Airway changes in patients with unilateral cleft lip/palate (UCL/P) after maxillary advancement.

Objectives: To assess the effect on the retropalatal airway (RPA), retroglossal airway (RGA), and total airway (TA) volumes and cephalometrics (SNA, SNB, ANB, PP-SN, Occl-SN, N-A, A-TVL, B-TVL) after maxillary advancement orthognathic surgery in patients with unilateral cleft lip/palate (UCL/P) using cone-beam computed tomography (CBCT).

Materials And Methods: The CBCT scans of 30 patients (13 males and 17 females, 17-20 years old) with UCL/P were evaluated at two time points: preoperative (T1) and postoperative (T2). The interval between T1 and T2 ranged from 9-14 weeks, except for two patients in whom the interval was 24 weeks.

Photosynthetic down-regulation over long-term CO enrichment in leaves of sour orange (Citrus aurantium) trees.

•  Understanding how trees are affected by a long-term increase in atmospheric CO is crucial to understanding the future impact of global climate change. Measurements of photosynthetic characteristics were made in sour orange trees (Citrus aurantium) growing under an enhanced CO atmosphere and N-replete soil for 14 yr to determine whether photosynthetic down-regulation had occurred. •  Photosynthesis, A : C gas exchange relationships and Rubisco activity and content were measured throughout the 14th year of the experiment.

The effect of long-term atmospheric CO2 enrichment on the intrinsic water-use efficiency of sour orange trees.

Every two months of 1992, as well as on three occasions in 1994-1995, we obtained leaf samples together with samples of surrounding air from eight well-watered and fertilized sour orange (Citrus aurantium L.) trees that were growing out-of-doors at Phoenix, Arizona, USA. These trees had been planted in the ground as small seedlings in July of 1987 and enclosed in pairs by four clear-plastic-wall open-top chambers of which two have been continuously maintained since November of that year at a CO2 concentration of 400 micromol mol(-1) and two have been maintained at 700 micromol mol(-1).

Effects of atmospheric CO(2) enrichment on plant constituents related to animal and human health.

Atmospheric CO(2) enrichment is known to significantly enhance the growth and development of nearly all plants, implying a potential for elevated levels of CO(2) to alter the concentrations of plant constituents related to animal and human health. Our review of this subject indicates that increases in the air's CO(2) content typically lead to reductions in the nitrogen and protein concentrations of animal-sustaining forage and human-sustaining cereal grains when soil nitrogen levels are sub-optimal. When plants are supplied with all the nitrogen they can use, however, no such reductions are observed.

Effects of atmospheric CO2 enrichment on the growth and development of Hymenocallis littoralis (Amaryllidaceae) and the concentrations of several antineoplastic and antiviral constituents of its bulbs.

Two 2-yr crops of tropical spider lily (Hymenocallis littoralis) plants were grown in field soil in clear-plastic-wall open-top enclosures in the Sonoran Desert environment of central Arizona. Half of the plants were exposed to ambient air of 400 ppm atmospheric CO(2) concentration and half of them were exposed to air of 700 ppm CO(2). This 75% increase in the air's CO(2) content resulted in a 48% increase in aboveground plant biomass and a 56% increase in belowground (bulb) biomass.

Effects of Atmospheric CO(2) Enrichment on Photosynthesis, Respiration, and Growth of Sour Orange Trees.

Numerous net photosynthetic and dark respiratory measurements were made over a period of 4 years on leaves of 24 sour orange (Citrus aurantium) trees; 8 of them growing in ambient air at a mean CO(2) concentration of 400 microliters per liter, and 16 growing in air enriched with CO(2) to concentrations approaching 1000 microliters per liter. Over this CO(2) concentration range, net photosynthesis increased linearly with CO(2) by more than 200%, whereas dark respiration decreased linearly to only 20% of its initial value. These results, together with those of a comprehensive fine-root biomass determination and two independent aboveground trunk and branch volume inventories, suggest that a doubling of the air's current mean CO(2) concentration of 360 microliters per liter would enhance the growth of the trees by a factor of 3.

Downward Regulation of Photosynthesis and Growth at High CO(2) Levels : No Evidence for Either Phenomenon in Three-Year Study of Sour Orange Trees.

Numerous photosynthesis and growth measurements of sour orange (Citrus aurantium L.) trees maintained in ambient air and air enriched with an extra 300 microliters per liter of CO(2) have revealed the CO(2)-enriched trees to have consistently sequestered approximately 2.8 times more carbon than the control trees over a period of three full years.

Three Phases of Plant Response to Atmospheric CO(2) Enrichment.

Several years of research on seven different plants (five terrestrial and two aquatic species) suggest that the beneficial effects of atmospheric CO(2) enrichment may be divided into three distinct growth response phases. First is a well-watered optimum-growth-rate phase where a 300 parts per million increase in the CO(2) content of the air generally increases plant productivity by approximately 30%. Next comes a nonlethal water-stressed phase where the same increase in atmospheric CO(2) is more than half again as effective in increasing plant productivity.

