features of both the radial arm maze and the Morris water maze paradigms was used. The participants had to find and remember five out of twenty hidden locations within a completely controlled environment. Different spatial memory errors and inter-response intervals were recorded automatically. Fourteen patients with idiopathic PD and fourteen healthy controls matched for age, sex, handedness, and education were investigated. Patients and controls were widely comparable with respect to intelligence, verbal memory, and executive functions. Results show that performance deteriorated in about half of the patients if the starting position was moved by 90 degrees and the proximal cues were deleted simultaneously. This deficit was systematically related to specific measures of attention. Moreover, patients were less able to update their locomotor strategies towards a more effective strategy. Results are discussed with respect to the patient's inability to generate rules which can be flexibly used in changing environments, especially if proximal cues are removed. It is concluded that deficits in spatial behaviour can be elicited even in near-to-real-life situations if appropriate testing procedures are used.

Adult↗

PubMed2006

The laboratory school protocol: its origin, use, and new applications.

OBJECTIVE: ADHD is the most common childhood psychiatric disorder, with impairments seen in home and academic settings. To investigate such impairments in a school-like setting, the laboratory school protocol (LSP) was developed at the University of California, Irvine. METHOD: This model provides a rigorously controlled environment to examine pharmacodynamic and pharmacokinetic aspects of responses to treatment. A key principle of this methodology is to exercise tight control of the timing and context of measurements by establishing a cycle of activities repeated across each study day. In addition, the LSP approach has been extended to both younger and older populations than the typically studied school-aged group. This extension requires corresponding modifications in measures to characterize drug efficacy and to allow evaluation of ADHD symptoms in a highly standardized setting. RESULTS: This article provides guidelines for employing the LSP for the assessment of medication effects for both preschool and adolescent/adult populations. CONCLUSION: The LSP can be modified to form either an Adult Workplace Environment or a Preschool Assessment Laboratory.

Attention Deficit Disorder with Hyperactivity↗

PubMed1987

Influence of internal sugar levels on apoplasmic retrieval of exogenous sucrose in source leaf tissue.

Sugar levels in Beta vulgaris leaves were increased by heat-girdling the petiole and returning the plant to the controlled-environment chamber for 10 and 34 hours. After 10 hours, sucrose influx into the treated leaves was similar to the controls, although sucrose levels increased from 2.1 to 5.3 micromoles per milligram chlorophyll. However, after a 34-hour treatment, sucrose levels increased from 2.1 to 11.5 micromoles per milligram chlorophyll. In this instance, sucrose influx decreased relative to the untreated controls. Decreasing sugar levels by DCMU treatment resulted in a small stimulation of sucrose influx. A similar DCMU treatment applied to leaves of Allium cepa also resulted in an increase in sucrose influx. However, in A. cepa we could not attribute this increase to a lowering of sugar levels, as the kinetic profiles obtained from control leaves did not vary from each other throughout the day, despite considerable changes in sugar levels. Additionally, it appeared that sucrose uptake in onion may be set at some point and remains invariant throughout the day. Similar studies were also conducted on discs cut from mature leaves of Spinacia oleracea var America. Between 1 and 8 hours after the onset of the photoperiod, the sucrose content of the spinach leaves increased from 2.6 to 9.3 micromoles per milligram chlorophyll. A comparison of the kinetic profiles obtained from leaf discs, taken at these times, indicated that sucrose uptake was not influenced by these changes in internal sugar levels. The relationship between the above findings and ;trans' inhibition of exogenous sucrose uptake is discussed. Although intermediate changes in sugar levels in sugar beet leaves did not appear to affect sucrose influx, autoradiographic studies revealed that these changes dramatically affected the partitioning of exogenously supplied [(14)C]sucrose. Our results indicate that while intermediate changes in internal sugar levels have little effect on sucrose influx across the plasmalemma, they may dramatically affect partitioning between the phloem and the mesophyll vacuole.

Journal Article↗

PubMed2004

Environmental mycological study and respiratory disease investigation in tussah silk processing workers.

This study presents the results of an investigation of respiratory symptoms, pulmonary function and chest X-ray examinations, and analysis of antibodies to fungi of 197 tussah silk-processing workers and 40 control workers. An industrial hygiene survey and environmental mycological studies were also conducted. The dust concentrations in tussah silk processing workshops were less than 5.1 mg/m(3) on average, with a maximum of 7.8 mg/m(3) below the national health limit of 10 mg/m(3). Most dusts in all tussah silk processing workshops contained less than 1.2% silica. Numbers of isolated fungi in tussah silk processing workshops [755-6,544 cfu/m(3) (colony forming unit/m(3)), were significantly higher than those in control environments (63-472 cfu/m(3)). The prevalences of respiratory symptoms in tussah silk processing workers were higher than those in control workers. The prevalences of respiratory symptoms in exposed male non-smoking workers were 44.4% with chronic cough, and 38.9% with chronic phlegm respectively, which were significantly higher than those (12.5%, 12.5% respectively) in male non-smoking control workers (p<0.05). The prevalences in exposed male smoking workers were 42.9% with dyspnea, and 38.1% with chest tightness respectively, which were significantly higher than those (16.7%, 8.3% respectively) in male smoking control workers (p<0.01). The prevalences of respiratory symptoms in exposed female workers were 25.3% with chronic cough, 38.0% with chronic phlegm, 31.0% with dyspnea, and 29.1% with chest tightness respectively, which were significantly higher than those (10.0%, 10.0%, 10.0%, 5.0% respectively) in female control workers (p<0.01). Fifteen exposed workers often suffered from fever. Five X-rays were abnormal and four cases had nodular or patchy shadows. The prevalences of pulmonary function abnormalities in the exposed female group were significantly higher than those in control groups (p<0.01). The OD(450 nm) values for antibodies to fungi in tussah silk processing workers were significantly higher than those of control workers (p<0.05). The positive rates of anti-fungal antibodies in tussah silk-processing workers were also significantly higher than those of control workers (p<0.01). The results suggested that fungi might be one of the main allergens in respiratory diseases in the tussah silk processing workers.

Adult↗