Dual role of preputial gland secretion and its major components in sex recognition of mice.

PubMed

Zhang, Jian-Xu; Liu, Ying-Juan; Zhang, Jin-Hua; Sun, Lixing

2008-10-20

This study was aimed at validating the sexual attractiveness of hexadecanol and hexadecyl acetate, two putative pheromone compounds, from preputial gland secretion of mice. These two compounds have been reported to be among the major components of preputial gland secretion in both sexes but higher in quantity in males than females. In this study, we show that castration suppressed the production of the two compounds, further suggesting their association with maleness. Adding preputial gland secretion and the synthetic analogs of the two compounds to castrated male urine at their physiological levels in intact males increased the attractiveness of castrated male urine to female mice, showing that the two compounds were indeed male pheromones. Furthermore, their sexual attractiveness disappeared upon removing the vomeronasal organs (VNOs) from female recipients. Replenishing castrated male urine with preputial gland secretion and the two compounds at their physiological levels in females increased the attractiveness of castrated male urine to males. Such a reversal of sexual attractiveness for hexadecanol and hexadecyl acetate suggests that they had opposing dual effects in sexual attractiveness in a dosage-dependent manner.

Odor of the muskox : A preliminary investigation.

PubMed

Flood, P F; Abrams, S R; Muir, G D; Rowell, J E

1989-08-01

The behavior of captive male muskoxen was observed closely during their characteristic superiority display, the anatomy of the preputial region was studied in two adults and three calves, and preputial washings and preorbital gland secretion were subjected to gas chromatography and mass spectroscopy. During the superiority display, the prepuce was everted to form a pendulous tube tipped with a fringe of matted hair. Owing to the movement of the animal, the urine that dribbled from the preputial opening was liberally applied to the long guard hairs of the belly. The superiority display was almost exclusively confined to dominant males and apparently accounted for their odor. In the quiescent state, the hair seen around the preputial opening was drawn inside and formed an 8 cm-wide band on the lining of the prepuce. The preputial washings contained large amounts of benzoic acid andp-cresol. The infraorbital gland secretion contained cholesterol, benzaldehyde, and a homologous series of saturated γ-lactones ranging from 8 to 12 carbons. The latter compounds and the natural secretion smell similar to the human nose.

Preputial Demodex species in big brown bats (Eptesicus fuscus) in eastern Tennessee.

PubMed

Lankton, Julia S; Chapman, Alycia; Ramsay, Edward C; Kania, Stephen A; Newkirk, Kimberly M

2013-03-01

The presence of preputial Demodex species in four captive, wild-caught big brown bats (Eptesicus fuscus) in eastern Tennessee, USA, examined between 2008 and 2010 is reported. In three of four cases, there was associated folliculitis, dermatitis, or preputial adenitis. There were no clinical signs directly attributable to the mites, although penile prolapse was present in one case. Mites were retrieved from preputial skin samples of other archival big brown bats by potassium hydroxide digestion and analyzed by polymerase chain reaction (PCR). DNA sequencing of the 16S rRNA gene revealed 99.6% homology to Demodex canis, although morphologic differences distinguish the two species. Mites of this report differ in anatomic location from Demodex spp. previously reported in bats and represent a species unreported to public databases.

De virginibus puerisque: the function of the human foreskin considered from an evolutionary perspective.

PubMed

Cox, G

1995-12-01

The functional significance of the human male foreskin is considered in evolutionary terms. It is postulated that there is a lifetime's reproductive advantage in delaying the age of first coitus, and hence of first childbirth, for some years after puberty, until the parents are better established as providers. Phimosis and preputial adhesions are common in human males because they have selective advantage, tending to impede and therefore delay the onset of sexual activity. The physical signs of female virginity have an analogous function, and have been selected for in the same way. This hypothesis also provides a consistent explanation for the worldwide tradition of circumcision and for the common practice of masturbation by human males.

Effects of prenatal exposure to a low dose atrazine metabolite mixture on pubertal timing and prostate development of male Long-Evans rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanko, Jason; Enoch, Rolondo; Rayner, Jennifer L

The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and deisopropylatrazine. Pregnant Long-Evans rats were treated by gavage with 0.09, 0.87, or 8.73 mg AMM/kg body weight (BW), vehicle, or 100 mg ATR/kg BW positive control, on gestation days 15 19. Preputial separation was significantly delayed in 0.87 mg and 8.73 mg AMM-exposed males. AMM-exposed males demonstrated a significant treatment-related increase in incidence and severity of inflammation in the prostate on postnatal day (PND) 120. A dose-dependentmore » increase in epididymal fat masses and prostate foci were grossly visible in AMM-exposed offspring. These results indicate that a short, late prenatal exposure to mixture of chlorotriazine metabolites can cause chronic prostatitis in male LE rats. The mode of action for these effects is presently unclear.« less

Initial steps in defining the environment of the prepuce of the bull by measuring pH and temperature.

PubMed

Koziol, J H; Fraser, N S; Passler, T; Wolfe, D F

2017-12-01

To determine the baseline pH and temperature of the preputial cavity of bulls. We enrolled 55 bulls ranging in age from 15 to 84 months. The preputial temperature and pH were measured by insertion of temperature and pH probes, respectively, into the preputial orifice prior to routine breeding soundness examinations. Information was obtained from owners regarding the diet of each bull and categorised as one of three categories: forage only, grain supplemented or silage supplemented. The average temperature of the prepuce was 37.81°C ± 1.76 and the median pH of the prepuce was 8.45 (6.35-9.46). Preputial temperatures of the bull weakly correlated with ambient temperatures (r s  = -0.29, P = 0.028). The preputial pH of silage-fed bulls was significantly lower than that of bulls fed forage only (P = 0.025) or grain-supplemented diets (P = 0.002). The median preputial pH of bulls fed a silage-based diet was 7.6 (6.3-8.9) compared with a median pH 8.7 (7.8-9.1) for bulls fed forage-based diets or a median of 8.5 (7.7-9.4) for those given grain-supplemented diets. Diet and ambient temperature can, respectively, affect pH and the temperature in the prepuce. Further studies to describe and understand the microbiota of the prepuce and penis may assist in developing treatments for diseases of the genital tract in bulls. © 2017 Australian Veterinary Association.

Combined preputial advancement and phallopexy as a revision technique for treating paraphimosis in a dog.

PubMed

Wasik, S M; Wallace, A M

2014-11-01

A 7-year-old neutered male Jack Russell terrier-cross was presented for signs of recurrent paraphimosis, despite previous surgical enlargement of the preputial ostium. Revision surgery was performed using a combination of preputial advancement and phallopexy, which resulted in complete and permanent coverage of the glans penis by the prepuce, and at 1 year postoperatively, no recurrence of paraphimosis had been observed. The combined techniques allow preservation of the normal penile anatomy, are relatively simple to perform and provide a cosmetic result. We recommend this combination for the treatment of paraphimosis in the dog, particularly when other techniques have failed. © 2014 Australian Veterinary Association.

An unusual foreign body in the preputial sac.

PubMed Central

Jaiswal, A K

1992-01-01

A 28 year old Indian male presented with an unusual foreign body, a penicillin bottle containing tincture of iodine, in the preputial sac. The purpose of introducing the bottle was to tickle his glans penis as a form of masturbation. The bottle was so firmly impacted that it could be removed only under general anaesthesia. Images PMID:1427809

Diversion of the urine stream by surgical modification of the preputial ostium in a dog.

PubMed

Pavletic, Michael M; Brum, Douglas E

2009-11-01

A 1.4-year-old sexually intact male Standard Poodle was evaluated with a history of urinating on its left forelimb and lower portion of the thorax. Physical examination revealed that the dog had an unusually elevated (tucked) abdominal wall and prominent dome-shaped thoracic wall. These anatomic changes altered the angle of the urine stream, resulting in the dog's soiling the xiphoid region of the thorax and left forelimb. The dorsal half of the preputial ostium was closed surgically to divert the urine stream in a ventral direction. The ventral portion of the ostium was reciprocally enlarged. Postoperatively, the dog urinated in a downward direction, eliminating urine contact with the body. The preputial orifice (ostium) plays an important role in the shape and direction of the urine stream exiting the penile urethra. Dogs with an elevated abdominal wall and prominent dome-shaped thorax may be prone to contamination of the lower portion of the thorax and forelimbs with urine during normal micturition. Partial closure of the dorsal preputial ostium, with reciprocal enlargement of the lower half of the orifice, can create a deflective barrier that effectively diverts the urine stream in a ventral direction.

Disrupted kisspeptin signaling in GnRH neurons leads to hypogonadotrophic hypogonadism.

PubMed

Novaira, Horacio J; Sonko, Momodou L; Hoffman, Gloria; Koo, Yongbum; Ko, Chemyong; Wolfe, Andrew; Radovick, Sally

2014-02-01

Landmark studies have shown that mutations in kisspeptin and the kisspeptin receptor (Kiss1r) result in reproductive dysfunction in humans and genetically altered mouse models. However, because kisspeptin and its receptor are present in target cells of the central and peripheral reproductive axis, the precise location(s) for the pathogenic signal is unknown. The study described herein shows that the kisspeptin-Kiss1r signaling pathway in the GnRH neuron is singularly critical for both the onset of puberty as well as the attainment of normal reproductive function. In this study, we directly test the hypothesis that kisspeptin neurons regulate GnRH secretion through the activation of Kiss1r on the plasma membrane of GnRH neurons. A GnRH neuron-specific Kiss1r knockout mouse model (GKirKO) was generated, and reproductive development and phenotype were assessed. Both female and male GKirKO mice were infertile, having low serum LH and FSH levels. External abnormalities such as microphallus and decreased anogenital distance associated with failure of preputial gland separation were present in GKirKO males. A delay in pubertal onset and abnormal estrous cyclicity were observed in female GKirKO mice. Taken together, these data provide in vivo evidence that Kiss1r in GnRH neurons is critical for reproductive development and fertility.

Disruption of testosterone homeostasis as a mode of action for the reproductive toxicity of triazole fungicides in the male rat.

PubMed

Goetz, Amber K; Ren, Hongzu; Schmid, Judith E; Blystone, Chad R; Thillainadarajah, Inthirany; Best, Deborah S; Nichols, Harriette P; Strader, Lillian F; Wolf, Douglas C; Narotsky, Michael G; Rockett, John C; Dix, David J

2007-01-01

Triazole fungicides associated with a range of reported male reproductive effects in experimental animals were selected to assess potential toxic modes of action. Wistar Han rats were fed myclobutanil (M: 100, 500, or 2000 ppm), propiconazole (P: 100, 500, or 2500 ppm), or triadimefon (T: 100, 500, or 1800 ppm) from gestation day 6 to postnatal day (PND) 120. One male per litter was necropsied on PND1, 22, 50, or 92. Measurements included anogenital distance (AGD) at PND0, body and organ weights, serum hormone levels, age at preputial separation (PPS), sperm morphology and motility, and fertility and fecundity. AGD was increased by the high dose of all three triazoles, indicating hypervirilization. Triadimefon delayed PPS, consistent with delayed puberty, at 1800 ppm. Relative liver weights were increased at PND1, 50, and 92 by all three triazoles. Hepatocellular hypertrophy was present at PND50 from propiconazole and triadimefon and at PND92 from all three high-dose triazole treatments. Relative pituitary weights were decreased at PND92 by middle- and high-dose myclobutanil treatment. Absolute testis weights were increased at PND1 by myclobutanil, at PND22 by myclobutanil and triadimefon, and at PND50 by propiconazole and triadimefon treatment. Relative ventral prostate weights were increased at PND92 by myclobutanil and triadimefon treatment. Serum testosterone was increased at PND50 by triadimefon and at PND92/99 by all three triazole treatments. Insemination and fertility were impaired by myclobutanil and triadimefon treatment. In addition to the reproductive system effects, total serum thyroxine levels were decreased at PND92 by high-dose triadimefon. These reproductive effects are consistent with the disruption of testosterone homeostasis as a key event in the mode of action for triazole-induced reproductive toxicity.

Modulation of male mouse genital sniff, attack, and mount behaviors by urogenital substances from estrous females.

PubMed

Weinhold, L L; Ingersoll, D W

1988-09-01

The modulation of attacks, genital sniffs, and mounts in male SJL/J mice by ovarian-dependent urogenital substances in the urine voided by estrous females was examined. Urogenital substances were applied onto the external urogenital areas of ovariectomized mice. When compared with urine voided by estrous females, which stimulated genital sniffing, mounting, and reduced aggression, bladder urine was ineffective. Genital sniffing and mounting was stimulated by estradiol-17 beta, vaginal fluids, and preputial extract. Aggression was reduced by estradiol-17 beta, urethral catheterized urine, and vaginal fluids. Preputialectomy reduced, but did not eliminate, urinary stimulation of genital sniffing and mounting. Preputial extract stimulated aggression. Urogenital substances from ovariectomized females were ineffective in reducing attacks and stimulating genital sniffs and mounts. It was concluded that the ovarian-dependent chemosignals in the urine voided by estrous females are contributed by the urethra, vagina, and preputial gland, perhaps in part through the excretion of unconjugated estrogens.

[Longitudinal preputial pedicled flap urethroplasty for chordee of Donnahoo type IV].

PubMed

Zeng, Li; Shan, Wei; Yuan, Miao; Huang, Guizhen; Huang, Lugang

2012-11-01

To investigate the effectiveness of longitudinal preputial pedicled flap urethroplasty for chordee of Donnahoo IV type. Between June 1994 and October 2011, 30 patients with chordee (Donnahoo type IV) underwent longitudinal preputial pedicled flap urethroplasty. The patients' age ranged from 2 to 16 years (mean, 5.8 years). The morphology of the balanus-navicular fossa-external urethral orifice ranged normal; the penis length was 2.5-6.8 cm (mean, 4.3 cm); the penis bending angle was 35-70 degrees (mean, 40.1 degrees). Primary and secondary operation was 27 cases and 3 cases, respectively. The size of flap ranged from 1.5 cm x 1.3 cm to 4.0 cm x 2.0 cm. After correction, the penis length was 3.0-8.5 cm (mean, 6.6 cm); the penis bending angle was 0-10 degrees (mean, 1.2 degrees). All patients were followed up 6 months to 12 years (mean, 33 months). No recurrence, stabbing pain of the balanus, or foreign body sensation occurred during follow-up. Of them, 4 patients (13.33%) had urinary fistular, they had satisfactory results after the second operation; 2 patients (6.67%) had urethral stricture 1 month after operation, they also had satisfactory results after arethral dilatation. The other patients showed no scattering urinary flow and good direction without complication. Six patients had satisfactory sexual function after puberty without erection disorder, pain, or dyspareunia. Longitudinal preputial pedicled flap urethroplasty can achieve maximum utilization of prepuce and aesthetic and functional improvement with less complication, so it is a relatively ideal mean for treating chordee of Donnahoo type IV.

Cost-effectiveness analysis of treatment alternatives for beef bulls with preputial prolapse.

PubMed

Kasari, T R; McGrann, J M; Hooper, R N

1997-10-01

To develop an economic model for comparing cost-effectiveness of medical and surgical treatment versus replacement of beef bulls with preputial prolapse. Economic analysis. Estimates determined from medical records of bulls treated for preputial prolapse at our hospital and from information about treatment of bulls published elsewhere. Annual depreciation cost for treatment (ADC(T)) and replacement (ADC(R)) were calculated. Total investment for an injured bull equaled the sum of salvage value, maintenance cost, and expected cost of the treatment option under consideration. Total investment for a replacement bull was purchase price. Net present value of cost was calculated for each year of bull use. Sensitivity analyses were constructed to determine the value that would warrant treatment of an injured bull. The decision to treat was indicated when ADC(T) was less than ADC(R). In our example, it was more cost-effective for owners to cull an injured bull. The ADC(R) was $97 less than ADC(T) for medical treatment ($365 vs $462) and $280 less than ADC(T) for surgical treatment ($365 vs $645). Likewise, net present value of cost values indicated that it was more cost-effective for owners to cull an injured bull. Sensitivity analysis indicated treatment decisions were justified on the basis of replacement value or planned number of breeding seasons remaining for the bull. The model described here can be used by practitioners to provide an objective basis to guide decision making of owners who seek advice on whether to treat or replace bulls with preputial prolapse.

Preputial skin free graft as dorsal onlay urethroplasty: Our experience of 73 patients.

PubMed

Bapat, Shivadeo S; Padhye, Abhijit S; Yadav, Pushkaraj B; Bhave, Ashish A

2007-10-01

To present the outcome of dorsal onlay urethroplasty in 73 patients for stricture urethra over a period of eight years. Seventy-three patients of stricture urethra have undergone dorsal onlay urethroplasty from July 1998 to February 2006. Age distribution: 14-58 years. Trauma 20/73 (27.39%), Balanitis Xerotica Obliterans 2/73 (2.73%), Iatrogenic 26/73(35.61%), Infection 3/73 (4.10%), Idiopathic 22/73 (30.13%). Site: Penobulbar-25/73, bulbar-38/73, membranous-8/73 and long length-2/73. Suprapubic catheter was inserted preoperatively: 21/73 patients. Preputial / distal penile skin was used in all patients. Buccal mucosa was not used in any patient. Hospitalization was for four to five days. Catheter was removed after 21 days. All patients had their first endoscopic checkup after three months. Subsequently they were followed up by uroflometry. Routine imaging of urethra for follow-up was not carried out. 63/73 (86.30%) patients had satisfactory outcome not requiring any further treatment, 8/73 (10.95%) developed anastomotic stricture (3/8-optical internal urethrotomy, 5/8 dilatation alone). 2/73 (2.75%) developed external meatal stenosis. None had urinary fistula and required repeat urethroplasty. Follow-up ranged from three months to eight years. Dorsal onlay urethroplasty using preputial/distal penile skin is a satisfactory procedure. Preputial/distal penile skin is devoid of hair and fat and hence an ideal graft material. Even in circumscribed patients distal penile skin can be harvested. Long-term follow-up is required in judging results of patients with stricture urethra.

Targeted deletion of Atg5 reveals differential roles of autophagy in keratin K5-expressing epithelia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sukseree, Supawadee; Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Bangkok; Rossiter, Heidemarie

2013-01-11

Highlights: Black-Right-Pointing-Pointer We generated mice lacking Atg5 and autophagy in keratin K5-positive epithelia. Black-Right-Pointing-Pointer Suppression of autophagy in thymic epithelium was not associated with signs of autoimmunity. Black-Right-Pointing-Pointer Autophagy was required for normal terminal differentiation of preputial gland cells. Black-Right-Pointing-Pointer Autophagy-deficient cells of the preputial glands degraded nuclear DNA prematurely. -- Abstract: Autophagy contributes to the homeostasis of many tissues, yet its role in epithelia is incompletely understood. A recent report proposed that Atg5-dependent autophagy in thymic epithelial cells is essential for their function in the negative selection of self-reactive T-cells and, thus, for the suppression of tissue inflammation. Heremore » we crossed mice carrying floxed alleles of the Atg5 gene with mice expressing the Cre recombinase under the control of the keratin K5 promoter to suppress autophagy in all K5-positive epithelia. The efficiency of autophagy abrogation was confirmed by immunoanalyses of LC3, which was converted to the autophagy-associated LC3-II form in normal but not Atg5-deficient cells, and of p62, which accumulated in Atg5-deficient cells. Mice carrying the epithelium-specific deletion of Atg5 showed normal weight gain, absence of tissue inflammation, and a normal morphology of the thymic epithelium. By contrast, autophagy-deficient epithelial cells of the preputial gland showed aberrant eosinophilic staining in histology and premature degradation of nuclear DNA during terminal differentiation. Taken together, the results of this study suggest that autophagy is dispensable for the suppression of autoimmunity by thymic epithelial cells but essential for normal differentiation of the preputial gland in mice.« less

[PREPUTIAL PEDICLED FLAP PHALLOPLASTY FOR REPAIR OF SEVERE WEBBED PENIS].

PubMed

Huang, Yidong; Zeng, Li; Huang, Guizhen; Kang, Lei; Huang, Lugang

2016-11-08

To evaluate the effectiveness of preputial pedicled flap phalloplasty for repair of severe webbed penis. Between May 2011 and May 2015, 23 boys with severe webbed penis were treated. The age ranged from 2 years and 8 months to 8 years and 3 months (mean, 4 years and 8 months). According to El-Koutby & El Gohary classification, 14 cases were rated as grade 3 simple webbed penis and 9 cases as compound webbed penis (2 cases of type 1, 2 cases of type 2, and 5 cases of type 3). The penis length was 2.1-5.4 cm (mean, 3.4 cm), and the penoscrotal angle was 130-160° (mean, 144°). All the glans could not be exposed. No other urinary system diseases and no history of penile surgery were found in children. All cases underwent one stage preputial pedicled flap phalloplasty. After successful correction, the penis length was 3.6-6.4 cm (mean, 4.7 cm); the penoscrotal angle was 90-110° (mean, 97°). Clear skin boundaries were observed at penile and scrotal parts. No web skin or scrotal skin was left on the penis. Primary healing of incision was obtained, with no necrosis of the flap or infection. All cases were followed up 12 to 41 months (mean, 25 months). No penile curvature, abnormal sensation of glans, or recurrence of the penoscrotal angle occurred, and the patients had normal urination. Preputial pedicled flap phalloplasty can be used as one stage repair for severe webbed penis. The penis is close to natural state and had satisfactory appearance, avoiding the possibility of long-term edema and penile curvature.

Results of a Two-stage Technique for Treatment of Proximal Hypospadias with Severe Curvature: Creation of a Urethral Plate Using a Vascularized Preputial Island Flap.

PubMed

Ozcan, Rahsan; Emre, Senol; Kendigelen, Pinar; Elicevik, Mehmet; Emir, Haluk; Soylet, Yunus; Buyukunal, S N Cenk

2016-04-16

To present the results of a two-stage technique used for the treatment of proximal hypospadias with severe curvature. The medical records of children with proximal hypospadias and severe curvature were retrospectively analyzed. A 2-stage procedure was performed in 30 children. In the first stage, the release of chordee was performed, and a well-vascularized preputial island flap was created. The vascularized island flap was brought anteriorly and sutured over the ventral surface of the glans and degloved penile shaft. The second stage was performed 6-8 months later. A neourethra was reconstructed by the tubularization of the preputial-urethral plate utilizing the principles of Duplay technique. All surgical procedures were performed between 2005 and 2011. The mean age of the patients was 4.4 years (1-17 years). The mean duration of urethral catheterization was 6 days after the first stage and 10 days following the second stage. The flaps were viable in all of the children. There was no residual chordee. Following the second stage (n = 30), complications developed in 11 children (36%), namely, a fistula in 7, a pinpoint fistula in 3, and a diverticulum formation in 1. The cosmetic outcome was satisfactory. Uroflowmetry measurements were evaluated, and only one patient had a diverticulum formation at the late follow-up. Vascularized preputial island flap is an alternative to free grafts for the reconstruction of the urethra. The main advantage of this flap technique is the creation of a thick, healthy and well-vascularized urethral plate. The advantages of this technique include better aesthetic appearance, an acceptable complication rate, and a very low rate of diverticula formation.

A novel technique for repair of mid-penile hypospadias using a preputial skin flap: results of 110 patients.

PubMed

Elmoghazy, Hazem; Hussein, Mohamed M; Mohamed, Elnisr; Badawy, Abdelbasset; Alsagheer, Gamal; Abd Elhamed, Ahmed Mamdouh

2016-12-01

Several techniques have been used to repair mid-penile hypospadias; however, high failure rates and major complications have been reported. In this study, we describe a novel technique using a well-vascularized flap of the inner and outer preputial skin. A total of 110 male children with hypospadias underwent repair by our technique between 2008 and 2015. The inclusion criteria were children with mid-penile or slightly more proximal hypospadias, with or without ventral chordae, and an intact prepuce of the cobra eyes variety. Recurrent cases, patients with other preputial types, and circumcised children were excluded from this study. The prepared flap was sutured in its natural longitudinal orientation to the created urethral plate strip to form a neo-urethra over a urethral catheter. Outcome measures included surgical success without the formation of a urethra-cutaneous fistula, no ischaemia of the flaps, glans dehiscence or infection and functional outcome and cosmetic appearance. The median follow-up duration was 3.3 years. There were 63 cases of mid-penile hypospadias (57.3 %), and in 47 cases (42.7 %), the meatus was slightly more proximal. The age of the patients ranged from 1.1 to 8.0 years, with a mean age of 4.6 ± 1.2 years. Surgery was successful in 106 (96.4 %) cases. Minor complications occurred in 11 patients (10 %) and included oedema of glans in ten patients and bluish discoloration on the ventral aspect of the glans close to the suture line in three patients. All patients improved within 2 weeks after surgery. Long-term follow-up revealed a properly functioning urethra with a forward, projectile, single, compact, and rifled urinary stream of adequate calibre and cosmetically acceptable repair. No cases of meatal retraction, meatal stenosis, urethral stricture, or acquired urethral diverticulum occurred. Our technique is different from the split prepuce in situ technique. We create a narrow strip of the urethral plate that facilitates glanular closure, and we use the inner and adjacent outer skin in a vertical manner to preserve excess skin for penile coverage. Prepuce is split at midline to preserve more preputial skin with favourable dartos tissue for penile skin coverage. The glans is closed using a stitch-by-stitch method that has not been described previously. This study presents a novel technique for mid-penile hypospadias repair using a preputial skin flap with excellent results in terms of short- and long-term outcomes.

Ureaplasma serotypes associated with the bovine urogenital tract.

PubMed Central

Truscott, R B

1983-01-01

One hundred and thirty-one ureaplasma isolates were tested using the immunoperoxidase system. Thirty-four were from semen, 34 from preputial washes of normal bulls and 63 were from vaginal swabs from herds experiencing infertility problems and/or vulvovaginitis. The serotypes from semen were T44 (12.1%), Bu2 (11.2%), D48 (2.8%), T315 (0.9%) and T288 (0.9%). Those from preputial washes were T44 (9.3%), Bu2 (8.4%), T288 (7.5%), D48 (0.9%) and T95 (0.9%). From vaginal swabs the serotypes were D48 (22.4%), Bu2 (10.3%), T45 (4.7%), T288 (3.8%) and T315 (1.9%). PMID:6365295

Transverse preputial onlay island flap urethroplasty for single-stage correction of proximal hypospadias.

PubMed

Singal, Arbinder Kumar; Dubey, Manish; Jain, Viral

2016-07-01

Transverse preputial onlay island flap urethroplasty (TPOIF) was described initially for distal hypospadias, but has seen extended application for proximal hypospadias. We describe a set of modifications in the technique and results in a large series of proximal hypospadias. All children who underwent TPOIF repair for proximal hypospadias (proximal penile, penoscrotal and scrotal) from June 2006 to June 2013 by a single surgeon were prospectively followed till June, 2014. A standard technique and postoperative protocol were followed. Salient points to be emphasized in the technique: (1) dissection of the dartos pedicle till penopubic junction to prevent penile torsion, (2) incorporation of the spongiosum in the urethroplasty, (3) midline urethral plate incision in glans (hinging the plate), (4) Dartos blanket cover on whole urethroplasty. Out of 136 children with proximal hypospadias, 92 children who underwent TPOIF formed the study group. Out of 92 children, 48 (52 %) children required a tunica albuginea plication for chordee correction. In total, 16 (17 %) patients developed 24 complications and 11 children (12 %) required second surgeries: fistula closure in 7 (with meatoplasty in 5), glansplasty for glans dehiscence in 2 and excision of diverticulum in 2. Two children required a third surgery. Only 5 children had a noticeable penile torsion (less than 30 degree), and 7 had a patulous meatus. Transverse preputial onlay island flap urethroplasty can deliver reliable cosmetic and functional outcomes in proximal hypospadias.

Single-Staged Improved Tubularized Preputial/Penile Skin Flap Urethroplasty for Obliterated Anterior Urethral Stricture: Long-Term Results.

PubMed

Xue, Jing-Dong; Xie, Hong; Fu, Qiang; Feng, Chao; Guo, Hui; Xu, Yue-Min

2016-01-01

To present an improved tubularized flap (ITF) technique and report the outcome of single-stage urethroplasty using preputial/penile skin flaps (PSFs) for the treatment of obliterative anterior urethral strictures (AUSs). From January 2000 to June 2012, 42 cases of obliterative AUS (3-14 cm, mean 6.38 cm) with urethral plate unsalvageable were treated using PSF-ITF urethroplasty including longitudinal skin flap, circular island flap, L-flap, Q-flap. Patients were divided into 3 groups: pendulous urethral stricture (Group A), bulbar urethral stricture (Group B) and panurethral strictures (Group C). Patients were followed up by uroflowmetry, urethrography and ureteroscope when necessary. The mean follow-up in these patients was 65 months (range 36 months-15 years). The primary success rates at 3-year follow-up were 75, 75 and 60% for Groups A, B and C, respectively. The overall success rates were 85, 83 and 70% with the remedial measure of a single visual internal urethrotomy at 3-year follow-up. A total 60% of the patients in the study completed more than 5 years of follow-up with no additional recurrence. Improved tubularized preputial/PSF urethroplasty with relatively high overall satisfaction is a novel technique for treatment of AUS when there is inadequate urethral plate or obliterative defects. © 2016 S. Karger AG, Basel.

Balanitis xerotica obliterans in children and its incidence under the age of 5 years.

PubMed

Jayakumar, S; Antao, B; Bevington, O; Furness, P; Ninan, G K

2012-06-01

To analyse the incidence of BXO among paediatric circumcisions for preputial pathology, in particular in children under the age of 5 years. Retrospective review revealed 1769 paediatric circumcisions performed between 1997 and 2008 at our institution. Data were collected on patient's age, date when sample received by pathology department and histological findings for all the foreskin samples received and examined during the study period. Epidemiological data were obtained from the Office for National Statistics, UK. A total of 346 foreskin samples were received and BXO was found in 182 (52.6%). There were 31 children under the age of 5 years circumcised for preputial pathology. BXO was reported in 6 (19.3%) and chronic inflammation in 16 (51.6%) of these patients. The foreskin was reported normal in 2 (6.5%) and the remaining 7 (22.6%) patients had preputial cysts or other pathology. Epidemiological population data analysis revealed the incidence of BXO per year to be 3.01 cases/1000 boys under 15 years of age and 0.322 cases/1000 boys under 5 years. The incidence of BXO in boys noted in our study is higher than previously reported. BXO can result in significant complications and should be considered in children even under 5 years. Copyright © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Fly Caught in Foreskin: An Usual Case of Preputial Myiasis

PubMed Central

Parkinson, Richard J; Robinson, Simon; Lessells, Richard; Lemberger, John

2008-01-01

Cutaneous bot fly infestation is common in travellers to Mexico and Central America. Myiasis affecting the genitalia is rare, however, with few previous reports. We document an unusual case in Nottingham, UK PMID:18492386

Cumulative and antagonistic effects of a mixture of the antiandrogens vinclozolin and iprodione in the pubertal male rat.

PubMed

Blystone, Chad R; Lambright, Christy S; Cardon, Mary C; Furr, Johnathan; Rider, Cynthia V; Hartig, Phillip C; Wilson, Vickie S; Gray, Leon E

2009-09-01

Vinclozolin and iprodione are dicarboximide fungicides that display antiandrogenic effects in the male rat, which suggests that a mixture would lead to cumulative effects on androgen-sensitive end points. Iprodione is a steroid synthesis inhibitor, but androgen receptor antagonist activity, which is displayed by vinclozolin, has not been fully evaluated. Here, we demonstrate that iprodione binds to the human androgen receptor (IC(50) = 86.0 microM), reduces androgen-dependent gene expression, and reduces androgen-sensitive tissue weights in castrated male rats (Hershberger assay). Since vinclozolin and iprodione affect common targets in the pubertal male rat, we tested the hypothesis that a mixture would have cumulative antiandrogenic effects. An iprodione dose, that does not significantly affect androgen-dependent morphological end points, was combined with vinclozolin doses (2 x 5 factorial design). Sprague-Dawley rats were dosed by gavage with vinclozolin at 0, 10, 30, 60, and 100 mg/kg/day with and without 50 mg iprodione/kg/day from postnatal day (PND) 23 to 55-57 (n = 8 per group). The age at puberty (preputial separation [PPS]), organ weights, serum hormones, and ex vivo testis steroid hormone production were measured. Vinclozolin delayed PPS, reduced androgen-sensitive organ weights, and increased serum testosterone. The addition of iprodione enhanced the vinclozolin inhibition of PPS (PND 47.5 vs.49.1; two-way ANOVA: iprodione main effect p = 0.0002). The dose response for several reproductive and nonreproductive organ weights was affected in a cumulative manner. In contrast, iprodione antagonized the vinclozolin-induced increase in serum testosterone. These results demonstrate that these fungicides interact on common targets in a tissue-specific manner when coadministered to the pubertal male rat.

Anatomy of mole external genitalia: Setting the record straight

PubMed Central

Sinclair, Adriane Watkins; Glickman, Stephen; Baskin, Lawrence; Cunha, Gerald R.

2016-01-01

Anatomy of male and female external genitalia of adult mice (Mus musculus) and broad-footed moles (Scapanus latimanus) was re-examined to provide more meaningful anatomical terminology. In the past the perineal appendage of male broad-footed moles has been called the penis, while the female perineal appendage has been given several terms (e.g. clitoris, penile clitoris, peniform clitoris and others). Histological examination demonstrates that perineal appendages of male and female broad-footed moles are the prepuce, which in both sexes are covered externally with a hair-bearing epidermis and lacks erectile bodies. The inner preputial epithelium is non-hair-bearing and defines the preputial space in both sexes. The penis of broad-footed moles lies deep within the preputial space, is an “internal organ” in the resting state and contains the penile urethra, os penis, and erectile bodies. The clitoris of broad-footed moles is defined by a U-shaped clitoral epithelial lamina. Residing within clitoral stroma encompassed by the clitoral epithelial lamina is the corpus cavernosum, blood-filled spaces and the urethra. External genitalia of male and female mice are anatomically similar to that of broad-footed moles with the exception that in female mice the clitoris contains a small os clitoridis and lacks defined erectile bodies, while male mice have an os penis and a prominent distal cartilaginous structure within the male urogenital mating protuberance (MUMP). Clitori of female broad-footed moles lack an os clitoridis but contain defined erectile bodies, while male moles have an os penis similar to the mouse but lack the distal cartilaginous structure. PMID:26694958

Surgical Repair of Mid-shaft Hypospadias Using a Transverse Preputial Island Flap and Pedicled Dartos Flap Around Urethral Orifice.

