Directional emission of rhodamine 6G on top of a silver grating.

We have observed directional spontaneous emission of rhodamine 6G dye deposited on top of a silver grating and found that its angular distribution patterns were very different in TE and TM polarizations. The latter was related to the dispersion curves determined based on the polarized reflection spectra measured at multiple incidence angles. The most intriguing finding of this Letter was a resonance, which was coupled with TE-polarized light and determined the characteristic double-crescent patterns in the TE-polarized spontaneous emission. This observation, as well as nearly similar resonance observed in TM polarization, was tentatively explained in terms of leaky waveguide modes supported by a film of dye-doped polymer.

ß decay of (38)Ca: sensitive test of isospin symmetry-breaking corrections from mirror superallowed 0+ → 0+ transitions.

We report the first branching-ratio measurement of the superallowed 0+→0+ß transition from Ca38. The result, 0.7728(16), leads to an ft value of 3062.3(68) s with a relative precision of ±0.2%. This makes possible a high-precision comparison of the ft values for the mirror superallowed transitions, Ca38→38mK and K38m→Ar38, which sensitively tests the isospin symmetry-breaking corrections required to extract Vud, the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, from superallowed ß decay. The result supports the corrections currently used and points the way to even tighter constraints on CKM unitarity.

First Report of Embellisia hyacinthi Causing a Leaf Spot and Bulb Skin Spot Disease on Scilla peruviana in California.

The genus Scilla (Hyacinthaceae) includes more than 50 species of perennial, flowering bulbs grown in landscapes worldwide. In December 2000 and May 2009, an unknown leaf spot disease on Scilla peruviana was submitted to the California Department of Food and Agriculture Plant Pest Diagnostic Lab. Samples were collected during routine phytosanitary inspections of production fields in Santa Cruz County in 2000 and Monterey County in 2009. The disease was detected before plants flowered in one field at each location each year and appeared to have a scattered distribution. Foliar spots were large, elliptical to oblong with grayish black centers and brown margins. Yellow halos surrounded many of the spots. Examination of the bulb material revealed small necrotic patches on the outer bulb scales. A rapidly growing fungus was isolated on one-half-strength acidified potato dextrose agar (APDA) from the sporulating leaf spots and necrotic patches on the bulbs. The colonies were greenish gray and became dark olivaceous with age. Dictyospores, which formed on simple to branched, geniculate conidiophores, were oblong, fusiform or obclavate and usually had a triangular apical cell. They were initially hyaline, turning olivaceous brown with age. Conidia measured 14 to 39 × 8 to 13 µm (average 24.6 × 9.9 µm) typically with two to four (but up to seven) thick, transverse septa and one to two longitudinal septa. Morphologically, the fungus matched the description of Embellisia hyacinthi de Hoog & Miller (1,3). To confirm pathogenicity, four leaves of four S. peruviana plants were inoculated by taking colonized mycelial plugs from 2-week-old cultures and placing them in a plastic screw-cap lid filled with sterile water. The water plus mycelial plug suspension in the lid was then clipped to the adaxial side of a pushpin-wounded leaf (4). Plants were placed in a dark dew chamber at 20°C for 48 h and then moved to a growth chamber at 20°C with a 12-h photoperiod. After 48 h, the clips, caps, and plugs were removed. An equal number of control plants were wounded and mock inoculated with noncolonized APDA agar plugs and the experiment was repeated. Leaf lesions were visible 3 days after clip removal and expanded to an average of 26 × 10 mm, 14 days after inoculation. Sporulation was observed in the lesions after 5 to 7 days and the fungus was isolated from all inoculated leaves. No symptoms developed on the control leaves. DNA sequencing of the internal transcribed spacer region of the isolate (GenBank Accession No. HQ425562) using primers ITS1 and ITS4 matched the identity of E. hyacinthi (2,4). E. hyacinthi has been reported as a foliar and bulb pathogen on Hyacinthus, Freesia, and Scilla in Japan and Europe including Great Britain. Bulbs infected with E. hyacinthi are generally less sound and less valuable than noninfected bulbs (1). To our knowledge, this is the first report of the disease on S. peruviana in California. References: (1) G. S. de Hoog and P. J. Muller. Neth. J. Plant Pathol. 79:85, 1973. (2) B. Pryor and D. M. Bigelow. Mycologia 95:1141, 2003. (3) E. Simmons. Mycotaxon 17:216, 1983. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

Stomatal vs. genome size in angiosperms: the somatic tail wagging the genomic dog?