Growth Response of a Succulent Plant, Agave vilmoriniana, to Elevated CO(2).

Large (about 200 grams dry weight) and small (about 5 grams dry weight) specimens of the leaf succulent Agave vilmoriniana Berger were grown outdoors at Phoenix, Arizona. Potted plants were maintained in open-top chambers constructed with clear, plastic wall material. Four CO(2) concentrations of 350, 560, 675, and 885 microliters per liter were used during two growth periods and two water treatments.

Plant stress detection by remote measurement of fluorescence.

Chlorophyll fluorescence of mature lemon trees was measured with a Fraunhofer line discriminator (FLD). An increase in fluorescence was correlated with plant water stress as measured by stomatal resistance and twig water potential.

Complexities of nadir-looking radiometric temperature measurements of plant canopies.

Effective radiant temperatures (ERTs) of five wheat canopies in different stages of development were measured during morning and noon periods. The observed variability in nadir sensor response was quantitatively described as a function of canopy structure and the vertical temperature profile of canopy components. In many cases, the nadir sensor ERT was a poor measure of vegetation temperature due to effects of soil emissions.

The Climatological Significance of a Doubling of Earth's Atmospheric Carbon Dioxide Concentration.

The mean global increase in thermal radiation received at the surface of the earth as a consequence of a doubling of the atmospheric carbon dioxide content is calculated to be 2.28 watts per square meter. Multiplying this forcing function by the atmosphere's surface air temperature response function, which has recently been determined by three independent experimental analyses to have a mean global value of 0.

Plant canopy information extraction from composite scene reflectance of row crops.

As an aid in the interpretation of remotely sensed data from row crops with incomplete canopies, a model was developed that allowed the calculation of the fractions of sunlit soil, shaded soil, sunlit vegetation, and shaded vegetation for each resolution element in a scan of a remote sensor for a given set of conditions (plant cover, plant height/width ratio, row spacing, row orientation, time of day, day of year, latitude, and size of resolution element). Using measured representative reflectances of the four surfaces, composite reflectances were calculated as a function of view angle. Also, representative temperatures for each surface were used to simulate composite temperatures viewed by an IR scanner.

Remote detection of biological stresses in plants with infrared thermometry.

Green leaves of mature sugar beets infected with Pythium aphanidermatum and cotton infected with Phymatotrichum omnivorum had midday radiant leaf temperatures 3 degrees to 5 degrees warmer than adjacent plants with no sign of disease. The temperature difference persisted under varying conditions of soil moisture and could be used to detect biological stress imposed by these soilborne root-rotting fungi.

Remote-sensing of crop yields.

Our research efforts with durum wheat have led to the development of the SDD concept. Its application makes possible crop yield estimates from remotely acquired canopy temperatures and auxiliary air temperature measurements obtained during the period from head emergence to the cessation of head growth. Canopy albedo measurements appear adequate to delineate this critical period, making the technique potentially adaptable to predictions of crop yields by remote-sensing.

Estimating evaporation: a technique adaptable to remote sensing.

A procedure is presented for calculating 24-hour totals of evaporation from wet and drying soils. Its application requires a knowledge of the daily solar radiation and the maximum and minimum air temperatures (standard Weather Service measurements), moist surface albedo (readily estimated or obtainable from a one-time measurement), and maximum and minimum surface temperatures (obtainable from surface or airborne sensors). Tests of the technique on a bare field of Avondale loam at Phoenix, Arizona, have shown it to be independent of season.

Light and assimilation number in a small desert, recharged-groundwater pond.

Measurements of irradiance, chlorophyll a concentration, respiration, and net and gross photosynthesis were carried out in a small desert pond containing recharged-groundwater from the Flushing Meadows water reclamation project at Phoenix, Arizona. Over the 6-month period May-October, chl. a concentration averaged 119 mg m; and gross primary productivity in terms of the mean daily carbon fixation rate was 8.

An analytical study of three characteristic forms of light-forced primary production in aquatic ecosystems.

Primary production in aquatic ecosystems is largely a function of irradiance, with photosynthetic response to light ranging from "light saturation" through "asymptotic inhibition" to "complete inhibition". Equations describing these three basic types of response have been solved to yield instantaneous integral photosynthesis as a function of irradiance, chlorophyll a concentration, light extinction coefficient, and photosynthetic capacity of the phytoplankton at optimum irradiance. These results were used to calculate diurnal trends of instantaneous integral photosynthesis for several different latitudes and seasons and finally day-rate integrals of photosynthesis as a function of time of year at several latitudes.

Thermal blanketing: a case for aerosol-induced climatic alteration.

Long-term temperature records at Phoenix, Arizona, indicate the existence of a post-1946 warming trend that may be attributed to the buildup of pollution in the lower layers of the atmosphere. The causative mechanism appears to be an enhancement of the so-called "greenhouse effect," induced by the inter-action of aerosol with long-wavelength thermal radiation in the lower atmosphere.