PubMed

Liang, Weiqiang; Ji, Chenyang; Chen, Yuhong; Zhang, Ganling; Zhang, Jiaqi; Yao, Yuanyuan; Zhang, Jinming

2016-08-01

To evaluate the effects, particularly the incidence of anastomotic fistula, of a pedicled dartos flap around the urethral orifice in the treatment of urethroplasty of mid-shaft hypospadias. A total of 46 cases of congenital mid-shaft hypospadias were included in this study. The patients ranged in age from 0.7 to 25.4 years and the average was 5.8 years. The patients received penis chordee correction. A transverse preputial island flap was developed for urethral reconstruction. The proximal dartos of the urethral orifice was used to develop a pedicled dartos flap, which was transposed to cover and strengthen neourethral anastomosis. The ventral penile skin defect was repaired by another flap. The 46 patients were examined during follow-up visits for 6 months to 3 years. An anastomotic fistula was observed in one case (2.2 %). Scar healing without fistula was observed in another patient due to poor blood supply to part of the ventral penile skin. No other incidences of fistula, urethral rupture, flap necrosis, wound infections, urinary tract (meatal) stenosis, or urethral diverticulum were observed in the patients. A pedicled dartos flap around the urethral orifice can take advantage of well-vascularized local tissue to add a protective layer to the proximal aspect of the neourethral anastomosis for reducing the incidence of anastomotic fistula in mid-shaft hypospadias repair using a transverse preputial island flap. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Vibriosis: Demonstration of Vibrio fetus and Vibrio bubulus Organisms in Preputial Fluid by Immunofluorescence and Cultural Techniques

PubMed Central

Ruckerbauer, Gerda M.; Malkin, K.; Mitchell, D.; Boulanger, P.

1974-01-01

Fluorescent conjugates were prepared from the sera of calves immunized with four Vibrio fetus strains and one Vibrio bubulus strain. The fluorescent antibody technique (FAT) was then used to detect vibrio organisms in preputial fluid collected from 67 bulls belonging to a Canadian artificial insemination (AI) unit. The V. fetus conjugates reacted with both V. fetus var venerealis and V. fetus var intestinalis. V. fetus was found in 20 animals (29.9%), 13 of which also harboured V. bubulus. In two cases, the FAT failed to detect V. fetus which was isolated by concurrent bacteriological examinations. It was concluded that the FAT can be a rapid method of detecting some carrier bulls but more reliable results are obtained when a combination of FAT and bacteriological methods is employed. It was found that a single sample giving negative results is inconclusive and additional tests are required before making a final diagnosis. The FAT can also be used to differentiate V. fetus isolates from V. bubulus. PMID:4277756

Evaluation of long-acting oxytetracycline and a commercial monovalent vaccine for the control of Campylobacter fetus subsp. venerealis infection in beef bulls.

PubMed

Erickson, Nathan E N; Lanigan, Emily; Waugh, Taryn; Gesy, Karen; Waldner, Cheryl

2017-10-01

A blinded randomized controlled trial was used to evaluate a multi-modal therapeutic regime for treatment of beef bulls infected with Campylobacter fetus subsp. venerealis (Cfv) . Treatment included 2 doses of a commercially available monovalent vaccine and long-acting oxytetracycline applied twice at a 2-week interval with treatment completed 2 weeks before post-treatment observation. Fifteen confirmed Cfv infected bulls were randomly allocated to control ( n = 8) or treatment groups ( n = 7). Preputial scrapings were collected each week from before infection to 11 weeks following the last treatment. When the polymerase chain reaction (PCR) results for both culture and preputial scrapings were interpreted in parallel, there were no significant differences between treated and untreated bulls. Regardless of the type of diagnostic testing considered, treatment with 2 label doses of this regime did not stop shedding of Cfv in all treated bulls and is, therefore, not recommended as an effective management strategy.

Evaluation of long-acting oxytetracycline and a commercial monovalent vaccine for the control of Campylobacter fetus subsp. venerealis infection in beef bulls

PubMed Central

Erickson, Nathan E.N.; Lanigan, Emily; Waugh, Taryn; Gesy, Karen; Waldner, Cheryl

2017-01-01

A blinded randomized controlled trial was used to evaluate a multi-modal therapeutic regime for treatment of beef bulls infected with Campylobacter fetus subsp. venerealis (Cfv). Treatment included 2 doses of a commercially available monovalent vaccine and long-acting oxytetracycline applied twice at a 2-week interval with treatment completed 2 weeks before post-treatment observation. Fifteen confirmed Cfv infected bulls were randomly allocated to control (n = 8) or treatment groups (n = 7). Preputial scrapings were collected each week from before infection to 11 weeks following the last treatment. When the polymerase chain reaction (PCR) results for both culture and preputial scrapings were interpreted in parallel, there were no significant differences between treated and untreated bulls. Regardless of the type of diagnostic testing considered, treatment with 2 label doses of this regime did not stop shedding of Cfv in all treated bulls and is, therefore, not recommended as an effective management strategy. PMID:28966354

HORMONAL AND PHYSICAL MARKERS OF PUBERTY AND THEIR RELATIONSHIP TO ADOLESCENT-TYPICAL NOVELTY-DIRECTED BEHAVIOR

PubMed Central

Vetter-O’Hagen, Courtney S.; Spear, Linda P.

2011-01-01

The extent to which characteristic adolescent behaviors are associated with pubertal changes or driven by more general, puberty-independent developmental alterations is largely unknown. Using physiological and hormonal markers of puberty, this experiment characterized pubertal timing across adolescence and examined the relationships among these variables and novelty-directed behaviors. Males and females were tested for response to novelty at P28, P32, P36, P40, P44, P48 and P75, and examined for balano-preputial skinfold separation and sperm presence (males) or vaginal opening (females), followed by blood collection for hormonal assessments. Despite earlier pubertal maturation in females, with maturation generally completed by P36 in females and P44 in males, novelty-directed behavior peaked at P32 and P36 in both sexes, and was unrelated to pubertal measures. These data support the suggestion that the ontogenetic peak in this behavior during adolescence is not notably puberty-dependent. PMID:21953609

Intra-operative hyperthermia in a young Angus bull with a fatal outcome.

PubMed

Skelding, Alicia; Valverde, Alexander

2017-06-01

A healthy, 9-month-old black Angus bull was presented for elective penile-preputial translocation and caudal epididymectomy. After premedication and induction, general anesthesia was maintained with inhalant anesthetic. Over an hour into the anesthetic period the bull developed severe hyperthermia and hypercapnia that resulted in fatality despite treatment efforts.

Identification of volatiles from the secretions and excretions of African wild dogs (Lycaon pictus).

PubMed

Apps, Peter; Mmualefe, Lesego; McNutt, J Weldon

2012-11-01

Gas chromatography/mass spectrometry was used to identify 103 organic compounds from urine, feces, anal glands, and preputial glands of free-ranging African wild dogs, Lycaon pictus. Aliphatic acids were the dominant class of compound in all materials. In addition to aliphatic acids, urine contained dimethyl sulfone, 1,3-propanediol, benzoic acid, 1-methyl-2,4-imidazolidinedione, and squalene as major components: feces contained indole and cholesterol; and both contained 2-piperidone, phenol, 4-methyl phenol, benzeneacetic acid, and benzenepropanoic acid and other compounds. Anal gland secretion was particularly rich in cholesterol and fatty acids, and preputial gland secretion rich in squalene. A large majority of the identified compounds have been reported from other mammals, including species sympatric with African wild dogs. Eleven of the African wild dog components have not been reported previously from mammals and have not been found in sympatric species; one component, 1-methylimidazole-5-carboxaldehyde has not been reported previously as a natural product. In the chemical profiles of their urine, feces, and anal gland secretion African wild dogs differ markedly from other canids.

An F1-extended one-generation reproductive toxicity study in Crl:CD(SD) rats with 2,4-dichlorophenoxyacetic acid.

PubMed

Marty, Mary Sue; Neal, Barbara H; Zablotny, Carol L; Yano, Barry L; Andrus, Amanda K; Woolhiser, Michael R; Boverhof, Darrell R; Saghir, Shakil A; Perala, Adam W; Passage, Julie K; Lawson, Marie A; Bus, James S; Lamb, James C; Hammond, Larry

2013-12-01

2,4-Dichlorophenoxyacetic acid (2,4-D) was assessed for systemic toxicity, reproductive toxicity, developmental neurotoxicity (DNT), developmental immunotoxicity (DIT), and endocrine toxicity. CD rats (27/sex/dose) were exposed to 0, 100, 300, 600 (female), or 800 (male) ppm 2,4-D in diet. Nonlinear toxicokinetic behavior was shown at high doses; the renal clearance saturation threshold for 2,4-D was exceeded markedly in females and slightly exceeded in males. Exposure was 4 weeks premating, 7 weeks postmating for P1 males and through lactation for P1 females. F1 offspring were examined for survival and development, and at weaning, pups were divided in cohorts, by sex and dose, and by systemic toxicity (10), DNT (10), DIT (20), and reproductive toxicity (≥ 23). Remaining weanlings were evaluated for systemic toxicity and neuropathology (10-12). Body weight decreased during lactation in high-dose P1 females and in F1 pups. Kidney was the primary target organ, with slight degeneration of proximal convoluted tubules observed in high-dose P1 males and in high-dose F1 males and females. A slight intergenerational difference in kidney toxicity was attributed to increased intake of 2,4-D in F1 offspring. Decreased weanling testes weights and delayed preputial separation in F1 males were attributed to decreased body weights. Endocrine-related effects were limited to slight thyroid hormone changes and adaptive histopathology in high-dose GD 17 dams seen only at a nonlinear toxicokinetic dose. 2,4-D did not cause reproductive toxicity, DNT, or DIT. The "No Observed Adverse Effect Level" for systemic toxicity was 300 ppm in both males (16.6 mg/kg/day) and females (20.6 mg/kg/day), which is approximately 6700- to 93 000-fold higher than that reported for 2,4-D exposures in human biomonitoring studies.

An F1-Extended One-Generation Reproductive Toxicity Study in Crl:CD(SD) Rats With 2,4-Dichlorophenoxyacetic Acid

PubMed Central

Marty, Mary Sue

2013-01-01

2,4-Dichlorophenoxyacetic acid (2,4-D) was assessed for systemic toxicity, reproductive toxicity, developmental neurotoxicity (DNT), developmental immunotoxicity (DIT), and endocrine toxicity. CD rats (27/sex/dose) were exposed to 0, 100, 300, 600 (female), or 800 (male) ppm 2,4-D in diet. Nonlinear toxicokinetic behavior was shown at high doses; the renal clearance saturation threshold for 2,4-D was exceeded markedly in females and slightly exceeded in males. Exposure was 4 weeks premating, 7 weeks postmating for P1 males and through lactation for P1 females. F1 offspring were examined for survival and development, and at weaning, pups were divided in cohorts, by sex and dose, and by systemic toxicity (10), DNT (10), DIT (20), and reproductive toxicity (≥ 23). Remaining weanlings were evaluated for systemic toxicity and neuropathology (10–12). Body weight decreased during lactation in high-dose P1 females and in F1 pups. Kidney was the primary target organ, with slight degeneration of proximal convoluted tubules observed in high-dose P1 males and in high-dose F1 males and females. A slight intergenerational difference in kidney toxicity was attributed to increased intake of 2,4-D in F1 offspring. Decreased weanling testes weights and delayed preputial separation in F1 males were attributed to decreased body weights. Endocrine-related effects were limited to slight thyroid hormone changes and adaptive histopathology in high-dose GD 17 dams seen only at a nonlinear toxicokinetic dose. 2,4-D did not cause reproductive toxicity, DNT, or DIT. The “No Observed Adverse Effect Level” for systemic toxicity was 300 ppm in both males (16.6mg/kg/day) and females (20.6mg/kg/day), which is approximately 6700- to 93 000-fold higher than that reported for 2,4-D exposures in human biomonitoring studies. PMID:24072463

New Technique for the Treatment of Buried Penis in Children.

PubMed

Liu, Feng; Lin, Tao; He, Dawei; Wei, Guanghui; Liu, Junhong; Liu, Xing; Hua, Yi; Zhang, Deying; Lu, Peng; Wu, Shengde; Li, Xuliang

2016-02-01

To present our treatment experience of buried penis, which has no consensus therapeutic technique for all cases of buried penis, by using a new technique for the repair of this condition, in which the approach is through the ventral penile root. We performed a retrospective review of 153 patients (median age: 6.5 years) who underwent repair of a buried penis between March 2005 and March 2013. The technique involves the creation of a wedge-shaped cut of the ventral penile skin, followed by fixation of the subcutaneous penile skin at the base of the degloved penis to the Buck fascia at the 2- and 10-o'clock positions. The ventral outer preputial skin is split down the midline, and the dorsal inner preputial skin is cut with oblique incision. All patients were followed for an average of 12 months after repair. Other than 2 cases (1.3%) of trapped penis with a ring of scar tissue, which required subsequent excision, there were no complications and the cosmetic appearance was satisfactory. The described ventral penile approach is a simple and effective procedure with good cosmetic outcomes and few complications. Copyright © 2016 Elsevier Inc. All rights reserved.

Severe forms of concealed penis without hypospadias: Surgical strategies

PubMed Central

de Jesus, Lisieux Eyer; Dekermacher, Samuel; Anderson, Kleber M.

2015-01-01

Introduction: Concealed penis (CP) may vary in severity and includes megaprepuce (MP) as a variant. Many different surgical strategies have been described in order to maximize penile exposure and to deal with skin deficiency. We describe the strategies that we use to overcome technical problems in severe cases of CP. Materials and Methods: Six consecutive cases of severe CP (including 3 with MP) were treated in a 2-year period between January 2011 and April 2013. These patients were treated using extensive degloving, removal of dysplastic dartos, Alexander's preputial flap, scrotal flaps and skin grafts. Three patients had been previously circumcised. Cases associated with hypospadias, obesity, disorders of sexual differentiation and micropenises were excluded. Results: All six patients attained good results, with good exposure of the penis, ability to void standing with a well-directed flow and reasonable esthetic results. A technical algorithm for the treatment of primary or recurring cases of CP is proposed. Conclusion: Alexander’ s distally based ventral preputial flap is a useful technical resource to treat MP cases. Free skin grafts and/or laterally based scrotal flaps may be used to cover the penis after release in severe cases of CP. PMID:26604447

Optimal Integration of Departures and Arrivals in Terminal Airspace

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2013-01-01

Coordination of operations with spatially and temporally shared resources, such as route segments, fixes, and runways, improves the efficiency of terminal airspace management. Problems in this category are, in general, computationally difficult compared to conventional scheduling problems. This paper presents a fast time algorithm formulation using a non-dominated sorting genetic algorithm (NSGA). It was first applied to a test problem introduced in existing literature. An experiment with a test problem showed that new methods can solve the 20 aircraft problem in fast time with a 65% or 440 second delay reduction using shared departure fixes. In order to test its application in a more realistic and complicated problem, the NSGA algorithm was applied to a problem in LAX terminal airspace, where interactions between 28% of LAX arrivals and 10% of LAX departures are resolved by spatial separation in current operations, which may introduce unnecessary delays. In this work, three types of separations - spatial, temporal, and hybrid separations - were formulated using the new algorithm. The hybrid separation combines both temporal and spatial separations. Results showed that although temporal separation achieved less delay than spatial separation with a small uncertainty buffer, spatial separation outperformed temporal separation when the uncertainty buffer was increased. Hybrid separation introduced much less delay than both spatial and temporal approaches. For a total of 15 interacting departures and arrivals, when compared to spatial separation, the delay reduction of hybrid separation varied between 11% or 3.1 minutes and 64% or 10.7 minutes corresponding to an uncertainty buffer from 0 to 60 seconds. Furthermore, as a comparison with the NSGA algorithm, a First-Come-First-Serve based heuristic method was implemented for the hybrid separation. Experiments showed that the results from the NSGA algorithm have 9% to 42% less delay than the heuristic method with varied uncertainty buffer sizes.

Use of lomustine (CCNU) in a case of cutaneous equine lymphoma

PubMed Central

Doyle, Aimie J.; MacDonald, Valerie S.; Bourque, Andrea

2013-01-01

A 12-year-old gelding was diagnosed with recurrent lymphoma in multiple cutaneous sites. A highly invasive preputial mass caused urethral obstruction. The horse was treated with surgery and chemotherapy consisting of lomustine (CCNU) and prednisolone. The treatment was well-tolerated and effective. This is the first reported use of lomustine (CCNU) in a horse for the treatment of equine lymphoma. PMID:24293673

The effect of atrazine on puberty in male wistar rats: an evaluation in the protocol for the assessment of pubertal development and thyroid function.

PubMed

Stoker, T E; Laws, S C; Guidici, D L; Cooper, R L

2000-11-01

Since atrazine (ATR), a chlorotriazine herbicide, has been shown previously to alter the secretion of luteinizing hormone (LH) and prolactin (PRL) through a direct effect on the central nervous system (CNS), we hypothesized that exposure to ATR in the EDSTAC male pubertal protocol (juvenile to peripubertal) would alter the development of the male rat reproductive system. We dosed intact male Wistar rats from postnatal day (PND) 23 to 53 and examined several reproductive endpoints. ATR (0, 12.5, 25, 50, 100, 150, or 200 mg/kg) was administered by gavage and an additional pair-fed group was added to compare the effects of any decreased food consumption in the high dose group. Preputial separation (PPS) was significantly delayed in the 12.5, 50, 100, 150, and 200 mg/kg ATR dose groups. PPS was also delayed in the pair-fed group, although significantly less than in the high dose-ATR group. The males were killed on PND 53 or 54, and pituitary, thyroid, testes, epididymides, seminal vesicles, and ventral and lateral prostates were removed. ATR (50 to 200 mg/kg) treatment resulted in a significant reduction in ventral prostate weights, as did the reduced food consumption of the pair-fed group. Testes weights were unaffected by atrazine treatment. Seminal vesicle and epididymal weights were decreased in the high dose-ATR group and the control pair-fed group. However, the difference in epididymal weights was no longer significantly different when body weight was entered as a covariable. Intratesticular testosterone was significantly decreased in the high dose-ATR group on PND 45, but apparent decreases in serum testosterone were not statistically significantly on PND 53. There was a trend for a decrease in luteinizing hormone (LH) as the dose of ATR increased; however, dose group mean LH was not different from controls. Due to the variability of serum prolactin concentrations on PND 53, no significant difference was identified. Although prolactin is involved in the maintenance of LH receptors prior to puberty, we observed no difference in LH receptor number at PND 45 or 53. Serum estrone and estradiol showed dose-related increases that were significant only in the 200 mg/kg-ATR group. No differences were observed in thyroid stimulating hormone (TSH) and thyroxine (T4) between the ATR groups and the control; however triiodothyronine (T3) was elevated in the high dose-ATR group. No differences in hormone levels were observed in the pair-fed animals. These results indicate that ATR delays puberty in the male rat and its mode of action appears to be altering the secretion of steroids and having subsequent effects on the development of the reproductive tract, which appear to be due to ATR's effects on the CNS. Thus, ATR tested positive in the pubertal male screen that the Endocrine-Disrupter Screening and Testing Advisory Committee (EDSTAC) is considering as an optional screen for endocrine disrupters.

OECD validation of the rodent Hershberger assay using three reference chemicals; 17alpha-methyltestosterone, procymidone, and p,p'-DDE.

PubMed

Shin, Jae-Ho; Moon, Hyun Ju; Kang, Il Hyun; Kim, Tae Sung; Lee, Su Jung; Ahn, Ji Youn; Bae, Hoon; Jeung, Eui Bae; Han, Soon Young

2007-05-01

The rodent Hershberger assay is being validated as an in vivo test method for detecting androgenic or antiandrogenic compounds by the Organization for Economic Cooperation and Development (OECD). As part of the international validation work, we studied 17alpha-methyltestosterone for evaluating androgenic activity, and procymidone and p,p'-DDE for evaluating antiandrogenic activity. Male Sprague-Dawley rats were castrated at postnatal day 42, and only the rats that showed preputial separation were used in this study. Seven days after castration, chemicals were administered daily by gavages to groups of rats for 10 days, as recommended by OECD phase-2 protocol. Administration of 17alpha-methyltestosterone induced increases of weights of accessory sex tissues and glands in a dose-dependent manner. Administration of procymidone and p,p'-DDE produced a dose-dependent decrease of weights of accessory sex tissues and glands in the rats co-treated with testosterone propionate (0.4 mg/kg/day) subcutaneously. Our data strongly suggested that the current protocol of OECD Hershberger assay (phase-2) should be used as a reliable method for the detection of endocrine related toxicity of other chemicals.

Mammalian Wax Biosynthesis

PubMed Central

Cheng, Jeffrey B.; Russell, David W.

2009-01-01

Wax monoesters are synthesized by the esterification of fatty alcohols and fatty acids. A mammalian enzyme that catalyzes this reaction has not been isolated. We used expression cloning to identify cDNAs encoding a wax synthase in the mouse preputial gland. The wax synthase gene is located on the X chromosome and encodes a member of the acyltransferase family of enzymes that synthesize neutral lipids. Expression of wax synthase in cultured cells led to the formation of wax monoesters from straight chain saturated, unsaturated, and polyunsaturated fatty alcohols and acids. Polyisoprenols also were incorporated into wax monoesters by the enzyme. The wax synthase had little or no ability to synthesize cholesteryl esters, diacylglycerols, or triacylglycerols, whereas other acyltransferases, including the acyl-CoA:monoacylglycerol acyltransferase 1 and 2 enzymes and the acyl-CoA:diacylglycerol acyltransferase 1 and 2 enzymes, exhibited modest wax monoester synthesis activities. Confocal light microscopy indicated that the wax synthase was localized in membranes of the endoplasmic reticulum. Wax synthase mRNA was abundant in tissues rich in sebaceous glands such as the preputial gland and eyelid and was present at lower levels in other tissues. Coexpression of cDNAs specifying fatty acyl-CoA reductase 1 and wax synthase led to the synthesis of wax monoesters. The data suggest that wax monoester synthesis in mammals involves a two step biosynthetic pathway catalyzed by fatty acyl-CoA reductase and wax synthase enzymes. PMID:15220349

Impact of Pilot Delay and Non-Responsiveness on the Safety Performance of Airborne Separation

NASA Technical Reports Server (NTRS)

Consiglio, Maria; Hoadley, Sherwood; Wing, David; Baxley, Brian; Allen, Bonnie Danette

2008-01-01

Assessing the safety effects of prediction errors and uncertainty on automationsupported functions in the Next Generation Air Transportation System concept of operations is of foremost importance, particularly safety critical functions such as separation that involve human decision-making. Both ground-based and airborne, the automation of separation functions must be designed to account for, and mitigate the impact of, information uncertainty and varying human response. This paper describes an experiment that addresses the potential impact of operator delay when interacting with separation support systems. In this study, we evaluated an airborne separation capability operated by a simulated pilot. The experimental runs are part of the Safety Performance of Airborne Separation (SPAS) experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assistance systems. Pilot actions required by the airborne separation automation to resolve traffic conflicts were delayed within a wide range, varying from five to 240 seconds while a percentage of randomly selected pilots were programmed to completely miss the conflict alerts and therefore take no action. Results indicate that the strategicAirborne Separation Assistance System (ASAS) functions exercised in the experiment can sustain pilot response delays of up to 90 seconds and more, depending on the traffic density. However, when pilots or operators fail to respond to conflict alerts the safety effects are substantial, particularly at higher traffic densities.

Developmental Treatment with Ethinyl Estradiol, but Not Bisphenol A, Causes Alterations in Sexually Dimorphic Behaviors in Male and Female Sprague Dawley Rats

PubMed Central

Ferguson, Sherry A.; Law, Charles Delbert; Kissling, Grace E.

2014-01-01

The developing central nervous system may be particularly sensitive to bisphenol A (BPA)-induced alterations. Here, pregnant Sprague Dawley rats (n = 11–12/group) were gavaged daily with vehicle, 2.5 or 25.0 μg/kg BPA, or 5.0 or 10.0 μg/kg ethinyl estradiol (EE2) on gestational days 6–21. The BPA doses were selected to be below the no-observed-adverse-effect level (NOAEL) of 5 mg/kg/day. On postnatal days 1–21, all offspring/litter were orally treated with the same dose. A naïve control group was not gavaged. Body weight, pubertal age, estrous cyclicity, and adult serum hormone levels were measured. Adolescent play, running wheel activity, flavored solution intake, female sex behavior, and manually elicited lordosis were assessed. No significant differences existed between the vehicle and naïve control groups. Vehicle controls exhibited significant sexual dimorphism for most behaviors, indicating these evaluations were sensitive to sex differences. However, only EE2 treatment caused significant effects. Relative to female controls, EE2-treated females were heavier, exhibited delayed vaginal opening, aberrant estrous cyclicity, increased play behavior, decreased running wheel activity, and increased aggression toward the stimulus male during sexual behavior assessments. Relative to male controls, EE2-treated males were older at testes descent and preputial separation and had lower testosterone levels. These results suggest EE2-induced masculinization/defeminization of females and are consistent with increased volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) at weaning in female siblings of these subjects (He, Z., Paule, M. G. and Ferguson, S. A. (2012) Low oral doses of bisphenol A increase volume of the sexually dimorphic nucleus of the preoptic area in male, but not female, rats at postnatal day 21. Neurotoxicol. Teratol. 34, 331–337). Although EE2 treatment caused pubertal delays and decreased testosterone levels in males, their behaviors were within the range of control males. Conversely, BPA treatment did not alter any measured endpoint. Similar to our previous reports (Ferguson, S. A., Law, C. D. Jr and Abshire, J. S. (2011) Developmental treatment with bisphenol A or ethinyl estradiol causes few alterations on early preweaning measures. Toxicol. Sci. 124, 149–160; Ferguson, S. A., Law, C. D. and Abshire, J. S. (2012) Developmental treatment with bisphenol A causes few alterations on measures of postweaning activity and learning. Neurotoxicol. Teratol. 34, 598–606), the BPA doses and design used here produced few alterations. PMID:24798382

Time delay spectrum conditioner

DOEpatents

Greiner, Norman R.

1980-01-01

A device for delaying specified frequencies of a multiple frequency laser beam. The device separates the multiple frequency beam into a series of spatially separated single frequency beams. The propagation distance of the single frequency beam is subsequently altered to provide the desired delay for each specific frequency. Focusing reflectors can be utilized to provide a simple but nonadjustable system or, flat reflectors with collimating and focusing optics can be utilized to provide an adjustable system.

Effect of red maca (Lepidium meyenii) on prostate zinc levels in rats with testosterone-induced prostatic hyperplasia.

PubMed

Gonzales, C; Leiva-Revilla, J; Rubio, J; Gasco, M; Gonzales, G F

2012-05-01

Lepidium meyenii (maca) is a plant that grows exclusively above 4000 m in the Peruvian central Andes. Red maca (RM) extract significantly reduced prostate size in rats with benign prostatic hyperplasia (BPH) induced by testosterone enanthate (TE). Zinc is an important regulator of prostate function. This study aimed to determine the effect of RM on prostate zinc levels in rats with BPH induced by TE. Also, the study attempted to determine the best marker for the effect of RM on sex accessory glands. Rats treated with RM extract from day 1 to day 14 reversed the effect of TE administration on prostate weight and zinc levels. However, RM administered from day 7 to day 14 did not reduce the effect of TE on all studied variables. Finasteride (FN) reduced prostate, seminal vesicle and preputial gland weights in rats treated with TE. Although RM and FN reduced prostate zinc levels, the greatest effect was observed in TE-treated rats with RM from day 1 to day 14. In addition, prostate weight and zinc levels showed the higher diagnosis values than preputial and seminal vesicle weights. In conclusion, RM administered from day 1 to day 14 reduced prostate size and zinc levels in rats where prostatic hyperplasia was induced with TE. Also, this experimental model could be used as accurately assay to determine the effect of maca obtained under different conditions and/or the effect of different products based on maca. © 2011 Blackwell Verlag GmbH.

Apparatus for and method of monitoring for breached fuel elements

DOEpatents

Gross, K.C.; Strain, R.V.

1981-04-28

This invention teaches improved apparatus for the method of detecting a breach in cladded fuel used in a nuclear reactor. The detector apparatus uses a separate bypass loop for conveying part of the reactor coolant away from the core, and at least three separate delayed-neutron detectors mounted proximate this detector loop. The detectors are spaced apart so that the coolant flow time from the core to each detector is different, and these differences are known. The delayed-neutron activity at the detectors is a function of the delay time after the reaction in the fuel until the coolant carrying the delayed-neutron emitter passes the respective detector. This time delay is broken down into separate components including an isotopic holdup time required for the emitter to move through the fuel from the reaction to the coolant at the breach, and two transit times required for the emitter now in the coolant to flow from the breach to the detector loop and then via the loop to the detector.

Obesity causes weight increases in prepubertal and pubertal male offspring and is related to changes in spermatogenesis and sperm production in rats.

PubMed

Navya, Harish; Yajurvedi, Hanumant Narasinhacharya

2017-04-01

The effect of obesity on testicular activity in prepubertal and pubertal rats was investigated in the present study. Obesity was induced in adult females by feeding a high-calorie diet (HCD). These females were mated with normal males and were fed an HCD during pregnancy and lactation. The male offspring born to obese mothers and fed an HCD after weaning were found to be obese. Seminiferous tubules of offspring from control mothers (OCM) and offspring from HCD-fed mothers (OHCDM) had the same set of germ cells at different age intervals, namely spermatogonia, leptotene spermatocytes, zygotene spermatocytes, pachytene spermatocytes and round and elongated spermatids on postnatal days (PND) 7, 13, 17, 24 and 36, and on the day of preputial separation, respectively. However, there was a significant decrease in round and elongated spermatids and the epididymal sperm count, coupled with a significant decrease in testosterone and an increase in leptin serum concentrations in OHCDM compared with OCM. These results show that obesity in prepubertal rats does not affect the age-dependent appearance of germ cells according to developmental hierarchy, but it does interfere with spermatid formation, resulting in a reduced sperm count, which may be due to a deficiency of testosterone mediated by hyperleptinaemia.

[Venereal granuloma (donovaniasis) in France].

PubMed

Duperrat, B; Labouche, F

1975-01-01

The study of six cases of MacLeod-Donovan chancre, 2 in Paris, 4 in Brest, in young men coming from the West Indies, showed after 15 days incubation, a balano-preputial lesion consisting of an oval-shaped granuloma, 1 to 4 cm diameter, raised, indurated, ulcerated, reddish-yellow, spontaneously painful, bleeding easily, accompanied in 50 p. 100 of cases by inguinal adenitis, due to secondary infection. Swabs, which should be repeated, showed Donovan bodies within numerous histiocytes. The inactivity of penicillin may be contrasted with the rapidly favourable effect of streptomycin, chloramphenicol or aureomycin.

Mitigating Communication Delays in Remotely Connected Hardware-in-the-loop Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cale, James; Johnson, Brian; Dall'Anese, Emiliano

Here, this paper introduces a potential approach for mitigating the effects of communication delays between multiple, closed-loop hardware-in-the-loop experiments which are virtually connected, yet physically separated. The method consists of an analytical method for the compensation of communication delays, along with the supporting computational and communication infrastructure. The control design leverages tools for the design of observers for the compensation of measurement errors in systems with time-varying delays. The proposed methodology is validated through computer simulation and hardware experimentation connecting hardware-in-the-loop experiments conducted between laboratories separated by a distance of over 100 km.

Mitigating Communication Delays in Remotely Connected Hardware-in-the-loop Experiments

DOE PAGES

Cale, James; Johnson, Brian; Dall'Anese, Emiliano; ...

2018-03-30

Here, this paper introduces a potential approach for mitigating the effects of communication delays between multiple, closed-loop hardware-in-the-loop experiments which are virtually connected, yet physically separated. The method consists of an analytical method for the compensation of communication delays, along with the supporting computational and communication infrastructure. The control design leverages tools for the design of observers for the compensation of measurement errors in systems with time-varying delays. The proposed methodology is validated through computer simulation and hardware experimentation connecting hardware-in-the-loop experiments conducted between laboratories separated by a distance of over 100 km.

Separation attenuation in swept shock wave-boundary-layer interactions using different microvortex generator geometries

NASA Astrophysics Data System (ADS)

Martis, R. R.; Misra, A.

2017-09-01

A numerical study is conducted to determine the effectiveness of six different microvortex generator geometries in controlling swept shock wave/boundary-layer interactions. The geometries considered are base ramp, base ramp with declining angle of 45°, blunt ramp, split ramp, thick vanes, and ramped vanes. Microvortex generators with a gap were found to be better suited for delaying the separation. Thick vanes showed the largest delay in separation among the devices studied.

Separation dynamics of the COMET FreeFlyer and an upper stage STAR-48V motor

NASA Technical Reports Server (NTRS)

Fuller, Kevin M.; Myers, Carter H.

1993-01-01

In this report, the orbital separation between a STAR-48V upperstage motor and the COMET FreeFlyer is investigated. The time from nominal STAR-48 engine burnout is to be determined such that the STAR-48 will not collide with the FreeFlyer once the separation process has been initiated. To analyze this separation, the forces acting upon both the FreeFlyer and the STAR-48 are described in a body fixed coordinate system. These coordinates are then transformed into an Euler coordinate system and then further transformed into a relative inertial coordinate system. From this analysis and some basic assumptions about the Star-48/FreeFlyer vehicle, it can be concluded that the STAR-48 will not collide with the Free Flyer if the separation occurs at 120 seconds after nominal burnout of the STAR-48. In fact, the separation delay could be a shorter period of time, but it is recommended that this separation delay be as long as possible for risk mitigation. This delay is currently designed to be 120 seconds and the analysis presented in this report shows that this time is acceptable.

Evaluation of a Campylobacter fetus subspecies venerealis real-time quantitative polymerase chain reaction for direct analysis of bovine preputial samples

PubMed Central

Chaban, Bonnie; Chu, Shirley; Hendrick, Steven; Waldner, Cheryl; Hill, Janet E.

2012-01-01

The detection and subspeciation of Campylobacter fetus subsp. venerealis (CFV) from veterinary samples is important for both clinical and economic reasons. Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a venereal disease that can lead to serious reproductive problems in cattle, and strict international regulations require animals and animal products to be CFV-free for trade. This study evaluated methods reported in the literature for CFV detection and reports the translation of an extensively tested CFV-specific polymerase chain reaction (PCR) primer set; including the VenSF/VenSR primers and a real-time, quantitative PCR (qPCR) platform using SYBR Green chemistry. Three methods of preputial sample preparation for direct qPCR were evaluated and a heat lysis DNA extraction method was shown to allow for CFV detection at the level of approximately one cell equivalent per reaction (or 1.0 × 103 CFU/mL) from prepuce. The optimized sample preparation and qPCR protocols were then used to evaluate 3 western Canadian bull cohorts, which included 377 bulls, for CFV. The qPCR assay detected 11 positive bulls for the CFV-specific parA gene target. DNA sequence data confirmed the identity of the amplified product and revealed that positive samples were comprised of 2 sequence types; one identical to previously reported CFV parA gene sequences and one with a 9% sequence divergence. These results add valuable information towards our understanding of an important CFV subspeciation target and offer a significantly improved format for an internationally recognized PCR test. PMID:23277694

Tissue-specific and hormonally regulated expression of a rat alpha 2u globulin gene in transgenic mice.

