Accreting protoplanets in the LkCa 15 transition disk.

Exoplanet detections have revolutionized astronomy, offering new insights into solar system architecture and planet demographics. While nearly 1,900 exoplanets have now been discovered and confirmed, none are still in the process of formation. Transition disks, protoplanetary disks with inner clearings best explained by the influence of accreting planets, are natural laboratories for the study of planet formation. Some transition disks show evidence for the presence of young planets in the form of disk asymmetries or infrared sources detected within their clearings, as in the case of LkCa 15 (refs 8, 9). Attempts to observe directly signatures of accretion onto protoplanets have hitherto proven unsuccessful. Here we report adaptive optics observations of LkCa 15 that probe within the disk clearing. With accurate source positions over multiple epochs spanning 2009-2015, we infer the presence of multiple companions on Keplerian orbits. We directly detect Hα emission from the innermost companion, LkCa 15 b, evincing hot (about 10,000 kelvin) gas falling deep into the potential well of an accreting protoplanet.

Vector-apodizing phase plate coronagraph: design, current performance, and future development [Invited].

Over the last decade, the vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8 m class telescopes. The vAPP is a geometric-phase patterned coronagraph that is inherently broadband, and its manufacturing is enabled only by direct-write technology for liquid-crystal patterns. The vAPP generates two coronagraphic point spread functions (PSFs) that cancel starlight on opposite sides of the PSF and have opposite circular polarization states. The efficiency, that is, the amount of light in these PSFs, depends on the retardance offset from a half-wave of the liquid-crystal retarder. Using different liquid-crystal recipes to tune the retardance, different vAPPs operate with high efficiencies (${\gt}96\%$) in the visible and thermal infrared (0.55 µm to 5 µm). Since 2015, seven vAPPs have been installed in a total of six different instruments, including Magellan/MagAO, Magellan/MagAO-X, Subaru/SCExAO, and LBT/LMIRcam. Using two integral field spectrographs installed on the latter two instruments, these vAPPs can provide low-resolution spectra (${\rm{R}} \sim 30$) between 1 µm and 5 µm. We review the design process, development, commissioning, on-sky performance, and first scientific results of all commissioned vAPPs. We report on the lessons learned and conclude with perspectives for future developments and applications.

Comparative study of long-term outcomes of accelerated and conventional collagen crosslinking for progressive keratoconus.

PurposeTo compare the long-term outcomes of accelerated corneal collagen crosslinking (CXL) to conventional CXL for progressive keratoconus.Patients and methodsComparative clinical study of consecutive progressive keratoconic eyes that underwent either accelerated CXL (9 mW/cm2 ultraviolet A (UVA) light irradiance for 10 min) or conventional CXL (3 mW/cm2 UVA light irradiance for 30 min). Eyes with minimum 12 months' follow-up were included. Post-procedure changes in keratometry readings (Flat meridian: K1; steep meridian: K2), central corneal thickness (CCT), best spectacle-corrected visual acuity (BSCVA), and manifest refraction spherical equivalent (MRSE) were analysed.ResultsA total of 42 eyes were included. In all, 21 eyes had accelerated CXL (20.5±5.5 months' follow-up) and 21 eyes had conventional CXL group (20.2±5.6 months' follow-up). In the accelerated CXL group, a significant reduction in K2 (P=0.02), however no significant change in K1 (P=0.35) and CCT (P=0.62) was noted. In the conventional CXL group, a significant reduction was seen in K1 (P=0.01) and K2 (P=0.04), but not in CCT (P=0.95). Although both groups exhibited significant reductions in K2 readings, no noteworthy differences were noted between them (P=0.36). Improvements in BSCVA (accelerated CXL; P=0.22 and conventional CXL; P=0.20) and MRSE (accelerated CXL; P=0.97 and conventional CXL; P=0.54) were noted, however were not significant in either group.ConclusionAccelerated and conventional CXL appear to be effective procedures for stabilising progressive keratoconus in the long-term.

Turner's syndrome: index case after 44 years (a tribute to Dr. Henry H. Turner).

