Search

Methane and nitrous oxide are important radiatively active gases that are influenced by agricultural practices. This study assesses long-term tillage, crop residue management, and N fertilization rates on the flux of these two gases at a high latitude site representing the northern fringe of large-scale agriculture. Cumulative methane uptake for the summer was higher from no-tillage plots than tilled plots. This was associated with lower soil water contents with tillage. Thus, the reduction in CH4 uptake was attributed to water stress on methane oxidizers. At planting, soil water contents were near field capacity, and the no-till plots had the lowest uptake which was attributed to restricted diffusion of methane to active sites. A similar pattern of methane uptake to soil water content was found with the residue management treatments. Removing the straw lowered the soil water content and for most of the season methane uptake was also lower than where the straw had been left on the plots. Nitrogen fertilizer rate had little effect on methane uptake over the summer, but high N rates lowered consumption during the time of active nitrification early in the season. This corresponded to the time of maximum efflux of nitrous oxide. Nitrous oxide efflux was greatest at the high N rate where straw was retained on the plots. Key words: Methane, nitrous oxide, nitrification, denitrification, barley

The root causes of atherosclerosis lie in cellular events that precede the clinical presentation of the disease by many years. The initiating events centre around the response of endothelial cells to chronic injury, such as that sustained in hypercholesterolemia. These responses involve the activation, attachment and migration of leucocytes and platelets.

DiDomenico and Eyrich question the definition of radiocontrast-induced nephropathy (RCIN) and whether contrast nephropathy occurred in the RAPPID study. The definition of RCIN employed (a rise in serum creatinine ≥25%) is a widely accepted one and has been used extensively [(1–4)][1].

Natural snow dendrites sometimes display symmetry of side branches along each arm, whereas on other occasions such symmetry does not occur. Laboratory studies under simulated atmospheric conditions show that a fluctuation of local airflow, equivalent to changing supersaturation, for a period of only a few seconds leads to symmetrical initiation of arms. Growth under uniform conditions does not give symmetrical arms, neither does growth in uniformly supercooled water. It is hypothesized that each side branch is initialized by a local short term fluctuation, in temperature or supersaturation; symmetrical branches form from longer period fluctuations that affect each side of an arm simultaneously. Asymmetrical arms result from local fluctuations such as the close approach of a cloud drop. Symmetry of side branches therefore suggests that the crystals have grown in an environment with a turbulence scale of several meters.

Collocation of a 5.5-cm weather radar and a 33-cm wind profiler during the Hawaiian Rainband Project of 1990 presented several opportunities to compare vertical profiles of reflectivity in the atmosphere at the two wavelengths. On three occasions the beams of both systems were pointed vertically as light rain drifted overhead. The atmospheric reflectivity structure was then dominated by rain at low altitudes but included an elevated layer at the height of the trade wind inversion. Allowing for minor uncertainties in radar sensitivity and range, we found close agreement in the patterns of reflectivity factor Z in the rain as measured by the two systems. The reflectivity factor of the inversion echo at 33 cm then exceeded that at 5.5 cm by approximately 29 dB on average, an amount predicted by the theory of scattering by spatial fluctuations in the clear-air refractive index. These observations are consistent with the assumptions that (1) the inversion echo is a clear-air echo, uncontaminated by raindrops or other Rayleigh scatterers and (2) the reflectivity of the inversion at both wavelengths is explained by Bragg scattering from refractive index fluctuations induced by mixing in the inertial subrange of homogeneous turbulence.

The Rain in Cumulus over the Ocean (RICO) field campaign carried out a wide array of educational activities, including a major first in a field project—a complete mission, including research flights, planned and executed entirely by students. This article describes the educational opportunities provided to the 24 graduate and 9 undergraduate students who participated in RICO.

Hypertrophic cardiomyopathy is a familial cardiac disorder with heterogeneous expression and a diversity of morphological, functional and clinical features. Some individuals with hypertrophic cardiomyopathy may be asymptomatic while others are disabled by symptoms of angina and breathlessness. This article summarizes the genetics, pathophysiology and present management of this important condition.