BACKGROUND AND AIMS: Genome size is a function, and the product, of cell volume. As such it is contingent on ecological circumstance. The nature of 'this ecological circumstance' is, however, hotly debated. Here, we investigate for angiosperms whether stomatal size may be this 'missing link': the primary determinant of genome size. Stomata are crucial for photosynthesis and their size affects functional efficiency. METHODS: Stomatal and leaf characteristics were measured for 1442 species from Argentina, Iran, Spain and the UK and, using PCA, some emergent ecological and taxonomic patterns identified. Subsequently, an assessment of the relationship between genome-size values obtained from the Plant DNA C-values database and measurements of stomatal size was carried out. KEY RESULTS: Stomatal size is an ecologically important attribute. It varies with life-history (woody species < herbaceous species < vernal geophytes) and contributes to ecologically and physiologically important axes of leaf specialization. Moreover, it is positively correlated with genome size across a wide range of major taxa. CONCLUSIONS: Stomatal size predicts genome size within angiosperms. Correlation is not, however, proof of causality and here our interpretation is hampered by unexpected deficiencies in the scientific literature. Firstly, there are discrepancies between our own observations and established ideas about the ecological significance of stomatal size; very large stomata, theoretically facilitating photosynthesis in deep shade, were, in this study (and in other studies), primarily associated with vernal geophytes of unshaded habitats. Secondly, the lower size limit at which stomata can function efficiently, and the ecological circumstances under which these minute stomata might occur, have not been satisfactorally resolved. Thus, our hypothesis, that the optimization of stomatal size for functional efficiency is a major ecological determinant of genome size, remains unproven.

Cyclic erythropoiesis in W/Wv mice following a single small dose of 89Sr.

Young adult female W/Wv mice were given 0.5 microCi 89Sr/g intravenously, a dose which produces no anemia and only mild transient thrombocytopenia in normal mice. In the W/Wv animals platelet counts fell from 10(6) to 3 x 10(5)/mm3, and hematocrits from 39% to 25% in two weeks. In the following 2 weeks, platelet counts rose to 7 x 10(5), stabilizing at this level. Average hematocrit values were observed to oscillate from a nadir of 26% to a zenith of 42%, with a periodicity of about 16 days. In a repeat experiment we found the average hematocrit fluctuation from 28 to 40%, amplitude of reticulocyte fluctuation 6 to 31%, periodicity of cycle 16 days. Several animals have been observed through as many as six complete cycles. Further study of cyclical erythropoiesis in the W/Wv mouse following hematopoietic injury produced by 89Sr may shed light on the causes of cyclical hematopoiesis observed occasionally in man and other animals.

The erythropoietic effect, in mice, of androgens combined with hypoxia.

Progressively higher levels of erythrocytosis were observed in female mice residing at simulated altitudes of 9, 12, and 18 thousand feet. Administration of testosterone enhanced red-cell production in female mice under all but the most severe hypoxic conditions. The spleen contributed to the extent of erythropoiesis produced by hypoxia and by the combination of hypoxia and androgen, but this extramedullary site of red-cell formation was not necessary for erythrocytosis to occur. As little as 0.1 mg of testosterone enanthate weekly had an erythropoietic effect in female mice residing at 12,000 feet. Normal male mice also responded to hypoxia, but did not demonstrate a further erythropoietic effect in response to the concurrent administration of androgen.

Further studies on cyclic erythropoiesis in mice.