PubMed Central

Soares, V da C; Gubits, R M; Feigelson, P; Costantini, F

1987-01-01

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene. Images PMID:2446121

The Causes of Logging Truck Delays on Two West Virginia Logging Operations

Treesearch

John E. Baumgras

1978-01-01

Logging truck downtime increases timber harvesting costs. To determine the extent and causes of truck delays, four logging trucks on two separate operations were monitored for a 7-month period by recording speedometers and with tallies of delay causes. The results show the number of truck delays per shift, their duration, and the total delay time per shift for eight...

Study of Enlistment Test Scores and Other Attrition Factors from the Navy’s Delayed Entry Program

DTIC Science & Technology

2009-03-01

fiscal years 1999 through 2008 and were provided by the Defense Manpower Data Center (DMDC). Men and women were analyzed separately because of...years 1999 through 2008 and were provided by the Defense Manpower Data Center (DMDC). Men and women were analyzed separately because of historic...ANALYSIS OF DELAYED ENTRY PROGRAM ATTRITION BY WOMEN

DISCOUNTING OF DELAYED AND PROBABILISTIC LOSSES OVER A WIDE RANGE OF AMOUNTS

PubMed Central

Green, Leonard; Myerson, Joel; Oliveira, Luís; Chang, Seo Eun

2014-01-01

The present study examined delay and probability discounting of hypothetical monetary losses over a wide range of amounts (from $20 to $500,000) in order to determine how amount affects the parameters of the hyperboloid discounting function. In separate conditions, college students chose between immediate payments and larger, delayed payments and between certain payments and larger, probabilistic payments. The hyperboloid function accurately described both types of discounting, and amount of loss had little or no systematic effect on the degree of discounting. Importantly, the amount of loss also had little systematic effect on either the rate parameter or the exponent of the delay and probability discounting functions. The finding that the parameters of the hyperboloid function remain relatively constant across a wide range of amounts of delayed and probabilistic loss stands in contrast to the robust amount effects observed with delayed and probabilistic rewards. At the individual level, the degree to which delayed losses were discounted was uncorrelated with the degree to which probabilistic losses were discounted, and delay and probability loaded on two separate factors, similar to what is observed with delayed and probabilistic rewards. Taken together, these findings argue that although delay and probability discounting involve fundamentally different decision-making mechanisms, nevertheless the discounting of delayed and probabilistic losses share an insensitivity to amount that distinguishes it from the discounting of delayed and probabilistic gains. PMID:24745086

Additive-free size-controlled synthesis of gold square nanoplates using photochemical reaction in dynamic phase-separating media.

PubMed

Kajimoto, Shinji; Shirasawa, Daisuke; Horimoto, Noriko Nishizawa; Fukumura, Hiroshi

2013-05-14

Ultrafast phase separation of water and 2-butoxyethanol mixture was induced by nanosecond IR laser pulse irradiation. After a certain delay time, a UV laser pulse was introduced to induce photoreduction of aurate ions, which led to the formation of gold nanoparticles in dynamic phase-separating media. The structure and size of the nanoparticles varied depending on the delay time between the IR and UV pulses. For a delay time of 5 and 6 μs, gold square plates having edge lengths of 150 and 100 nm were selectively obtained, respectively. With a delay time of 3 μs, on the other hand, the size of the square plates varied widely from 100 nm to a few micrometers. The size of the gold square plates was also varied by varying the total irradiation time of the IR and UV pulses. The size distribution of the square plates obtained under different conditions suggests that the growth process of the square plates was affected by the size of the nanophases during phase separation. Electron diffraction patterns of the synthesized square plates showed that the square plates were highly crystalline with a Au(100) surface. These results showed that the nanophases formed during laser-induced phase separation can provide detergent-free reaction fields for size-controlled nanomaterial synthesis.

The role of strategic attention deployment in development of self-regulation: predicting preschoolers' delay of gratification from mother-toddler interactions.

PubMed

Sethi, A; Mischel, W; Aber, J L; Shoda, Y; Rodriguez, M L

2000-11-01

Toddlers' use of effective attention deployment strategies to cope with separation from the mother and with maternal behavior predicted the use of effective delay-of-gratification strategies at age 5, even though the contexts, measures, and manifest behaviors were different. Toddlers who used distraction strategies during a brief separation from the mother were able, at age 5, to delay immediate gratification longer for more valued rewards. Toddlers who explored at a distance from a controlling mother when she tried to engage the child also delayed longer and used more effective delay strategies at age 5, compared with toddlers who did not distance themselves. Toddlers whose mothers were not controlling showed the opposite pattern: Those who did not distance themselves from the mother's bids had longer preschool delay times and more effective strategies. Strategic attention deployment was shown to be an enduring self-regulatory skill visible in early development across domains, measures, and over time.

Passivity of memristive BAM neural networks with leakage and additive time-varying delays

NASA Astrophysics Data System (ADS)

Wang, Weiping; Wang, Meiqi; Luo, Xiong; Li, Lixiang; Zhao, Wenbing; Liu, Linlin; Ping, Yuan

2018-02-01

This paper investigates the passivity of memristive bidirectional associate memory neural networks (MBAMNNs) with leakage and additive time-varying delays. Based on some useful inequalities and appropriate Lyapunov-Krasovskii functionals (LKFs), several delay-dependent conditions for passivity performance are obtained in linear matrix inequalities (LMIs). Moreover, the leakage delays as well as additive delays are considered separately. Finally, numerical simulations are provided to demonstrate the feasibility of the theoretical results.

Studies on the age of puberty of male camels (Camelus dromedaries) in Saudi Arabia.

PubMed

Abdel Rahim, S E

1997-07-01

Aspects of sexual development and attainment of sexual and breeding maturity were studied in two groups of Najdi camels (Mojaheem and Wadah), maintained in stalls under good nutritional conditions. Body weight, testes diameter and degree of penile freedom were recorded weekly. Sexual maturity was assessed by the examination of semen collected by an artificial vagina. Puberty was defined as the stage when the animal was able to produce viable sperms. Mating, followed by strong jerks and ejaculation of mature sperms, was taken to indicate onset of breeding maturity. Mojaheem camels reached sexual maturity at a significantly younger age and heavier weight (164 weeks and 360 kg) than Wadah camels (182 weeks and 336.5 kg) (P < 0.001). Complete separation of the penis from preputial adhesions occurred at an average age of 138.6 weeks in both breeds. At the point of sexual maturity, the mean percentage of live spermatozoa was 65.1 +/- 5.2 while percentage of abnormal sperms was 17.6 +/- 2.2; total motility was 40 +/- 16% and progressive motility (48 +/- 2.2% (semen pH range 7.8-8.2). The percentage of live sperm was 65 +/- 1.5 (normal sperms 82 +/- 4). It is suggested that the encouragement of rapid growth during the pubertal period in camels managed under good nutritional and environmental conditions could assist early sexual development and breeding maturity.

ZEB1 is Estrogen Responsive In Vitro in Human Foreskin Cells and is Over Expressed in Penile Skin in Patients With Severe Hypospadias

PubMed Central

Qiao, Liang; Tasian, Gregory E.; Zhang, Haiyang; Cunha, Gerald R.; Baskin, Laurence

2012-01-01

Purpose We determined the effect of estrogen on ZEB1 in vitro and tested the hypothesis that ZEB1 is over expressed in the penile skin of subjects with hypospadias. Materials and Methods Hs68 cells, a fibroblast cell line derived from human foreskin, were exposed to 0, 1, 10 and 100 nM estrogen, and the expression level of ZEB1 was assessed using reverse transcription real-time polymerase chain reaction, Western blot and immunocytochemical analysis. Next, preputial skin was prospectively collected from case and control subjects at hypospadias repair (37 cases) and circumcision (11). Hypospadias was classified as severe (13 cases) or mild (24) based on the position of the urethral meatus. ZEB1 expression was quantified using reverse transcription real-time polymerase chain reaction, Western blot and immunohistochemical analysis. Results Estrogen increased ZEB1 expression at the mRNA and protein levels in Hs68 cells in a concentration dependent fashion (p <0.01). Subjects with severe hypospadias had significantly higher ZEB1 mRNA levels and protein expression compared to controls or subjects with mild hypospadias (both p <0.01). Subjects with severe hypospadias had increased expression of ZEB1 in the basal layers of the preputial epidermis. Conclusions Estrogen increases ZEB1 expression in a human foreskin fibroblast cell line in vitro. Furthermore, ZEB1 is significantly over expressed in the penile skin of subjects with severe hypospadias. We propose that ZEB1 overexpression may contribute to development of hypospadias and may mediate the effect of estrogen on developing external male genitalia. PMID:21421232

Glow Discharge Plasma Demonstrated for Separation Control in the Low-Pressure Turbine

NASA Technical Reports Server (NTRS)

Ashpis, David e.; Hultgren, Lennart S.

2004-01-01

Flow separation in the low-pressure turbine (LPT) is a major barrier that limits further improvements of aerodynamic designs of turbine airfoils. The separation is responsible for performance degradation, and it prevents the design of highly loaded airfoils. The separation can be delayed, reduced, or eliminated completely if flow control techniques are used. Successful flow control technology will enable breakthrough improvements in gas turbine performance and design. The focus of this research project was the development and experimental demonstration of active separation control using glow discharge plasma (GDP) actuators in flow conditions simulating the LPT. The separation delay was shown to be successful, laying the foundation for further development of the technologies to practical application in the LPT. In a fluid mechanics context, the term "flow control" means a technology by which a very small input results in a very large effect on the flow. In this project, the interest is to eliminate or delay flow separation on LPT airfoils by using an active flow control approach, in which disturbances are dynamically inserted into the flow, they interact with the flow, and they delay separation. The disturbances can be inserted using a localized, externally powered, actuating device, examples are acoustic, pneumatic, or mechanical devices that generate vibrations, flow oscillations, or pulses. A variety of flow control devices have been demonstrated in recent years in the context of the external aerodynamics of aircraft wings and airframes, where the incoming flow is quiescent or of a very low turbulence level. However, the flow conditions in the LPT are significantly different because there are high levels of disturbances in the incoming flow that are characterized by high free-stream turbulence intensity. In addition, the Reynolds number, which characterizes the viscous forces in the flow and is related to the flow speed, is very low in the LPT passages.

Time signal distribution in communication networks based on synchronous digital hierarchy

NASA Technical Reports Server (NTRS)

Imaoka, Atsushi; Kihara, Masami

1993-01-01

A new method that uses round-trip paths to accurately measure transmission delay for time synchronization is proposed. The performance of the method in Synchronous Digital Hierarchy networks is discussed. The feature of this method is that it separately measures the initial round trip path delay and the variations in round-trip path delay. The delay generated in SDH equipment is determined by measuring the initial round-trip path delay. In an experiment with actual SDH equipment, the error of initial delay measurement was suppressed to 30ns.

Metabolomic Quality Assessment of EDTA Plasma and Serum Samples.

PubMed

Malm, Linus; Tybring, Gunnel; Moritz, Thomas; Landin, Britta; Galli, Joakim

2016-10-01

Handling and processing of blood can significantly alter the molecular composition and consistency of biobank samples and can have a major impact on the identification of biomarkers. It is thus crucial to identify tools to determine the quality of samples to be used in biomarker discovery studies. In this study, a non-targeted gas chromatography/time-of-flight mass spectrometry (GC-TOFMS) metabolomic strategy was used with the aim of identifying quality markers for serum and plasma biobank collections lacking proper documentation of preanalytical handling. The effect of postcentrifugation delay was examined in serum stored in tubes with gel separation plugs and ethylenediaminetetraacetic acid (EDTA) plasma in tubes with or without gel separation plugs. The change in metabolic pattern was negligible in all sample types processed within 3 hours after centrifugation regardless of whether the samples were kept at 4°C or 22°C. After 8 and 24 hours postcentrifugation delay before aliquoting, there was a pronounced increase in the number of affected metabolites, as well as in the magnitude of the observed changes. No protective effect on the metabolites was observed in gel-separated EDTA plasma samples. In a separate series of experiments, lactate and glucose levels were determined in plasma to estimate the effect of precentrifugation delay. This separate experiment indicates that the lactate to glucose ratio may serve as a marker to identify samples with delayed time to centrifugation. Although our data from the untargeted GC-TOFMS analysis did not identify any specific markers, we conclude that plasma and serum metabolic profiles remain quite stable when plasma and serum are centrifuged and separated from the blood cells within 3 hours.

Apparatus for and method of monitoring for breached fuel elements

DOEpatents

Gross, Kenny C.; Strain, Robert V.

1983-01-01

This invention teaches improved apparatus for the method of detecting a breach in cladded fuel used in a nuclear reactor. The detector apparatus uses a separate bypass loop for conveying part of the reactor coolant away from the core, and at least three separate delayed-neutron detectors mounted proximate this detector loop. The detectors are spaced apart so that the coolant flow time from the core to each detector is different, and these differences are known. The delayed-neutron activity at the detectors is a function of the dealy time after the reaction in the fuel until the coolant carrying the delayed-neutron emitter passes the respective detector. This time delay is broken down into separate components including an isotopic holdup time required for the emitter to move through the fuel from the reaction to the coolant at the breach, and two transit times required for the emitter now in the coolant to flow from the breach to the detector loop and then via the loop to the detector. At least two of these time components are determined during calibrated operation of the reactor. Thereafter during normal reactor operation, repeated comparisons are made by the method of regression approximation of the third time component for the best-fit line correlating measured delayed-neutron activity against activity that is approximated according to specific equations. The equations use these time-delay components and known parameter values of the fuel and of the part and emitting daughter isotopes.

The flow separation delay in the boundary layer by induced vortices.

PubMed

Chaudhry, Ishtiaq A; Sultan, Tipu; Siddiqui, Farrukh A; Farhan, M; Asim, M

2017-01-01

A series of experiments involving the particle image velocimetry technique are carried out to analyse the quantitative effectiveness of the synthesized vortical structures towards actual flow separation control. The streamwise vortices are synthesized from the synthetic jet actuator and introduced into the attached and separating boundary layer developed on the flat plate surface. Two types of actuators with different geometrical set-ups are used to analyse the evolution of vortical structures in the near wall region and their impact towards achieving separation delay in the boundary layer. First, a single circular jet is synthesized by varying actuator operating parameters and issued into the boundary layer to evaluate the dynamics of the interaction between the vortical structures and the near wall low momentum fluid in the separated region. Second, an array of jets has been issued into the artificially separated region to assess the effectiveness of various vortical structures towards achieving the reattachment of the separated flow in the streamwise direction.

Limitations to Dual Frequency Ionosphere Corrections for Frequency Switched K-Q-Band Observations with the VLBA

NASA Technical Reports Server (NTRS)

Lanyi, Gabor; Gordon, David; Sovers, Ojars J.

2004-01-01

A series of VLBA experiments were carried out at K and Q bands for astrometry and imaging within the KQ VLBI Survey Collaboration. The paired K and Q observations of each source are separated by approximately 3 minutes of time. We investigate the delay effect of the ionosphere between K and Q bands involving the interscan separation. This differential delay effect is intermixed with the differential fluctuation effect of the troposphere.

Time Delay of CGM Sensors

PubMed Central

Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

2015-01-01

Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

Miami International Airport Data Package Number 7. Airport Improvement Task Force Delay Studies.

DTIC Science & Technology

1980-07-01

scenario indica- td the aircraft separation values to be used for the experiments for either VFR or IFR weather conditions. Persent day VFR separation...5. . 2 1q%3 L- VFf.-W None- To CO s /.a Irr. 44, /.4t#37 \\q~ VFf~l-V’ Iq~3 e,4 __I_3 a,3 4,5-" /, @,’ 35A F -3, Iq, a19 a,%.1 39 )92i34* FIW Iee.. Td ...DELAY AVERAGE DELAY (MINUTES) (MINUTES) EXP DEMAND WEATHER IMPROVEMENTS ATC ARR DEP ARR DEP I2 i995" 4FPZ-w 13 3 P q3 . i q. 7 3. 7 11. 1q3 ,, vfepz?-w

Estimation of time-delayed mutual information and bias for irregularly and sparsely sampled time-series

PubMed Central

Albers, D. J.; Hripcsak, George

2012-01-01

A method to estimate the time-dependent correlation via an empirical bias estimate of the time-delayed mutual information for a time-series is proposed. In particular, the bias of the time-delayed mutual information is shown to often be equivalent to the mutual information between two distributions of points from the same system separated by infinite time. Thus intuitively, estimation of the bias is reduced to estimation of the mutual information between distributions of data points separated by large time intervals. The proposed bias estimation techniques are shown to work for Lorenz equations data and glucose time series data of three patients from the Columbia University Medical Center database. PMID:22536009

Numerical Bifurcation Analysis of Delayed Recycle Stream in a Continuously Stirred Tank Reactor

NASA Astrophysics Data System (ADS)

Gangadhar, Nalwala Rohitbabu; Balasubramanian, Periyasamy

2010-10-01

In this paper, we present the stability analysis of delay differential equations which arise as a result of transportation lag in the CSTR-mechanical separator recycle system. A first order irreversible elementary reaction is considered to model the system and is governed by the delay differential equations. The DDE-BIFTOOL software package is used to analyze the stability of the delay system. The present analysis reveals that the system exhibits delay independent stability for isothermal operation of the CSTR. In the absence of delay, the system is dynamically unstable for non-isothermal operation of the CSTR, and as a result of delay, the system exhibits delay dependent stability.

Delayed childbearing: determining responsibilities for prime gamete quality.

PubMed

Campagne, Daniel M

2013-01-01

Delayed parenting affects fertility in women and in men, and cryopreservation of oocytes and sperm is becoming the latest trend as a solution for those who want or need to postpone procreation, in an attempt to avoid the damage medical conditions or time itself produces in gametes. Although "social freezing" is considered legitimate, its ethical and social aspects are in need of an overdue medical, public and legal debate. Assisted reproduction and cryopreservation, in combination with womb outsourcing, have opened the door to biological ectogenesis and the subsequent question of whether delayed childbearing means we should formally separate procreation from sexual activity. This article briefly summarizes what cryotechniques are capable of presently and in the near future, to separate fact from fiction. It names the implications for and discusses the practically virgin subject of the underlying responsibilities of delayed parenting techniques towards the child-to-be-not only the unborn but also the not-yet-conceived child. Considering the medical, economic, legal and social consequences of these rapidly growing developments in reproduction, several reasons point at the need to formally separate procreation from sexual activity, specifying responsibilities in the first while respecting personal choice in the second.

Use of information entropy measures of sitting postural sway to quantify developmental delay in infants

PubMed Central

Deffeyes, Joan E; Harbourne, Regina T; DeJong, Stacey L; Kyvelidou, Anastasia; Stuberg, Wayne A; Stergiou, Nicholas

2009-01-01

Background By quantifying the information entropy of postural sway data, the complexity of the postural movement of different populations can be assessed, giving insight into pathologic motor control functioning. Methods In this study, developmental delay of motor control function in infants was assessed by analysis of sitting postural sway data acquired from force plate center of pressure measurements. Two types of entropy measures were used: symbolic entropy, including a new asymmetric symbolic entropy measure, and approximate entropy, a more widely used entropy measure. For each method of analysis, parameters were adjusted to optimize the separation of the results from the infants with delayed development from infants with typical development. Results The method that gave the widest separation between the populations was the asymmetric symbolic entropy method, which we developed by modification of the symbolic entropy algorithm. The approximate entropy algorithm also performed well, using parameters optimized for the infant sitting data. The infants with delayed development were found to have less complex patterns of postural sway in the medial-lateral direction, and were found to have different left-right symmetry in their postural sway, as compared to typically developing infants. Conclusion The results of this study indicate that optimization of the entropy algorithm for infant sitting postural sway data can greatly improve the ability to separate the infants with developmental delay from typically developing infants. PMID:19671183

Evolutionary Calculations of Phase Separation in Crystallizing White Dwarf Stars

NASA Astrophysics Data System (ADS)

Montgomery, M. H.; Klumpe, E. W.; Winget, D. E.; Wood, M. A.

1999-11-01

We present an exploration of the significance of carbon/oxygen phase separation in white dwarf stars in the context of self-consistent evolutionary calculations. Because phase separation can potentially increase the calculated ages of the oldest white dwarfs, it can affect the age of the Galactic disk as derived from the downturn in the white dwarf luminosity function. We find that the largest possible increase in ages due to phase separation is ~1.5 Gyr, with a most likely value of approximately 0.6 Gyr, depending on the parameters of our white dwarf models. The most important factors influencing the size of this delay are the total stellar mass, the initial composition profile, and the phase diagram assumed for crystallization. We find a maximum age delay in models with masses of ~0.6 Msolar, which is near the peak in the observed white dwarf mass distribution. In addition, we note that the prescription that we have adopted for the mixing during crystallization provides an upper bound for the efficiency of this process, and hence a maximum for the age delays. More realistic treatments of the mixing process may reduce the size of this effect. We find that varying the opacities (via the metallicity) has little effect on the calculated age delays. In the context of Galactic evolution, age estimates for the oldest Galactic globular clusters range from 11.5 to 16 Gyr and depend on a variety of parameters. In addition, a 4-6 Gyr delay is expected between the formation of the globular clusters and the formation of the Galactic thin disk, while the observed white dwarf luminosity function gives an age estimate for the thin disk of 9.5+1.1-0.8 Gyr, without including the effect of phase separation. Using the above numbers, we see that phase separation could add between 0 and 3 Gyr to the white dwarf ages and still be consistent with the overall picture of Galaxy formation. Our calculated maximum value of <~1.5 Gyr fits within these bounds, as does our best-guess value of ~0.6 Gyr.

The big brown bat's perceptual dimension of target range

NASA Astrophysics Data System (ADS)

Simmons, James A.

2005-09-01

Big brown bats determine the distance to targets from echo delay, but information actually is entered onto the bat's psychological delay scale from two sources. The first is the target-ranging system itself, from the time that elapses between single-spike neural responses evoked by the broadcast and similar responses evoked by echoes at different delays. These responses register the FM sweeps of broadcasts or echoes, and the associated system of neural delay lines and coincidence detectors cross correlates the spectrograms along the time axis. The second source is the echo spectrum, which relates to shape expressed as range profile. The target-ranging system extracts this by fanning out to encompass parallel representations of many possible notch frequencies and notch widths in echoes. Bats perceive delay separations of 5-30 μs and have a resolution limit of about 2 μs, but interference amplifies small delay separations by transposing them into large changes in notch frequency, so only perception of intervals smaller than 5 μs is surprising. Experiments with phase-shifted echoes show that the psychological time scale can represent two different delays originating entirely in the time domain when they are at least as close together as 10 μs. [Work supported by NIH and ONR.

The Role of Strategic Attention Deployment in Development of Self-Regulation: Predicting Preschoolers' Delay of Gratification from Mother-Toddler Interactions.

ERIC Educational Resources Information Center

Sethi, Anita; Mischel, Walter; Aber, J. Lawrence; Shoda, Yuichi; Rodriguez, Monica Larrea

2000-01-01

Examined role of toddlers' attention deployment strategies in predicting 5-year-olds' delay-of-gratification strategies. Found that toddlers' use of effective attention deployment strategies to cope with separation from mother and with maternal behavior (controlling or noncontrolling) predicted effective delay-of-gratification strategies at age 5,…

Two memories for geographical slant: separation and interdependence of action and awareness

NASA Technical Reports Server (NTRS)

Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

1998-01-01

The present study extended previous findings of geographical slant perception, in which verbal judgments of the incline of hills were greatly overestimated but motoric (haptic) adjustments were much more accurate. In judging slant from memory following a brief or extended time delay, subjects' verbal judgments were greater than those given when viewing hills. Motoric estimates differed depending on the length of the delay and place of response. With a short delay, motoric adjustments made in the proximity of the hill did not differ from those evoked during perception. When given a longer delay or when taken away from the hill, subjects' motoric responses increased along with the increase in verbal reports. These results suggest two different memorial influences on action. With a short delay at the hill, memory for visual guidance is separate from the explicit memory informing the conscious response. With short or long delays away from the hill, short-term visual guidance memory no longer persists, and both motor and verbal responses are driven by an explicit representation. These results support recent research involving visual guidance from memory, where actions become influenced by conscious awareness, and provide evidence for communication between the "what" and "how" visual processing systems.

C/EBPα and C/EBPβ Are Required for Sebocyte Differentiation and Stratified Squamous Differentiation in Adult Mouse Skin

PubMed Central

House, John S.; Zhu, Songyun; Ranjan, Rakesh; Linder, Keith; Smart, Robert C.

2010-01-01

C/EBPα and C/EBPβ are bZIP transcription factors that are highly expressed in the interfollicular epidermis and sebaceous glands of skin and yet germ line deletion of either family member alone has only mild or no effect on keratinocyte biology and their role in sebocyte biology has never been examined. To address possible functional redundancies and reveal functional roles of C/EBPα and C/EBPβ in postnatal skin, mouse models were developed in which either family member could be acutely ablated alone or together in the epidermis and sebaceous glands of adult mice. Acute removal of either C/EBPα or C/EBPβ alone in adult mouse skin revealed modest to no discernable changes in epidermis or sebaceous glands. In contrast, co-ablation of C/EBPα and C/EBPβ in postnatal epidermis resulted in disruption of stratified squamous differentiation characterized by hyperproliferation of basal and suprabasal keratinocytes and a defective basal to spinous keratinocyte transition involving an expanded basal compartment and a diminished and delayed spinous compartment. Acute co-ablation of C/EBPα and C/EBPβ in sebaceous glands resulted in severe morphological defects, and sebocyte differentiation was blocked as determined by lack of sebum production and reduced expression of stearoyl-CoA desaturase (SCD3) and melanocortin 5 receptor (MC5R), two markers of terminal sebocyte differentiation. Specialized sebocytes of Meibomian glands and preputial glands were also affected. Our results indicate that in adult mouse skin, C/EBPα and C/EBPβ are critically involved in regulating sebocyte differentiation and epidermal homeostasis involving the basal to spinous keratinocyte transition and basal cell cycle withdrawal. PMID:20352127

C/EBPalpha and C/EBPbeta are required for Sebocyte differentiation and stratified squamous differentiation in adult mouse skin.

PubMed

House, John S; Zhu, Songyun; Ranjan, Rakesh; Linder, Keith; Smart, Robert C

2010-03-23

C/EBPalpha and C/EBPbeta are bZIP transcription factors that are highly expressed in the interfollicular epidermis and sebaceous glands of skin and yet germ line deletion of either family member alone has only mild or no effect on keratinocyte biology and their role in sebocyte biology has never been examined. To address possible functional redundancies and reveal functional roles of C/EBPalpha and C/EBPbeta in postnatal skin, mouse models were developed in which either family member could be acutely ablated alone or together in the epidermis and sebaceous glands of adult mice. Acute removal of either C/EBPalpha or C/EBPbeta alone in adult mouse skin revealed modest to no discernable changes in epidermis or sebaceous glands. In contrast, co-ablation of C/EBPalpha and C/EBPbeta in postnatal epidermis resulted in disruption of stratified squamous differentiation characterized by hyperproliferation of basal and suprabasal keratinocytes and a defective basal to spinous keratinocyte transition involving an expanded basal compartment and a diminished and delayed spinous compartment. Acute co-ablation of C/EBPalpha and C/EBPbeta in sebaceous glands resulted in severe morphological defects, and sebocyte differentiation was blocked as determined by lack of sebum production and reduced expression of stearoyl-CoA desaturase (SCD3) and melanocortin 5 receptor (MC5R), two markers of terminal sebocyte differentiation. Specialized sebocytes of Meibomian glands and preputial glands were also affected. Our results indicate that in adult mouse skin, C/EBPalpha and C/EBPbeta are critically involved in regulating sebocyte differentiation and epidermal homeostasis involving the basal to spinous keratinocyte transition and basal cell cycle withdrawal.

IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Congdon, Arthur B.; Keeton, Charles R.; Nordgren, C. Erik, E-mail: acongdon@jpl.nasa.go, E-mail: keeton@physics.rutgers.ed, E-mail: nordgren@sas.upenn.ed

2010-02-01

We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. In a previous paper, we predicted how the time delay between the bright pair of images in a 'fold' lens scales with the image separation, for smooth lens potentials. Here we show that the proportionality constant increases with the quadrupole moment of the lens potential, and depends only weakly on the position of the source along the caustic. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxiesmore » with tidal shear. We can then identify outliers as 'time delay anomalies'. We find evidence for anomalies in close image pairs in the cusp lenses RX J1131 - 1231 and B1422+231. The anomalies in RX J1131 - 1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time delay anomalies in larger-separation image pairs in the fold lenses, B1608+656 and WFI 2033 - 4723, and the cusp lens RX J0911+0551. We suggest that these anomalies are caused by some combination of substructure and a complex lens environment. Finally, to assist future monitoring campaigns we use our smooth models with shear to predict the time delays for all known four-image lenses.« less

Identifying Anomalies in Gravitational Lens Time Delays

NASA Astrophysics Data System (ADS)

Congdon, Arthur B.; Keeton, Charles R.; Nordgren, C. Erik

2010-02-01

We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. In a previous paper, we predicted how the time delay between the bright pair of images in a "fold" lens scales with the image separation, for smooth lens potentials. Here we show that the proportionality constant increases with the quadrupole moment of the lens potential, and depends only weakly on the position of the source along the caustic. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxies with tidal shear. We can then identify outliers as "time delay anomalies." We find evidence for anomalies in close image pairs in the cusp lenses RX J1131 - 1231 and B1422+231. The anomalies in RX J1131 - 1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time delay anomalies in larger-separation image pairs in the fold lenses, B1608+656 and WFI 2033 - 4723, and the cusp lens RX J0911+0551. We suggest that these anomalies are caused by some combination of substructure and a complex lens environment. Finally, to assist future monitoring campaigns we use our smooth models with shear to predict the time delays for all known four-image lenses.

Nuclear reactor with internal thimble-type delayed neutron detection system

DOEpatents

Gross, Kenny C.; Poloncsik, John; Lambert, John D. B.

1990-01-01

This invention teaches improved apparatus for the method of detecting a breach in cladded fuel used in a nuclear reactor. The detector apparatus is located in the primary heat exchanger which conveys part of the reactor coolant past at least three separate delayed-neutron detectors mounted in this heat exchanger. The detectors are spaced apart such that the coolant flow time from the core to each detector is different, and these differences are known. The delayed-neutron activity at the detectors is a function of the delay time after the reaction in the fuel until the coolant carrying the delayed-neutron emitter passes the respective detector. This time delay is broken down into separate components including an isotopic holdup time required for the emitter to move through the fuel from the reaction to the coolant at the breach, and two transit times required for the emitter now in the coolant to flow from the breach to the detector loop and then via the loop to the detector. At least two of these time components are determined during calibrated operation of the reactor. Thereafter during normal reactor operation, repeated comparisons are made by the method of regression approximation of the third time component for the best-fit line correlating measured delayed-neutron activity against activity that is approximated according to specific equations. The equations use these time-delay components and known parameter values of the fuel and of the part and emitting daughter isotopes.

Surgical anatomy of penis in exstrophy-epispadias: a study of arrangement of fascial planes and superficial vessels of surgical significance.

PubMed

Kureel, Shiv Narain; Gupta, Archika; Singh, Chandra Shekhar; Kumar, Manoj

2013-10-01

To study the anatomic arrangement of the fascial planes and superficial vessels in relationship to the laid-open urethral plate, glans, corpus spongiosum, and corpora cavernosa in the penis of patients with exstrophy or epispadias. Of 6 patients, 4 had classic exstrophy and 2 had incontinent epispadias. These patients had presented beyond adolescence without previous intervention and were selected for the present study. Using a 1.5-T magnetic resonance imaging scanner and compatible 3-in. surface coil, the epispadiac penises were studied using fast spin echo sequences and contrast-enhanced sequences. In 2 patients, angiography of the superficial vessels was also performed using multidetector row helical computed tomography. The imaging findings were also verified during the subsequent reconstructive surgery. A clear demarcation of the skin, dartos fascia, Buck's fascia, corpora cavernosa, corpus spongiosum, and the intraglanular planes were seen with the course of the blood vessels. The penile dartos received axial pattern vessels from the external pudendal vessels, with collateral branches from the dorsal penile artery as transverse branches at the shaft of the penis and preputial branches at the coronal sulcus. Buck's fascia sleeved the corpora cavernosa, enveloped the neurovascular bundle, and fused with the corpus spongiosum without crossing the midline. Intraglanular extension of Buck's fascia separated the intraglanular vascular arcade from the tip of the corpora. Parallel to the ventral midline, axial pattern vessels to the skin-dartos complex are present, with an additional supply to the prepuce from the terminal penile arteries. These findings can be used for designing the skin coverage. The subfascial plane between the tip of the corpora and the intraglanular vascular arcade and the plane of cleavage between the cavernosa-spongiosum interface can be used for efficient corporal urethral separation. Copyright © 2013 Elsevier Inc. All rights reserved.

Output transformations and separation results for feedback linearisable delay systems

NASA Astrophysics Data System (ADS)

Cacace, F.; Conte, F.; Germani, A.

2018-04-01

The class of strict-feedback systems enjoys special properties that make it similar to linear systems. This paper proves that such a class is equivalent, under a change of coordinates, to the wider class of feedback linearisable systems with multiplicative input, when the multiplicative terms are functions of the measured variables only. We apply this result to the control problem of feedback linearisable nonlinear MIMO systems with input and/or output delays. In this way, we provide sufficient conditions under which a separation result holds for output feedback control and moreover a predictor-based controller exists. When these conditions are satisfied, we obtain that the existence of stabilising controllers for arbitrarily large delays in the input and/or the output can be proved for a wider class of systems than previously known.

A Fuel-Efficient Conflict Resolution Maneuver for Separation Assurance

NASA Technical Reports Server (NTRS)

Bowe, Aisha Ruth; Santiago, Confesor

2012-01-01

Automated separation assurance algorithms are envisioned to play an integral role in accommodating the forecasted increase in demand of the National Airspace System. Developing a robust, reliable, air traffic management system involves safely increasing efficiency and throughput while considering the potential impact on users. This experiment seeks to evaluate the benefit of augmenting a conflict detection and resolution algorithm to consider a fuel efficient, Zero-Delay Direct-To maneuver, when resolving a given conflict based on either minimum fuel burn or minimum delay. A total of twelve conditions were tested in a fast-time simulation conducted in three airspace regions with mixed aircraft types and light weather. Results show that inclusion of this maneuver has no appreciable effect on the ability of the algorithm to safely detect and resolve conflicts. The results further suggest that enabling the Zero-Delay Direct-To maneuver significantly increases the cumulative fuel burn savings when choosing resolution based on minimum fuel burn while marginally increasing the average delay per resolution.

Human in the Loop Simulation Measures of Pilot Response Delay in a Self-Separation Concept of Operations

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Wilson, Sara R.; Sturdy, James; Murdoch, Jennifer L.; Wing, David J.

2010-01-01

A human-in-the-loop (HITL) simulation experiment was conducted by the National Aeronautics and Space Administration (NASA) to assess airline transport pilots performance and reported acceptance of the use of procedures relying on airborne separation assistance and trajectory management tools. This study was part of a larger effort involving two NASA centers that includes multiple HITL experiments planned over the next few years to evaluate the use of automated separation assurance (SA) tools by both air traffic controllers and pilots. This paper presents results of measured pilot response delay that subject pilots incurred when interacting with cockpit tools for SA and discusses possible implications for future concept and procedures design.