Forty-four years after Dr. Henry Turner's original observations, the index case of Turner's syndrome was re-examined. Mild hypertension and sensorineural deafness were found in addition to the classic somatic changes of gonadal dysgenesis. Buccal smear examination and chromosome analysis, previously not performed, revealed absence of chromation bodies and 45,X, respectively.

1-Deamino-8-D-arginine vasopressin and urine cyclic adenosine monophosphate excretion in diabetes insipidus.

The response to 1-deamino-8-D-arginine vasopressin (DDAVP), an intranasally administered analogue of vasopressin, was investigated in children and adults with central diabetes insipidus. To assess the action of DDAVP on the distal nephron, cyclic adenosine monophosphate (cAMP) excretion was assayed in urine collected 4 hr before and during four subsequent 4-hr periods after intranasal administration of 5 micrograms DDAVP. Maximal effects on urine volume and concentration were observed between 4 and 12 hr, coinciding with an elevated cAMP excretion in seven subjects. The pretreatment 4-hr cAMP excretion (micrograms/gm creatinine) correlated inversely with age (p less than 0.02) and surface area (p less than 0.001). Subsequent cAMP excretion after DDAVP increased inconsistently with no relationship to duration of antidiuresis, indicating that urinary cAMP is a poor index of antidiuretic hormone action on the distal nephron. We also confirmed that DDAVP intranasally induces antidiuresis in patients with diabetes insipidus over approximately 12 hr.

Myxedema and obstructive sleep apnea.

Three cases of hypersomnolence, snoring and documented sleep apnea are reported. All three patients were profoundly myxedematous, both clinically and biochemically. Polygraphic studies during sleep documented the presence of repetitive episodes of obstructive sleep apnea in all three patients. These were accompanied by arterial oxygen desaturation. After becoming euthyroid following the administration of the l-thyroxine all patients underwent a repeat evaluation in the sleep laboratory. These studies revealed nearly complete resolution of obstructive sleep apnea in all patients. In addition, several sleep parameters showed marked improvement. These data strongly suggest that the presence of profound daytime sleepiness in hypothyroid patients could be indicative of a potentially lethal complication of myxedema, obstructive sleep apnea.

Progesterone levels and sleep-related breathing during menstrual cycles of normal women.

The respiratory stimulant effect of progesterone has been known for many years and has led to the hypothesis that this hormone protects young, premenopausal women from disordered breathing and apnea during sleep. Therefore, sleep, breathing, and gonadal hormone parameters were evaluated for 11 normal, menstruating women during times of high and low progesterone levels. No sleep or breathing parameter changed significantly with varying levels of progesterone. Although normal women show a significant change in progesterone levels across the course of the menstrual cycle, the levels achieved did not produce significant changes in breathing parameters.

Hyperparathyroidism after radiation of the head and neck: a case report and review of the literature.

A 66-year-old woman presented with hypercalcemia and a past history of external radiation to the neck. Hyperparathyroidism in this patient was caused by a parathyroid adenoma. The literature associating hyerparathyroidism with prior radiation of the head and neck was reviewed and analyzed. Current evidence supports a relationship between external radiation of the head or neck and the development of hyperparathyroidism as a late complication. Analysis of data available suggests that radiation-association hyperparathyroidsim develops after an average latent period of 38 years. Parathyroid adenoma occurred more often than did hyperplasia. Parathyroid carcinoma has not been reported in irradiated patients with hyperparathyroidsim. Neither age at radiation exposure, age at diagnosis of hyperparathyroidsim, nor interval between exposure and diagnosis was associated with a specific histologic diagnosis (adenoma or hyperplasis).

Epinephrine fraction of adrenal vein blood in pheochromocytoma.

Variability in the levels of epinephrine (E) and norepinephrine (NE) in adrenal vein blood is thought to preclude their usefulness in caval sampling studies for localizing abdominal pheochromocytoma. In this study we demonstrate, in three patients, that the fraction of the total catecholamine level in the adrenal effluent represented by E (E fraction) may differentiate the normal adrenal medulla from the gland containing a pheochromocytoma. This observation is additionally supported by calculations of the E fractions, from adrenal venous E and NE reported recently, in three other patients with pheochromocytoma. Our data, combined with those from the literature, yield a mean E fraction, in adrenal vein blood, of 63.8 +/- 11.4 (SD)% for seven normal adrenal medullae, and of 28.5 +/- 4.8% for five glands bearing pheochromocytoma. The use of this parameter for lateralizing adrenal pheochromocytoma is suggested if other procedures are unable to demonstrate the tumor.