When young adult female W/Wv mice are given 0.5 micro+Ci 89Sr/g body weight intravenously, their hematocrit values oscillate from nadirs of 26% to zeniths of 42% with a periodicity of 16 days [1]. The response of the W/Wv mouse to an assortment of radioactive and hematologic stresses have been examined in an effort to understand better the pathophysiology of cyclic erythropoiesis. When the dose of 89Sr is increased, the amplitude of cycling increases as nadirs are lowered, but periodicity is unchanged. When the dose of 89Sr is lowered to 0.3 microCi or less, cyclic erythropoiesis of substantial amplitude is observed only after five or six microoscillations. A single hematopoietic insult of 80 rad x-irradiation coupled with phlebotomy produces a transient form of cyclic erythropoiesis, namely, a series of dampened oscillations prior to recovery. Finally, we report that Wv/Wv mice exhibit a form of cyclic erythropoiesis in response to 0.5 microCi 89Sr/g body weight, in which the hematocrit values of successive nadirs gradually increase, and stabilize at about 100 days. 89Sr does not induce cyclic erythropoiesis in the +/+, W/+, or W/v/+ mice, the Hertwig strain of anemic mice, or in normal BDF1 mice.

Cyclic erythropoiesis in the S1/S1d mouse.

Previously we reported that when young adult female W/Wv mice are given 0.5 microCi strontium-89 per gram body weight IV, their hematocrit values oscillate from nadirs of 26% to zeniths of 42% with a periodicity of 16 days. We now report that a second strain of congenitally anemic female mice, the S1/ S1d , also exhibit large fluctuations in their hematocrit values following a dose of 0.5 microCi 89Sr/g body weight. The zeniths through which these mice cycled averaged 37% (range 35%-38%) and the nadirs averaged 13% (range 12%-14%). Reticulocytes fluctuated from highs averaging 40% (range 35%-45%) to lows that averaged 3% (range 1%-5%). The periodicity of cycling in these eight mice ranged from 16 to 19 days. The hematocrits of three out of five non-strontium-treated mice were found to cycle spontaneously in the absence of 89Sr-mediated hematopoietic insult, with nadirs averaging 22% and zeniths averaging 39%. Similarly, doses as small as 0.1 microCi 89Sr/g body weight coupled with antecedent phlebotomy induced cyclic erythropoiesis of substantial amplitude (average nadir 16% and average zenith of 39%). Splenectomy in the S1/ S1d mouse eliminates both spontaneous and 89Sr-induced cyclic erythropoiesis. If the spleen is removed prior to radiostrontium treatment, then cyclic erythropoiesis is not observed following a dose of 0.5 microCi 89Sr/g body weight.

Cicatricial pemphigoid (Brunsting-Perry type). Case report and immunofluorescence findings.

We describe clinical and immunofluorescence findings of a patient with Brunsting-Perry-type cicatricial pemphigoid. Direct immunofluorescence showed tissue-fixed basement membrane zone antibodies similar to those characteristic of bullous pemphigoid. Circulating antibodies to the basement membrane zone were not found. Brunsting-Perry-type cicatricial pemphigoid probably represents a clinical variation midway in the cicatricial pemphigoid-bullous pemphigoid spectrum of disease. Management with intralesional corticosteroids was successful in controlling the skin lesions.

Age-related changes in the human femoral cortex.

Bone undergoes structural changes with aging, but the nature of qualitative changes remains to be established. Blocks of midshaft femur were taken at autopsy from men of four different age groups: 20-25 years, 40-45 years, 60-65 years, and 80-85 years. Each femoral specimen was analyzed by density fractionation, a technique that allows the separation of bone by extent of mineralization and maturity. In the 20-25 group, lower density bone predominates. The 40-45 group is characterized by more highly mineralized bone with an increase in the 2.1-2.2 g/cc fraction. At 60-65 years, an increase in the lower density fraction was found, indicating an increase in new bone formation. At 80-85 years, there is an increase in the highest density bone (2.2-2.3 g/cc), which may represent regions of interstitial bone not properly removed through remodeling processes. Chemical studies did not reveal any change in Ca, P, Ca + PO4, or Ca/P molar ratio with respect to age. X-ray diffraction studies show no changes in apatite crystal size with respect to age or degree of mineralization. Morphological studies documented increased remodeling activity and endosteal trabecularization in the older age groups, as well as increased intracortical porosity. An increase in the highest density fraction with aging may represent a pool of bone mineral that is less accessible to remodeling, which may be the interstitial bone.