Effect of Conflict Resolution Maneuver Execution Delay on Losses of Separation

NASA Technical Reports Server (NTRS)

Cone, Andrew C.

2010-01-01

This paper examines uncertainty in the maneuver execution delay for data linked conflict resolution maneuvers. This uncertainty could cause the previously cleared primary conflict to reoccur or a secondary conflict to appear. Results show that the likelihood of a primary conflict reoccurring during a horizontal conflict resolution maneuver increases with larger initial turn-out angles and with shorter times until loss of separation. There is also a significant increase in the probability of a primary conflict reoccurring when the time until loss falls under three minutes. Increasing horizontal separation by an additional 1.5 nmi lowers the risk, but does not completely eliminate it. Secondary conflicts were shown to have a small probability of occurring in all tested configurations.

Running Improves Pattern Separation during Novel Object Recognition.

PubMed

Bolz, Leoni; Heigele, Stefanie; Bischofberger, Josef

2015-10-09

Running increases adult neurogenesis and improves pattern separation in various memory tasks including context fear conditioning or touch-screen based spatial learning. However, it is unknown whether pattern separation is improved in spontaneous behavior, not emotionally biased by positive or negative reinforcement. Here we investigated the effect of voluntary running on pattern separation during novel object recognition in mice using relatively similar or substantially different objects.We show that running increases hippocampal neurogenesis but does not affect object recognition memory with 1.5 h delay after sample phase. By contrast, at 24 h delay, running significantly improves recognition memory for similar objects, whereas highly different objects can be distinguished by both, running and sedentary mice. These data show that physical exercise improves pattern separation, independent of negative or positive reinforcement. In sedentary mice there is a pronounced temporal gradient for remembering object details. In running mice, however, increased neurogenesis improves hippocampal coding and temporally preserves distinction of novel objects from familiar ones.

Willing to wait: Elevated reward-processing EEG activity associated with a greater preference for larger-but-delayed rewards.

PubMed

Pornpattananangkul, Narun; Nusslock, Robin

2016-10-01

While almost everyone discounts the value of future rewards over immediate rewards, people differ in their so-called delay-discounting. One of the several factors that may explain individual differences in delay-discounting is reward-processing. To study individual-differences in reward-processing, however, one needs to consider the heterogeneity of neural-activity at each reward-processing stage. Here using EEG, we separated reward-related neural activity into distinct reward-anticipation and reward-outcome stages using time-frequency characteristics. Thirty-seven individuals first completed a behavioral delay-discounting task. Then reward-processing EEG activity was assessed using a separate reward-learning task, called a reward time-estimation task. During this EEG task, participants were instructed to estimate time duration and were provided performance feedback on a trial-by-trial basis. Participants received monetary-reward for accurate-performance on Reward trials, but not on No-Reward trials. Reward trials, relative to No-Reward trials, enhanced EEG activity during both reward-anticipation (including, cued-locked delta power during cue-evaluation and pre-feedback alpha suppression during feedback-anticipation) and reward-outcome (including, feedback-locked delta, theta and beta power) stages. Moreover, all of these EEG indices correlated with behavioral performance in the time-estimation task, suggesting their essential roles in learning and adjusting performance to maximize winnings in a reward-learning situation. Importantly, enhanced EEG power during Reward trials, as reflected by stronger 1) pre-feedback alpha suppression, 2) feedback-locked theta and 3) feedback-locked beta, was associated with a greater preference for larger-but-delayed rewards in a separate, behavioral delay-discounting task. Results highlight the association between a stronger preference toward larger-but-delayed rewards and enhanced reward-processing. Moreover, our reward-processing EEG indices detail the specific stages of reward-processing where these associations occur. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ablation of silicon with bursts of femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Gaudiuso, Caterina; Kämmer, Helena; Dreisow, Felix; Ancona, Antonio; Tünnermann, Andreas; Nolte, Stefan

2016-03-01

We report on an experimental investigation of ultrafast laser ablation of silicon with bursts of pulses. The pristine 1030nm-wavelength 200-fs pulses were split into bursts of up to 16 sub-pulses with time separation ranging from 0.5ps to 4080ps. The total ablation threshold fluence was measured depending on the burst features, finding that it strongly increases with the number of sub-pulses for longer sub-pulse delays, while a slowly increasing trend is observed for shorter separation time. The ablation depth per burst follows two different trends according to the time separation between the sub-pulses, as well as the total threshold fluence. For delays shorter than 4ps it decreases with the number of pulses, while for time separations longer than 510ps, deeper craters were achieved by increasing the number of subpulses in the burst, probably due to a change of the effective penetration depth.

Protein separation using an electrically tunable membrane

NASA Astrophysics Data System (ADS)

Jou, Ining; Melnikov, Dmitriy; Gracheva, Maria

Separation of small proteins by charge with a solid-state porous membrane requires control over the protein's movement. Semiconductor membrane has this ability due to the electrically tunable electric potential profile inside the nanopore. In this work we investigate the possibility to separate the solution of two similar sized proteins by charge. As an example, we consider two small globular proteins abundant in humans: insulin (negatively charged) and ubiquitin (neutral). We find that the localized electric field inside the pore either attracts or repels the charged protein to or from the pore wall which affects the delay time before a successful translocation of the protein through the nanopore. However, the motion of the uncharged ubiquitin is unaffected. The difference in the delay time (and hence the separation) can be further increased by the application of the electrolyte bias which induces an electroosmotic flow in the pore. NSF DMR and CBET Grant No. 1352218.

β -delayed neutron emission from 85Ga

NASA Astrophysics Data System (ADS)

Miernik, K.; Rykaczewski, K. P.; Grzywacz, R.; Gross, C. J.; Madurga, M.; Miller, D.; Stracener, D. W.; Batchelder, J. C.; Brewer, N. T.; Korgul, A.; Mazzocchi, C.; Mendez, A. J.; Liu, Y.; Paulauskas, S. V.; Winger, J. A.; Wolińska-Cichocka, M.; Zganjar, E. F.

2018-05-01

Decay of 85Ga was studied by means of β -neutron-γ spectroscopy. A pure beam of 85Ga was produced at the Holifield Radioactive Ion Beam Facility using a resonance ionization laser ion source and a high-resolution electromagnetic separator. The β -delayed neutron emission probability was measured for the first time, yielding 70(5)%. An upper limit of 0.1% for β -delayed two-neutron emission was also experimentally established for the first time. A detailed decay scheme including absolute γ -ray intensities was obtained. Results are compared with theoretical β -delayed emission models.

Neo-yoke repair for severe hypospadias: A simple modification for better outcome.

PubMed

Seleim, Hamed M; Morsi, Hani; Elbarbary, Mohamed M

2017-06-01

Although staged repair for reconstructing severe hypospadias is more popular, various one-stage repairs have been attempted. Koyanagi repair (parameatal-based and fully extended circumferential foreskin flap urethroplasty) has enabled correction of severe hypospadias in one stage. However, its un-acceptably high incidence of complications has initiated a series of technical modifications, including the "yoke" repair. To retrospectively analyze the outcome of a proposed modification of the originally described yoke repair, for patients with severe hypospadias. This modification was developed to reduce complications. Over 4 years (between Jan 2011 and Jan 2015), all cases of severe hypospadias were included in this study; except those with prior attempts at repair, circumcised cases, and cases with severe hypogonadism - because of partial androgen insensitivity - not responding to hormonal manipulations. The make-up of the neo-urethra in this modification is the urethral plate with its spongiosal tissue proximally, a circum-coronal preputial pedicled flap in the middle, and an incorporated part of the augmented preputial flap and the preserved V-shaped glanular urethra, distally. Close postoperative follow-up was conducted to investigate the outcome. Thirty-one children with a median age of 32.48 months had repair of severe hypospadias using the neo-yoke technique. After a median follow-up of 26.7 months, the overall complication rate was 16.1%. Four children developed urethrocutaneous fistula (12.9%). Meatal drop-back occurred in one case (3.2%). No meatal stenosis or urethral sacculation was detected during follow-up of the studied group. Almost all cases had cosmetically appealing outlook. Single-staged repair of severe hypospadias using parameatal foreskin-based urethroplasty has passed through different modifications, all aimed at optimizing the outcome (Table). Neo-yoke repair for severe hypospadias is a natural development of established one-stage techniques, which resulted in better mid-term outcomes. However, an extended study is needed to declare the long-term results. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Species differences in the disposition and metabolism of nalidixic acid.

PubMed

Nomeir, A A; Markham, P; Burka, L T; Griffin, R J; Ghanayem, B I

1996-10-01

Nalidixic acid (NA) is an antimicrobial drug that has been used to treat urinary tract infections. A study of NA by the National Toxicology Program indicated that chronic administration in the diet at doses equivalent to 82 and 175 mg/kg/day for rats, and 175 and 475 mg/kg/day for mice resulted in neoplastic lesions in the preputial and clitoral glands of male and female Fischer 344 rats, respectively, but not in male and female B6C3F1 mice. Our study was designed to evaluate the metabolic basis of this species and tissue-dependent carcinogenicity. [14C]NA was administered by oral gavage as a suspension in corn oil at doses of 20, 200 or 500 mg/kg. Based on urinary excretion data, at least 35 to 46 and 57 to 79% of dose was absorbed from the gastrointestinal tracts of mice and rats, respectively. NA-derived radioactivity was excreted primarily in urine and feces. The urinary and fecal metabolite profiles were species dependent. At 72 hr after administration, in both genders of rats and mice, the highest concentrations of radioactivity were observed in the liver, and the lowest were in the brain and adipose tissue. The preputial and clitoral glands of male and female rats, respectively, contained consistently and substantially higher concentrations of radioactivity compared to all other tissues, with the exception of liver. In mice, the levels of radioactivity in these tissues were near or below quantifiable levels. The metabolism and disposition characteristics of NA were linear in male and female mice over a dose range of 20 to 500 mg/kg: in rats, they were dose dependent. Results of this study suggest that the species- and tissue-dependent differences in carcinogenicity of NA were associated with differences in metabolism and disposition between the two species.

Properties of a Variable-Delay Polarization Modulator

NASA Technical Reports Server (NTRS)

Chuss, David T.; Wollack, Edward J.; Henry, Ross; Hui, Howard; Juarez, Aaron J.; Krenjy, Megan; Moseley, Harvey; Novak, Giles

2011-01-01

We investigate the polarization modulation properties of a variable-delay polarization modulator (VPM). The VPM modulates polarization via a variable separation between a polarizing grid and a parallel mirror. We find that in the limit where the wavelength is much larger than the diameter of the metal wires that comprise the grid, the phase delay derived from the geometric separation between the mirror and the grid is sufficient to characterize the device. However, outside of this range, additional parameters describing the polarizing grid geometry must be included to fully characterize the modulator response. In this paper, we report test results of a VPM at wavelengths of 350 micron and 3 mm. Electromagnetic simulations of wire grid polarizers were performed and are summarized using a simple circuit model that incorporates the loss and polarization properties of the device.

Robust stability bounds for multi-delay networked control systems

NASA Astrophysics Data System (ADS)

Seitz, Timothy; Yedavalli, Rama K.; Behbahani, Alireza

2018-04-01

In this paper, the robust stability of a perturbed linear continuous-time system is examined when controlled using a sampled-data networked control system (NCS) framework. Three new robust stability bounds on the time-invariant perturbations to the original continuous-time plant matrix are presented guaranteeing stability for the corresponding discrete closed-loop augmented delay-free system (ADFS) with multiple time-varying sensor and actuator delays. The bounds are differentiated from previous work by accounting for the sampled-data nature of the NCS and for separate communication delays for each sensor and actuator, not a single delay. Therefore, this paper expands the knowledge base in multiple inputs multiple outputs (MIMO) sampled-data time delay systems. Bounds are presented for unstructured, semi-structured, and structured perturbations.

Optimal Time Advance In Terminal Area Arrivals: Throughput vs. Fuel Savings

NASA Technical Reports Server (NTRS)

Sadovsky, Alexander V .; Swenson, Harry N.; Haskell, William B.; Rakas, Jasenka

2011-01-01

The current operational practice in scheduling air traffic arriving at an airport is to adjust flight schedules by delay, i.e. a postponement of an aircrafts arrival at a scheduled location, to manage safely the FAA-mandated separation constraints between aircraft. To meet the observed and forecast growth in traffic demand, however, the practice of time advance (speeding up an aircraft toward a scheduled location) is envisioned for future operations as a practice additional to delay. Time advance has two potential advantages. The first is the capability to minimize, or at least reduce, the excess separation (the distances between pairs of aircraft immediately in-trail) and thereby to increase the throughput of the arriving traffic. The second is to reduce the total traffic delay when the traffic sample is below saturation density. A cost associated with time advance is the fuel expenditure required by an aircraft to speed up. We present an optimal control model of air traffic arriving in a terminal area and solve it using the Pontryagin Maximum Principle. The admissible controls allow time advance, as well as delay, some of the way. The cost function reflects the trade-off between minimizing two competing objectives: excess separation (negatively correlated with throughput) and fuel burn. A number of instances are solved using three different methods, to demonstrate consistency of solutions.

Examining Relationships between Executive Functioning and Delay Aversion in Attention Deficit Hyperactivity Disorder

ERIC Educational Resources Information Center

Karalunas, Sarah L.; Huang-Pollock, Cynthia L.

2011-01-01

Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002). This model…

Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers.

PubMed

Chin, Sanghoon; Thévenaz, Luc; Sancho, Juan; Sales, Salvador; Capmany, José; Berger, Perrine; Bourderionnet, Jérôme; Dolfi, Daniel

2010-10-11

We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shifter and slow light, based on stimulated Brillouin scattering in fibers. Dispersion properties of fibers are controlled, separately at optical carrier frequency and in the vicinity of microwave signal bandwidth. This way time delay induced within the signal bandwidth can be manipulated to correctly act as true time delay with a proper phase compensation introduced to the optical carrier. We completely analyzed the generated true time delay as a promising solution to feed phased array antenna for radar systems and to develop dynamically reconfigurable microwave photonic filters.

Design Considerations for a New Terminal Area Arrival Scheduler

NASA Technical Reports Server (NTRS)

Thipphavong, Jane; Mulfinger, Daniel

2010-01-01

Design of a terminal area arrival scheduler depends on the interrelationship between throughput, delay and controller intervention. The main contribution of this paper is an analysis of the above interdependence for several stochastic behaviors of expected system performance distributions in the aircraft s time of arrival at the meter fix and runway. Results of this analysis serve to guide the scheduler design choices for key control variables. Two types of variables are analyzed, separation buffers and terminal delay margins. The choice for these decision variables was tested using sensitivity analysis. Analysis suggests that it is best to set the separation buffer at the meter fix to its minimum and adjust the runway buffer to attain the desired system performance. Delay margin was found to have the least effect. These results help characterize the variables most influential in the scheduling operations of terminal area arrivals.

P-code enhanced method for processing encrypted GPS signals without knowledge of the encryption code

NASA Technical Reports Server (NTRS)

Young, Lawrence E. (Inventor); Meehan, Thomas K. (Inventor); Thomas, Jr., Jess Brooks (Inventor)

2000-01-01

In the preferred embodiment, an encrypted GPS signal is down-converted from RF to baseband to generate two quadrature components for each RF signal (L1 and L2). Separately and independently for each RF signal and each quadrature component, the four down-converted signals are counter-rotated with a respective model phase, correlated with a respective model P code, and then successively summed and dumped over presum intervals substantially coincident with chips of the respective encryption code. Without knowledge of the encryption-code signs, the effect of encryption-code sign flips is then substantially reduced by selected combinations of the resulting presums between associated quadrature components for each RF signal, separately and independently for the L1 and L2 signals. The resulting combined presums are then summed and dumped over longer intervals and further processed to extract amplitude, phase and delay for each RF signal. Precision of the resulting phase and delay values is approximately four times better than that obtained from straight cross-correlation of L1 and L2. This improved method provides the following options: separate and independent tracking of the L1-Y and L2-Y channels; separate and independent measurement of amplitude, phase and delay L1-Y channel; and removal of the half-cycle ambiguity in L1-Y and L2-Y carrier phase.

Neutron-flux profile monitor for use in a fission reactor

DOEpatents

Kopp, M.K.; Valentine, K.H.

1981-09-15

A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occurred. Neutron flux profiles of reactor cores can be more accurately measured as a result.

Neutron flux profile monitor for use in a fission reactor

DOEpatents

Kopp, Manfred K.; Valentine, Kenneth H.

1983-01-01

A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occured. Neutron flux profiles of reactor cores can be more accurately measured as a result.

KC-46 Tanker Modernization: Delivery of First Fully Capable Aircraft Has Been Delayed over One Year and Additional Delays Are Possible

DTIC Science & Technology

2017-03-01

delays. As shown, the remaining schedule was modified to allow Boeing to deliver the first 18 aircraft and pods separately by October 2018, 14...testing. Among other things, Boeing is contractually required to deliver a total of 18 aircraft and 9 wing air refueling pod sets by August 2017...Parameters and System Attributes and Status of Technical Performance Capabilities 18 Appendix II GAO Contact and Staff Acknowledgments 20 Related

Active flow separation control by a position-based iterative learning control algorithm with experimental validation

NASA Astrophysics Data System (ADS)

Cai, Zhonglun; Chen, Peng; Angland, David; Zhang, Xin

2014-03-01

A novel iterative learning control (ILC) algorithm was developed and applied to an active flow control problem. The technique uses pulsed air jets to delay flow separation on a two-element high-lift wing. The ILC algorithm uses position-based pressure measurements to update the actuation. The method was experimentally tested on a wing model in a 0.9 m × 0.6 m low-speed wind tunnel at the University of Southampton. Compressed air and fast switching solenoid valves were used as actuators to excite the flow, and the pressure distribution around the chord of the wing was measured as a feedback control signal for the ILC controller. Experimental results showed that the actuation was able to delay the separation and increase the lift by approximately 10%-15%. By using the ILC algorithm, the controller was able to find the optimum control input and maintain the improvement despite sudden changes of the separation position.

Runway Scheduling Using Generalized Dynamic Programming

NASA Technical Reports Server (NTRS)

Montoya, Justin; Wood, Zachary; Rathinam, Sivakumar

2011-01-01

A generalized dynamic programming method for finding a set of pareto optimal solutions for a runway scheduling problem is introduced. The algorithm generates a set of runway fight sequences that are optimal for both runway throughput and delay. Realistic time-based operational constraints are considered, including miles-in-trail separation, runway crossings, and wake vortex separation. The authors also model divergent runway takeoff operations to allow for reduced wake vortex separation. A modeled Dallas/Fort Worth International airport and three baseline heuristics are used to illustrate preliminary benefits of using the generalized dynamic programming method. Simulated traffic levels ranged from 10 aircraft to 30 aircraft with each test case spanning 15 minutes. The optimal solution shows a 40-70 percent decrease in the expected delay per aircraft over the baseline schedulers. Computational results suggest that the algorithm is promising for real-time application with an average computation time of 4.5 seconds. For even faster computation times, two heuristics are developed. As compared to the optimal, the heuristics are within 5% of the expected delay per aircraft and 1% of the expected number of runway operations per hour ad can be 100x faster.

NEANDC specialists meeting on yields and decay data of fission product nuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chrien, R.E.; Burrows, T.W.

Separate abstracts were prepared for the 29 papers presented. Workshop reports on decay heat, fission yields, beta- and gamma-ray spectroscopy, and delayed neutrons are included. An appendix contains a survey of the most recent compilations and evaluations containing fission product yield, fission product decay data, and delayed neutron yield information. (WHK)

Reliability and synchronization in a delay-coupled neuronal network with synaptic plasticity

NASA Astrophysics Data System (ADS)

Pérez, Toni; Uchida, Atsushi

2011-06-01

We investigate the characteristics of reliability and synchronization of a neuronal network of delay-coupled integrate and fire neurons. Reliability and synchronization appear in separated regions of the phase space of the parameters considered. The effect of including synaptic plasticity and different delay values between the connections are also considered. We found that plasticity strongly changes the characteristics of reliability and synchronization in the parameter space of the coupling strength and the drive amplitude for the neuronal network. We also found that delay does not affect the reliability of the network but has a determinant influence on the synchronization of the neurons.

Discounting of Monetary Rewards that are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, not Additively

PubMed Central

Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

2014-01-01

The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects of reward amount. Previous research has focused on the discounting of delayed and probabilistic rewards separately, with little research examining more complex situations in which rewards are both delayed and probabilistic. In two experiments, participants made choices between smaller rewards that were both immediate and certain and larger rewards that were both delayed and probabilistic. Analyses revealed significant interactions between delay and probability factors inconsistent with an additive model. In contrast, a hyperboloid discounting model in which delay and probability were combined multiplicatively provided an excellent fit to the data. These results suggest that the hyperboloid is a good descriptor of decision making in complicated monetary choice situations like those people encounter in everyday life. PMID:24933696

Short nights reduce light-induced circadian phase delays in humans.

PubMed

Burgess, Helen J; Eastman, Charmane I

2006-01-01

Short sleep episodes are common in modern society. We recently demonstrated that short nights reduce phase advances to light. Here we show that short nights also reduce phase delays to light. Two weeks of 6-hour sleep episodes in the dark (short nights) and 2 weeks of long 9-hour sleep episodes (long nights) in counterbalanced order, separated by 7 days. Following each series of nights, there was a dim-light phase assessment to assess baseline phase. Three days later, subjects were exposed to a phase-delaying light stimulus for 2 days, followed by a final phase assessment. Subjects slept at home in dark bedrooms but came to the laboratory for the phase assessments and light stimulus. Seven young healthy subjects. The 3.5-hour light stimulus was four 30-minute pulses of bright light (-5000 lux) separated by 30-minute intervals of room light. The stimulus began 2.5 hours after each subject's dim-light melatonin onset, followed by a 6- or 9-hour sleep episode. On the second night, the bright light and sleep episode began 1 hour later. The dim-light melatonin onset and dimlight melatonin offset phase delayed 1.4 and 0.7 hours less in the short nights, respectively (both p < or = .015). These results indicate for the first time that short nights can reduce circadian phase delays, that long nights can increase phase delays to light, or both. People who curtail their sleep may inadvertently reduce their circadian responsiveness to evening light.

An analysis of landing rates and separations at the Dallas/Fort Worth International Airport

NASA Technical Reports Server (NTRS)

Ballin, Mark G.; Erzberger, Heinz

1996-01-01

Advanced air traffic management systems such as the Center/TRACON Automation System (CTAS) should yield a wide range of benefits, including reduced aircraft delays and controller workload. To determine the traffic-flow benefits achievable from future terminal airspace automation, live radar information was used to perform an analysis of current aircraft landing rates and separations at the Dallas/Fort Worth International Airport. Separation statistics that result when controllers balance complex control procedural constraints in order to maintain high landing rates are presented. In addition, the analysis estimates the potential for airport capacity improvements by determining the unused landing opportunities that occur during rush traffic periods. Results suggest a large potential for improving the accuracy and consistency of spacing between arrivals on final approach, and they support earlier simulation findings that improved air traffic management would increase capacity and reduce delays.

Parenting Predictors of Delay Inhibition in Socioeconomically Disadvantaged Preschoolers

PubMed Central

Merz, Emily C.; Landry, Susan H.; Zucker, Tricia A.; Barnes, Marcia A.; Assel, Michael; Taylor, Heather B.; Lonigan, Christopher J.; Phillips, Beth M.; Clancy-Menchetti, Jeanine; Eisenberg, Nancy; Spinrad, Tracy L.; Valiente, Carlos; de Villiers, Jill; Consortium, the School Readiness Research

2016-01-01

This study examined longitudinal associations between specific parenting factors and delay inhibition in socioeconomically disadvantaged preschoolers. At Time 1, parents and 2- to 4-year-old children (mean age = 3.21 years; N = 247) participated in a videotaped parent-child free play session, and children completed delay inhibition tasks (gift delay-wrap, gift delay-bow, and snack delay tasks). Three months later, at Time 2, children completed the same set of tasks. Parental responsiveness was coded from the parent-child free play sessions, and parental directive language was coded from transcripts of a subset of 127 of these sessions. Structural equation modeling was used, and covariates included age, gender, language skills, parental education, and Time 1 delay inhibition. Results indicated that in separate models, Time 1 parental directive language was significantly negatively associated with Time 2 delay inhibition, and Time 1 parental responsiveness was significantly positively associated with Time 2 delay inhibition. When these parenting factors were entered simultaneously, Time 1 parental directive language significantly predicted Time 2 delay inhibition whereas Time 1 parental responsiveness was no longer significant. Findings suggest that parental language that modulates the amount of autonomy allotted the child may be an important predictor of early delay inhibition skills. PMID:27833461

Microwave radiometry as a tool to calibrate tropospheric water-vapor delay

NASA Technical Reports Server (NTRS)

Resch, G. M.; Claflin, E. S.

1980-01-01

Microwave radiometers were used to measure the emission line due to the water vapor molecules of atmospheric emission. Four separate field tests were completed which compared radiometers to other techniques which measure water vapor. It is shown that water vapor induced delay can be estimated with an accuracy of plus or minus 2 cm for elevation angles above 17 degrees.

Medial Prefrontal Cortex and Dorsomedial Striatum Are Necessary for the Trial-Unique, Delayed Nonmatching-to-Location (TUNL) Task in Rats: Role of NMDA Receptors

ERIC Educational Resources Information Center

Davies, Don A.; Hurtubise, Jessica L.; Greba, Quentin; Howland, John G.

2017-01-01

The trial-unique, delayed nonmatching-to-location (TUNL) task is a recently developed behavioral task that measures spatial working memory and a form of pattern separation in touchscreen-equipped operant conditioning chambers. Limited information exists regarding the neurotransmitters and neural substrates involved in the task. The present…

24-Month-Olds Use Conceptual Similarity to Solve New Problems after a Delay

ERIC Educational Resources Information Center

Hayne, Harlene; Gross, Julien

2015-01-01

In this experiment, we used the deferred imitation paradigm to assess 24-month-olds' ability to use conceptual similarity to solve new problems after a delay. Infants in the experimental condition participated in four sessions that were each separated by 24 h. In Session 1, the experimenter modeled three target actions using one set of stimuli and…

Performance of an Automated System for Control of Traffic in Terminal Airspace

NASA Technical Reports Server (NTRS)

Nikoleris, Tasos; Erzberger, Heinz; Paielli, Russell A.; Chu, Yung-Cheng

2016-01-01

This paper examines the performance of a system that performs automated conflict resolution and arrival scheduling for aircraft in the terminal airspace around major airports. Such a system has the potential to perform separation assurance and arrival sequencing tasks that are currently handled manually by human controllers. The performance of the system is tested against several simulated traffic scenarios that are characterized by the rate at which air traffic is metered into the terminal airspace. For each traffic scenario, the levels of performance that are examined include: number of conflicts predicted to occur, types of resolution maneuver used to resolve predicted conflicts, and the amount of delay for all flights. The simulation results indicate that the percentage of arrivals that required a maneuver that changes the flight's horizontal route ranged between 11% and 15% in all traffic scenarios. That finding has certain implications if this automated system were to be implemented simply as a decision support tool. It is also found that arrival delay due to purely wake vortex separation requirements on final approach constituted only between 29% and 35% of total arrival delay, while the remaining major portion of it is mainly due to delay back propagation effects.

Mathematical model describing the thyroids-pituitary axis with distributed time delays in hormone transportation

NASA Astrophysics Data System (ADS)

Neamţu, Mihaela; Stoian, Dana; Navolan, Dan Bogdan

2014-12-01

In the present paper we provide a mathematical model that describe the hypothalamus-pituitary-thyroid axis in autoimmune (Hashimoto's) thyroiditis. Since there is a spatial separation between thyroid and pituitary gland in the body, time is needed for transportation of thyrotropin and thyroxine between the glands. Thus, the distributed time delays are considered as both weak and Dirac kernels. The delayed model is analyzed regarding the stability and bifurcation behavior. The last part contains some numerical simulations to illustrate the effectiveness of our results and conclusions.

Bi-frontal direct current stimulation affects delay discounting choices.

PubMed

Hecht, David; Walsh, Vincent; Lavidor, Michal

2013-01-01

In delay discounting tasks, participants decide between receiving a certain amount of money now or a larger sum sometime in the future. This study investigated the effects of transcranial direct current stimulation on delay discounting. Participants made delay discounting choices while receiving a bi-frontal stimulation of right-hemisphere anodal/left-hemisphere cathodal, left-hemisphere anodal/right-hemisphere cathodal, and sham stimulation, in three separate sessions. When the difference between the alternatives was 10% or more, participants generally preferred to wait for the larger sum. Nevertheless, there were more choices of smaller "immediate" gains, instead of the larger delayed options, when the left dorsolateral prefrontal cortex (DLPFC) was facilitated and the right DLPFC inhibited, compared to the sham stimulation. These observations indicate the significant role of the prefrontal cortex in delay discounting choices, and demonstrate that increased left frontal activation combined with decreased right frontal activation can alter decision-making by intensifying a tendency to choose immediate gains.

Application of X-Y Separable 2-D Array Beamforming for Increased Frame Rate and Energy Efficiency in Handheld Devices

PubMed Central

Owen, Kevin; Fuller, Michael I.; Hossack, John A.

2015-01-01

Two-dimensional arrays present significant beamforming computational challenges because of their high channel count and data rate. These challenges are even more stringent when incorporating a 2-D transducer array into a battery-powered hand-held device, placing significant demands on power efficiency. Previous work in sonar and ultrasound indicates that 2-D array beamforming can be decomposed into two separable line-array beamforming operations. This has been used in conjunction with frequency-domain phase-based focusing to achieve fast volume imaging. In this paper, we analyze the imaging and computational performance of approximate near-field separable beamforming for high-quality delay-and-sum (DAS) beamforming and for a low-cost, phaserotation-only beamforming method known as direct-sampled in-phase quadrature (DSIQ) beamforming. We show that when high-quality time-delay interpolation is used, separable DAS focusing introduces no noticeable imaging degradation under practical conditions. Similar results for DSIQ focusing are observed. In addition, a slight modification to the DSIQ focusing method greatly increases imaging contrast, making it comparable to that of DAS, despite having a wider main lobe and higher side lobes resulting from the limitations of phase-only time-delay interpolation. Compared with non-separable 2-D imaging, up to a 20-fold increase in frame rate is possible with the separable method. When implemented on a smart-phone-oriented processor to focus data from a 60 × 60 channel array using a 40 × 40 aperture, the frame rate per C-mode volume slice increases from 16 to 255 Hz for DAS, and from 11 to 193 Hz for DSIQ. Energy usage per frame is similarly reduced from 75 to 4.8 mJ/ frame for DAS, and from 107 to 6.3 mJ/frame for DSIQ. We also show that the separable method outperforms 2-D FFT-based focusing by a factor of 1.64 at these data sizes. This data indicates that with the optimal design choices, separable 2-D beamforming can significantly improve frame rate and battery life for hand-held devices with 2-D arrays. PMID:22828829

Single-scan dual-tracer FLT+FDG PET tumor characterization.

PubMed

Kadrmas, Dan J; Rust, Thomas C; Hoffman, John M

2013-02-07

Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both (18)F-fluorodeoxyglucose (FDG) and (18)F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems--both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10-60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), K(net), and K(1) as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k(2), k(3)) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging studies in five patients with primary brain tumors where the data from separate scans of each tracer were combined to synthesize dual-tracer scans with known single-tracer components; results demonstrated similar dual-tracer signal recovery performance. We conclude that rapid dual-tracer FLT+FDG tumor imaging is feasible and can provide quantitative tumor imaging measures comparable to those from conventional separate-scan imaging.

Single-scan dual-tracer FLT+FDG PET tumor characterization

NASA Astrophysics Data System (ADS)

Kadrmas, Dan J.; Rust, Thomas C.; Hoffman, John M.

2013-02-01

Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems—both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10-60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), Knet, and K1 as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k2, k3) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging studies in five patients with primary brain tumors where the data from separate scans of each tracer were combined to synthesize dual-tracer scans with known single-tracer components; results demonstrated similar dual-tracer signal recovery performance. We conclude that rapid dual-tracer FLT+FDG tumor imaging is feasible and can provide quantitative tumor imaging measures comparable to those from conventional separate-scan imaging.

Single-scan dual-tracer FLT+FDG PET tumor characterization

PubMed Central

Kadrmas, Dan J; Rust, Thomas C; Hoffman, John M

2013-01-01

Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems—both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10–60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), Knet, and K1 as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k2, k3) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging studies in five patients with primary brain tumors where the data from separate scans of each tracer were combined to synthesize dual-tracer scans with known single-tracer components; results demonstrated similar dual-tracer signal recovery performance. We conclude that rapid dual-tracer FLT+FDG tumor imaging is feasible and can provide quantitative tumor imaging measures comparable to those from conventional separate-scan imaging. PMID:23296314

The role of early visual cortex in visual short-term memory and visual attention.

PubMed

Offen, Shani; Schluppeck, Denis; Heeger, David J

2009-06-01

We measured cortical activity with functional magnetic resonance imaging to probe the involvement of early visual cortex in visual short-term memory and visual attention. In four experimental tasks, human subjects viewed two visual stimuli separated by a variable delay period. The tasks placed differential demands on short-term memory and attention, but the stimuli were visually identical until after the delay period. Early visual cortex exhibited sustained responses throughout the delay when subjects performed attention-demanding tasks, but delay-period activity was not distinguishable from zero when subjects performed a task that required short-term memory. This dissociation reveals different computational mechanisms underlying the two processes.

Evaluation of Scheduling Methods for Multiple Runways

NASA Technical Reports Server (NTRS)

Bolender, Michael A.; Slater, G. L.

1996-01-01

Several scheduling strategies are analyzed in order to determine the most efficient means of scheduling aircraft when multiple runways are operational and the airport is operating at different utilization rates. The study compares simulation data for two and three runway scenarios to results from queuing theory for an M/D/n queue. The direction taken, however, is not to do a steady-state, or equilibrium, analysis since this is not the case during a rush period at a typical airport. Instead, a transient analysis of the delay per aircraft is performed. It is shown that the scheduling strategy that reduces the delay depends upon the density of the arrival traffic. For light traffic, scheduling aircraft to their preferred runways is sufficient; however, as the arrival rate increases, it becomes more important to separate traffic by weight class. Significant delay reduction is realized when aircraft that belong to the heavy and small weight classes are sent to separate runways with large aircraft put into the 'best' landing slot.

In situ Observations of Heliospheric Current Sheets Evolution

NASA Astrophysics Data System (ADS)

Liu, Yong; Peng, Jun; Huang, Jia; Klecker, Berndt

2017-04-01

We investigate the Heliospheric current sheet observation time difference of the spacecraft using the STEREO, ACE and WIND data. The observations are first compared to a simple theory in which the time difference is only determined by the radial and longitudinal separation between the spacecraft. The predictions fit well with the observations except for a few events. Then the time delay caused by the latitudinal separation is taken in consideration. The latitude of each spacecraft is calculated based on the PFSS model assuming that heliospheric current sheets propagate at the solar wind speed without changing their shapes from the origin to spacecraft near 1AU. However, including the latitudinal effects does not improve the prediction, possibly because that the PFSS model may not locate the current sheets accurately enough. A new latitudinal delay is predicted based on the time delay using the observations on ACE data. The new method improved the prediction on the time lag between spacecraft; however, further study is needed to predict the location of the heliospheric current sheet more accurately.

