The frog, with two distinct ventilatory acts, provides a useful model to investigate the prospective interaction of two oscillators in generating the respiratory rhythm. Building on evidence ...supporting the existence of separate oscillators generating buccal and lung ventilation, we have attempted to uncouple the two rhythms in the isolated brain stem preparation. Opioid preferentially inhibits the lung rhythm, suggesting an uncoupling of the lung from the buccal oscillator. Reduction of the superfusate chloride concentration alters both the buccal and the lung rhythms. Joint application of opioid and reduced‐chloride superfusate leads to an increase in the variability of the buccal burst–to–lung burst intervals. This increase in variability suggests that chloride‐mediated mechanisms are involved in coupling the buccal oscillator to the lung oscillator. Given the results from these interventions, we propose a simple schematic model of the frog respiratory rhythm generator, outlining the coupling of the lung and buccal oscillators.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper discusses the Glasgow School of Art in the context of the wider history of the Victorian art school as a distinctive building type. It explores the precedents for the school in Manchester, ...Birmingham, and London, and reveals that its design was informed by predominantly environmental considerations. The internal spaces of Victorian art schools display an unprecedented qualitative concern for the provision of light in the context of the soot-laden skies of the industrial city. The Glasgow School of Art was also equipped with a mechanical plenum system that provided clean and tempered air in variable quantities to the different spaces of the building. The innovativeness of this system has been widely disputed — this paper aims to cast light on its precedents and situate its significance in the wider history of the development of building servicing. This includes discussion of a contemporary report detailing the engineers' commissioning of the building in 1910, as well as a recent study undertaken to evaluate the environmental management of the school today. The paper demonstrates that the Glasgow School of Art represents a key milestone in the development of our modern conception of the internal environment of large buildings, brought about in response to the atmospheric degradation of the industrial city. The sophisticated integration of the environmental qualities of the Arts and Crafts movement with thoroughly modern servicing technology is indicative not only of Mackintosh's principle of 'total design', but also of the architectural possibilities inherent in the construction of a particularly specialised building type in a specific time and place.
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The aim of this study was to determine the herd prevalence of veal and dairy herds and to identify risk factors for VTEC O157 positive veal herds. The study was based on monitoring data from November ...1996 through July 2005 of 1051 dairy herds and 930 veal herds. The herd level prevalence (95% CI) was 8.0% (6.4–9.6) for dairy herds and 12.6% (10.5–14.7) for veal herds. Within the population of veal herds, a prevalence of 39.8% (33.9–45.6) was found for pink veal herds (
n
=
269) and 1.5% (0.7–2.8) for white veal herds (
n
=
661).
Multivariable logistic regression showed that the type of veal (pink
vs. white; OR
=
21.6; 95% CI: 10.4–45.0), ventilation (mechanical
vs. natural; OR
=
0.4; 95% CI: 0.2–0.8), time between arrival in the herd and sampling (3–5 months
vs. 0–2 months: OR
=
2.33; 95% CI: 1.1–5.1, ≥6 months
vs. 0–2 months: OR
=
4.11; CI: 1.9–8.9), other feed than the 7 most common (yes
vs. no; OR
=
2.1; 95% CI: 1.2–3.7) and at least one dog present in the stable (yes
vs. no; OR
=
2.6; 95% CI: 1.5–4.6) were significantly (
P
<
0.05) associated with the presence of VTEC O157. The large difference in the VTEC O157 prevalences for pink veal and white veal production might have been caused by a very different management of these type of herds. However, this could not be studied with the data collected.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
abstract Objectives: To identify the number and current location of children, aged 0 to 16 years, requiring long term ventilation in the United Kingdom, and to establish their underlying diagnoses ...and ventilatory needs. Design: Postal questionnaires sent to consultant respiratory paediatricians and all lead clinicians of intensive care and special care baby units in the United Kingdom. Subjects: All children in the United Kingdom who, when medically stable, continueto need a mechanical aid for breathing. Results: 141 children requiring long term ventilation were identified from the initial questionnaire. Detailed information was then obtained on 136 children from 30 units. Thirty three children (24%) required continuous positive pressure ventilation by tracheostomy over 24 hours, and 103 received ventilation when asleep by a non-invasive mask (n=62; 46%), tracheostomy (n=32; 24%), or negative pressure ventilation (n=9; 7%). Underlying conditions included neuromuscular disease (n=62; 46%), congenital central hypoventilation syndrome (n=18; 13%), spinal injury (n=16; 12%), craniofacial syndromes (n=9; 7%), bronchopulmonary dysplasia (n=6; 4%), and others (n=25; 18%). 93 children were cared for at home. 43 children remained in hospital because of home circumstances, inadequate funding, or lack of provision of home carers. 96 children were of school age and 43 were attending mainstream school. Conclusions: A significant increase in the number of children requiring long term ventilation in the United Kingdom has occurred over the past decade. Contributing factors include improved technology, developments in paediatric non-invasive ventilatory support, and a change in attitude towards home care. Successful discharge home and return to school is occurring even for severely disabled patients. Funding and home carers are common obstacles to discharge.