Bone mineral in the castrated rat model of osteopenia.

The effects of castration on cortical bone structure and chemistry were studied in male Wistar rats of two age groups, 8 and 24 months. Some rats were castrated and some were sham operated (control) in each group. All animals were killed after 4 months. Although no changes in serum chemistry, bone chemistry, or bone histology could be found, the young castrated animals versus controls showed less density of bone mineral as determined by the density fractionation technique and smaller crystallite size of mineral particles as determined by x-ray diffraction line-broadening analysis. These changes, indicative of less mature bone formation, were not observed in mature castrated or control rats despite a decreased amount of bone compared with young rats. In this model, castration appears to affect bone mineral quality in young but not in old animals.

Thermocycling of pit and fissure sealants.

Both sealants experience early thermocyclic failure, which is manifested as marginal breakdown or separation. From the 20 to 70% failure range (Fig 5) Nuva Seal was three times as resistant to thermocyclic stressing as was Epoxylite 9075. That is, the Nuva Seal-sealed teeth had to be cycled three times more than the Epoxylite 9075-sealed teeth to effect the same failure rates. Both Epoxylite and Nuva Seal reach the same failure rate at 7,000 cycles (75% failure rate). Extremely careful visual examination is required to detect marginal separation failures of pit and fissure sealants.

The effect of spinal distraction on regional spinal cord blood flow in cats.

Distraction is considered to be a factor in many spinal cord injuries. With a specially designed distraction apparatus and the 14C-antipyrine autoradiographic technique, the effect of distraction on spinal cord blood flow (SCBF) in cats was studied. Distraction was performed at L2-3 at a rate of 0.25 cm/10 min, and the spinal evoked response (SER) was monitored by stimulating the sciatic nerve and recording at T-13. The SCBF was assessed in five control animals, four animals in whom the SER was markedly altered by distraction, and five animals after the SER had been abolished and an additional 0.5 cm distraction applied. Control cats had gray- and white-matter flows of 44.5 +/- 1.4 (SEM) and 10.5 +/- 0.4 ml/100 gm/min, respectively. Distraction to the point of marked SER alteration caused a 50% loss of SCBF at and caudal to the distraction site. An additional 0.5 cm distraction produced total abolition of SCBF at the distraction site and for a considerable distance rostral and caudal to it. Thus, it is shown that spinal distraction causes cord ischemia similar to that seen with other types of spinal cord injury. In addition, distraction severe enough to cause loss of the SER has already produced severe cord ischemia.

Cervical orthoses. A study comparing their effectiveness in restricting cervical motion in normal subjects.

The effectiveness of five cervical orthoses in restricting cervical motion was evaluated quantitatively in normal subjects using roentgenograms and overhead photographs made at the extremes of three planes of motion, while the effectiveness of the halo with a plastic body-vest was studied in seven patients with cervical fractures or local fusions. Flexion and extension were measured at each cervical intervertebral joint and combined cervical motion was measured for rotation and lateral bending. The best conventional braces restricted only 45 per cent of flexion-extension at the atlanto-axial joint; the halo restricted 75 per cent. The conventional braces were more effective in the middle and lower portions of the cervical spine. The results may prove to be useful guidelines for the selection of an appropriate orthosis to control motion in different planes and at different levels of the spine.

Capitellocondylar total elbow replacement in rheumatoid arthritis. Long-term results.

We evaluated the long-term results of 202 capitellocondylar total elbow replacements that had been performed, from July 1974 through June 1987, in 172 patients. The duration of follow-up averaged sixty-nine months (range, twenty-four to 178 months). At the most recent follow-up examination, use of a 100-point rating score demonstrated an improvement from an average preoperative score of 26 points (range, 2 to 50 points) to an average postoperative score of 91 points (range, 45 to 100 points). The most improvement occurred in the categories of relief of pain, functional status, and range of motion in all planes except extension. The improvements in these categories and in the roentgenographic appearance that were seen in the early postoperative period did not deteriorate with time. The average preoperative arc of motion at the elbow ranged from -37 degrees of extension to 118 degrees of flexion. The average postoperative arc of motion at the elbow ranged from -30 degrees of extension to 135 degrees of flexion. Supination improved from 45 degrees preoperatively to 64 degrees postoperatively; pronation improved from 56 degrees preoperatively to 72 degrees postoperatively. The roentgenograms showed a radiolucent line adjacent to eight humeral and nineteen ulnar components; most of the lines were incomplete and one millimeter wide or less. Revision of the prosthesis was necessary in three elbows (1.5 per cent) because of loosening without infection, and in three additional elbows because of dislocation of the prosthesis. Complications included deep infection in three elbows (1.5 per cent); problems related to the wound in fifteen (7 per cent); permanent, partial sensory ulnar-nerve palsy in five (2.5 per cent); permanent, partial motor ulnar-nerve palsy in one (0.5 per cent); and dislocation in seven (3.5 per cent).