Delay compensation in integrated communication and control systems. I - Conceptual development and analysis

NASA Technical Reports Server (NTRS)

Luck, Rogelio; Ray, Asok

1990-01-01

A procedure for compensating for the effects of distributed network-induced delays in integrated communication and control systems (ICCS) is proposed. The problem of analyzing systems with time-varying and possibly stochastic delays could be circumvented by use of a deterministic observer which is designed to perform under certain restrictive but realistic assumptions. The proposed delay-compensation algorithm is based on a deterministic state estimator and a linear state-variable-feedback control law. The deterministic observer can be replaced by a stochastic observer without any structural modifications of the delay compensation algorithm. However, if a feedforward-feedback control law is chosen instead of the state-variable feedback control law, the observer must be modified as a conventional nondelayed system would be. Under these circumstances, the delay compensation algorithm would be accordingly changed. The separation principle of the classical Luenberger observer holds true for the proposed delay compensator. The algorithm is suitable for ICCS in advanced aircraft, spacecraft, manufacturing automation, and chemical process applications.

Proximal hypospadias treated with a transverse preputial island tube: long-term functional, sexual, and cosmetic outcomes.

PubMed

Rynja, Sybren P; de Jong, Tom P V M; Bosch, J L H Ruud; de Kort, Laetitia M O

2018-04-06

To study long-term urinary and sexual function, and cosmetic outcomes in adult patients who underwent single-stage transverse preputial island tube (TPIT) for proximal hypospadias repair in childhood. Long-term data on outcomes of patients with proximal hypospadias with severe coexisting curvature and insufficient urethral plate are scarce, but are necessary to decide which repair technique is most beneficial. Patients with proximal hypospadias operated with TPIT (TPIT Group) were compared to patients with distal hypospadias repair (Distal Group) and to a control group of male medical students (Control Group). Participants completed the International Prostate Symptom Score, the International Index of Erectile Function (IIEF-15), additional non-validated questions, and performed uroflowmetry. Cosmesis was assessed in the patients with hypospadias using the Pediatric Penile Perception Score (PPPS); stretched penile length was also measured. Of the 121 eligible patients with hypospadias, 54 with either TPIT or distal hypospadias repairs participated. The TPIT Group comprised 12 patients (median age of 20.0 years) and the Distal Group comprised 42 patients (median age of 19.6 years). The complication rates were similar, at 8 of the 12 patients in the TPIT Group vs 26/42 (62%) in the Distal Group (P = 0.76). Urinary outcomes were similar in the TPIT, Distal, and the Control (comprised of 148 medical students with a median age of 21.0 years) groups. The TPIT Group had a lower maximum urinary flow rate compared to the Control Group, at 24.1 vs 28.6 mL/s (P < 0.05). IIEF-15 scores were similar in the TPIT, Distal and Control groups, except for 'Orgasmic Function' (7.5 vs 10.0 vs 10.0, respectively; P < 0.01). Although the TPIT Group had a smaller penile length compared to the Distal Group (10.1 vs 12.9 cm, P < 0.01), PPPS outcomes were similar. In these TPIT patients, long-term urinary, sexual and cosmetic outcomes were similar to those in patients with distal hypospadias repairs and controls. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

Seasonal changes in steroid hormone profiles, body weight, semen quality, and the reproductive tract in captive African wild dogs (Lycaon pictus) in South Africa.

PubMed

Newell-Fugate, Annie E; O Nöthling, Johan; J Bertschinger, Henk

2012-09-01

Characterization of reproductive seasonality in the African wild dog (Lycaon pictus) could assist reintroduction programs. Male wild dogs (n=14) were assessed quarterly (January, mid-summer; April, late summer; August, late winter; November, early summer) for serum testosterone, body weight, testicular and prostatic volume, preputial gland measurement, and ejaculate characteristics. Bi-monthly fecal samples were collected from male (n=11) and female (n=4) wild dogs for analysis of fecal androgens and progestagens. Fecal androgens were higher in early summer (246.4 ± 14.5 ng/g) than in early winter (218.6 ± 13.4 ng/g). Serum testosterone was higher in mid-summer (1.4 ± 0.3 ng/ml) than in late winter (0.7 ± 0.1 ng/ml). Number of spermatozoa per ejaculate was greatest in late summer (301.4 ± 39.3 × 10(6)). Other semen parameters peaked in mid-summer (pH: 7.4; progressive motility: 85.0 ± 0.1%; live spermatozoa: 81.0 ± 16%; normal morphology: 71.5 ± 8.2%). Total testicular and prostatic volume were greater during summer (testicular: 36.7 ± 4.2 cm(3); prostatic: 12.0 ± 1.9 cm(3)) than winter (testicular: 25.2 ± 1.9 cm(3); prostatic: 5.8 ± 0.8 cm(3)). Preputial pendulance also was greater in summer (7.1 ± 0.5 cm; n=9) than winter (5.9 ± 0.2 cm). Baseline fecal progestagen metabolites were 6.2 ± 2.5 μg/g and peak fecal progestagen metabolites were 14.7 ± 2.8 μg/g. Copulations resulting in pregnancies (n=2) occurred in late summer and gestation was 71 days. Female wild dogs were seasonally monoestrous with mating in summer and winter. In conclusion, wild dogs are reproductively seasonal with improvement in male reproductive variables during summer and a bi-phasic seasonal pattern to female receptivity. Copyright © 2012 Elsevier Inc. All rights reserved.

Developmental delay in moderately preterm-born children with low socioeconomic status: risks multiply.

PubMed

Potijk, Marieke R; Kerstjens, Jorien M; Bos, Arend F; Reijneveld, Sijmen A; de Winter, Andrea F

2013-11-01

To assess separate and joint effects of low socioeconomic status (SES) and moderate prematurity on preschool developmental delay. Prospective cohort study with a community-based sample of preterm- and term-born children (Longitudinal Preterm Outcome Project). We assessed SES on the basis of education, occupation, and family income. The Ages and Stages Questionnaire was used to assess developmental delay at age 4 years. We determined scores for overall development, and domains fine motor, gross motor, communication, problem-solving, and personal-social of 926 moderately preterm-born (MP) (32-36 weeks gestation) and 544 term-born children. In multivariable logistic regression analyses, we used standardized values for SES and gestational age (GA). Prevalence rates for overall developmental delay were 12.5%, 7.8%, and 5.6% in MP children with low, intermediate, and high SES, respectively, and 7.2%, 4.0%, and 2.8% in term-born children, respectively. The risk for overall developmental delay increased more with decreasing SES than with decreasing GA, but the difference was not statistically significant: OR (95% CI) for a 1 standard deviation decrease were: 1.62 (1.30-2.03) and 1.34 (1.05-1.69), respectively, after adjustment for sex, number of siblings, and maternal age. No interaction was found except for communication, showing that effects of SES and GA are mostly multiplicative. Low SES and moderate prematurity are separate risk factors with multiplicative effects on developmental delay. The double jeopardy of MP children with low SES needs special attention in pediatric care. Copyright © 2013 Mosby, Inc. All rights reserved.

Separate valuation subsystems for delay and effort decision costs.

PubMed

Prévost, Charlotte; Pessiglione, Mathias; Météreau, Elise; Cléry-Melin, Marie-Laure; Dreher, Jean-Claude

2010-10-20

Decision making consists of choosing among available options on the basis of a valuation of their potential costs and benefits. Most theoretical models of decision making in behavioral economics, psychology, and computer science propose that the desirability of outcomes expected from alternative options can be quantified by utility functions. These utility functions allow a decision maker to assign subjective values to each option under consideration by weighting the likely benefits and costs resulting from an action and to select the one with the highest subjective value. Here, we used model-based neuroimaging to test whether the human brain uses separate valuation systems for rewards (erotic stimuli) associated with different types of costs, namely, delay and effort. We show that humans devalue rewards associated with physical effort in a strikingly similar fashion to those they devalue that are associated with delays, and that a single computational model derived from economics theory can account for the behavior observed in both delay discounting and effort discounting. However, our neuroimaging data reveal that the human brain uses distinct valuation subsystems for different types of costs, reflecting in opposite fashion delayed reward and future energetic expenses. The ventral striatum and the ventromedial prefrontal cortex represent the increasing subjective value of delayed rewards, whereas a distinct network, composed of the anterior cingulate cortex and the anterior insula, represent the decreasing value of the effortful option, coding the expected expense of energy. Together, these data demonstrate that the valuation processes underlying different types of costs can be fractionated at the cerebral level.

Gross separation approaching a blunt trailing edge as the turbulence intensity increases.

PubMed

Scheichl, B

2014-07-28

A novel rational description of incompressible two-dimensional time-mean turbulent boundary layer (BL) flow separating from a bluff body at an arbitrarily large globally formed Reynolds number, Re, is devised. Partly in contrast to and partly complementing previous approaches, it predicts a pronounced delay of massive separation as the turbulence intensity level increases. This is bounded from above by a weakly decaying Re-dependent gauge function (hence, the BL approximation stays intact locally), and thus the finite intensity level characterizing fully developed turbulence. However, it by far exceeds the moderate level found in a preceding study which copes with the associated moderate delay of separation. Thus, the present analysis bridges this self-consistent and another forerunner theory, proposing extremely retarded separation by anticipating a fully attached external potential flow. Specifically, it is shown upon formulation of a respective distinguished limit at which rate the separation point and the attached-flow trailing edge collapse as [Formula: see text] and how on a short streamwise scale the typical small velocity deficit in the core region of the incident BL evolves to a large one. Hence, at its base, the separating velocity profile varies generically with the one-third power of the wall distance, and the classical triple-deck problem describing local viscous-inviscid interaction crucial for moderately retarded separation is superseded by a Rayleigh problem, governing separation of that core layer. Its targeted solution proves vital for understanding the separation process more close to the wall. Most importantly, the analysis does not resort to any specific turbulence closure. A first comparison with the available experimentally found positions of separation for the canonical flow past a circular cylinder is encouraging. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Influence of the electrode gap separation on the pseudospark-sourced electron beam generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, J., E-mail: junping.zhao@qq.com; State Key Laboratory of Electrical Insulation and Power Equipment, West Xianning Road, Xi'an 710049; Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG Scotland

Pseudospark-sourced electron beam is a self-focused intense electron beam which can propagate without any external focusing magnetic field. This electron beam can drive a beam-wave interaction directly or after being post-accelerated. It is especially suitable for terahertz radiation generation due to the ability of a pseudospark discharge to produce small size in the micron range and very high current density and bright electron beams. In this paper, a single-gap pseudospark discharge chamber has been built and tested with several electrode gap separations to explore the dependence of the pseudospark-sourced electron beam current on the discharge voltage and the electrode gapmore » separation. Experimental results show that the beam pulses have similar pulse width and delay time from the distinct drop of the applied voltage for smaller electrode gap separations but longer delay time for the largest gap separation used in the experiment. It has been found that the electron beam only starts to occur when the charging voltage is above a certain value, which is defined as the starting voltage of the electron beam. The starting voltage is different for different electrode gap separations and decreases with increasing electrode gap separation in our pseudospark discharge configuration. The electron beam current increases with the increasing discharge voltage following two tendencies. Under the same discharge voltage, the configuration with the larger electrode gap separation will generate higher electron beam current. When the discharge voltage is higher than 10 kV, the beam current generated at the electrode gap separation of 17.0 mm, is much higher than that generated at smaller gap separations. The ionization of the neutral gas in the main gap is inferred to contribute more to the current increase with increasing electrode gap separation.« less

Constructing Hopf bifurcation lines for the stability of nonlinear systems with two time delays

NASA Astrophysics Data System (ADS)

Nguimdo, Romain Modeste

2018-03-01

Although the plethora real-life systems modeled by nonlinear systems with two independent time delays, the algebraic expressions for determining the stability of their fixed points remain the Achilles' heel. Typically, the approach for studying the stability of delay systems consists in finding the bifurcation lines separating the stable and unstable parameter regions. This work deals with the parametric construction of algebraic expressions and their use for the determination of the stability boundaries of fixed points in nonlinear systems with two independent time delays. In particular, we concentrate on the cases for which the stability of the fixed points can be ascertained from a characteristic equation corresponding to that of scalar two-delay differential equations, one-component dual-delay feedback, or nonscalar differential equations with two delays for which the characteristic equation for the stability analysis can be reduced to that of a scalar case. Then, we apply our obtained algebraic expressions to identify either the parameter regions of stable microwaves generated by dual-delay optoelectronic oscillators or the regions of amplitude death in identical coupled oscillators.

Pacemaker mediated tachycardia as a complication of the autointrinsic conduction search function.

PubMed

Dennis, Malcolm J; Sparks, Paul B

2004-06-01

The autointrinsic conduction search (AICS) option, featured on some DDD pacemakers, performs periodic assessments of atrioventricular (AV) conduction capability during a single beat AV delay extension. Demonstration of ventricular conduction during the prolonged AV delay, permits ongoing AV delay extension if the patient's intrinsic conduction is preferred to ventricular pacing. A case is presented where the wide separation of atrial and ventricular pacing during the conduction search permitted retrograde ventriculoatrial conduction, precipitating pacemaker mediated tachycardia (PMT) on seven occasions in one patient. Two onset patterns are reported, both attributable to the AICS option. Recommendations for prevention strategies are made.

Evaluation of ammonium perchlorate in the endocrine disruptor screening and testing program's male pubertal protocol: ability to detect effects on thyroid endpoints.

PubMed

Stoker, T E; Ferrell, J M; Laws, S C; Cooper, R L; Buckalew, A

2006-11-10

The U.S. EPA Endocrine Disruptor Screening Program (EDSP) Tier 1 male pubertal protocol was designed as a screen to detect endocrine-disrupting chemicals which may alter reproductive development or thyroid function. One purpose of this in vivo screening protocol is to detect thyrotoxicants via a number of different mechanisms of action, such as thyroid hormone synthesis or clearance. Here we evaluate the ability of this EDSP male pubertal protocol to detect the known thyrotoxicant ammonium perchlorate as an endocrine disruptor. Ammonium perchlorate is a primary ingredient in rocket fuel, fertilizers, paints, and lubricants. Over the past 50 years, potassium perchlorate has been used to treat hyperthyroidism in humans. Perchlorate alters thyroid hormone secretion by competitively inhibiting iodide uptake by the thyroid gland. In this study, ammonium perchlorate was administered at 62.5, 125, 250, and 500 mg/kg to male Wistar rats based on a pilot study of oral dosing. Doses of 125-500 mg/kg perchlorate decreased T4 in a dose-dependent manner. TSH was significantly increased in a dose-responsive manner at the same doses, while T3 was unchanged at any dose. Thyroid histology was significantly altered at all doses, even at the 62.5 mg/kg, with a clear dose-dependent decrease in colloid area and increase in follicular cell height. No effects on preputial separation, a marker of pubertal progression, or reproductive tract development were observed at any dose. These results demonstrate that the male pubertal protocol is useful for detecting thyrotoxicants which target the thyroid axis by this mechanism (altered uptake of iodide). This study also found that perchlorate exposure during this period did not alter any of the reproductive developmental endpoints.

Key Lessons from Performance of the U.S. EPA Endocrine Disruptor Screening Program (EDSP) Tier 1 Male and Female Pubertal Assays

PubMed Central

Stump, Donald G; O'Connor, John C; Lewis, Joseph M; Marty, M Sue

2014-01-01

The male and female pubertal assays, which are included in the U.S. Environmental Protection Agency's (EPA) Endocrine Disruptor Screening Program (EDSP) Tier 1 battery, can detect endocrine-active compounds operating by various modes of action. This article uses the collective experience of three laboratories to provide information on pubertal assay conduct, interlaboratory reproducibility, endpoint redundancy, and data interpretation. The various criteria used to select the maximum tolerated dose are described. A comparison of historical control data across laboratories confirmed reasonably good interlaboratory reproducibility. With a reliance on apical endpoints, interpretation of pubertal assay effects as specifically endocrine-mediated or secondary to other systemic effects can be problematic and mode of action may be difficult to discern. Across 21–23 data sets, relative liver weight, a nonspecific endocrine endpoint, was the most commonly affected endpoint in male and female assays. For endocrine endpoints, patterns of effects were generally seen; rarely was an endocrine-sensitive endpoint affected in isolation. In males, most frequently missed EPA-established performance criteria included mean weights for kidney and thyroid, and the coefficient of variation for age and body weight at preputial separation, seminal vesicle weight, and final body weight. In females, the frequently missed EPA-established performance criteria included mean adrenal weight and mean age at vaginal opening. To ensure specificity for endocrine effects, the pubertal assays should be interpreted using a weight-of-evidence approach as part of the entire EDSP battery. Based on the frequency with which certain performance criteria were missed, an EPA review of these criteria is warranted. PMID:24510766

Developmental exposure to a commercial PBDE mixture, DE-71: neurobehavioral, hormonal, and reproductive effects.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodavanti, Prasada; Coburn, Cary; Moser, Virginia

2010-06-01

Developmental effects of polybrominated diphenyl ethers (PBDEs) have been suspected due to their structural similarities to polychlorinated biphenyls (PCBs). This study evaluated neurobehavioral, hormonal, and reproductive effects in rat offspring perinatally exposed to a widely used pentabrominated commercial mixture, DE-71. Pregnant Long-Evans rats were exposed to 0, 1.7, 10.2, or 30.6 mg/kg/day DE-71 in corn oil by oral gavage from gestational day 6 to weaning. DE-71 did not alter maternal or male offspring body weights. However, female offspring were smaller compared with controls from postnatal days (PNDs) 35-60. Although several neurobehavioral endpoints were assessed, the only statistically significant behavioral findingmore » was a dose-by-age interaction in the number of rears in an open-field test. Developmental exposure to DE-71 caused severe hypothyroxinemia in the dams and early postnatal offspring. DE-71 also affected anogenital distance and preputial separation in male pups. Body weight gain over time, reproductive tissue weights, and serum testosterone concentrations at PND 60 were not altered. Mammary gland development of female offspring was significantly affected at PND 21. Congener-specific analysis of PBDEs indicated accumulation in all tissues examined. Highest PBDE concentrations were found in fat including milk, whereas blood had the lowest concentrations on a wet weight basis. PBDE concentrations were comparable among various brain regions. Thus, perinatal exposure to DE-71 leads to accumulation of PBDE congeners in various tissues crossing blood-placenta and blood-brain barriers, causing subtle changes in some parameters of neurobehavior and dramatic changes in circulating thyroid hormone levels, as well as changes in both male and female reproductive endpoints. Some of these effects are similar to those seen with PCBs, and the persistence of these changes requires further investigation.« less

Pyogranulomatous panniculitis in ferrets (Mustela putorius furo) with intralesional demonstration of Pseudomonas luteola.

PubMed

Baum, B; Richter, B; Reifinger, M; Klang, A; Finnberg, C; Loncaric, I; Spergser, J; Eisenberg, T; Künzel, F; Preis, S; Pantchev, N; Rütgen, B; Guija de Arespacochaga, A; Hewicker-Trautwein, M

2015-01-01

One ferret (Mustela putorius furo) from Finland and two ferrets from Austria, aged 1-4.5 years and of both genders, were presented with pyogranulomatous subcutaneous inflammation affecting the inguinal, preputial and femoral regions, respectively. Histologically, microorganisms were detected within the lesions. The organisms had a capsule that stained positively by the periodic acid-Schiff reaction. Pseudomonas spp. were cultured from the lesions in two cases. In the third case, electron microscopy revealed a prokaryotic organism surrounded by an electron lucent matrix. 16S rRNA gene sequencing showed highest sequence homology to Pseudomonas luteola in all three cases. In combination with recent reports of pleuropneumonia in ferrets due to P. luteola infection, these cases might indicate a predisposition of ferrets for infection by these bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fiber bundle endomicroscopy with multi-illumination for three-dimensional reflectance image reconstruction

NASA Astrophysics Data System (ADS)

Ando, Yoriko; Sawahata, Hirohito; Kawano, Takeshi; Koida, Kowa; Numano, Rika

2018-02-01

Bundled fiber optics allow in vivo imaging at deep sites in a body. The intrinsic optical contrast detects detailed structures in blood vessels and organs. We developed a bundled-fiber-coupled endomicroscope, enabling stereoscopic three-dimensional (3-D) reflectance imaging with a multipositional illumination scheme. Two illumination sites were attached to obtain reflectance images with left and right illumination. Depth was estimated by the horizontal disparity between the two images under alternative illuminations and was calibrated by the targets with known depths. This depth reconstruction was applied to an animal model to obtain the 3-D structure of blood vessels of the cerebral cortex (Cereb cortex) and preputial gland (Pre gla). The 3-D endomicroscope could be instrumental to microlevel reflectance imaging, improving the precision in subjective depth perception, spatial orientation, and identification of anatomical structures.

Core Noise Diagnostics of Turbofan Engine Noise Using Correlation and Coherence Functions

NASA Technical Reports Server (NTRS)

Miles, Jeffrey H.

2009-01-01

Cross-correlation and coherence functions are used to look for periodic acoustic components in turbofan engine combustor time histories, to investigate direct and indirect combustion noise source separation based on signal propagation time delays, and to provide information on combustor acoustics. Using the cross-correlation function, time delays were identified in all cases, clearly indicating the combustor is the source of the noise. In addition, unfiltered and low-pass filtered at 400 Hz signals had a cross-correlation time delay near 90 ms, while the low-pass filtered at less than 400 Hz signals had a cross-correlation time delay longer than 90 ms. Low-pass filtering at frequencies less than 400 Hz partially removes the direct combustion noise signals. The remainder includes the indirect combustion noise signal, which travels more slowly because of the dependence on the entropy convection velocity in the combustor. Source separation of direct and indirect combustion noise is demonstrated by proper use of low-pass filters with the cross-correlation function for a range of operating conditions. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting direct and indirect combustion noise.

Time Variation of the Distance Separating Bomb and Dive Bomber Subsequent to Bomb Release

NASA Technical Reports Server (NTRS)

Mathews, Charles W.

1952-01-01

A study has been made of the variation of the distance separating bomb and aircraft with time after release as applied to dive-bombing operations, Separation distances determined from this study are presented in terms of two variables only, dive angle and maximum airplane accelerometer reading; the values of separation distance include the effects of delay in initiation of the pull-out and lag in attainment of the maximum normal acceleration.Contains analysis and calculations of the separation distances between bomb and dive bomber following bomb release, Separation distances as determined by the dive angle and the maximum airplane accelerometer reading are presented in a single chart.

Delay Times From Clustered Multi-Channel Cross Correlation and Simulated Annealing

NASA Astrophysics Data System (ADS)

Creager, K. C.; Sambridge, M. S.

2004-12-01

Several techniques exist to estimate relative delay times of seismic phases based on the assumption that the waveforms observed at several stations can be expressed as a common waveform that has been time shifted and distorted by random uncorrelated noise. We explore the more general problem of estimating the relative delay times for regional or even global distributions of seismometers in cases where waveforms vary systematically across the array. The estimation of relative delay times is formulated as a global optimization of the weighted sum of squares of cross correlations of each seismogram pair evaluated at the corresponding difference in their relative delay times. As there are many local minima in this penalty function, a simulated annealing algorithm is used to obtain a solution. The weights depend strongly on the separation distance among seismogram pairs as well as a measure of the similarity of waveforms. Thus, seismograph pairs that are physically close to each other and have similar waveforms are expected to be well aligned while those with dissimilar waveforms or large separation distances are severely down-weighted and thus need not be well aligned. As a result noisy seismograms, which are not similar to other seismograms, are down-weighted so they do not adversely effect the relative delay times of other seismograms. Finally, natural clusters of seismograms are determined from the weight matrix. Examples of aligning a few hundred P and PKP waveforms from a broadband global array and from a mixed broadband and short-period continental-scale array will be shown. While this method has applications in many situations, it may be especially useful for arrays such as the EarthScope Bigfoot Array.

Willing to Wait: Elevated Reward-Processing EEG Activity Associated with a Greater Preference for Larger-But-Delayed Rewards

PubMed Central

Pornpattananangkul, Narun; Nusslock, Robin

2016-01-01

While almost everyone discounts the value of future rewards over immediate rewards, people differ in their so-called delay-discounting. One of the several factors that may explain individual differences in delay-discounting is reward-processing. To study individual-differences in reward-processing, however, one needs to consider the heterogeneity of neural-activity at each reward-processing stage. Here using EEG, we separated reward-related neural activity into distinct reward-anticipation and reward-outcome stages using time-frequency characteristics. Thirty-seven individuals completed a behavioral delay-discounting task. Reward-processing EEG activity was assessed using a separate reward-learning task, called a reward time-estimation task. During this task, participants were instructed to estimate time duration and were provided performance feedback on a trial-by-trial basis. Participants received monetary-reward for accurate-performance on Reward trials, but not on No-Reward trials. Reward trials, relative to No-Reward trials, enhanced EEG activity during both reward-anticipation stage (including, cued-locked delta power during cue-evaluation and pre-feedback alpha suppression during feedback-anticipation) and at the reward-outcome stage (including, feedback-locked delta, theta and beta power). Moreover, all of these EEG indices correlated with behavioral performance in the time-estimation task, suggesting their essential roles in learning and adjusting performance to maximize winnings in a reward-learning situation. Importantly, enhanced EEG power during Reward trials for 1) pre-feedback alpha suppression, 2) feedback-locked theta and 3) feedback-locked beta was associated with a greater preference for larger-but-delayed rewards. Results highlight the association between a stronger preference toward larger-but-delayed rewards and enhanced reward-processing. Moreover, our reward-processing EEG indices detail the specific stages of reward-processing where these associations occur. PMID:27477630

Beta Decay Study of the Tz = - 256Zn Nucleus and the Determination of the Half-Lives of a Few fp-shell Nuclei

NASA Astrophysics Data System (ADS)

Rubio, B.; Orrigo, S. E. A.; Kucuk, L.; Montaner-Pizá, A.; Fujita, Y.; Fujita, H.; Blank, B.; Gelletly, W.; Adachi, T.; Agramunt, J.; Algora, A.; Ascher, P.; Bilgier, B.; Cáceres, L.; Cakirli, R. B.; de France, G.; Ganioğlu, E.; Gerbaux, M.; Giovinazzo, J.; Grevy, S.; Kamalou, O.; Kozer, H. C.; Kurtukian-Nieto, T.; Marqués, F. M.; Molina, F.; Oktem, Y.; de Oliveira Santos, F.; Perrot, L.; Popescu, L.; Raabe, R.; Rogers, A. M.; Srivastava, P. C.; Susoy, G.; Suzuki, T.; Tamii, A.; Thomas, J. C.

2014-06-01

This paper concerns the experimental study of the β decay properties of few proton-rich fp-shell nuclei. The nuclei were produced at GANIL in fragmentation reactions, separated with the LISE spectrometer and stopped in an implantation detector surrounded by Ge detectors. The β-delayed gammas, β-delayed protons and the exotic β-delayed gamma-proton emission have been studied. Preliminary results are presented. The decay of the Tz = - 2 nucleus 56Zn has been studied in detail. Information from the β-delayed protons and β-delayed gammas has been used to deduce the decay scheme. The exotic beta-delayed gamma-proton decay has been observed for the first time in the fp-shell. The interpretation of the data was made possible thanks to the detailed knowledge of the mirror Charge Exchange (CE) process and the gamma de-excitation of the states in 56Co, the mirror nucleus of 56Cu.

Way-Scaling to Reduce Power of Cache with Delay Variation

NASA Astrophysics Data System (ADS)

Goudarzi, Maziar; Matsumura, Tadayuki; Ishihara, Tohru

The share of leakage in cache power consumption increases with technology scaling. Choosing a higher threshold voltage (Vth) and/or gate-oxide thickness (Tox) for cache transistors improves leakage, but impacts cell delay. We show that due to uncorrelated random within-die delay variation, only some (not all) of cells actually violate the cache delay after the above change. We propose to add a spare cache way to replace delay-violating cache-lines separately in each cache-set. By SPICE and gate-level simulations in a commercial 90nm process, we show that choosing higher Vth, Tox and adding one spare way to a 4-way 16KB cache reduces leakage power by 42%, which depending on the share of leakage in total cache power, gives up to 22.59% and 41.37% reduction of total energy respectively in L1 instruction- and L2 unified-cache with a negligible delay penalty, but without sacrificing cache capacity or timing-yield.

On-resonance Variable Delay Multi Pulse Scheme for Imaging of Fast-exchanging Protons and semi-solid Macromolecules

PubMed Central

Xu, Jiadi; Chan, Kannie W.Y.; Xu, Xiang; Yadav, Nibhay; Liu, Guanshu; van Zijl, Peter C. M.

2016-01-01

Purpose To develop an on-resonance variable delay multi-pulse (VDMP) scheme to image magnetization transfer contrast (MTC) as well as the chemical exchange saturation transfer (CEST) contrast of total fast-exchanging protons (TFP) with exchange rate above about 1 kHz. Methods A train of high power binomial pulses was applied at the water resonance. The inter-pulse delay, called mixing time, was varied to observe its effect on the water signal reduction, allowing separation and quantification of MTC and CEST contributions due to their different proton transfer rates. The fast-exchanging protons in CEST and MTC are labeled together with the short T2 components in MTC and separated out using a variable mixing time. Results Phantom studies of selected metabolite solutions (glucose, glutamate, creatine, myo-inositol), bovine serum albumin (BSA) and hair conditioner show the capability of on-resonance VDMP to separate out exchangeable protons with exchange rates above 1 kHz. Quantitative MTC and TFP maps were acquired on healthy mouse brains using this method showing strong gray/white matter contrast for the slowly transferring MTC protons while the TFP map was more uniform across the brain but somewhat higher in gray matter. Conclusions The new method provides a simple way of imaging fast-exchanging protons, as well as MTC components with a slow transfer rate. PMID:26900759

Ethanol exposure can inhibit red spruce ( Picea rubens ) seed germination

Treesearch

John R. Butnor; Brittany M. Verrico; Victor Vankus; Stephen R. Keller

2018-01-01

Flotation of seeds in solvents is a common means of separating unfilled and filled seeds. While a few protocols for processing red spruce (Picea rubens) seeds recommend ethanol flotation, delayed and reduced germination have been reported. We conducted an ethanol bioassay on seeds previously stored at -20°C to quantify the concentration required to separate red spruce...

A computational study of incipient leading-edge separation on a 65-deg delta wing at M = 1.60

NASA Technical Reports Server (NTRS)

Mcmillin, S. Naomi; Pittman, James L.; Thomas, James L.

1990-01-01

A computational study on a 65-deg delta wing at a freestream Mach number of 1.60 has been conducted by obtaining conical Reynolds-averaged Navier-Stokes solutions on a parametric series of geometries which varied in leading-edge radius and/or circular-arc camber. The computational results showed that increasing leading-edge radius or camber can delay the onset of leading-edge separation on the leeside of a delta wing at a specific angle of attack. Reynolds number was varied from 1 x 10 to the 6th to 5 x 10 to the 6th for a turbulent boundary-layer and was shown to have a minor effect on the effectiveness of leading-edge radius and/or camber in delaying the onset of leading-edge separation. Both laminar and turbulent boundary-layer models were investigated at a Reynolds number of 1 x 10 to the 6th, and the predicted flow pattern was found to change from attached flow for the turbulent boundary-layer model to separated flow for the laminar boundary-layer model. Based upon these results, three wind-tunnel models have been designed to be tested in the Langley Unitary Plan Wind Tunnel.

A Diffusion Model Analysis of Decision Biases Affecting Delayed Recognition of Emotional Stimuli.

PubMed

Bowen, Holly J; Spaniol, Julia; Patel, Ronak; Voss, Andreas

2016-01-01

Previous empirical work suggests that emotion can influence accuracy and cognitive biases underlying recognition memory, depending on the experimental conditions. The current study examines the effects of arousal and valence on delayed recognition memory using the diffusion model, which allows the separation of two decision biases thought to underlie memory: response bias and memory bias. Memory bias has not been given much attention in the literature but can provide insight into the retrieval dynamics of emotion modulated memory. Participants viewed emotional pictorial stimuli; half were given a recognition test 1-day later and the other half 7-days later. Analyses revealed that emotional valence generally evokes liberal responding, whereas high arousal evokes liberal responding only at a short retention interval. The memory bias analyses indicated that participants experienced greater familiarity with high-arousal compared to low-arousal items and this pattern became more pronounced as study-test lag increased; positive items evoke greater familiarity compared to negative and this pattern remained stable across retention interval. The findings provide insight into the separate contributions of valence and arousal to the cognitive mechanisms underlying delayed emotion modulated memory.

The aging eyewitness: effects of age on face, delay, and source-memory ability.

PubMed

Memon, Amina; Bartlett, James; Rose, Rachel; Gray, Colin

2003-11-01

As a way to examine the nature of age-related differences in lineup identification accuracy, young (16-33 years) and older (60-82 years) witnesses viewed two similar videotaped incidents, one involving a young perpetrator and the other involving an older perpetrator. The incidents were followed by two separate lineups, one for the younger perpetrator and one for the older perpetrator. When the test delay was short (35 min), the young and older witnesses performed similarly on the lineups, but when the tests were delayed by 1 week, the older witnesses were substantially less accurate. When the target was absent from the lineups, the older witnesses made more false alarm errors, particularly when the faces were young. When the target was present in the lineups, correct identifications by both young and older witnesses were positively correlated with a measure of source recollection derived from a separate face-recognition task. Older witnesses scored poorly on this measure, suggesting that source-recollection deficits are partially responsible for age-related differences in performance on the lineup task.

Fundamental Limits of Delay and Security in Device-to-Device Communication

DTIC Science & Technology

2013-01-01

systematic MDS (maximum distance separable) codes and random binning strategies that achieve a Pareto optimal delayreconstruction tradeoff. The erasure MD...file, and a coding scheme based on erasure compression and Slepian-Wolf binning is presented. The coding scheme is shown to provide a Pareto optimal...ble) codes and random binning strategies that achieve a Pareto optimal delay- reconstruction tradeoff. The erasure MD setup is then used to propose a

A rate-controlled teleoperator task with simulated transport delays

NASA Technical Reports Server (NTRS)

Pennington, J. E.

1983-01-01

A teleoperator-system simulation was used to examine the effects of two control modes (joint-by-joint and resolved-rate), a proximity-display method, and time delays (up to 2 sec) on the control of a five-degree-of-freedom manipulator performing a probe-in-hole alignment task. Four subjects used proportional rotational control and discrete (on-off) translation control with computer-generated visual displays. The proximity display enabled subjects to separate rotational errors from displacement (translation) errors; thus, when the proximity display was used with resolved-rate control, the simulated task was trivial. The time required to perform the simulated task increased linearly with time delay, but time delays had no effect on alignment accuracy. Based on the results of this simulation, several future studies are recommended.