8The new Health Care Agreements for 1998?2003 are currently being negotiatedbetween the Commonwealth and State and Territory governments. TheCommonwealth?s offer aims to address the major problems associated with the currentAgreements, including cost-shifting incentives and funding rigidities.It has proposed a funding model whereby admitted and non-admitted patient servicesare funded on an output basis. Other aspects of the proposal include funding forquality enhancement and structural change, and specific funds for mental health andpalliative care. The proposal also aims to achieve a more equal sharing of risks andbenefits between the Commonwealth and the States and Territories.The views expressed are those of the authors and should not be taken as an officialview of the Department or the Minister. While the authors have had primaryresponsibility for the development of the Commonwealth model and the preparationof this paper, they wish to thank other members of the Health Care Agreements Branch(Heather Cocks, Ian Macdonald, Elaine Pringle and Shane Wright) for theirassistance.

Abstract Platelet activation state and responsiveness to physiological agonists were measured in 65 patients with documented coronary artery disease (54 male and 11 female; mean age, 58 years). Twelve patients (mean age, 52 years), selected at random from the male cohort, were compared with 12 age-matched male control subjects (mean age, 52 years) and with 10 normal, young male subjects (mean age, 25 years). Whole-blood flow cytometry was used to measure platelet activation status ex vivo and platelet responsiveness to physiological agonists in vitro. Peripheral blood samples were analyzed for bound fibrinogen and expression of P-selectin, GPIb, and GPIIb-IIIa at rest and in response to ADP (0.1 to 10 μmol/L) and thrombin (0.02 to 0.32 μ/mL). No significant differences were seen in the basal levels of fibrinogen binding between any of the groups, but P-selectin expression was significantly lower in patients compared with age-matched control subjects ( P =.0005). When stimulated with agonists, patients’ platelets had significantly decreased fibrinogen binding ( P P

The National Institute for Clinical Excellence (NICE) was set up in 1999, with the aim of creating an independent body to evaluate and recommend therapies for NHS patients. NICE examines research evidence, assesses effectiveness (likely effects on patients in the community) and takes into account efficiency (cost effectiveness) before making recommendations.

It is difficult to analyze a large, complex structure in sufficient detail to obtain accurate results everywhere. One approach to this problem is simply to refine the whole structure model in the regions of interest which is obviously costly. Another approach is to identify a subregion of the structure and develop a separate refined model of the subregion. The most recent method for subregion analysis presented in the literature[1] is called the Specified Boundary Stiffness and Force (SBSF) method. While the method is relatively straight forward and efficient, none of the commercial code vendors has yet included an implementation. This paper gives a brief review of the theory behind the method and then describes its application in two commercial finite element programs. Examples of the application of this method to the problem of a plate with a center hole in tensile loading are presented using ANSYS® and CAEDS(IDEAS)®. The results compare favorably to the theoretical value and show significant improvement in accuracy over the specified boundary displacement method implemented in ANSYS. The capability of the method is also demonstrated by transfer from a 2-D global model to a 3-D subregion model in a laminated composite plate. A laminated plate with a center hole is analyzed overall by use of a layered shell element model. A subregion around the hole is then analyzed using 3-D solid elements with nodal coupling to the layered shell elements on the subregion interface. The 3-D element model provides the well-known interlaminar stresses existing at the composite edge along the hole that are not available from the shell model.

The double stapling technique for rectal reconstruction after resection involves closing the lower rectal segment with a linear stapler and performing the anastomosis using a circular stapler across the linear staple row. The purpose of this report is to review the results of double stapling, present our experience, and draw conclusions from the material available. We have utilized the double stapling technique in 80 patients for primary anastomoses and in 11 patients for secondary anastomoses following Hartmann procedures. Twenty-one anastomoses were at or near the dentate line. Fifty-six patients had rectal carcinoma, 29 patients had diverticulitis, 3 patients had carcinoma of the ovary, and 1 patient each had traumatic rectal perforation, volvulus, or rectal prolapse. Complications in the total 91 patients included 3 anastomotic leaks (3.3%), 1 postoperative hemoperitoneum (1.1%), and 3 strictures (3.3%). No anastomosis was protected by diverting colostomy. There were no operative deaths. Of 43 patients with cancer available for follow-up, 4 patients have developed local recurrence. The technique has been modified for ileoanal anastomosis during abdominal restorative proctocolectomy for ulcerative colitis and familial polyposis and early results are favorable. The double stapling technique provides a safe method for rectal reconstruction at or near the dentate line and offers the following advantages over other stapler techniques: (1) It eliminates the frustrating distal pursestring; (2) The rectal segment is not opened, minimizing contamination; and (3) It avoids gathering the sometimes generous circumference of the rectum on a pursestring thus allowing a more precise distal donut.

