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Quantum optics has progressed a long way in the last sixty years and much is now understood about coherence. Nevertheless, the description of the quantum nature of optical phase has been a longstanding problem. Classically, phase is a useful and easily-understood concept, and it might be expected that the classical phase observable should, according to the usual quantization procedures, correspond to an Hermitian phase operator ϕ. Indeed, the existence of this operator was indeed originally postulated by Dirac,1 but problems associated with finding such an operator have led to the present wide-spread belief that no such operator exists.2 Attempts to construct a phase operator have involved the use of an infinite dimensional state space and a polar decomposition of the annihilation operator. This procedure does not provide a unique operator. Specifically, the action of exp (iϕ) on the vacuum is not determined. The usual ad hoc assumption is to set exp (iϕ) ∣ 0 > = 0. This removes the indeterminacy but destroys the unitarity of exp (iϕ), along with the possibility of extracting an Hermitian operator from the exponential.

The authors present an argument for assigning a definite phase to an assembly of Bose-Einstein Condensed atoms. This relies on the demonstration that a coherent state of the condensed system is a robust state in the presence of interactions between the condensate and its environment.

The sensitivity of groundwater recharge estimates was investigated for the semiarid Ellensburg basin, located on the Columbia Plateau, Washington, to historic and projected climatic regimes. Recharge was estimated for predevelopment and current (1980s) land use conditions using a daily energy-soil-water balance model. A synthetic daily weather generator was used to simulate lengthy sequences with parameters estimated from subsets of the historical record that were unusually wet and unusually dry. Comparison of recharge estimates corresponding to relatively wet and dry periods showed that recharge for predevelopment land use varies considerably within the range of climatic conditions observed in the 87-year historical observation period. Recharge variations for present land use conditions were less sensitive to the same range of historical climatic conditions because of irrigation. The estimated recharge based on the 87-year historical climatology was compared with adjustments to the historical precipitation and temperature records for the same record to reflect CO2-doubling climates as projected by general circulation models (GCMs). Two GCM scenarios were considered: an average of conditions for three different GCMs with CO2 doubling, and a most severe “maximum” case. For the average GCM scenario, predevelopment recharge increased, and current recharge decreased. Also considered was the sensitivity of recharge to the variability of climate within the historical and adjusted historical records. Predevelopment and current recharge were less and more sensitive, respectively, to the climate variability for the average GCM scenario as compared to the variability within the historical record. For the maximum GCM scenario, recharge for both predevelopment and current land use decreased, and the sensitivity to the CO2-related climate change was larger than sensitivity to the variability in the historical and adjusted historical climate records.

Recently introduced unitary and hermitian phase operators are used to examine the phase properties of squeezed states of light with particular reference to the squeezed vacuum. The results differ markedly from previous calculations involving the Susskind and Glogower operators. The new formalism allows the construction of a phase probability density which, on a polar diagram, is a circle for the vacuum state, becomes elliptical with gentle squeezing and collapses to a line through the origin for full squeezing. This probability density together with the calculation of expectation values of various trigonometrical functions of phase show how squeezing impresses phase information onto the vacuum.

We study the interaction of light with an amplifier or attenuator which can be approximated by a collection of two-level atoms which are prepared in identical atomic coherent states, giving a non-zero coherence in the initial ensemble-averaged atomic density matrix. It is found that light in an initial coherent state can be squeezed if the system is used in the attenuator mode, but not if it is used as an amplifier.

In studying the amplification of squeezed light by a linear atomic light amplifier, various authors have found that the output light will not be squeezed for intensity gains greater than a limiting value of 2. In this paper we examine the general conditions under which this limiting value is applicable and find that for the atomic light amplifier it is associated with the vanishing of the initial average coherence of the atoms. A multi-stage atomic light amplifier is discussed, in which the atoms are in specially prepared initial states, which allows in principle a squeezed output for any value of the gain.

A total of 6 patients underwent a major urological operation with simultaneous elective cholecystectomy for cholelithiasis. All patients did well with no morbidity or increased hospital stay attributable to the biliary operation. Numerous articles in the vascular, general and gynecological surgery literature advocate concomitant cholecystectomy when gallstones are present. The complications of nonoperated biliary calculous disease, including postoperative cholecystitis, are well known. A concomitant operation could reduce over-all risks and costs to the patient and health care system.

Ten patients with hematoceles associated with blunt trauma have been seen during the last 4 years. In 80 per cent of the cases the hematocele was caused by rupture of the testicle. Prompt early exploration, adequate debridement, primary repair of the tunical laceration and Penrose drainage resulted in a salvage rate of 75 per cent.

We describe the prospective evaluation of 90 patients seen at 2 medical centers who presented with acute urinary retention. All patients had a pre-retention history obtained, as well as careful prostate examination, perineal prostate biopsy and followup treatment or monitoring. Prostate cancer was found in 12 of the 90 patients (13.3 per cent), while 1 had metastatic leukemia to the prostate. Of the 90 patients 69 (76.7 per cent) had a palpably benign prostate and 2 malignancies (2.9 per cent) were diagnosed, while 11 malignancies occurred in 21 patients (52.4 per cent) with a suspicious examination. A total of 46 patients (51.1 per cent) underwent further prostate resection and no malignancy was found in any of these specimens: 43 underwent transurethral resection (24.9 gm. average), while 3 underwent open prostatectomy (97 gm. average). Other etiologies of acute retention included benign hyperplasia, other underlying illness, medical procedures, medications, prostatitis and prostatic infarction. Among the 44 patients who did not undergo prostatectomy 13 had treatment of the diagnosed cancer, 9 had resolution of retention and symptoms without intervention, 9 remained catheterized due to severe medical problems, 8 were treated for prostatitis, 2 had discontinuation of sympathomimetic drugs and 1 each underwent urethrotomy, bladder neck incision and resolution of prostatic infarction. In contrast to the older literature in which approximately 25 per cent of the patients presenting with acute urinary retention had prostate cancer, our data suggest a lower incidence. Prostatic biopsy for patients who present with acute urinary retention and a benign examination does not appear to be justified.

Seminal vesicle abscesses are extremely rare and worthy of report. Computerized tomography easily verifies the diagnosis and simplifies the treatment of transurethral incision and drainage.

In the antibiotic era prostatic abscesses are rare and the clinical picture often can be confusing. In 2 recent cases computerized tomography scanning not only proved the diagnosis easily but it also simplified greatly the definitive surgical procedure.

Summary form only given. Many studies have been made of electromagnetically induced transparency (EIT) and probe gain under steady-state conditions. We have carried out experimental studies of transient effects in rubidium lambda systems in the non-adiabatic regime where the coupling field is rapidly switched on using a Pockels cell in a time that is short compared with transient time scales. Our preliminary work has confirmed predictions that the steady-state EIT is approached through damped oscillations characterised by the coupling field Rabi frequency /spl Omega//sub c/ and the spontaneous decay rate /spl Gamma/. We report results of our recent investigations into the effects of strong coupling fields conducted in several different lambda schemes in the rubidium 5S/sub 1/2/-5P/sub 3/2/ hyperfine levels in a magnetooptical trap. We also studied the effects of the initial conditions of population and optical coherence, probe absorption on uncoupled Zeeman transitions, and incoherent pumping.

Adenomatoid tumors are rare, benign mesotheliomas that usually are associated with the genitourinary tract. The suprarenal occurrence of this tumor is uncommon. We present such a case and review the origin of the adenomatoid tumor.