Measuring Ultrasonic Acoustic Velocity in a Thin Sheet of Graphite Epoxy Composite

NASA Technical Reports Server (NTRS)

2008-01-01

A method for measuring the acoustic velocity in a thin sheet of a graphite epoxy composite (GEC) material was investigated. This method uses two identical acoustic-emission (AE) sensors, one to transmit and one to receive. The delay time as a function of distance between sensors determines a bulk velocity. A lightweight fixture (balsa wood in the current implementation) provides a consistent method of positioning the sensors, thus providing multiple measurements of the time delay between sensors at different known distances. A linear fit to separation, x, versus delay time, t, will yield an estimate of the velocity from the slope of the line.

Effects of Acute and Chronic Flunitrazepam on Delay Discounting in Pigeons

PubMed Central

Eppolito, Amy K; France, Charles P; Gerak, Lisa R

2011-01-01

Delay to delivery of a reinforcer can decrease responding for that reinforcer and increase responding for smaller reinforcers that are available concurrently and delivered without delay; acute administration of drugs can alter responding for large, delayed reinforcers, although the impact of chronic treatment on delay discounting is not well understood. In this experiment, the effects of repeated administration of the benzodiazepine flunitrazepam were studied in 6 pigeons responding on one key to receive food that was delivered immediately and on a second key to receive a larger amount of food that was delivered following delays which increased across a single session. Pigeons responded predominantly for the large reinforcer when there were no delays and when delays were short; however, as delays increased, responding for the large reinforcer decreased. Acutely, flunitrazepam (0.32, 1.0 and 3.2 mg/kg) dose-dependently increased responding for the large reinforcer, shifting the discounting curve rightward and upward. Repeated administration of flunitrazepam (0.32, 1.0 and 3.2 mg/kg, each for six sessions, separated by one session during which vehicle was administered) did not markedly alter its effects on responding for the large reinforcer, indicating that the development of tolerance to this effect of flunitrazepam is modest under these conditions. PMID:21541119

Using spatiotemporal source separation to identify prominent features in multichannel data without sinusoidal filters.

PubMed

Cohen, Michael X

2017-09-27

The number of simultaneously recorded electrodes in neuroscience is steadily increasing, providing new opportunities for understanding brain function, but also new challenges for appropriately dealing with the increase in dimensionality. Multivariate source separation analysis methods have been particularly effective at improving signal-to-noise ratio while reducing the dimensionality of the data and are widely used for cleaning, classifying and source-localizing multichannel neural time series data. Most source separation methods produce a spatial component (that is, a weighted combination of channels to produce one time series); here, this is extended to apply source separation to a time series, with the idea of obtaining a weighted combination of successive time points, such that the weights are optimized to satisfy some criteria. This is achieved via a two-stage source separation procedure, in which an optimal spatial filter is first constructed and then its optimal temporal basis function is computed. This second stage is achieved with a time-delay-embedding matrix, in which additional rows of a matrix are created from time-delayed versions of existing rows. The optimal spatial and temporal weights can be obtained by solving a generalized eigendecomposition of covariance matrices. The method is demonstrated in simulated data and in an empirical electroencephalogram study on theta-band activity during response conflict. Spatiotemporal source separation has several advantages, including defining empirical filters without the need to apply sinusoidal narrowband filters. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Introducing causality violation for improved DPOAE component unmixing

NASA Astrophysics Data System (ADS)

Moleti, Arturo; Sisto, Renata; Shera, Christopher A.

2018-05-01

The DPOAE response consists of the linear superposition of two components, a nonlinear distortion component generated in the overlap region, and a reflection component generated by roughness in the DP resonant region. Due to approximate scaling symmetry, the DPOAE distortion component has approximately constant phase. As the reflection component may be considered as a SFOAE generated by the forward DP traveling wave, it has rapidly rotating phase, relative to that of its source, which is also equal to the phase of the DPOAE distortion component. This different phase behavior permits effective separation of the DPOAE components (unmixing), using time-domain or time-frequency domain filtering. Departures from scaling symmetry imply fluctuations around zero delay of the distortion component, which may seriously jeopardize the accuracy of these filtering techniques. The differential phase-gradient delay of the reflection component obeys causality requirements, i.e., the delay is positive only, and the fine-structure oscillations of amplitude and phase are correlated to each other, as happens for TEOAEs and SFOAEs relative to their stimulus phase. Performing the inverse Fourier (or wavelet) transform of a modified DPOAE complex spectrum, in which a constant phase function is substituted for the measured one, the time (or time-frequency) distribution shows a peak at (exactly) zero delay and long-latency specular symmetric components, with a modified (positive and negative) delay, which is that relative to that of the distortion component in the original response. Component separation, applied to this symmetrized distribution, becomes insensitive to systematic errors associated with violation of the scaling symmetry in specific frequency ranges.

[The meaning of erection, genitality, and other representations of urologic topics in the paleolithic imaginary].

PubMed

Angulo Cuesta, Javier; García Díez, Marcos

2007-10-01

The history of urology starts with written documents making express reference to procedures, practices and descriptions of morbid processes related with the male genitourinary tract. Oddly, the most recent prehistoric period, the superior Paleolithic (from approximately 40.000 years to 12.000 years ago; the longest period since our species entered the history of humanity) also has graphic documents expressing how the human being understood the physiologic phenomena and how he observed the pathologic processes of this organism. The representations with genitality expressions enable us to understand the meaning of erection from the Paleolithic perspective, and even the possible existence of a culture based on preputial retraction or rituals of circumcision. Several urologic disorders such us phimosis, paraphimosis, discharge, priapism, and even scrotal mass appear represented at that time and constitute the first sign of knowledge of what can be called primitive urologic knowledge.

The prevalence of bovine venereal campylobacteriosis in cattle herds in the Lake Chad basin of Nigeria.

PubMed

Mshelia, Gideon Dauda; Amin, Jibrilla Dahiru; Egwu, Godwin Onyeamaechi; Woldehiwet, Zerai; Murray, Richard Donald

2012-10-01

The prevalence of bovine venereal campylobacteriosis (BVC) was investigated in the Lake Chad basin of Nigeria. Preputial washings and cervico-vaginal mucus samples were obtained from 270 cattle presenting a history of abortion and lowered fertility, kept in traditional and institutional farms. All the samples investigated were cultured using standard bacteriological technique. Campylobacter fetus was isolated from six bulls and four cows. In all cattle sampled, the isolation rates were 2.2% for C. fetus subsp. venerealis and 1.5% for C. fetus subsp. fetus; the herd and within-herd prevalence rates for C. fetus were 22.2% and 3.4%, respectively, while the overall active infectivity rate was 3.7%. BVC probably contributes to lowered fertility and abortions found in cattle in the Lake Chad basin of Nigeria, associated more with C. fetus subsp. venerealis than C. fetus subsp. fetus.

Detection of the Haemophilus somnus antibodies in the bulls' reproductive tract fluids using the ELISA. I. Elaboration of the ELISA for the detection of the specific antibodies in the IgG, IgM and IgA classes.

PubMed

Stefaniak, T

1993-01-01

The conditions of the ELISA for detecting the Haemophilus somnus antibodies in IgG, IgM and IgA classes were elaborated. The test was adapted for examining the seminal plasma, preputial washings and blood serum samples of bulls. In order to obtain the more precise evaluation of results, the tests were made for two different dilutions of the examined material. The arising out of this method difficulty in the evaluation of the intensity of reaction was solved by introducing the specific, semi-quantitative method of classification, using the eleven-degree scale. The mean arithmetic classificational values calculated from absorbance readings were called "absorbance index". The introduced parameter proved to be especially useful while comparing the reaction of antibodies in reproductive tract fluids samples.

[Isolation of anaerobes during a 30-month observation at a hospital microbiology laboratory].

PubMed

Pistono, P G; Rapetti, I; Stacchini, E; Vironda, N; D'Usi, M P; Guasco, C

1989-01-01

The authors evaluate retrospectively the results obtained from the research of anaerobial bacteria on 1313 samples received at the Microbiology Laboratory of the "Ospedale Civile di Ivrea" over a period of 31 months (6/1/86-12/31/88). From this evaluation, high percentages of detection of anaerobic bacteria are emerging in the following infections: appendiculare abscesses (60%), intestinal operations (71%), wounds (57%), tubovarian abscesses (100%), as well as thoracic empyema (50%). Also relevant are the isolations from skin and subcutaneous tissues: breast infections (50%) preputial infections (60%), perineal and perirectal abscesses (60%). The incident of anaerobic bacteria in bacteriemia is 17%. The most representative anaerobic bacteria group are: Bacteroides spp. (56%), Peptostreptococcus spp. (12%), Propionibacterium spp. (9%), Fusobacterium spp. (7%) Clostridium spp. (6%), Veillonella spp. and Eubacterium spp. (3%). In the intraabdominal infections prevails the Bacteroides group, particularly fragilis species, while in the skin and subcutaneous infections prevails the Peptostreptococcus group.

Conversion of hexadecanoic acid to hexadecenoic acid by rat Delta 6-desaturase.

PubMed

Guillou, Hervé; Rioux, Vincent; Catheline, Daniel; Thibault, Jean-Nöel; Bouriel, Monique; Jan, Sophie; D'Andrea, Sabine; Legrand, Philippe

2003-03-01

A higher content of C16:1 n-10 has recently been reported in the preputial gland of mice with a targeted disruption of the gene encoding stearoyl-CoA desaturase 1 (SCD1-/- mice) when compared with wild-type mice. This result has provided the first physiological evidence for the presence and regulation of a palmitoyl-CoA Delta 6-desaturase in mammals. To investigate the putative involvement of the known Delta 6-desaturase (FADS2) in this process, COS-7 cells expressing rat Delta 6-desaturase were incubated with C16:0. Transfected cells were able to synthesize C16:1 n-10, while nontransfected cells did not produce any C16:1 n-10. Evidence is therefore presented that the rat Delta 6-desaturase, which acts on the 18- and 24-carbon fatty acids of the n-6 and n-3 series, is also able to catalyze palmitic acid Delta 6 -desaturation.

Analog Correlator Based on One Bit Digital Correlator

NASA Technical Reports Server (NTRS)

Prokop, Norman (Inventor); Krasowski, Michael (Inventor)

2017-01-01

A two input time domain correlator may perform analog correlation. In order to achieve high throughput rates with reduced or minimal computational overhead, the input data streams may be hard limited through adaptive thresholding to yield two binary bit streams. Correlation may be achieved through the use of a Hamming distance calculation, where the distance between the two bit streams approximates the time delay that separates them. The resulting Hamming distance approximates the correlation time delay with high accuracy.

Lambert-St. Louis International Airport Data Package Number 5. Airport Improvement Task Force Delay Studies.

DTIC Science & Technology

1980-06-01

conrol 25 34parrozre alrspacecosrit Is 06pazture queue 27 ? Amway cros sin; delay control d.* Aizcaraft Czeratioiaj (Mrter:stics 21 Exit taxiway %a±l... Amway identification 12, Departure runway aMnds 1 ittaxiway location 17General aLV4ation basinq areas C.A= procedurei Is Aircraft separations...Number of runwry. _____________________________ U3 Amway identification 1.2 Deparure runway end Linksj 13 Runay crassinq Links 14Exit taxiway

Control of flow separation in a turbulent boundary layer

NASA Astrophysics Data System (ADS)

Cho, Minjeong; Choi, Sangho; Choi, Haecheon

2015-11-01

Towards the development of successful control methods for separation delay in a turbulent boundary layer, we adopt a model flow field, in which a turbulent separation occurs above a flat plate (Na and Moin 1998 JFM), and apply controls to this flow for reducing the size of the separation bubble and investigating the interaction between the forcing and flow near the separation bubble. We provide a single-frequency forcing with zero net mass flow rate at the upstream of the separation bubble. At low forcing frequencies, spanwise vortices are generated and travel downstream, bringing high momentum toward the wall and reducing the size of the separation bubble. Also, these vortices cause the separation and reattachment points to travel downstream. On the other hand, at high forcing frequencies, the size of the separation bubble becomes smaller and larger in time, respectively, due to the pressure gradient alternating favorably and adversely in time. Supported by NRF-2011-0028032 and 2014048162.

Suppression of Cocaine Self-Administration in Monkeys: Effects of Delayed Punishment

PubMed Central

Woolverton, William L.; Freeman, Kevin B.; Myerson, Joel; Green, Leonard

2014-01-01

Rationale Delaying presentation of a drug can decrease its effectiveness as a reinforcer, but the effect of delaying punishment of drug self-administration is unknown. Objective This study examined whether a histamine injection could punish cocaine self-administration in a drug-drug choice, whether delaying histamine would decrease its effectiveness, and whether the effects of delay could be described within a delay discounting framework. Methods Monkeys were implanted with double-lumen catheters to allow separate injection of cocaine and histamine. In discrete trials, subjects first chose between cocaine (50 or 100 μg/kg/inj) alone and an injection of the same dose of cocaine followed immediately by an injection of histamine (0.37–50 μg/kg). Next, they chose between cocaine followed immediately by histamine and cocaine followed by an equal but delayed dose of histamine. Results When choosing between cocaine alone and cocaine followed immediately by histamine, preference increased with histamine dose from indifference to > 80% choice of cocaine alone. When choosing between cocaine followed by immediate histamine and cocaine followed by delayed histamine, monkeys showed strong position preferences. When delayed histamine was associated with the non-preferred position, preference for that option increased with delay from ≤ 30% to > 85%. The corresponding decrease in choice of the preferred position was well described by a hyperboloid discounting function. Conclusions Histamine can function as a punisher in the choice between injections of cocaine and delay can decrease its effectiveness as a punisher. The effects of delaying punishment of drug self-administration can be conceptualized within the delay discounting framework. PMID:21956240

Suppression of cocaine self-administration in monkeys: effects of delayed punishment.

PubMed

Woolverton, William L; Freeman, Kevin B; Myerson, Joel; Green, Leonard

2012-04-01

Delaying presentation of a drug can decrease its effectiveness as a reinforcer, but the effect of delaying punishment of drug self-administration is unknown. This study examined whether a histamine injection could punish cocaine self-administration in a drug-drug choice, whether delaying histamine would decrease its effectiveness, and whether the effects of delay could be described within a delay discounting framework. Monkeys were implanted with double-lumen catheters to allow separate injection of cocaine and histamine. In discrete trials, subjects first chose between cocaine (50 or 100 μg/kg/inj) alone and an injection of the same dose of cocaine followed immediately by an injection of histamine (0.37-50 μg/kg). Next, they chose between cocaine followed immediately by histamine and cocaine followed by an equal but delayed dose of histamine. When choosing between cocaine alone and cocaine followed immediately by histamine, preference increased with histamine dose from indifference to >80% choice of cocaine alone. When choosing between cocaine followed by immediate histamine and cocaine followed by delayed histamine, monkeys showed strong position preferences. When delayed histamine was associated with the nonpreferred position, preference for that option increased with delay from ≤30% to >85%. The corresponding decrease in choice of the preferred position was well described by a hyperboloid discounting function. Histamine can function as a punisher in the choice between injections of cocaine and delay can decrease its effectiveness as a punisher. The effects of delaying punishment of drug self-administration can be conceptualized within the delay discounting framework.

Beta-delayed proton emission from 20Mg

NASA Astrophysics Data System (ADS)

Lund, M. V.; Andreyev, A.; Borge, M. J. G.; Cederkäll, J.; De Witte, H.; Fraile, L. M.; Fynbo, H. O. U.; Greenlees, P. T.; Harkness-Brennan, L. J.; Howard, A. M.; Huyse, M.; Jonson, B.; Judson, D. S.; Kirsebom, O. S.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Lica, R.; Lindberg, S.; Madurga, M.; Marginean, N.; Marginean, R.; Marroquin, I.; Mihai, C.; Munch, M.; Nacher, E.; Negret, A.; Nilsson, T.; Page, R. D.; Pascu, S.; Perea, A.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Riisager, K.; Rotaru, F.; Sotty, C.; Stanoiu, M.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Wadsworth, R.; Warr, N.

2016-10-01

Beta-delayed proton emission from 20 Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in 20 Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in 20 Na is observed. This may allow studies of the 4032.9(2.4)keV resonance in 19 Ne through the beta decay of 20 Mg, which is important for the astrophysically relevant reaction 15O( α, γ)19Ne . Beta-delayed protons were used to obtain a more precise value for the half-life of 20 Mg, 91.4(1.0)ms.

32 CFR 776.80 - Initial screening and Rules Counsel.

Code of Federal Regulations, 2010 CFR

2010-07-01

... not be unduly delayed to await the covered attorney's submission. (d) The Rules Counsel shall..., administrative separation, or nonjudicial punishment proceeding. If so, the Rules Counsel shall forward a copy of...

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system

DOEpatents

Johnson, Donald W.

1988-01-01

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a central line attached between the payload and the cutter is stretched upon deployment of the cluster. A pyrotechnic or electronic time delay may be included in the cutter to delay the actual simultaneous cutting of all lines until the clustered parachutes attain a measure of stability prior to being disreefed. A second set of reefing lines and second tether lines may be provided for each parachute, to enable a two-stage, separately timed, step-by-step disreefing.

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system

DOEpatents

Johnson, D.W.

1988-06-21

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a central line attached between the payload and the cutter is stretched upon deployment of the cluster. A pyrotechnic or electronic time delay may be included in the cutter to delay the actual simultaneous cutting of all lines until the clustered parachutes attain a measure of stability prior to being disreefed. A second set of reefing lines and second tether lines may be provided for each parachute, to enable a two-stage, separately timed, step-by-step disreefing. 13 figs.

Neonatal maternal separation delays the GABA excitatory-to-inhibitory functional switch by inhibiting KCC2 expression.

PubMed

Furukawa, Minami; Tsukahara, Takao; Tomita, Kazuo; Iwai, Haruki; Sonomura, Takahiro; Miyawaki, Shouichi; Sato, Tomoaki

2017-11-25

The excitatory-to-inhibitory functional switch of γ-aminobutyric acid (GABA; GABA switch), which normally occurs in the first to the second postnatal week in the hippocampus, is necessary for the development of appropriate central nervous system function. A deficit in GABAergic inhibitory function could cause excitatory/inhibitory (E/I) neuron imbalance that is found in many neurodegenerative disorders. In the present study, we examined whether neonatal stress can affect the timing of the GABA functional switch and cause disorders during adolescence. Neonatal stress was induced in C57BL/6J male mouse pups by maternal separation (MS) on postnatal days (PND) 1-21. Histological quantification of K + -Cl - co-transporter (KCC2) and Ca 2+ imaging were performed to examine the timing of the GABA switch during the MS period. To evaluate the influence of neonatal MS on adolescent hippocampal function, we quantified KCC2 expression and evaluated hippocampal-related behavioral tasks at PND35-38. We showed that MS delayed the timing of the GABA switch in the hippocampus and inhibited the increase in membrane KCC2 expression, with KCC2 expression inhibition persisting until adolescence. Behavioral tests showed impaired cognition, declined attention, hyperlocomotion, and aggressive character in maternally separated mice. Taken together, our results show that neonatal stress delayed the timing of the GABA switch, which could change the E/I balance and cause neurodegenerative disorders in later life. Copyright © 2017 Elsevier Inc. All rights reserved.

On-resonance variable delay multipulse scheme for imaging of fast-exchanging protons and semisolid macromolecules.

PubMed

Xu, Jiadi; Chan, Kannie W Y; Xu, Xiang; Yadav, Nirbhay; Liu, Guanshu; van Zijl, Peter C M

2017-02-01

To develop an on-resonance variable delay multipulse (VDMP) scheme to image magnetization transfer contrast (MTC) and the chemical exchange saturation transfer (CEST) contrast of total fast-exchanging protons (TFP) with exchange rate above approximately 1 kHz. A train of high power binomial pulses was applied at the water resonance. The interpulse delay, called mixing time, was varied to observe its effect on the water signal reduction, allowing separation and quantification of MTC and CEST contributions as a result of their different proton transfer rates. The fast-exchanging protons in CEST and MTC are labeled together with the short T 2 components in MTC and separated out using a variable mixing time. Phantom studies of selected metabolite solutions (glucose, glutamate, creatine, myo-inositol), bovine serum albumin (BSA), and hair conditioner show the capability of on-resonance VDMP to separate out exchangeable protons with exchange rates above 1 kHz. Quantitative MTC and TFP maps were acquired on healthy mouse brains using this method, showing strong gray/white matter contrast for the slowly transferring MTC protons, whereas the TFP map was more uniform across the brain but somewhat higher in gray matter. The new method provides a simple way of imaging fast-exchanging protons and MTC components with a slow transfer rate. Magn Reson Med 77:730-739, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Strong field gravitational lensing by a charged Galileon black hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Shan-Shan; Xie, Yi, E-mail: clefairy035@163.com, E-mail: yixie@nju.edu.cn

Strong field gravitational lensings are dramatically disparate from those in the weak field by representing relativistic images due to light winds one to infinity loops around a lens before escaping. We study such a lensing caused by a charged Galileon black hole, which is expected to have possibility to evade no-hair theorem. We calculate the angular separations and time delays between different relativistic images of the charged Galileon black hole. All these observables can potentially be used to discriminate a charged Galileon black hole from others. We estimate the magnitudes of these observables for the closest supermassive black hole Sgrmore » A*. The strong field lensing observables of the charged Galileon black hole can be close to those of a tidal Reissner-Nordström black hole or those of a Reissner-Nordström black hole. It will be helpful to distinguish these black holes if we can separate the outermost relativistic images and determine their angular separation, brightness difference and time delay, although it requires techniques beyond the current limit.« less

Controller Strategies for Automation Tool Use under Varying Levels of Trajectory Prediction Uncertainty

NASA Technical Reports Server (NTRS)

Morey, Susan; Prevot, Thomas; Mercer, Joey; Martin, Lynne; Bienert, Nancy; Cabrall, Christopher; Hunt, Sarah; Homola, Jeffrey; Kraut, Joshua

2013-01-01

A human-in-the-loop simulation was conducted to examine the effects of varying levels of trajectory prediction uncertainty on air traffic controller workload and performance, as well as how strategies and the use of decision support tools change in response. This paper focuses on the strategies employed by two controllers from separate teams who worked in parallel but independently under identical conditions (airspace, arrival traffic, tools) with the goal of ensuring schedule conformance and safe separation for a dense arrival flow in en route airspace. Despite differences in strategy and methods, both controllers achieved high levels of schedule conformance and safe separation. Overall, results show that trajectory uncertainties introduced by wind and aircraft performance prediction errors do not affect the controllers' ability to manage traffic. Controller strategies were fairly robust to changes in error, though strategies were affected by the amount of delay to absorb (scheduled time of arrival minus estimated time of arrival). Using the results and observations, this paper proposes an ability to dynamically customize the display of information including delay time based on observed error to better accommodate different strategies and objectives.

Photonic single nonlinear-delay dynamical node for information processing

NASA Astrophysics Data System (ADS)

Ortín, Silvia; San-Martín, Daniel; Pesquera, Luis; Gutiérrez, José Manuel

2012-06-01

An electro-optical system with a delay loop based on semiconductor lasers is investigated for information processing by performing numerical simulations. This system can replace a complex network of many nonlinear elements for the implementation of Reservoir Computing. We show that a single nonlinear-delay dynamical system has the basic properties to perform as reservoir: short-term memory and separation property. The computing performance of this system is evaluated for two prediction tasks: Lorenz chaotic time series and nonlinear auto-regressive moving average (NARMA) model. We sweep the parameters of the system to find the best performance. The results achieved for the Lorenz and the NARMA-10 tasks are comparable to those obtained by other machine learning methods.

TIMEDELN: A programme for the detection and parametrization of overlapping resonances using the time-delay method

NASA Astrophysics Data System (ADS)

Little, Duncan A.; Tennyson, Jonathan; Plummer, Martin; Noble, Clifford J.; Sunderland, Andrew G.

2017-06-01

TIMEDELN implements the time-delay method of determining resonance parameters from the characteristic Lorentzian form displayed by the largest eigenvalues of the time-delay matrix. TIMEDELN constructs the time-delay matrix from input K-matrices and analyses its eigenvalues. This new version implements multi-resonance fitting and may be run serially or as a high performance parallel code with three levels of parallelism. TIMEDELN takes K-matrices from a scattering calculation, either read from a file or calculated on a dynamically adjusted grid, and calculates the time-delay matrix. This is then diagonalized, with the largest eigenvalue representing the longest time-delay experienced by the scattering particle. A resonance shows up as a characteristic Lorentzian form in the time-delay: the programme searches the time-delay eigenvalues for maxima and traces resonances when they pass through different eigenvalues, separating overlapping resonances. It also performs the fitting of the calculated data to the Lorentzian form and outputs resonance positions and widths. Any remaining overlapping resonances can be fitted jointly. The branching ratios of decay into the open channels can also be found. The programme may be run serially or in parallel with three levels of parallelism. The parallel code modules are abstracted from the main physics code and can be used independently.

Leveraging delay discounting for health: Can time delays influence food choice?

PubMed

Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

2018-07-01

Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

Frequency adjustment and synchrony in networks of delayed pulse-coupled oscillators

NASA Astrophysics Data System (ADS)

Nishimura, Joel

2015-01-01

We introduce a system of pulse-coupled oscillators that can change both their phases and frequencies and prove that when there is a separation of time scales between phase and frequency adjustment the system converges to exact synchrony on strongly connected graphs with time delays. The analysis involves decomposing the network into a forest of tree-like structures that capture causality. These results provide a robust method of sensor net synchronization as well as demonstrate a new avenue of possible pulse-coupled oscillator research.

Effects of the delay and duration of self-generated wind on behavioral compensation in unilaterally cercus-ablated crickets, Gryllus bimaculatus.

PubMed

Takuwa, Hiroyuki; Mori, Daichi; Ozaki, Naoko; Kanou, Masamichi

2013-05-01

The effects of the delay and duration of wind self-generated during walking on the compensational recovery of escape direction were investigated in unilaterally cercus-ablated crickets, Gryllus bimaculatus. Artificial self-generated winds (self-stimulations; hereafter, SSts) from a nozzle set in front of a cricket placed on a styrofoam ball for stationary walking were used for training after unilateral cercus ablation. The delay and duration of artificial SSts were separately controlled. When the stimulus duration was fixed to 100 msec, the crickets trained with artificial SSts of 1000 msec delay showed a compensational recovery of the escape direction. However, no such compensational recovery was observed in crickets trained with artificial SSts of 1200, 1500, and 2000 msec delays. The relationship between the delay and duration of artificial SSts for compensational recovery was investigated. An artificial SSt with a longer delay required a longer-duration air current to cause a recovery of the escape direction. In contrast, an artificial SSt with a shorter delay was effective even when the duration was short. On the basis of the results obtained in the present study, we propose a hypothesis to explain the initial step for the compensation, that is, how the delay and duration of SSts are traded in terms of the compensational recovery of the escape direction.

Influence of UAS Pilot Communication and Execution Delay on Controller's Acceptability Ratings of UAS-ATC Interactions

NASA Technical Reports Server (NTRS)

Vu, Kim-Phuong L.; Morales, Gregory; Chiappe, Dan; Strybel, Thomas Z.; Battiste, Vernol; Shively, Jay; Buker, Timothy J

2013-01-01

Successful integration of UAS in the NAS will require that UAS interactions with the air traffic management system be similar to interactions between manned aircraft and air traffic management. For example, UAS response times to air traffic controller (ATCo) clearances should be equivalent to those that are currently found to be acceptable with manned aircraft. Prior studies have examined communication delays with manned aircraft. Unfortunately, there is no analogous body of research for UAS. The goal of the present study was to determine how UAS pilot communication and execution delays affect ATCos' acceptability ratings of UAS pilot responses when the UAS is operating in the NAS. Eight radar-certified controllers managed traffic in a modified ZLA sector with one UAS flying in it. In separate scenarios, the UAS pilot verbal communication and execution delays were either short (1.5 s) or long (5 s) and either constant or variable. The ATCo acceptability of UAS pilot communication and execution delays were measured subjectively via post trial ratings. UAS verbal pilot communication delay, were rated as acceptable 92% of the time when the delay was short. This acceptability level decreased to 64% when the delay was long. UAS pilot execution delay had less of an influence on ATCo acceptability ratings in the present stimulation. Implications of these findings for UAS in the NAS integration are discussed.

0-6810 : guidelines for applying right-turn slip lanes.

DOT National Transportation Integrated Search

2014-10-01

Rightturn slip lanes are advantageous to : motorists because they reduce delays by : separating right-turning traffic from adjacent : lanes and accommodating higherspeed right : turns. The right-turn slip lane channelizing : island may also pro...

A Diffusion Model Analysis of Decision Biases Affecting Delayed Recognition of Emotional Stimuli

PubMed Central

Bowen, Holly J.; Spaniol, Julia; Patel, Ronak; Voss, Andreas

2016-01-01

Previous empirical work suggests that emotion can influence accuracy and cognitive biases underlying recognition memory, depending on the experimental conditions. The current study examines the effects of arousal and valence on delayed recognition memory using the diffusion model, which allows the separation of two decision biases thought to underlie memory: response bias and memory bias. Memory bias has not been given much attention in the literature but can provide insight into the retrieval dynamics of emotion modulated memory. Participants viewed emotional pictorial stimuli; half were given a recognition test 1-day later and the other half 7-days later. Analyses revealed that emotional valence generally evokes liberal responding, whereas high arousal evokes liberal responding only at a short retention interval. The memory bias analyses indicated that participants experienced greater familiarity with high-arousal compared to low-arousal items and this pattern became more pronounced as study-test lag increased; positive items evoke greater familiarity compared to negative and this pattern remained stable across retention interval. The findings provide insight into the separate contributions of valence and arousal to the cognitive mechanisms underlying delayed emotion modulated memory. PMID:26784108

Time delay signature elimination of chaos in a semiconductor laser by dispersive feedback from a chirped FBG.

PubMed

Wang, Daming; Wang, Longsheng; Zhao, Tong; Gao, Hua; Wang, Yuncai; Chen, Xianfeng; Wang, Anbang

2017-05-15

Time delay signature (TDS) of a semiconductor laser subject to dispersive optical feedback from a chirped fibre Bragg grating (CFBG) is investigated experimentally and numerically. Different from mirror, CFBG provides additional frequency-dependent delay caused by dispersion, and thus induces external-cavity modes with irregular mode separation rather than a fixed separation induced by mirror feedback. Compared with mirror feedback, the CFBG feedback can greatly depress and even eliminate the TDS, although it leads to a similar quasi-period route to chaos with increases of feedback. In experiments, by using a CFBG with dispersion of 2000ps/nm, the TDS is decreased by 90% to about 0.04 compared with mirror feedback. Furthermore, both numerical and experimental results show that the TDS evolution is quite different: the TDS decreases more quickly down to a lower plateau (even background noise level of autocorrelation function) and never rises again. This evolution tendency is also different from that of FBG feedback, of which the TDS first decreases to a minimal value and then increases again as feedback strength increases. In addition, the CFBG feedback has no filtering effects and does not require amplification for feedback light.

Adolescent social defeat decreases spatial working memory performance in adulthood.

PubMed

Novick, Andrew M; Miiller, Leah C; Forster, Gina L; Watt, Michael J

2013-10-17

Adolescent social stress is associated with increased incidence of mental illnesses in adulthood that are characterized by deficits in cognitive focus and flexibility. Such enhanced vulnerability may be due to psychosocial stress-induced disruption of the developing mesocortical dopamine system, which plays a fundamental role in facilitating complex cognitive processes such as spatial working memory. Adolescent rats exposed to repeated social defeat as a model of social stress develop dopaminergic hypofunction in the medial prefrontal cortex as adults. To evaluate a direct link between adolescent social stress and later deficits in cognitive function, the present study tested the effects of adolescent social defeat on two separate tests of spatial working memory performance. Adult rats exposed to adolescent social defeat and their controls were trained on either the delayed win-shift task or the delayed alternating T-Maze task and then challenged with various delay periods. To evaluate potential differences in motivation for the food reward used in memory tasks, consumption and conditioned place preference for sweetened condensed milk were tested in a separate cohort of previously defeated rats and controls. Compared to controls, adult rats defeated in adolescence showed a delay-dependent deficit in spatial working memory performance, committing more errors at a 90 s and 5 min delay period on the T-maze and win-shift tasks, respectively. Observed memory deficits were likely independent of differences in reward motivation, as conditioned place preference for the palatable food used on both tasks was similar between the adolescent social defeat group and control. The results demonstrate that severe social stressors during adolescence can produce long term deficits in aspects of cognitive function. Given the dependence of spatial working memory on prefrontal dopamine, pharmacologically reversing dopaminergic deficiencies caused by adolescent social stress has the potential to treat such cognitive deficits.

Incorporating Active Runway Crossings in Airport Departure Scheduling

NASA Technical Reports Server (NTRS)

Gupta, Gautam; Malik, Waqar; Jung, Yoon C.

2010-01-01

A mixed integer linear program is presented for deterministically scheduling departure and ar rival aircraft at airport runways. This method addresses different schemes of managing the departure queuing area by treating it as first-in-first-out queues or as a simple par king area where any available aircraft can take-off ir respective of its relative sequence with others. In addition, this method explicitly considers separation criteria between successive aircraft and also incorporates an optional prioritization scheme using time windows. Multiple objectives pertaining to throughput and system delay are used independently. Results indicate improvement over a basic first-come-first-serve rule in both system delay and throughput. Minimizing system delay results in small deviations from optimal throughput, whereas minimizing throughput results in large deviations in system delay. Enhancements for computational efficiency are also presented in the form of reformulating certain constraints and defining additional inequalities for better bounds.

Independence of Echo-Threshold and Echo-Delay in the Barn Owl

PubMed Central

Nelson, Brian S.; Takahashi, Terry T.

2008-01-01

Despite their prevalence in nature, echoes are not perceived as events separate from the sounds arriving directly from an active source, until the echo's delay is long. We measured the head-saccades of barn owls and the responses of neurons in their auditory space-maps while presenting a long duration noise-burst and a simulated echo. Under this paradigm, there were two possible stimulus segments that could potentially signal the location of the echo. One was at the onset of the echo; the other, after the offset of the direct (leading) sound, when only the echo was present. By lengthening the echo's duration, independently of its delay, spikes and saccades were evoked by the source of the echo even at delays that normally evoked saccades to only the direct source. An echo's location thus appears to be signaled by the neural response evoked after the offset of the direct sound. PMID:18974886

Speed Measurement and Motion Analysis of Chang'E-3 Rover Based on Differential Phase Delay

NASA Astrophysics Data System (ADS)

Pan, C.; Liu, Q. H.; Zheng, X.; He, Q. B.; Wu, Y. J.

2015-07-01

On 2013 December 14, the Chang'E-3 made a successful soft landing on the lunar surface, and then carried out the tasks of separating the lander and the rover, and taking the photos of each other. With the same beam VLBI (Very long baseline interferometry) technique to observe the signals transmitted by the lander and the rover simultaneously, the differential phase delay between them is calculated, which can reflect a minor change of the rover's position on a scale of a few centimeters. Based on the high sensitivity of differential phase delay, the rover's speeds during 5 movements are obtained with an average of 0.056 m/s. The relationship between the rover's shake in moving process, and lunar terrain is analyzed by using the spectrum of the residual of the differential phase delay after the first-order polynomial fitting.