T HE PROTEAN QUALITY of satire is generally recognized (e.g., Worcester 3-10). Homer's account of the capture of Proteus (Odyssey 4) suggests that to perceive the identity of satire we must begin with its disguises or formal appearances. A number of critics have noted the tendency of satire to parody or imitate other genres or literary models. Frederic Stopp finds that "traditionally satire has always borrowed its ground-plan, parasitically and by ironic inversion, from other forms of ordered expression in art or in life" (201). James W. Nichols distinguishes between parody ("an imitation and alteration or distortion of the style or structure of an original for the purpose of criticizing it") and what he calls "pattern" ("any adaptation of an original for satiric purposes when the chief purpose is not parody," 54). Nichols goes on to distinguish between patterns that imitate specific literary works, those that imitate "originals found in a number of literary works," and those that are not literary at all (59). The basic process Nichols identifies as "pattern" is described by Leon Guilhamet as "transformation." For Guilhamet, satire is essentially "a borrower of forms" (13), which it "de-forms" and transforms into "a new generic identity" by disruptive, fictive techniques (11-12). The satiric practice of imitating, parodying, and borrowing other forms is undertaken, as definers of satire agree, in the interests of attacking not only evil but the actual, historical individuals who perpetrate it. Satire becomes problematic as a genre because of the tensions between the self-consciously formal character of its medium and particular reality of its attack. If satire were merely self-referential and ahistorical, readers might well wonder why one should bother; if it were merely historical rather than formal, its issues could be resolved by libel courts rather than literary critics. The formal nature of

In June 1988, the Second International Symposium on Stapling in Surgery was held in Luxembourg. Fifty-one papers by 132 authors from 14 countries were presented. This book is a compilation of those papers. On opening this book, one senses that it is a special volume because of a picture of Mark and Irene Ravitch. This is occasioned by the death of Mark Ravitch, one of the book's editors, between the symposium and the book's publication. A tribute to Ravitch by his fellow editor, collaborator, and friend, Felicien Steichen, follows the picture and will be appreciated by Ravitch's many friends and admirers. It is fitting that the early chapters are devoted to a review of the historic aspects of mechanical sutures as recounted by Ravitch and Steichen. These chapters are a continuation of their classic contributions in this field and make fascinating reading. This book is well organized into 10 parts

The Satyricon of Petronius simultaneously fascinates and mystifies, and the difficulties of interpreting it are intensified by the fragmentary nature of its text and the uncertainties of its authorship. The identification of its author with the Petronius Arbiter described by Tacitus is an unverifiable probability. The significance and even the spelling of the title have been subject to debate. The text survives in imperfect manuscripts, most of which do not contain the Cena, others little else. There is little evidence, beyond the numbering of books in several manuscripts, the existence of a handful of quotations in later writers, and several references in the text to lost episodes, that the original work was completed in the very long form traditionally supposed.

Using quantitative analysis of time-lapse motion pictures from aircraft and a sensitive meteorological radar, the cloud top history is related to the early radar echo development in 12 vigorous, summer, convective cloud turrets in northeastern Colorado. At a threshold of about 5 dB(Z), the first echoes appear typically 5–10 min after the cloud top passes the -−20°C level. The first echo either appears at cloud top or reaches the top very quickly. It sometimes appears at a well-defined height, but sometimes nearly simultaneously over an altitude range of 3 km or more. Radar echo at 5 dB(Z) typically fills the visual cloud 5–10 min after first echo. In terms of overall cloud lifetime there is plenty of time for the particles responsible for the first echo to form by the ice process. A detailed model of the rates of ice particle formation by vapor growth followed by riming gives a 5 dB(Z) radar echo within 7–10 min at concentrations as low as 1 m−3, at most temperatures between −10 and −20°C and in ...

Duodenal duplication cysts are rare malformations that characteristically manifest with intestinal obstruction. In a 50-year experience, we found a duodenal duplication cyst in only three patients, one of whom had massive gastrointestinal bleeding as the initial symptom. Six other duplication cysts (two esophageal, one jejunal, and three ileal) were found. All patients who had extraduodenal intestinal cysts were neonates or infants who initially had an abdominal mass or obstruction. Of the two patients with an esophageal cyst, one had odynophagia and the other had respiratory obstruction. Unusual features of our series of patients were male preponderance (eight of nine patients), the low incidence of other developmental abnormalities, and, in the patients with the duodenal cysts, an age of 14 years or older at the time of onset of symptoms and diagnosis. In an adult, a duodenal duplication cyst may cause upper gastrointestinal hemorrhage. This cause of gastrointestinal bleeding should be considered in the differential diagnosis if an intramural duodenal mass is detected within the medial wall of the second portion of the duodenum distal to the papilla of Vater.