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While a number of studies have addressed the economic cost associated with adverse health and productivity effects of poor indoor air quality (IAQ), few have addressed the value of economic ...expenditures and job creation associated with this industry. This article estimates that the annual sale of IAQ products and services is valued at $18–$30 billion and is associated with approximately 150,000–250,000 current jobs. Compared with other familiar industries, the IAQ market remains relatively small. Given the close association between good IAQ and both job performance of adults and learning performance of children, however, the expenditure to maintain good IAQ in commercial and educational facilities is a useful complement to programs designed to improve education and economic growth.
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BFBNIB, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The cooling efficiency
η
c
of wet pad and fan systems, which is currently used for fogging systems, is defined assuming that the dry bulb temperature in the greenhouse
T
db
,
i
is lower than the ...outside dry bulb temperature
T
db
,
o
and is measured directly at the outlet of the wet pad. However, in the case of
η
c
of a fogging system,
T
db
,
i
is typically measured at different locations in the greenhouse to obtain an average value. The inside air is sensibly heated mainly by solar energy transmitted into the greenhouse under sunny summer conditions. Then
T
db
,
i
is often higher than
T
db
,
o
, giving negative values of
η
c
. Even though,
T
db
,
i
is lower than
T
db
,
o
, the current definition of
η
c
gives unrealistic values due to the latent heat added to the inside air.
In this study,
η
c
of a fogging system was newly defined, taking into consideration the sensible and latent heat added to the greenhouse air. The definition is based on the energy and mass (water vapour) balance of the un-cooled air in the greenhouse during the operation of fogging. The value of
η
c
was determined for an experimental greenhouse with a floor area of 26
m
2 and contained 150 potted tomato plants. The greenhouse was cooled intermittently at a fogging rate of 10
g
s
−1 for three different fogging times of 30, 60 and 90
s with interval times of 90, 180 and 270
s, respectively. The results showed that a fogging cycle of 60
s on, 180
s off provided a relatively higher value of
η
c
than other cycles. Under this condition, two approximate expressions of
η
c
could be used to estimate the
η
c
value with an error less than ±5%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
An increasing number of rodents are housed in individually ventilated cage (IVC) systems, as these seem to be very effective for the protection of animals against infections, as well as protecting ...the staff against allergens. For the IVC systems to be properly ventilated, a huge amount of air has to be blown into the cage, which may cause a draught at animal level inside the cage. The aim of the present study was to evaluate the preferences of mice for differing levels of air speeds and air changes inside the cage. It has been concluded that mice do react to draughts, whereas they do not seem to be affected by a high number of air changes delivered without draught, which underlines the importance of applying draught-free IVC systems for mice.
The years 1960-1990 saw an extensive construction of apartment buildings in Estonia. In 1970s the specific heat consumption of apartment buildings made up about 350 kWh/m(2) per year. The 1990s saw ...the beginning of the renovation of heat substations, heating and ventilation systems and building envelopes. The renovation of windows in old apartment buildings was accompanied by problems in the indoor climate. The problem of indoor climate seriously concerns educational buildings without mechanical ventilation and partly renovated old apartment buildings. With the help of simulation programs energy conservation achievable with renovation has been analysed in apartment buildings as well as in educational buildings. Characterised is the influence of the new domestic hot water (DHW) calculation method on the determination on the equipment of heat substations and district heating network. The increase of energy efficiency of buildings by heat recovery of heat of exhaust air by heat pump is analyzed. In old apartment buildings one of the possible solutions is the air change arrangement by room heat recovery units and programmable exhaust ventilators in toilets, bathrooms and kitchens.
Analysis of the emergency operation modes of tunnel ventilation systems used in subways has shown that these modes do not provide the steady gas-air flows in case of fire in the rolling stock and its ...stop in the tunnel; and there is no methodological support for calculations of stability of gas-air flows in tunnel fires. The existing technology for assessing the stability of ventilation flows applied in coal mines and road tunnels can not account for the peculiarities of fires in subways.
Аналіз аварійних режимів роботи систем тунельної вентиляції, що застосовуються в метрополітенах показав, що вони не забезпечують сталий рух газоповітряних потоків при пожежі в рухомому складі та його зупинці в тунелі, а також відсутнє методичне забезпечення розрахунків стійкості газоповітряних потоків при пожежах в тунелях. Існуюча технологія оцінки стійкості вентиляційних потоків, що застосовується на вугільних шахтах і в автодорожніх тунелях не дозволяє врахувати особливості пожеж в метрополітенах.
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