Speed Measurement and Motion Analysis of Chang'E-3 Rover Based on Differential Phase Delay

NASA Astrophysics Data System (ADS)

Chao, Pan; Qing-hui, Liu; Xin, Zheng; Qing-bao, He; Ya-jun, Wu

2016-04-01

On 14th December 2013, the Chang'E-3 made a successful soft landing on the lunar surface, and then carried out the tasks of separating the lander and the rover, and taking pictures of each other. With the same beam VLBI (Very Long Baseline Interferometry) technique to observe the signals transmitted by the lander and the rover simultaneously, the differential phase delay between them is calculated, which can reflect the minor changes of the rover's position on a scale of a few centimeters. Based on the high sensitivity of differential phase delay, the rover's speeds during 5 movements are obtained with an average of 0.056 m/s. The relationship between the rover's shake in the moving process and the lunar terrain is analyzed by using the spectrum of the residual of the differential phase delay after the first-order polynomial fitting.

Control system estimation and design for aerospace vehicles with time delay

NASA Technical Reports Server (NTRS)

Allgaier, G. R.; Williams, T. L.

1972-01-01

The problems of estimation and control of discrete, linear, time-varying systems are considered. Previous solutions to these problems involved either approximate techniques, open-loop control solutions, or results which required excessive computation. The estimation problem is solved by two different methods, both of which yield the identical algorithm for determining the optimal filter. The partitioned results achieve a substantial reduction in computation time and storage requirements over the expanded solution, however. The results reduce to the Kalman filter when no delays are present in the system. The control problem is also solved by two different methods, both of which yield identical algorithms for determining the optimal control gains. The stochastic control is shown to be identical to the deterministic control, thus extending the separation principle to time delay systems. The results obtained reduce to the familiar optimal control solution when no time delays are present in the system.

THz field engineering in two-color femtosecond filaments using chirped and delayed laser pulses

NASA Astrophysics Data System (ADS)

Nguyen, A.; González de Alaiza Martínez, P.; Thiele, I.; Skupin, S.; Bergé, L.

2018-03-01

We numerically study the influence of chirping and delaying several ionizing two-color light pulses in order to engineer terahertz (THz) wave generation in air. By means of comprehensive 3D simulations, it is shown that two chirped pulses can increase the THz yield when they are separated by a suitable time delay for the same laser energy in focused propagation geometry. To interpret these results, the local current theory is revisited and we propose an easy, accessible all-optical criterion that predicts the laser-to-THz conversion efficiencies given any input laser spectrum. In the filamentation regime, numerical simulations display evidence that a chirped pulse is able to produce more THz radiation due to propagation effects, which maintain the two colors of the laser field more efficiently coupled over long distances. A large delay between two pulses promotes multi-peaked THz spectra as well as conversion efficiencies above 10‑4.

UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2016-01-01

This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

Safety Performance of Airborne Separation: Preliminary Baseline Testing

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Hoadley, Sherwood T.; Wing, David J.; Baxley, Brian T.

2007-01-01

The Safety Performance of Airborne Separation (SPAS) study is a suite of Monte Carlo simulation experiments designed to analyze and quantify safety behavior of airborne separation. This paper presents results of preliminary baseline testing. The preliminary baseline scenario is designed to be very challenging, consisting of randomized routes in generic high-density airspace in which all aircraft are constrained to the same flight level. Sustained traffic density is varied from approximately 3 to 15 aircraft per 10,000 square miles, approximating up to about 5 times today s traffic density in a typical sector. Research at high traffic densities and at multiple flight levels are planned within the next two years. Basic safety metrics for aircraft separation are collected and analyzed. During the progression of experiments, various errors, uncertainties, delays, and other variables potentially impacting system safety will be incrementally introduced to analyze the effect on safety of the individual factors as well as their interaction and collective effect. In this paper we report the results of the first experiment that addresses the preliminary baseline condition tested over a range of traffic densities. Early results at five times the typical traffic density in today s NAS indicate that, under the assumptions of this study, airborne separation can be safely performed. In addition, we report on initial observations from an exploration of four additional factors tested at a single traffic density: broadcast surveillance signal interference, extent of intent sharing, pilot delay, and wind prediction error.

Experimental evaluation of fluctuating density and radiated noise from a high temperature jet

NASA Technical Reports Server (NTRS)

Massier, P. F.; Parthasarathy, S. P.; Cuffel, R. F.

1973-01-01

An experimental investigation has been conducted to characterize the fluctuating density within a high-temperature (1100 K) subsonic jet and to characterize by the noise radiated to the surroundings. Cross correlations obtained by introducing time delay to the signals detected from spatially separated crossed laser beams set up as a Schlieren system were used to determine radial and axial distributions of the convection velocity of the moving noise sources (eddies). In addition, the autocorrelation of the fluctuating density was evaluated in the moving frame of reference of the eddies. Also, the autocorrelation of the radiated noise in the moving reference frame was evaluated from cross correlations by introducing time delay to the signals detected by spatially separated pairs of microphones. Radial distributions of the mean velocity were obtained from measurements of the stagnation temperature, and stagnation and static pressures with the use of probes.

[Evaluation of the risk of delayed adverse effects of chronic combined exposure to radiation and chemical factors with the purpose to ensure safety in orbital and exploration space missions].

PubMed

Shafirkin, A V; Mukhamedieva, L N; Tatarkin, S V; Barantseva, M Iu

2012-01-01

The work had the aim to anatomize the existing issues with providing safety in extended orbital and exploration missions for ensuing estimation of actual values of the total radiation risk for the crew, and risks of other delayed effects of simultaneous exposure to ionizing radiation and chemical pollutants in cabin air, and a number of other stressful factors inevitable in space flight. The flow of chronic experiments for separate and combined studies with reproduction of air makeup and radiation doses in actual orbital and predicted exploration missions is outlined. To set safety limits, new approaches should be applied to the description of gradual norm degradation to pathologies in addition to several generalized quantitative indices of adaptation and straining of the regulatory systems, as well as of effectiveness of the compensatory body reserve against separate and combined exposure.

Stator hub treatment study

NASA Technical Reports Server (NTRS)

Wisler, D. C.; Hilvers, D. E.

1974-01-01

The results of an experimental research program to investigate the potential of improving compressor stall margin by the application of hub treatment are presented. Extensive tuft probing showed that the two-stage, 0.5 radius ratio compressor selected for the test was indeed hub critical. Circumferential groove and baffled wide blade angle slot hub treatments under the stators were tested. Performance measurements were made with total and static pressure probes, wall static pressure taps, flow angle measuring instrumentation and hot film anemometers. Stator hub treatment was not found to be effective in improving compressor stall margin by delaying the point of onset of rotating stall or in modifying compressor performance for any of the configurations tested. Extensive regions of separated flow were observed on the suction surface of the stators near the hub. However, the treatment did not delay the point where flow separation in the stator hub region becomes apparent.

The use of clopidogrel (Plavix) in patients undergoing nonelective orthopaedic surgery.

PubMed

Nydick, Jason A; Farrell, Eric D; Marcantonio, Andrew J; Hume, Eric L; Marburger, Robert; Ostrum, Robert F

2010-06-01

To assess the effects of Plavix on patients requiring nonelective orthopaedic surgery. Retrospective cohort study. University-affiliated teaching institutions. The orthopaedic trauma registry was used to retrospectively identify all patients taking clopidogrel (Plavix; Bristol-Myers Squibb/Sanofi Pharmaceuticals, Bridgewater, NJ) who required nonelective orthopaedic surgery from 2004 to 2008. Twenty-nine patients were identified on Plavix (PG) and 32 matched patients in the control group not taking Plavix (NPG). The Plavix group was separated into those with a surgical delay less than 5 days of the last dose (PG < 5) (n = 28) and a delay greater than 5 days (PG > 5) (n = 1). A randomized age- and injury-matched control group not on Plavix was separated with surgical delay less than 5 days (NPG < 5) (n = 29) and delay greater than 5 days (NPG > 5) (n = 3). A retrospective review was performed comparing pre- and postoperative hemoglobin, blood transfusion requirements, surgical delay, 30-day mortality, and postoperative complications. Statistical analyses were performed using the Student t test and chi square test to identify differences between the groups. : The mean preoperative hemoglobin of the PG and the NPG was 11.2 g/dL and 12.3 g/dL (P = 0.03). Transfusion rates were similar with 18 of 28 in the PG compared with 13 of 29 in the NPG (P = 0.22). The mean surgical delay between the PG and NPG was 1.88 and 1.68 days (P = 0.64). Overall complications between the PG and NPG was nine of 28 and nine of 29 (P = 0.92). In both groups, two patients had postoperative wound drainage, which resolved without intervention. One patient in each group required revision surgery for nonunion. The 30-day mortality in the Plavix group was zero of 28 (0%) compared with one of 29 (3%) in the control group (cardiac arrest) (P = 0.32). In this study, there were no serious complications or increased transfusion requirements in the Plavix group. Avoiding surgical delay for patients on Plavix requiring nonelective orthopaedic surgery appears to be safe. The goal should be early operative intervention to decrease the morbidity and mortality of surgical delay. This is especially true for patients with hip fractures, which was the most common nonelective orthopaedic surgery required of patients on Plavix in this study.

Approximation-based adaptive tracking control of pure-feedback nonlinear systems with multiple unknown time-varying delays.

PubMed

Wang, Min; Ge, Shuzhi Sam; Hong, Keum-Shik

2010-11-01

This paper presents adaptive neural tracking control for a class of non-affine pure-feedback systems with multiple unknown state time-varying delays. To overcome the design difficulty from non-affine structure of pure-feedback system, mean value theorem is exploited to deduce affine appearance of state variables x(i) as virtual controls α(i), and of the actual control u. The separation technique is introduced to decompose unknown functions of all time-varying delayed states into a series of continuous functions of each delayed state. The novel Lyapunov-Krasovskii functionals are employed to compensate for the unknown functions of current delayed state, which is effectively free from any restriction on unknown time-delay functions and overcomes the circular construction of controller caused by the neural approximation of a function of u and [Formula: see text] . Novel continuous functions are introduced to overcome the design difficulty deduced from the use of one adaptive parameter. To achieve uniformly ultimate boundedness of all the signals in the closed-loop system and tracking performance, control gains are effectively modified as a dynamic form with a class of even function, which makes stability analysis be carried out at the present of multiple time-varying delays. Simulation studies are provided to demonstrate the effectiveness of the proposed scheme.

Value of evidence from syndromic surveillance with cumulative evidence from multiple data streams with delayed reporting.

PubMed

Struchen, R; Vial, F; Andersson, M G

2017-04-26

Delayed reporting of health data may hamper the early detection of infectious diseases in surveillance systems. Furthermore, combining multiple data streams, e.g. aiming at improving a system's sensitivity, can be challenging. In this study, we used a Bayesian framework where the result is presented as the value of evidence, i.e. the likelihood ratio for the evidence under outbreak versus baseline conditions. Based on a historical data set of routinely collected cattle mortality events, we evaluated outbreak detection performance (sensitivity, time to detection, in-control run length) under the Bayesian approach among three scenarios: presence of delayed data reporting, but not accounting for it; presence of delayed data reporting accounted for; and absence of delayed data reporting (i.e. an ideal system). Performance on larger and smaller outbreaks was compared with a classical approach, considering syndromes separately or combined. We found that the Bayesian approach performed better than the classical approach, especially for the smaller outbreaks. Furthermore, the Bayesian approach performed similarly well in the scenario where delayed reporting was accounted for to the scenario where it was absent. We argue that the value of evidence framework may be suitable for surveillance systems with multiple syndromes and delayed reporting of data.

Delay-dependent stability and added damping of SDOF real-time dynamic hybrid testing

NASA Astrophysics Data System (ADS)

Chi, Fudong; Wang, Jinting; Jin, Feng

2010-09-01

It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing (RTDHT). This paper focuses on the delay-dependent stability and added damping of SDOF systems in RTDHT. The exponential delay term is transferred into a rational fraction by the Padé approximation, and the delay-dependent stability conditions and instability mechanism of SDOF RTDHT systems are investigated by the root locus technique. First, the stability conditions are discussed separately for the cases of stiffness, mass, and damping experimental substructure. The use of root locus plots shows that the added damping effect and instability mechanism for mass are different from those for stiffness. For the stiffness experimental substructure case, the instability results from the inherent mode because of an obvious negative damping effect of the delay. For the mass case, the delay introduces an equivalent positive damping into the inherent mode, and instability occurs at an added high frequency mode. Then, the compound stability condition is investigated for a general case and the results show that the mass ratio may have both upper and lower limits to remain stable. Finally, a high-emulational virtual shaking table model is built to validate the stability conclusions.

Separate and overlapping brain areas encode subjective value during delay and effort discounting.

PubMed

Massar, Stijn A A; Libedinsky, Camilo; Weiyan, Chee; Huettel, Scott A; Chee, Michael W L

2015-10-15

Making decisions about rewards that involve delay or effort requires the integration of value and cost information. The brain areas recruited in this integration have been well characterized for delay discounting. However only a few studies have investigated how effort costs are integrated into value signals to eventually determine choice. In contrast to previous studies that have evaluated fMRI signals related to physical effort, we used a task that focused on cognitive effort. Participants discounted the value of delayed and effortful rewards. The value of cognitively effortful rewards was represented in the anterior portion of the inferior frontal gyrus and dorsolateral prefrontal cortex. Additionally, the value of the chosen option was encoded in the anterior cingulate cortex, caudate, and cerebellum. While most brain regions showed no significant dissociation between effort discounting and delay discounting, the ACC was significantly more activated in effort compared to delay discounting tasks. Finally, overlapping regions within the right orbitofrontal cortex and lateral temporal and parietal cortices encoded the value of the chosen option during both delay and effort discounting tasks. These results indicate that encoding of rewards discounted by cognitive effort and delay involves partially dissociable brain areas, but a common representation of chosen value is present in the orbitofrontal, temporal and parietal cortices. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A stethoscope with wavelet separation of cardiac and respiratory sounds for real time telemedicine implemented on field-programmable gate array

NASA Astrophysics Data System (ADS)

Castro, Víctor M.; Muñoz, Nestor A.; Salazar, Antonio J.

2015-01-01

Auscultation is one of the most utilized physical examination procedures for listening to lung, heart and intestinal sounds during routine consults and emergencies. Heart and lung sounds overlap in the thorax. An algorithm was used to separate them based on the discrete wavelet transform with multi-resolution analysis, which decomposes the signal into approximations and details. The algorithm was implemented in software and in hardware to achieve real-time signal separation. The heart signal was found in detail eight and the lung signal in approximation six. The hardware was used to separate the signals with a delay of 256 ms. Sending wavelet decomposition data - instead of the separated full signa - allows telemedicine applications to function in real time over low-bandwidth communication channels.

Geometric subspace methods and time-delay embedding for EEG artifact removal and classification.

PubMed

Anderson, Charles W; Knight, James N; O'Connor, Tim; Kirby, Michael J; Sokolov, Artem

2006-06-01

Generalized singular-value decomposition is used to separate multichannel electroencephalogram (EEG) into components found by optimizing a signal-to-noise quotient. These components are used to filter out artifacts. Short-time principal components analysis of time-delay embedded EEG is used to represent windowed EEG data to classify EEG according to which mental task is being performed. Examples are presented of the filtering of various artifacts and results are shown of classification of EEG from five mental tasks using committees of decision trees.

Active Flow Control at Low Reynolds Numbers on a NACA 0015 Airfoil

NASA Technical Reports Server (NTRS)

Melton, LaTunia Pack; Hannon, Judith; Yao, Chung-Sheng; Harris, Jerome

2008-01-01

Results from a low Reynolds number wind tunnel experiment on a NACA 0015 airfoil with a 30% chord trailing edge flap tested at deflection angles of 0, 20, and 40 are presented and discussed. Zero net mass flux periodic excitation was applied at the ap shoulder to control flow separation for flap deflections larger than 0. The primary objective of the experiment was to compare force and moment data obtained from integrating surface pressures to data obtained from a 5-component strain-gage balance in preparation for additional three-dimensional testing of the model. To achieve this objective, active flow control is applied at an angle of attack of 6 where published results indicate that oscillatory momentum coefficients exceeding 1% are required to delay separation. Periodic excitation with an oscillatory momentum coefficient of 1.5% and a reduced frequency of 0.71 caused a significant delay of separation on the airfoil with a flap deflection of 20. Higher momentum coefficients at the same reduced frequency were required to achieve a similar level of flow attachment on the airfoil with a flap deflection of 40. There was a favorable comparison between the balance and integrated pressure force and moment results.

Delays during the administration of acetylcysteine for the treatment of paracetamol overdose

PubMed Central

Bailey, George P.; Najafi, Javad; Elamin, Muhammad E. M. O.; Waring, W. Stephen; Thomas, Simon H. L.; Archer, John R. H.; Wood, David M.

2016-01-01

Background The licensed intravenous acetylcysteine regimen for treating paracetamol overdose in most countries uses three separate infusions over 21 h. This complex regimen, requiring different infusion concentrations and rates, has been associated with administration errors. The aim of the present study was to assess the extent of administration delays occurring during this acetylcysteine regimen. Method A 6‐month retrospective observational study was conducted at three English teaching hospitals with clinical toxicology services from October 2014. Patients aged 16 years and over, treated with intravenous acetylcysteine for paracetamol overdose, were included. The start times for infusions were recorded and the delays compared with the prescribed infusion times were calculated. Anaphylactoid reactions, intravenous cannula problems, overdose intent and smoking status were recorded to assess their contribution to delays. Results From 263 cases identified, 198 met the study inclusion criteria. The median time between the start of infusions 1 and 3 was delayed from the intended 5 h by a median (interquartile range) of 90 (50–163) min, with 135 (68%) cases delayed by more than 1 h. Significantly longer delays were observed in patients with anaphylactoid reactions [median delay 267 (217–413) min, n = 8] and accidental/supratherapeutic overdose [median delay 170 (95–260) min, n = 29]. There were no significant differences between smokers and nonsmokers, or for patients with intravenous cannula problems. Conclusion Long delays were identified during the three‐infusion acetylcysteine regimen for the treatment of paracetamol overdose. These were of clinical significance and could lead to periods of subtherapeutic plasma acetylcysteine concentrations and potentially avoidable hepatotoxicity, as well as delaying hospital discharge. PMID:27412926

Delays during the administration of acetylcysteine for the treatment of paracetamol overdose.

PubMed

Bailey, George P; Najafi, Javad; Elamin, Muhammad E M O; Waring, W Stephen; Thomas, Simon H L; Archer, John R H; Wood, David M; Dargan, Paul I

2016-11-01

The licensed intravenous acetylcysteine regimen for treating paracetamol overdose in most countries uses three separate infusions over 21 h. This complex regimen, requiring different infusion concentrations and rates, has been associated with administration errors. The aim of the present study was to assess the extent of administration delays occurring during this acetylcysteine regimen. A 6-month retrospective observational study was conducted at three English teaching hospitals with clinical toxicology services from October 2014. Patients aged 16 years and over, treated with intravenous acetylcysteine for paracetamol overdose, were included. The start times for infusions were recorded and the delays compared with the prescribed infusion times were calculated. Anaphylactoid reactions, intravenous cannula problems, overdose intent and smoking status were recorded to assess their contribution to delays. From 263 cases identified, 198 met the study inclusion criteria. The median time between the start of infusions 1 and 3 was delayed from the intended 5 h by a median (interquartile range) of 90 (50-163) min, with 135 (68%) cases delayed by more than 1 h. Significantly longer delays were observed in patients with anaphylactoid reactions [median delay 267 (217-413) min, n = 8] and accidental/supratherapeutic overdose [median delay 170 (95-260) min, n = 29]. There were no significant differences between smokers and nonsmokers, or for patients with intravenous cannula problems. Long delays were identified during the three-infusion acetylcysteine regimen for the treatment of paracetamol overdose. These were of clinical significance and could lead to periods of subtherapeutic plasma acetylcysteine concentrations and potentially avoidable hepatotoxicity, as well as delaying hospital discharge. © 2016 The British Pharmacological Society.

Separation control by vortex generator devices in a transonic channel flow

NASA Astrophysics Data System (ADS)

Bur, Reynald; Coponet, Didier; Carpels, Yves

2009-12-01

An experimental study was conducted in a transonic channel to control by mechanical vortex generator devices the strong interaction between a shock wave and a separated turbulent boundary layer. Control devices—co-rotating and counter-rotating vane-type vortex generators—were implemented upstream of the shock foot region and tested both on a steady shock wave and on a forced shock oscillation configurations. The spanwise spacing of vortex generator devices along the channel appeared to be an important parameter to control the flow separation region. When the distance between each device is decreased, the vortices merging is more efficient to reduce the separation. Their placement upstream of the shock wave is determinant to ensure that vortices have mixed momentum all spanwise long before they reach the separation line, so as to avoid separation cells. Then, vortex generators slightly reduced the amplitude of the forced shock wave oscillation by delaying the upstream displacement of the leading shock.

High-frequency tone-pip-evoked otoacoustic emissions in chinchillas

NASA Astrophysics Data System (ADS)

Siegel, Jonathan H.; Charaziak, Karolina K.

2015-12-01

We measured otoacoustic emissions in anesthetized chinchillas evoked by short (1 ms) high-frequency (4 kHz) tone-pips (TEOAE) using either a compression or suppression method to separate the stimulus from the emission. Both methods revealed consistent features of the TEOAEs. The main spectral band of the emission generally corresponded to the spectrum of the stimulus, exhibiting a group delay similar to that of SFOAEs [9]. However, a second spectral band below 1.5 kHz, clearly separated from the low-frequency cut-off frequency of the stimulus spectrum, corresponded to an amplitude modulation of the waveform of the TEOAE. The group delay of this low-frequency band was similar to that of the main band near the probe frequency. The average level and group delay of the main band declined monotonically when revealed as the suppressor frequency was raised above the probe. The low-frequency band was more sensitive than the main band to shifts in compound action potential thresholds near the probe frequency induced by acute exposure to intense tones. Taken together, the experiments indicate that both the main and low-frequency bands of the TEOAE are generated primarily near the cochlear region maximally stimulated by the probe, but that significant contributions arise over a large region even more basal.

Beta-delayed neutron emission from 94Rb at CARIBU

NASA Astrophysics Data System (ADS)

Wilson, Gemma; Chowdhury, P.; Lister, C.; Brown, T.; Chillery, T.; Copp, P.; Doucet, E.; Carpenter, M.; Savard, G.; Zhu, S.; Mitchell, Aj

2017-09-01

Beta-delayed neutron emission studies are important in the astrophysical r-process, nuclear structure and for nuclear reactor safety and design. The probability of β-delayed neutron emission in 94Sr is 10.2(2)%. Many of the γ rays in 94Sr are misplaced, and an estimated 26% are thought to be missing. Recently, substantial γ strength from above the neutron separation energy in 94Sr has been reported. An experiment to understand this high-lying γ strength was performed with the X-Array (a high-efficiency HPGe clover array), SCANS (Small CLYC Array for Neutron Scattering) and the SATURN decay station (Scintillator And Tape Using Radioactive Nuclei) for γ, fast-neutron and β-particle detection, respectively. Data from β decay of 94Rb ions delivered from CARIBU were collected in a triggerless digital data acquisition system, with detected β, n, and γ events correlated offline. A new 94Sr level scheme will be presented, with confirmation of new levels and transitions, in addition to evidence of γ strength above the neutron separation energy. NNSA Stewardship Science Academic Alliance Program through USDOE under Grant DE-NA0002932; USDOE, Office of Nucl Phys, under Contract No. DE-FG02-96ER40978; Louisiana State Board of Regents RCS LEQSF(2016-19)-RD-A-09; DE-AC02-06CHI1357.

Control of pseudo-shock oscillation in scramjet inlet-isolator using periodical excitation

NASA Astrophysics Data System (ADS)

Su, Wei-Yi; Chen, Yun; Zhang, Feng-Rui; Tang, Piao-Ping

2018-02-01

To suppress the pressure oscillation, stabilize the shock train in the scramjet isolator and delay the hypersonic inlet unstart, flow control using periodic excitation was investigated with unsteady Reynolds averaged Navier-Stokes simulations. The results showed that by injecting air to manipulate the cowl reflected shock wave, the separation bubble induced by it was diminished and the pressure oscillations of the shock train were markedly suppressed. The power spectral density and standard deviation of wall pressure were significantly reduced. The simulations revealed that this active control method can raise the critical back pressure by 17.5% compared with the baseline, which would successfully delay the hypersonic inlet unstarts. The results demonstrated that this active control method is effective in suppressing pressure oscillation and delaying hypersonic inlet unstarts.

Elevated outcome-anticipation and outcome-evaluation ERPs associated with a greater preference for larger-but-delayed rewards.

PubMed

Pornpattananangkul, Narun; Nadig, Ajay; Heidinger, Storm; Walden, Keegan; Nusslock, Robin

2017-06-01

Although waiting for a reward reduces or discounts its value, some people have a stronger tendency to wait for larger rewards and forgo smaller-but-immediate rewards. This ability to delay gratification is captured by individual differences in so-called intertemporal choices in which individuals are asked to choose between larger-but-delayed versus smaller-but-immediate rewards. The current study used event-related potentials (ERPs) to examine whether enhancement in two neurocognitive processes, outcome anticipation and outcome evaluation, modulate individual variability in intertemporal responses. After completing a behavioral intertemporal choice task, 34 participants performed an ERP gambling task. From this ERP task, we separately examined individual differences in outcome anticipation (stimulus-preceding negativity; SPN), early outcome valuation (feedback-related negativity; FRN), and late outcome evaluation (P3). We observed that both elevated outcome-anticipation (SPN) and late outcome-evaluation (P3) neural processes predicted a stronger preference toward larger-but-delayed rewards. No relationship was observed between intertemporal responses and early outcome evaluation (FRN), indicating that the relationship between outcome evaluation and intertemporal responses was specific to the late outcome-evaluation processing stream. Moreover, multiple regression analyses indicated that the SPN and P3 independently modulate individual differences in intertemporal responses, suggesting separate mechanisms underlie the relationship between these two neurocognitive processes and intertemporal responses. Accordingly, we identify two potential neurocognitive modulators of individual variability in intertemporal responses. We discuss the mechanisms underlying these modulators in terms of anticipation-related processing (SPN) and a saliency bias toward gain (compared to loss) outcomes (P3).

Generalization of Turbulent Pair Dispersion to Large Initial Separations

NASA Astrophysics Data System (ADS)

Shnapp, Ron; Liberzon, Alex; International Collaboration for Turbulence Research

2018-06-01

We present a generalization of turbulent pair dispersion to large initial separations (η

Cognitive and Neural Sciences Division. 1988 Programs

DTIC Science & Technology

1988-08-01

the P.I. uses a delayed reinforcement autoshaping procedure which incorporates features of both classical and operant conditioning paradigms...Progress: The PT has completed initial dose-response study of effects of TMT on autoshaping and has submitted a paper that separates "non-specific

'Batman excision' of ventral skin in hypospadias repair, clue to aesthetic repair (point of technique).

PubMed

Hoebeke, P B; De Kuyper, P; Van Laecke, E

2002-11-01

In the hypospadiac penis the ventral skin is poorly developed, while dorsal skin is redundant. The classical Byars' flaps are a way to use the excess dorsal skin to cover the penile shaft. The appearance after Byars' flaps however is not natural. We use a more natural looking skin allocation with superior aesthetic results. The clue in this reconstruction is an inverted triangle shaped excision of ventral skin expanding over the edges of the hooded prepuce (which makes it look like Batman). After excision of the ventral skin it is possible to close the penile skin in the midline, thus mimicking the natural raphe. In case of preputial reconstruction the excised ventral skin makes the prepuce look more natural. The trend of further refining aesthetic appearance of the hypospadiac penis often neglects the penile skin reconstruction. A technique is presented by which the total penile appearances after surgery ameliorates due to better skin reconstruction.

The effects of two Ureaplasma diversum strains on early pregnancy in heifers.

PubMed Central

Gale, S P

1987-01-01

Two field isolates of Ureaplasma diversum spp. were used to infect heifers at the time of insemination in a preliminary study to observe the effect of infection on early pregnancy. M84-14c-1 was a field isolate from a bull's prepuce typed by immunofluorescence to be similar to U. diversum strain T-44 (Group C). M84-477c-4 was a field isolate from bovine semen typed by immunofluorescence to be similar to U. diversum strain T-288 (Group A). All three heifers infected with M84-477c-4 had a mild granular vulvitis at some time during the trial. None was pregnant when slaughtered 27 days after infection. The result of infection with M84-14c-1, a preputial isolate, was not consistent. One heifer had no infection and a normal pregnancy, one heifer was infected with an abnormal pregnancy, and one heifer was open but ureaplasmas were not detected until day 17 of the trial. PMID:3453276

Impacts of delayed addition of N-rich and acidic substrates on nitrogen loss and compost quality during pig manure composting.

PubMed

Jiang, Jishao; Kang, Kang; Chen, Dan; Liu, Ningning

2018-02-01

Delayed addition of Nitrogen (N)-rich and acidic substrates was investigated to evaluate its effects on N loss and compost quality during the composting process. Three different delayed adding methods of N-rich (pig manure) and acidic substrates (phosphate fertilizer and rotten apples) were tested during the pig manure and wheat straw is composting. The results showed that delayed addition of pig manure and acidic materials led two temperature peaks, and the durations of two separate thermophilic phase were closely related to the amount of pig manure. Delayed addition reduced total N loss by up to 14% when using superphosphate as acidic substrates, and by up to 12% when using rotten apples as acidic substrates, which is mainly due to the decreased NH 3 emissions. At the end of composting, delayed the addition of pig manure caused a significant increase in the HS (humus substance) content, and the highest HS content was observed when 70% of the pig manure was applied at day 0 and the remaining 30% was applied on day 27. In the final compost, the GI in all treatments almost reached the maturity requirement by exceeding 80%. The results suggest that delayed addition of animal manure and acidic substrates could prevent the N loss during composting and improve the compost quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual Reliance for Balance Control in Older Adults Persists When Visual Information Is Disrupted by Artificial Feedback Delays

PubMed Central

Balasubramaniam, Ramesh

2014-01-01

Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP) in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance), or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task). We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds. PMID:24614576

Relationships between processing delay and microbial load of broiler neck skin samples.

PubMed

Lucianez, A; Holmes, M A; Tucker, A W

2010-01-01

The measurable microbial load on poultry carcasses during processing is determined by a number of factors including farm or origin, processing hygiene, and external temperature. This study investigated associations between carcass microbial load and progressive delays to processing. A total of 30 carcasses were delayed immediately after defeathering and before evisceration in a commercial abattoir in groups of five, and were held at ambient temperature for 1, 2, 3, 4, 6, and 8 h. Delayed carcasses were reintroduced to the processing line, and quantitative assessment of total viable count, coliforms, Staphylococcus aureus, and Pseudomonas spp. was undertaken on neck skin flap samples collected after carcass chilling and then pooled for each group. Sampling was repeated on 5 separate days, and the data were combined. Significant increases in total viable count (P = 0.001) and coliforms (P = 0.004), but not for S. aureus or Pseudomonas loads, were observed across the 8-h period of delay. In line with previous studies, there was significant variation in microbiological data according to sampling day. In conclusion, there is a significant and measurable decline in microbiological status of uneviscerated but defeathered poultry carcasses after an 8-h delay, but the variability of sampling results, reflecting the wide range of factors that impact microbial load, means that it is not possible to determine maximum or minimum acceptable periods of processing delay based on this criterion alone.

Assessment of tropospheric delay mapping function models in Egypt: Using PTD database model

NASA Astrophysics Data System (ADS)

Abdelfatah, M. A.; Mousa, Ashraf E.; El-Fiky, Gamal S.

2018-06-01

For space geodetic measurements, estimates of tropospheric delays are highly correlated with site coordinates and receiver clock biases. Thus, it is important to use the most accurate models for the tropospheric delay to reduce errors in the estimates of the other parameters. Both the zenith delay value and mapping function should be assigned correctly to reduce such errors. Several mapping function models can treat the troposphere slant delay. The recent models were not evaluated for the Egyptian local climate conditions. An assessment of these models is needed to choose the most suitable one. The goal of this paper is to test the quality of global mapping function which provides high consistency with precise troposphere delay (PTD) mapping functions. The PTD model is derived from radiosonde data using ray tracing, which consider in this paper as true value. The PTD mapping functions were compared, with three recent total mapping functions model and another three separate dry and wet mapping function model. The results of the research indicate that models are very close up to zenith angle 80°. Saastamoinen and 1/cos z model are behind accuracy. Niell model is better than VMF model. The model of Black and Eisner is a good model. The results also indicate that the geometric range error has insignificant effect on slant delay and the fluctuation of azimuth anti-symmetric is about 1%.

The neural basis of cultural differences in delay discounting

PubMed Central

Kim, Bokyung; Sung, Young Shin; McClure, Samuel M.

2012-01-01

People generally prefer to receive rewarding outcomes sooner rather than later. Such preferences result from delay discounting, or the process by which outcomes are devalued for the expected delay until their receipt. We investigated cultural differences in delay discounting by contrasting behaviour and brain activity in separate cohorts of Western (American) and Eastern (Korean) subjects. Consistent with previous reports, we find a dramatic difference in discounting behaviour, with Americans displaying much greater present bias and elevated discount rates. Recent neuroimaging findings suggest that differences in discounting may arise from differential involvement of either brain reward areas or regions in the prefrontal and parietal cortices associated with cognitive control. We find that the ventral striatum is more greatly recruited in Americans relative to Koreans when discounting future rewards, but there is no difference in prefrontal or parietal activity. This suggests that a cultural difference in emotional responsivity underlies the observed behavioural effect. We discuss the implications of this research for strategic interrelations between Easterners and Westerners. PMID:22271781

Delayed closure of the palatal defect using buccal inversion and palatal rotation flaps after maxillectomy.

PubMed

Jung, Seunggon; Kook, Min-Suk; Park, Hong-Ju; Oh, Hee-Kyun

2013-03-01

Maxillectomy leaves oronasal and oroantral defects that result in functional impairment of mastication, deglutition, and speech. Many treatment options are suggested and tried including the palatal flap as local flap. Although palatal flaps have been used to repair various oral cavity defects, they have certain limitations due to the dimensions. The amount and location of the palatal tissues available are important for palatal repair. Secondary intentional healing after maxillectomy will allow the epithelialization of the defect margin adjacent to remained palate, and there will be more mucosa that is available for closure of the defect. We delayed the closure of the palatal defect, while the patient underwent prosthetic treatment for functional recovery in 5 maxillectomy patients. Delayed closure of palatal defect with local flap was done at 10.8 ± 7.9 months after the maxillectomy. While delayed closure in hemimaxillectomy patients left postoperative fistula, it provided separation of the oral cavity and nasal/sinus cavity and adequate surface for prosthesis in partial maxillectomy patients.