Effects of potassium on macromineral absorption in sheep fed wheat straw-based diets.

Two experiments were conducted to determine the effect of increasing dietary K on macromineral bioavailability from a wheat straw-hay diet, and to monitor changes in the rumen that could affect mineral availability. In the first experiment, 12 mature wethers were used in a metabolism study to determine the effect of adding potassium chloride (KCl) to a supplement fed with a diet of 55% NH3-treated wheat straw and 45% bromegrass hay. In the second experiment, similar diets were fed to six wethers with ruminal and abomasal cannulae to determine the site of mineral absorption. Dietary K levels were 1, 2 and 3% of the diet dry matter. Increasing K tended to decrease (P less than .06) apparent absorption of Mg. Potassium absorption increased (P less than .01) with increasing dietary K, but retention was not altered. Quadratic effects (P less than .01) of K were observed for Ca and P apparent absorption and retention. Increased K lowered (P less than .05) plasma Mg in Exp. 1 but not in Exp. 2. Ruminal concentrations of K increased (P less than .01), and concentrations of Na decreased (P less than .05), as dietary K increased. Ruminal fermentation was influenced by dietary K level. Molar proportions of acetate in the rumen were increased (P less than .01) by the addition of K to the diet, while molar proportions of butyrate (P less than .01) and valerate (P less than .01) decreased linearly with increasing K. Time X treatment interactions were present for ruminal propionate, butyrate and NH3-N (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Macromineral absorption in sheep fed tetany-prone and non-tetany-prone hays.

Two experiments were conducted to determine some of the factors that led to hypomagnesemic tetany associated with the feeding of two orchardgrass hays. Sixteen mature Columbia and Suffolk wethers (62 to 72 kg), four of which were fitted with ruminal and abomasal cannulae, were fed one of two tetany-prone orchardgrass hays or a non-tetany-prone bromegrass hay. In Exp. 1, 12 wethers were used in a completely random design metabolism experiment to measure apparent absorption and retention of macrominerals. In Exp. 2, four wethers with ruminal and abomasal cannulae were used in a completely random design experiment to monitor pre-intestinal mineral absorption and ruminal characteristics. This experiment was replicated once, with wethers remaining on their diets for 16 d in each replication. In the metabolism experiment, apparent absorption and retention of Mg as a percentage of intake were lower (P less than .01 and P less than .05) for one tetany-prone orchardgrass hay compared with the other orchardgrass hay. Pre-intestinal absorption of Mg in the cannulated wethers was greater (P less than .01) for the orchardgrass hays than for the bromegrass hay. Pre-intestinal Mg absorption was higher (P less than .01), both in terms of grams per day and a percentage of intake for the orchardgrass hay with the highest Mg content. In the noncannulated wethers, the percentage of water-soluble Mg in the feces was lower (P less than .01) for the tetany-prone hays, indicating that a decrease in Mg solubility in the intestine may have influenced Mg apparent absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Performance, blood and ruminal characteristics of cows receiving monensin and a magnesium supplement.

Forty-eight Angus and Hereford cows were used in a completely random design with a 2 X 2 factorial arrangement of treatments to evaluate the effects of monensin and two sources of Mg on performance, ruminal characteristics and mineral status of mature beef cows. Cows were fed wheat straw treated with NH3 during late gestation and straw treated with NH3 plus bromegrass haylage after calving along with a protein supplement that contained either MgO (7.5 g/kg) or MgSO4 (11 g/kg). One half of the cows received monensin (1 g/kg) in their protein supplement. During the precalving period, MgO without monensin increased (P less than .01) plasma Mg compared with Mg in plasma of cows receiving MgSO4 or MgO with monensin. Magnesium oxide also increased cow weight gains during late gestation (P less than .05) compared with weight gains of cows supplemented with MgSO4, but magnesium source had no effect on weight gain postcalving. Plasma glucose was increased by monensin (P less than .05) and by MgSO4 (P less than .01) during early lactation. Monensin increased the proportion of propionate before (P less than .05) and after (P less than .10) calving in the ruminal fluid of cows. Monensin also increased (P less than .05) cow weight gain precalving and tended to decrease (P less than .10) milk fat in lactating cows. Calf weight gains were not affected by treatment of dam. Magnesium oxide appeared to have higher Mg bioavailability than MgSO4 for cows precalving, but Mg bioavailability was not different postcalving. Monensin increased cow weight gains precalving and improved feed efficiency postcalving.