Morphometry of the lumbar spine: anatomical perspectives related to transpedicular fixation.

The pedicles of lumbar vertebrae were measured both directly and radiographically to determine the differences between the sexes and the accuracy of radiographic measurement. The lumbar pedicles of cadavera of forty-nine patients--twenty-four men and twenty-five women--who died between the ages of sixty and ninety-eight years were measured directly and on radiographs. The pedicles of lumbar vertebrae from fifty-one patients--twenty-three men and twenty-eight women--between the ages of twenty and fifty years who had low-back problems were measured on radiographs and computerized tomographic scans. Comparison revealed that the average transverse and sagittal diameters of the pedicles and the distance from the posterior aspect of the laminar cortex to the anterior aspect of the cortex of the vertebral body along the central axis of the pedicles were 5 to 20 per cent greater in men, but the transverse and sagittal angles of the pedicle did not differ significantly between the sexes. Measurements on radiographs and computerized tomographic scans of the transverse angles of the pedicles and of the distances from the posterior aspect of the laminar cortex to the anterior aspect of the cortex of the vertebral body from the second to the fifth lumbar vertebra were greater than direct measurements, even without magnification. Direct measurements of the diameters of the transverse and sagittal diameters of the pedicle of the fifth lumbar vertebra, however, were greater than the radiographic measurements.

Spinal stenosis with scoliosis.

A retrospective review was carried out on 40 patients who met the criteria of 1) having a significant lumbar scoliosis associated with spinal stenosis, with symptoms of neurogenic claudication; and 2) having been treated with posterior decompression and pedicular screw fixation techniques. The average age of the patients was 61.5 years (range, 38-77 years), and 25 of the 40 patients were female. Eighty-eight percent of the patients had significant back pain in addition to lower extremity pain. All patients had pedicular screw fixation at all levels. Zielke instrumentation was used in 24 patients, Cotrel-Dubousset instrumentation in 8 patients, and Texas Scottish Rite Hospital instrumentation in the remaining 8 patients. After surgery, there was marked improvement in regard to pain status: 34 patients (83%) had severe pain before surgery, with 38 patients (93%) reporting mild or no pain at follow-up. Average length of follow-up was 44 months (range, 24-61 months). There were no deaths and no instrument-related failures or pseudarthroses noted in this series. A mean correction of the deformity of 19 degrees was obtained. Average scoliosis was 37 degrees before surgery and 18 degrees at follow-up.

The results of surgical treatment for adult scoliosis.

This study was done to define and characterize those adult patients with scoliosis who will have problems of pain and/or progression leading to a surgical procedure and to review the results of these surgical procedures. The authors reviewed the cases of 49 adult patients who had undergone surgical treatment for scoliosis (average follow-up, 34 months; range, 24-140 months). The patients were categorized according to age, which allowed analysis of the data comparing age and the incidence and level of pain, age versus the degree of curvature, and age versus the incidence of progression. The relative incidence of pain and progression as indications for surgery were found to vary with respect to age. In the younger groups, progression was more often the indication for surgery than in the older groups. The younger groups also had larger curves than did the older groups, on average. The degree of pain was not found to correlate with the magnitude of the deformity. Surgical complications occurred in 20 patients; however, 14 of these were minor complications during the perioperative period, which did not result in any sequelae. Surgical treatment can be done with a relatively low serious complication rate and good results in terms of pain relief and reasonable correction of the deformity.