An airborne photographic system, in which the cameras are coupled with an inertial navigation system, was developed and used in a 1978 convective cloud study, Photogrammetric analysis from such a system is enhanced: cloud-feature positions can be determined without external references such as the earth's horizon or cloud base in the photographs, and the data reduction process can be considerably automated. This paper describes the instrumentation, the photogrammetric theory, and the procedures for obtaining cloud measurements from the photographs. An empirical error analysis based on photographs of terrestrial targets is also presented. Cloud top heights determined without any reference height in the photographs are considered to be accurate to within 440 m at a range of 60 km. The largest source of error in determining cloud top height using the 1978 measurements is the uncertainty in determining the aircraft-to-cloud distance rather than inaccuracy in the photographic system. This error can be ...

The range of lobe structures found in natural hailstones is illustrated and classified on the basis of form and growth conditions. Lobes that form in dry growth are cusped, and probably result from a “collection efficiency” effect, lobes growing faster than their surroundings because they collect more material. These lobes probably only form to a marked extent when a hailstone is tumbling. Lobes in wet or spongy growth, icicle lobes, are not cusped and evidently form more as icicles form, by flow of liquid water over the hailstone surfaces and preferential freezing at the tips of projections. The icicle lobes are less developed in very spongy growth than in slightly spongy growth. Distinct, radial air bubble features in hailstones are associated with the cusp-lines between the dry growth lobes. Less distinct, radial air bubble trains are found along the icicle lobe axes.

n/a

The results of two new experiments designed to determine the contact angle of water on ice are reported. In one it is shown that the first stage of melting of a clean ice surface is liquid formation at discrete sites, not uniformly over the surface as would be predicted if the contact angle were zero. The water has a downward meniscus and a sharp contact angle against the ice during both melting and freezing. In the second experiment ice discs are grown in water at approximately 0·010°C supercooling, and contacted by air bubbles on their smooth, basal faces. According to this experiment the contact angle of water on ice is zero. These contradictory results may be a result of anisotropic surface energy, or an effect of disequilibrium.

Ice growing dendritically from supercooled water along some foreign surfaces changes its orientation as it grows, in response to asymmetrical temperature gradients. A qualitative, preliminary description and discussion of this phenomenon is presented. The only stable growth is with the c axis [0001] perpendicular to the surface. Other orientations in general curve toward this. Increased initial supercooling sharpens the curvature, and dissolved NaCl inhibits it. The curvature is discussed in terms of edge dislocations introduced during growth. The density of dislocations responsible for the curvature reaches 108 lines/cm2. Orientations of ice grown in containers is a consequence of curved growth. Direct formation of polycrystalline ice from supercooled water is reported. The method used in observing curved ice growth also allows observation of the formation of striations and related phenomena.

When a rapidly freezing, water-ice interface approaches a water-air interface at a low angle, the water shirnks away from the advancing intersection line. This effect seems to indicate that γ IA γ IW + γ WA . The apparent intersection angle decreases with decreasing freezing rate, -a fact which is explained qualitatively by an increase of the slope of the water-ice interface adjacent to the contact line with decreasing freezing rate, caused by experimental conditions. A minimum value for the receding contact angle of water on ice is 12 ± 1° at slightly below 0°C., at a receding rate of about 1 cm./sec. on a somewhat rough surface. The possible error from the fact that the water-ice interface can not be observed directly is less than three degrees.

n/a

Gastric carcinoma has not been recognized as a complication of Gardner's syndrome in the Western world. We report a 37-yr-old white woman with Gardner's syndrome who had gastric adenocarcinoma in association with diffuse gastric polyps. At the time of laparotomy, the disease was metastatic to regional lymph nodes. In addition, the patient had mesenteric and retroperitoneal fibromatosis, thyroid adenomas, a chest wall hemangioma, and fibrocystic disease of the breast. This is the first reported case of gastric adenocarcinoma complicating Gardner's syndrome in North America.