Effect of energy intake on the postpartum interval in beef cows and the adequacy of the cow's milk production for calf growth.

Lactating Hereford and Hereford X Angus cows, 2 to 6 yr old, and their calves were used in two trials to study the effects of energy intake on the postpartum interval (PPI) and the adequacy of the cow's milk production for calf growth. In trial 1, 23 cows were fed either 120 (high energy, HE) or 100% (adequate energy, AE) of National Research Council energy recommendations. Cow weights, calf weights and milk production were determined 1 wk after calving and every 2 wk until 17 wk postcalving . One-half of the calves received creep feed from the start of the study, whereas the other half did not receive creep feed until their average daily gain was below .23 kg/d. In trail 2, 19 cows were fed energy levels of 100 (AE) or 85% (low energy, LE). Estimated percentage body fat ( EPBF ) was estimated twice during the study; other variables were determined as in trial 1. In trial 1, the HE cows gained more weight (P less than .01) and produced more milk (P less than .01). In trial 2, the AE cows gained more weight (P less than .01) and produced calves 17 kg heavier (P less than .01) at the end of the study than did the LE cows. Milk production was not influenced by energy treatment (P greater than .2). It required 7.5 kg of milk and 2.3 kg of creep feed to produce 1 kg of calf gain in trial 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Feedlot performance of hysterectomized and ovariectomized heifers.

Seventy-five crossbred heifers (mean weight 304 kg) were stratified by weight and source and placed in eight pens. Four duplicate treatments were randomly assigned to pens as follows: (1) intact-control (n = 19), (2) intact + melengestrol acetate (MGA, n = 20), (3) hysterectomy (n = 17) and (4) ovariectomy (OVX, n = 19). All heifers were preconditioned for 2 mo before beginning the finishing study. Surgery was performed through a high lumbar incision approximately 3 wk before the finishing study began. Group 2 heifers were fed .4 mg X head-1 X d-1 MGA. Blood samples were collected at 28-d intervals throughout the 112-d finishing phase. Ovaries were collected at slaughter and carcass data were obtained 24 h after slaughter. On d 112, progesterone was higher (P less than .05) in hysterectomized heifers than in other treatment groups. Serum progesterone concentration was nondetectable (less than .35 ng/ml) in OVX and MGA heifers. There were no differences (P greater than .05) in feed efficiency or carcass characteristics among the four treatments. Hysterectomized and MGA heifers had similar (P greater than .05) average daily gains, which were higher (P less than .15) than control and OVX heifers. These data suggest that the elevated levels of progesterone from the maintained corpora lutea and the subsequent absence of estrous activity in the hysterectomized heifers are advantageous for promoting growth in feedlot heifers.

Pantoprazole versus omeprazole in the treatment of reflux esophagitis.

Pantoprazole is a new proton pump inhibitor with a potent antisecretory activity, well defined pharmacokinetics and safety profile. The aim of this single blind, randomized clinical trial was to compare the efficacy of pantoprazole (PAN) 40 mg/day and omeprazole (OME) 20 mg/day in patients with grade I and II GERD (Savary-Miller classification). A total of 120 patients were included (PAN = 60 and OME = 60). In the per protocol/analysis, healing rates at 4 weeks were 76.3% PAN and 71.2% OME (ns), and at 8 weeks 94.7% PAN and 92.9% OME (ns). In the intention to treat analysis, healing rates at 4 weeks were 75% PAN and 70% OME (ns), and at 8 weeks 90% PAN and 86.6% OME (ns). Both pantoprazole and omeprazole were well tolerated with no serious drug related adverse events. Pantoprazole 40 mg/day was found to be safe and effective therapy comparable to omeprazole 20 mg/day in the short-term treatment for reflux esophagitis (grade I and II).