The EEA stapler now offers an alternative to hand-sewn techniques for primary and staged low colorectal anastomoses. The stapler may allow a safer and lower resection than was previously possible. A review of 52 primary and 8 staged EEA anastomoses is presented, with emphasis on the combined stapler technique.

Transverse acoustic waves in pulsed lasers result from nonuniform pumping transverse to the flow direction. This theoretical study is based on linear acoustics and disregards hot/cold gas interfaces. First, transverse waves in an infinite parallel hard-walled duct are considered, in which case cavity medium inhomogeneity typically decays as t ~ ' / 2 . An idealized treatment is next given to show that exponential decay can be expected with an anode absorber. There is an optimum absorber resistivity and improved attenuation rate results with increased backing volume. Tilted sidewalls are the final topic. Decay is again exponential, and rapid attenuation requires fairly large tilt angles. Examples are chosen to apply to CO2 electric discharge, chemical, and excimer lasers.

Thermal homogeneity in a single-pulse excimer laser cavity is of interest because it directly impacts medium optical quality. This study is primarily oriented toward an XeF* laser in which the cavity is hot (500 K) and is pumped by an e-beam from a cold cathode structure in a vacuum chamber next to the cavity. The foil and support structure are on a vertical wall between these hot and cold zones. In consequence, due to radiative heat transfer, the wall assumes a nonuniform termperature and induces natural convection and thermal inhomogeneity within the cavity. Studies of radiative, conductive, and natural convective heat-transfer processes are summarized which lead to a plausible engineering approach to achieving medium homogeneity of (6p/p)rms - 5 X10 ~ 5 in the closed XeF* laser cavity.

Sidewall mufflers are used in pulsed exciplex lasers to rapidly attenuate pressure waves and restore cavity medium homogeneity at successive pulses. The technical basis for designing these is reviewed in the paper with primary focus on the near-cavity region and emphasis on physical understanding. The approach combines rudimentary theory and flow visualization, starting with simplest situation and building toward a more complete picture. Important results are as follows: longitudinal wave attenuation in a finite capacity muffler involves a balance between precursor pulse decay and recompression wave strength which defines an optimum configuration. Acoustic absorber is required in the backing volume, and a basis for choosing its resistivity is indicated. The contribution of a close-in muffler to transverse wave decay within the laser cavity is also characterized. Further, an entropy wave is shown to be generated within a muffler which is confined to the vicinity of the sidewalls. Other entropy sources in a closed loop flow system are noted.

n/a

n/a

But few diseases appeal more keenly to our sympathy than laryngeal phthisis. Extreme pain in swallowing, racking cough and stridulous breathing combine with other symptoms so well known to form a most distressing spectacle. A glance at the long list of medicines and measures which have been, at various times, advocated in its treatment proves the earnestness of the search for a remedy. Experiments with new drugs and new methods have been eagerly undertaken and hopelessly abandoned, until at last the majority of practitioners have settled down to the conclusion that palliative agents are the only resource. Of recent contributions lactic acid and menthol have, perhaps, attracted the most attention, in part because of the extraordinary claims made in their behalf. If the statements of Rosenberg, the most ardent champion of menthol, are to be accepted, we have in that drug almost a specific in laryngeal phthisis. His views have

A balloon-tipped catheter has proved a valuable addition in exploration of the common duct. The catheter with the balloon collapsed can be easily passed beyond stones in both the hepatic ducts and the terminal common duct. When the balloon is filled and the catheter is withdrawn, multiple stones are easily removed

THE TERMS THEMSELVES are so unstable that one wonders whether to see satire as the ideological tool of nationalism or nationalism as a satiric fantasy. Satire addresses history through the literary imagination, and this combination of actuality and fantasy gives satiric nationalism conflicting potential functions. The satiric imagination may assemble the diverse features of nationalism, or it may question the unreal connections that nations assert. The satiric nationalism of the eighteenth century exploits the vagueness of its terms. It conjoins a socio-political model including various developing characteristics with a literary form that is broad in its definition, open in its possibilities of attack, but powerful in enlisting emotion. In its simple form, satiric nationalism attacks other countries by manipulating local stereotypes; but complex nationalism emerges when satire shifts perspectives to insist on the priority of universal human nature over the eccentricities of national character and interest.1 Complex satires explore conflicts and connections between local culture and universal humanity. The yoking of imaginative and historical discourses in satire is applied to nationalistic purposes that are questionable in value and unstable in meaning.