Time-frequency model for echo-delay resolution in wideband biosonar.

PubMed

Neretti, Nicola; Sanderson, Mark I; Intrator, Nathan; Simmons, James A

2003-04-01

A time/frequency model of the bat's auditory system was developed to examine the basis for the fine (approximately 2 micros) echo-delay resolution of big brown bats (Eptesicus fuscus), and its performance at resolving closely spaced FM sonar echoes in the bat's 20-100-kHz band at different signal-to-noise ratios was computed. The model uses parallel bandpass filters spaced over this band to generate envelopes that individually can have much lower bandwidth than the bat's ultrasonic sonar sounds and still achieve fine delay resolution. Because fine delay separations are inside the integration time of the model's filters (approximately 250-300 micros), resolving them means using interference patterns along the frequency dimension (spectral peaks and notches). The low bandwidth content of the filter outputs is suitable for relay of information to higher auditory areas that have intrinsically poor temporal response properties. If implemented in fully parallel analog-digital hardware, the model is computationally extremely efficient and would improve resolution in military and industrial sonar receivers.

Automated delay measurement system for an Earth station for Two-Way Satellite Time and Frequency Transfer

NASA Technical Reports Server (NTRS)

Dejong, Gerrit; Polderman, Michel C.

1995-01-01

The measurement of the difference of the transmit and receive delays of the signals in a Two-Way Satellite Time and Frequency Transfer (TWSTFT) Earth station is crucial for its nanosecond time transfer capability. Also, the monitoring of the change of this delay difference with time, temperature, humidity, or barometric pressure is important for improving the TWSTFT capabilities. An automated system for this purpose has been developed from the initial design at NMi-VSL. It calibrates separately the transmit and receive delays in cables, amplifiers, upconverters and downconverters, and antenna feeds. The obtained results can be applied as corrections to the TWSTFT measurement when, before and after a measurement session, a calibration session is performed. Preliminary results obtained at NMi-VSL will be shown. Also, if available, the results of a manual version of the system that is planned to be circulated in Sept. 1994 together with a USNO portable station on a calibration trip to European TWSTFT Earth stations.

Separation Assurance and Scheduling Coordination in the Arrival Environment

NASA Technical Reports Server (NTRS)

Aweiss, Arwa S.; Cone, Andrew C.; Holladay, Joshua J.; Munoz, Epifanio; Lewis, Timothy A.

2016-01-01

Separation assurance (SA) automation has been proposed as either a ground-based or airborne paradigm. The arrival environment is complex because aircraft are being sequenced and spaced to the arrival fix. This paper examines the effect of the allocation of the SA and scheduling functions on the performance of the system. Two coordination configurations between an SA and an arrival management system are tested using both ground and airborne implementations. All configurations have a conflict detection and resolution (CD&R) system and either an integrated or separated scheduler. Performance metrics are presented for the ground and airborne systems based on arrival traffic headed to Dallas/ Fort Worth International airport. The total delay, time-spacing conformance, and schedule conformance are used to measure efficiency. The goal of the analysis is to use the metrics to identify performance differences between the configurations that are based on different function allocations. A surveillance range limitation of 100 nmi and a time delay for sharing updated trajectory intent of 30 seconds were implemented for the airborne system. Overall, these results indicate that the surveillance range and the sharing of trajectories and aircraft schedules are important factors in determining the efficiency of an airborne arrival management system. These parameters are not relevant to the ground-based system as modeled for this study because it has instantaneous access to all aircraft trajectories and intent. Creating a schedule external to the CD&R and the scheduling conformance system was seen to reduce total delays for the airborne system, and had a minor effect on the ground-based system. The effect of an external scheduler on other metrics was mixed.

Obtaining reliable phase-gradient delays from otoacoustic emission data.

PubMed

Shera, Christopher A; Bergevin, Christopher

2012-08-01

Reflection-source otoacoustic emission phase-gradient delays are widely used to obtain noninvasive estimates of cochlear function and properties, such as the sharpness of mechanical tuning and its variation along the length of the cochlear partition. Although different data-processing strategies are known to yield different delay estimates and trends, their relative reliability has not been established. This paper uses in silico experiments to evaluate six methods for extracting delay trends from reflection-source otoacoustic emissions (OAEs). The six methods include both previously published procedures (e.g., phase smoothing, energy-weighting, data exclusion based on signal-to-noise ratio) and novel strategies (e.g., peak-picking, all-pass factorization). Although some of the methods perform well (e.g., peak-picking), others introduce substantial bias (e.g., phase smoothing) and are not recommended. In addition, since standing waves caused by multiple internal reflection can complicate the interpretation and compromise the application of OAE delays, this paper develops and evaluates two promising signal-processing strategies, the first based on time-frequency filtering using the continuous wavelet transform and the second on cepstral analysis, for separating the direct emission from its subsequent reflections. Altogether, the results help to resolve previous disagreements about the frequency dependence of human OAE delays and the sharpness of cochlear tuning while providing useful analysis methods for future studies.

Prolonged, 24-h delayed peripheral inflammation increases short- and long-term functional impairment and histopathological damage after focal ischemia in the rat.

PubMed

Langdon, Kristopher D; Maclellan, Crystal L; Corbett, Dale

2010-08-01

The incidence of infection among stroke patients is alarmingly high and both acute and delayed infections increase morbidity and mortality. Experimental studies support the acute clinical data, but little attention has focused on delayed systemic infections. Here, we investigated the effects of prolonged systemic inflammation either before or 24-h after ischemia. Systemic inflammation was induced by injecting rats with three separate doses of lipopolysaccharide (LPS; 50 mug/kg, i.p.) with core temperature monitoring for 48-h after middle cerebral artery occlusion (MCAo). Lipopolysaccharide injected before MCAo increased injury by approximately 30%, whereas delayed injection increased injury by approximately 85% (30-day survival). Proinflammatory cytokines assessed repeatedly for 72 h were significantly and persistently elevated with inflammation. This was accompanied by increases in microglia/macrophage and infiltrating leukocyte numbers in delayed LPS-treated animals. Behavioral assessments at 7 and 30 days revealed approximately 15% deficit in hindlimb function in animals treated with LPS 24-h after ischemia. Clearly, delayed and prolonged postischemic systemic inflammation has devastating effects on stroke outcome, in the absence of a prolonged febrile response. These findings, together with corroborative clinical data, emphasize the importance of early intervention to counteract the deleterious consequences of stroke-associated inflammation and infection.

Both trace and delay conditioned eyeblink responding can be dissociated from outcome expectancy.

PubMed

Weidemann, Gabrielle; Broderick, Joshua; Lovibond, Peter F; Mitchell, Christopher J

2012-01-01

Squire and colleagues have proposed that trace and delay eyeblink conditioning are fundamentally different kinds of learning: trace conditioning requires acquisition of a conscious declarative memory for the stimulus contingencies whereas delay conditioning does not. Declarative memory in trace conditioning is thought to generate conditioned responding through the activation of a conscious expectancy for when the unconditioned stimulus (US) is going to occur. Perruchet (1985) has previously shown that in a 50% partial reinforcement design it is possible to dissociate single cue delay eyeblink conditioning from conscious expectancy for the US by examining performance over runs of reinforced and nonreinforced trials. Clark, Manns, and Squire (2001) claim that this dissociation does not occur in trace eyeblink conditioning. In the present experiment we examined the Perruchet effect for short, moderate, and long trace intervals (600, 1000, and 1400 ms) and for the equivalent interstimulus intervals (ISIs) in a delay conditioning procedure. We found evidence for a dissociation of eyeblink CRs and US expectancy over runs regardless of whether there was a delay or a trace arrangement of cues. The reasons for the Perruchet effect are still unclear, but the present data suggest that it does not depend on a separate nondeclarative system of the type proposed by Squire and colleagues. (c) 2012 APA, all rights reserved.

Effects of immediate and delayed loading on peri-implant trabecular structures: a cone beam CT evaluation.

PubMed

Huang, Yan; Van Dessel, Jeroen; Liang, Xin; Depypere, Maarten; Zhong, Weijian; Ma, Guowu; Lambrichts, Ivo; Maes, Frederik; Jacobs, Reinhilde

2014-12-01

To develop a method for characterizing trabecular bone microarchitecture using cone beam computed tomography (CBCT) and to evaluate trabecular bone changes after rehabilitation using immediate versus delayed implant protocols. Six mongrel dogs randomly received 27 titanium implants in the maxillary incisor or mandibular premolar areas, following one of four protocols: (1) normal extraction socket healing; (2) immediate implant placement and immediate loading; (3) delayed implant placement and delayed loading; (4) delayed implant placement and immediate loading. The animals were euthanized at 8 weeks, and block biopsies were scanned using high resolution CBCT. Standard bone structural variables were assessed in coronal, middle, and apical levels. Coronal and middle regions had more compact, more platelike, and thicker trabeculae. Protocols (2), (3), and (4) had significantly higher values (p < 0.001) than protocol (1) for bone surface density, bone surface volume ratio, and connectivity density, while significantly lower values (p < 0.001) were found for trabecular separation and fractal dimension. However, protocols (2), (3), and (4) did not show significantly different bone remodeling. Compared with normal extraction healing, the implant protocols have an improved bone structural integration. Results do not suggest a different bone remodeling pattern when a delayed versus an immediate implant protocol is used. © 2013 Wiley Periodicals, Inc.

PARALYZER FOR PULSE HEIGHT DISTRIBUTION ANALYZER

DOEpatents

Fairstein, E.

1960-01-19

A paralyzer circuit is described for use with a pulseheight distribution analyzer to prevent the analyzer from counting overlapping pulses where they would serve to provide a false indication. The paralyzer circuit comprises a pair of cathode-coupled amplifiers for amplifying pulses of opposite polarity. Diodes are provided having their anodes coupled to the separate outputs of the amplifiers to produce only positive signals, and a trigger circuit is coupled to the diodes ior operation by input pulses of either polarity from the amplifiers. A delay network couples the output of the trigger circuit for delaying the pulses.

Active Control of Separation from the Slat Shoulder of a Supercritical Airfoil

NASA Technical Reports Server (NTRS)

Pack, LaTunia G.; Schaeffler, Norman W.; Yao, Chung-Sheng; Seifert, Avi

2002-01-01

Active flow control in the form of zero-mass-flux excitation was applied at the slat shoulder of a simplified high-lift airfoil to delay flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge slat and a 25% chord simply hinged trailing edge flap. The cruise configuration data was successfully reproduced, repeating previous experiments. The effects of flap and slat deflection angles on the performance of the airfoil integral parameters were quantified. Detailed flow features were measured as well, in an attempt to identify optimal actuator placement. The measurements included: steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization and Particle Image Velocimetry (PIV). High frequency periodic excitation was applied to delay the occurrence of slat stall and improve the maximum lift by 10 to 15%. Low frequency amplitude modulation was used to reduce the oscillatory momentum coefficient by roughly 50% with similar aerodynamic performance.

Adolescent social defeat decreases spatial working memory performance in adulthood

PubMed Central

2013-01-01

Background Adolescent social stress is associated with increased incidence of mental illnesses in adulthood that are characterized by deficits in cognitive focus and flexibility. Such enhanced vulnerability may be due to psychosocial stress-induced disruption of the developing mesocortical dopamine system, which plays a fundamental role in facilitating complex cognitive processes such as spatial working memory. Adolescent rats exposed to repeated social defeat as a model of social stress develop dopaminergic hypofunction in the medial prefrontal cortex as adults. To evaluate a direct link between adolescent social stress and later deficits in cognitive function, the present study tested the effects of adolescent social defeat on two separate tests of spatial working memory performance. Methods Adult rats exposed to adolescent social defeat and their controls were trained on either the delayed win-shift task or the delayed alternating T-Maze task and then challenged with various delay periods. To evaluate potential differences in motivation for the food reward used in memory tasks, consumption and conditioned place preference for sweetened condensed milk were tested in a separate cohort of previously defeated rats and controls. Results Compared to controls, adult rats defeated in adolescence showed a delay-dependent deficit in spatial working memory performance, committing more errors at a 90 s and 5 min delay period on the T-maze and win-shift tasks, respectively. Observed memory deficits were likely independent of differences in reward motivation, as conditioned place preference for the palatable food used on both tasks was similar between the adolescent social defeat group and control. Conclusions The results demonstrate that severe social stressors during adolescence can produce long term deficits in aspects of cognitive function. Given the dependence of spatial working memory on prefrontal dopamine, pharmacologically reversing dopaminergic deficiencies caused by adolescent social stress has the potential to treat such cognitive deficits. PMID:24134918

Delayed bunching for multi-reflection time-of-flight mass separation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenbusch, M.; Marx, G.; Schweikhard, L.

2015-06-29

Many experiments are handicapped when the ion sources do not only deliver the ions of interest but also contaminations, i.e., unwanted ions of similar mass. In the recent years, multi-reflection time-of-flight mass separation has become a promising method to isolate the ions of interest from the contaminants, in particular for measurements with low-energy short-lived nuclides. To further improve the performance of multi-reflection mass separators with respect to the limitations by space-charge effects, the simultaneously trapped ions are spatially widely distributed in the apparatus. Thus, the ions can propagate with reduced Coulomb interactions until, finally, they are bunched by a changemore » in the trapping conditions for high-resolution mass separation. Proof-of-principle measurements are presented.« less

Direct Numerical Simulation of Flow Over Passive Geometric Disturbances

NASA Astrophysics Data System (ADS)

Vizard, Alexander

It is well understood that delaying flow separation on a bluff body allows significant drag reduction, which is attractive in many applications. With this in mind, many separation control mechanisms, both active and passive, have been developed and tested to optimize the effects of this phenomenon. Although this idea is generally accepted, the physical occurrences in the near-wall region during transition that lead to separation delay are not well understood. The current study evaluates the impact of both spherical dimples, and sandgrain style roughness on downstream flow by performing direct numerical simulations over such geometries on a zero pressure gradient flat plate. It is shown that although dimples and random roughness of similar characteristic length scales exhibit similar boundary layer characteristics, dimples are more successful in developing high momentum in the vicinity of the wall. Additionally it is shown that increasing the relative size of the rough elements does not increase the near-wall momentum, and is undesirable in controlling separation. Finally, it is shown that the impact of roughness elements on the flow is more immediate, and that, for the case of one row of dimples and an equivalent area of roughness, the roughness patch is more successful in transitioning the near-wall region to a non-laminar state. It can be concluded from variation in the span of the flowfield for a single row of dimples that the size and orientation of the disturbance region is significant to the results.

Unexpected outcome of a modification of Bracka repair for proximal hypospadias: High incidence of diverticula with flaps.

PubMed

Tiryaki, Sibel; Ələkbərova, Vüsalə; Dokumcu, Zafer; Ergun, Raziye; Tekin, Ali; Yagmur, Ismail; Ulman, Ibrahim; Avanoglu, Ali

2016-12-01

Various graft and flap techniques have been proposed for urethral reconstruction in proximal hypospadias repair. The Bracka repair involving the transfer of inner prepuce like a Wolfe graft mostly results in satisfactory results besides a high fistula rate. The aim was to decrease the high fistula rate with Bracka repair; we wanted to use the advantages of vascularized skin in the Bracka method. The aim of this study was to evaluate our results with this modification. Our modification involves using a flap instead of a graft. In the first stage, chordee was corrected by transection of the urethral plate and dorsal midline plication when necessary. Instead of a graft as suggested by Bracka, inner preputial skin with ample blood supply was transferred and stitched to the denuded ventral penile surface. In the second stage after 6 months, this flap was tubularized in the Thiersch-Duplay fashion. Hospital records of patients who had undergone two stage modified Bracka repair between June 2007 and July 2012 were reviewed, including complaints, complications, and need for interventions. Thirty-eight patients had undergone this operation. Four patients were lost to follow-up. The main complaint was obstructed urinary flow. Voiding symptoms were first attributed to urethral stenosis, but were, however, found to be due to diverticulum and vortex of the urine in the dilated urethra. Twenty-one patients (61%) had voiding problems and 10 patients (29%) had urinary tract infections. Fistula was observed in 23 and diverticula were observed in 24 patients. Of these, 16 patients had both fistula and diverticula. Only two patients (5%) were free of complications and totally satisfied with the operation, and 23 of the 34 patients had complications requiring intervention (Figure). Inner preputial flaps used in proximal hypospadias repairs are prone to diverticula formation. They become redundant in time requiring reoperation, thus decreasing the success rate. Careful fixation of the flap to the corpora and allowing time for additional attachment of the urethral plate substitution through fibrotic activity could not overcome this complication. Our modification of the Bracka technique using a flap for the plate resulted in a high rate of complications (in particular diverticulum formation) and was therefore abandoned. We recommend careful use of flaps in hypospadias surgery and long-term follow-up studies to evaluate actual functional and cosmetic results. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Emotion Discourse, Social Cognition, and Social Skills in Children with and without Developmental Delays

PubMed Central

Fenning, RM; Baker, BL; Juvonen, J

2009-01-01

This study examined parent-child emotion discourse, children’s independent social information processing, and social skills outcomes in 146 families of 8-year-olds with and without developmental delays. Children’s emergent social-cognitive understanding (internal state understanding, perspective taking, and causal reasoning/problem solving) was coded in the context of parent-child conversations about emotion, and children were interviewed separately to assess social problem solving. Mothers, fathers, and teachers reported on children’s social skills. The proposed strengths-based model partially accounted for social skills differences between typically developing children and children with delays. A multigroup analysis of the model linking emotion discourse to social skills through children’s prosocial problem solving suggested that processes operated similarly across the two groups. Implications for ecologically focused prevention and intervention are discussed. PMID:21410465

The Parental Emotional Response to Children Index.

PubMed

Lambek, Rikke; Sonuga-Barke, Edmund; Psychogiou, Lamprini; Thompson, Margaret; Tannock, Rosemary; Daley, David; Damm, Dorte; Thomsen, Per Hove

2017-04-01

The current study introduces the Parental Emotional Response to Children Index (PERCI), a new questionnaire specifically designed to measure parents' emotional response to ADHD and related behaviors (delay discounting and delay aversion). The PERCI was completed by parents of 6- to 14-year-old children with ( n = 126) and without ( n = 160) ADHD. Factor analysis confirmed five separate subscales with acceptable psychometric properties. Parents of children with ADHD reported a stronger emotional response to ADHD behaviors than parents of typically developing children and inattention symptoms evoked the strongest emotional response in parents regardless of child diagnostic status. Parents' emotional responses appear to be differentiated in terms of specific ADHD-related triggers mapping onto the different domains of ADHD and delay-related responses. Further research is required to understand changes in parental emotional responses over time and their impact on children's developmental trajectories.

Fully nonlinear Goertler vortices in constricted channel flows and their effect on the onset of separation

NASA Technical Reports Server (NTRS)

Denier, James P.; Hall, Philip

1992-01-01

The development of fully nonlinear Goertler vortices in high Reynolds number flow in a symmetrically constricted channel is investigated. Attention is restricted to the case of 'strongly' constricted channels considered by Smith and Daniels (1981) for which the scaled constriction height is asymptotically large. Such flows are known to develop a Goldstein singularity and subsequently become separated at some downstream station past the point of maximum channel constriction. It is shown that these flows can support fully nonlinear Goertler vortices, of the form elucidated by Hall and Lakin (1988), for constrictions which have an appreciable region of local concave curvature upstream of the position at which separation occurs. The effect on the onset of separation due to the nonlinear Goertler modes is discussed. A brief discussion of other possible nonlinear states which may also have a dramatic effect in delaying (or promoting) separation is given.

Alcohol Increases Delay and Probability Discounting of Condom-Protected Sex: A Novel Vector for Alcohol-Related HIV Transmission.

PubMed

Johnson, Patrick S; Sweeney, Mary M; Herrmann, Evan S; Johnson, Matthew W

2016-06-01

Alcohol use, especially at binge levels, is associated with sexual HIV risk behavior, but the mechanisms through which alcohol increases sexual risk taking are not well-examined. Delay discounting, that is, devaluation of future consequences as a function of delay to their occurrence, has been implicated in a variety of problem behaviors, including risky sexual behavior. Probability discounting is studied with a similar framework as delay discounting, but is a distinct process in which a consequence is devalued because it is uncertain or probabilistic. Twenty-three, nondependent alcohol users (13 male, 10 female; mean age = 25.3 years old) orally consumed alcohol (1 g/kg) or placebo in 2 separate experimental sessions. During sessions, participants completed tasks examining delay and probability discounting of hypothetical condom-protected sex (Sexual Delay Discounting Task, Sexual Probability Discounting Task) and of hypothetical and real money. Alcohol decreased the likelihood that participants would wait to have condom-protected sex versus having immediate, unprotected sex. Alcohol also decreased the likelihood that participants would use an immediately available condom given a specified level of sexually transmitted infection (STI) risk. Alcohol did not affect delay discounting of money, but it did increase participants' preferences for larger, probabilistic monetary rewards over smaller, certain rewards. Acute, binge-level alcohol intoxication may increase sexual HIV risk by decreasing willingness to delay sex in order to acquire a condom in situations where one is not immediately available, and by decreasing sensitivity to perceived risk of STI contraction. These findings suggest that delay and probability discounting are critical, but heretofore unrecognized, processes that may mediate the relations between alcohol use and HIV risk. Copyright © 2016 by the Research Society on Alcoholism.

Juncture flow improvement for wing/pylon configurations by using CFD methodology

NASA Technical Reports Server (NTRS)

Gea, Lie-Mine; Chyu, Wei J.; Stortz, Michael W.; Chow, Chuen-Yen

1993-01-01

Transonic flow field around a fighter wing/pylon configuration was simulated by using an implicit upwinding Navier-Stokes flow solver (F3D) and overset grid technology (Chimera). Flow separation and local shocks near the wing/pylon junction were observed in flight and predicted by numerical calculations. A new pylon/fairing shape was proposed to improve the flow quality. Based on numerical results, the size of separation area is significantly reduced and the onset of separation is delayed farther downstream. A smoother pressure gradient is also obtained near the junction area. This paper demonstrates that computational fluid dynamics (CFD) methodology can be used as a practical tool for aircraft design.

Generation of real-time mode high-resolution water vapor fields from GPS observations

NASA Astrophysics Data System (ADS)

Yu, Chen; Penna, Nigel T.; Li, Zhenhong

2017-02-01

Pointwise GPS measurements of tropospheric zenith total delay can be interpolated to provide high-resolution water vapor maps which may be used for correcting synthetic aperture radar images, for numeral weather prediction, and for correcting Network Real-time Kinematic GPS observations. Several previous studies have addressed the importance of the elevation dependency of water vapor, but it is often a challenge to separate elevation-dependent tropospheric delays from turbulent components. In this paper, we present an iterative tropospheric decomposition interpolation model that decouples the elevation and turbulent tropospheric delay components. For a 150 km × 150 km California study region, we estimate real-time mode zenith total delays at 41 GPS stations over 1 year by using the precise point positioning technique and demonstrate that the decoupled interpolation model generates improved high-resolution tropospheric delay maps compared with previous tropospheric turbulence- and elevation-dependent models. Cross validation of the GPS zenith total delays yields an RMS error of 4.6 mm with the decoupled interpolation model, compared with 8.4 mm with the previous model. On converting the GPS zenith wet delays to precipitable water vapor and interpolating to 1 km grid cells across the region, validations with the Moderate Resolution Imaging Spectroradiometer near-IR water vapor product show 1.7 mm RMS differences by using the decoupled model, compared with 2.0 mm for the previous interpolation model. Such results are obtained without differencing the tropospheric delays or water vapor estimates in time or space, while the errors are similar over flat and mountainous terrains, as well as for both inland and coastal areas.

Recirculating cross-correlation detector

DOEpatents

Andrews, W.H. Jr.; Roberts, M.J.

1985-01-18

A digital cross-correlation detector is provided in which two time-varying signals are correlated by repetitively comparing data samples stored in digital form to detect correlation between the two signals. The signals are sampled at a selected rate converted to digital form, and stored in separate locations in separate memories. When the memories are filled, the data samples from each memory are first fed word-by-word through a multiplier and summing circuit and each result is compared to the last in a peak memory circuit and if larger than the last is retained in the peak memory. Then the address line to leading signal memory is offset by one byte to affect one sample period delay of a known amount in that memory and the data in the two memories are then multiplied word-by-word once again and summed. If a new result is larger than a former sum, it is saved in the peak memory together with the time delay. The recirculating process continues with the address of the one memory being offset one additional byte each cycle until the address is shifted through the length of the memory. The correlation between the two signals is indicated by the peak signal stored in the peak memory together with the delay time at which the peak occurred. The circuit is faster and considerably less expensive than comparable accuracy correlation detectors.

Elevated Outcome-Anticipation and Outcome-Evaluation ERPs Associated with a Greater Preference for Larger-But-Delayed Rewards

PubMed Central

Pornpattananangkul, Narun; Nadig, Ajay; Heidinger, Storm; Walden, Keegan; Nusslock, Robin

2017-01-01

Although waiting for a reward reduces or discounts its value, some people have a stronger tendency to wait for larger rewards and forgo smaller-but-immediate rewards. This ability to delay gratification is captured by individual differences in so-called inter-temporal choices in which individuals are asked to choose between larger-but-delayed versus smaller-but-immediate rewards. The current study used event-related potentials (ERPs) to examine whether enhancement in two neuro-cognitive processes, outcome-anticipation and outcome-evaluation, modulate individual variability in inter-temporal responses. After completing a behavioral inter-temporal choice task, 34 participants performed an ERP gambling task. From this ERP task, we separately examined individual differences in outcome-anticipation (Stimulus-Preceding Negativity, SPN), early outcome-evaluation (Feedback-Related Negativity; FRN) and late outcome-evaluation (P3). We observed that both elevated outcome-anticipation (SPN) and late outcome-evaluation (P3) neural processes predicted a stronger preference toward larger-but-delayed rewards. No relationship was observed between inter-temporal responses and early outcome-evaluation (FRN), indicating that the relationship between outcome-evaluation and inter-temporal responses was specific to the late outcome-evaluation processing stream. Moreover, multiple regression analyses indicated that the SPN and P3 independently modulate individual differences in inter-temporal responses, suggesting separate mechanisms underlie the relationship between these two neuro-cognitive processes and inter-temporal responses. Accordingly, we identify two potential neural-cognitive modulators of individual variability in inter-temporal responses. We discuss the mechanisms underlying these modulators in terms of anticipation-related processing (SPN) and a saliency-bias toward gain (compared to loss) outcomes (P3). PMID:28224457

CNS neuroplasticity and salt-sensitive hypertension induced by prior treatment with subpressor doses of ANG II or aldosterone.

PubMed

Clayton, Sarah C; Zhang, Zhongming; Beltz, Terry; Xue, Baojian; Johnson, Alan Kim

2014-06-15

Although sensitivity to high dietary NaCl is regarded to be a risk factor for cardiovascular disease, the causes of salt-sensitive hypertension remain elusive. Previously, we have shown that rats pretreated with subpressor doses of either ANG II or aldosterone (Aldo) show sensitized hypertensive responses to a mild pressor dose of ANG II when tested after an intervening delay. The current studies investigated whether such treatments will induce salt sensitivity. In studies employing an induction-delay-expression experimental design, male rats were instrumented for chronic mean arterial pressure (MAP) recording. In separate experiments, ANG II, Aldo, or vehicle was delivered either subcutaneously or intracerebroventricularly during the induction. There were no sustained differences in BP during the delay prior to being given 2% saline. While consuming 2% saline during the expression, both ANG II- and Aldo-pretreated rats showed significantly greater hypertension. When hexamethonium was used to assess autonomic control of MAP, no differences in the decrease of MAP in response to ganglionic blockade were detected during the induction. However, during the expression, the fall was greater in sensitized rats. In separate experiments, brain tissue that was collected at the end of delay showed increases in message or activation of putative markers of neuroplasticity (i.e., brain-derived neurotrophic factor, p38 mitogen-activated protein kinase, and cAMP response element-binding protein). These experiments demonstrate that prior administration of nonpressor doses of either ANG II or Aldo will induce salt sensitivity. Collectively, our findings indicate that treatment with subpressor doses of ANG II and Aldo initiate central neuroplastic changes that are involved in hypertension of different etiologies. Copyright © 2014 the American Physiological Society.

Psychophysical investigation of an auditory spatial illusion in cats: the precedence effect.

PubMed

Tollin, Daniel J; Yin, Tom C T

2003-10-01

The precedence effect (PE) describes several spatial perceptual phenomena that occur when similar sounds are presented from two different locations and separated by a delay. The mechanisms that produce the effect are thought to be responsible for the ability to localize sounds in reverberant environments. Although the physiological bases for the PE have been studied, little is known about how these sounds are localized by species other than humans. Here we used the search coil technique to measure the eye positions of cats trained to saccade to the apparent locations of sounds. To study the PE, brief broadband stimuli were presented from two locations, with a delay between their onsets; the delayed sound meant to simulate a single reflection. Although the cats accurately localized single sources, the apparent locations of the paired sources depended on the delay. First, the cats exhibited summing localization, the perception of a "phantom" sound located between the sources, for delays < +/-400 micros for sources positioned in azimuth along the horizontal plane, but not for sources positioned in elevation along the sagittal plane. Second, consistent with localization dominance, for delays from 400 micros to about 10 ms, the cats oriented toward the leading source location only, with little influence of the lagging source, both for horizontally and vertically placed sources. Finally, the echo threshold was reached for delays >10 ms, where the cats first began to orient to the lagging source on some trials. These data reveal that cats experience the PE phenomena similarly to humans.

Neuro-economics in chicks: foraging choices based on amount, delay and cost.

PubMed

Matsushima, Toshiya; Kawamori, Ai; Bem-Sojka, Tiaza

2008-06-15

Studies on the foraging choices are reviewed, with an emphasis on the neural representations of elementary factors of food (i.e., amount, delay and consumption time) in the avian brain. Domestic chicks serve as an ideal animal model in this respect, as they quickly associate cue colors with subsequently supplied food rewards, and their choices are quantitatively linked with the rewards. When a pair of such color cues was simultaneously presented, the trained chicks reliably made choices according to the profitability of food associated with each color. Two forebrain regions are involved in distinct aspects of choices; i.e., nucleus accumbens-medial striatum (Ac-MSt) and arcopallium intermedium (AI), an association area in the lateral forebrain. Localized lesions of Ac-MSt enhanced delay aversion, and the ablated chicks made impulsive choices of immediate reward more frequently than sham controls. On the other hand, lesions of AI enhanced consumption-time aversion, and the ablated chicks shifted their choices toward easily consumable reward with their impulsiveness unchanged; delay and consumption time are thus doubly dissociated. Furthermore, chicks showed distinct patterns of risk-sensitive choices depending on the factor that varied at trials. Risk aversion occurred when food amount varied, whereas consistent risk sensitivity was not found when the delay varied; amount and delay were not interchangeable. Choices are thus deviated from those predicted as optima. Instead, factors such as amount, delay and consumption time could be separately represented and processed to yield economically sub-optimal choices.

The study of membrane formation via phase inversion method by cloud point and light scattering experiment

NASA Astrophysics Data System (ADS)

Arahman, Nasrul; Maimun, Teuku; Mukramah, Syawaliah

2017-01-01

The composition of polymer solution and the methods of membrane preparation determine the solidification process of membrane. The formation of membrane structure prepared via non-solvent induced phase separation (NIPS) method is mostly determined by phase separation process between polymer, solvent, and non-solvent. This paper discusses the phase separation process of polymer solution containing Polyethersulfone (PES), N-methylpirrolidone (NMP), and surfactant Tetronic 1307 (Tet). Cloud point experiment is conducted to determine the amount of non-solvent needed on induced phase separation. Amount of water required as a non-solvent decreases by the addition of surfactant Tet. Kinetics of phase separation for such system is studied by the light scattering measurement. With the addition of Tet., the delayed phase separation is observed and the structure growth rate decreases. Moreover, the morphology of fabricated membrane from those polymer systems is analyzed by scanning electron microscopy (SEM). The images of both systems show the formation of finger-like macrovoids through the cross-section.

Influence of nanovoids on α-α' phase separation in FeCrAl oxide dispersion strengthened alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capdevila, Carlos; Aranda, M. M.; Rememnteria, R.

2015-08-10

The presence of nanovoids in the vicinity of oxide particles in FeCrAl oxide dispersion strengthened (ODS) alloy has been identified. These nanovoids are inherent to the manufacturing route and remain quite resistant during heat treatments. Positron annihilation spectroscopy (PAS) experiments demonstrate that these nanovoids trap Cr inside thereby reducing the Cr-content in the matrix. In conclusion, this might lead to a delay in the α–α' phase separation process as observed by atom probe tomography (APT).

End-to-End Commitment

NASA Technical Reports Server (NTRS)

Newcomb, John

2004-01-01

The end-to-end test would verify the complex sequence of events from lander separation to landing. Due to the large distances involved and the significant delay time in sending a command and receiving verification, the lander needed to operate autonomously after it separated from the orbiter. It had to sense conditions, make decisions, and act accordingly. We were flying into a relatively unknown set of conditions-a Martian atmosphere of unknown pressure, density, and consistency to land on a surface of unknown altitude, and one which had an unknown bearing strength.

All-optical phase discrimination using SOA.

PubMed

Power, Mark J; Webb, Roderick P; Manning, Robert J

2013-11-04

We describe the first experimental demonstration of a novel all-optical phase discrimination technique, which can separate the two orthogonal phase components of a signal onto different frequencies. This method exploits nonlinear mixing in a semiconductor optical amplifier (SOA) to separate a 10.65 Gbaud QPSK signal into two 10.65 Gb/s BPSK signals which are then demodulated using a delay interferometer (DI). Eye diagrams and spectral measurements verify correct operation and a conversion efficiency greater than 9 dB is observed on both output BPSK channels when compared with the input QPSK signal.

U.S. Women at Work.

ERIC Educational Resources Information Center

Waite, Linda J.

1981-01-01

Women comprised 43% of the United States labor force in 1980, up from 29% in 1950. The surge in women's employment is linked to more delayed marriage, divorce, separation, women's increased education, lower fertility, rapid growth in clerical and service jobs, inflation, and changed attitudes toward "women's place." Employment has risen…

Turbulent boundary layer separation over a rearward facing ramp and its control through mechanical excitation

NASA Technical Reports Server (NTRS)

Mckinzie, Daniel J., Jr.

1991-01-01

A vane oscillating about a fixed point at the inlet to a two-dimensional 20 degree rearward facing ramp has proven effective in delaying the separation of a turbulent boundary layer. Measurements of the ramp surface static pressure coefficient obtained under the condition of vane oscillation and constant inlet velocity revealed that two different effects occurred with surface distance along the ramp. In the vicinity of the oscillating vane, the pressure coefficients varied as a negative function of the vane's trailing edge rms velocity; the independent variable on which the rms velocity depends are the vane's oscillation frequency and its displacement amplitude. From a point downstream of the vane to the exit of the ramp; however, the pressure coefficient varied as a more complex function of the two independent variables. That is, it was found to vary as a function of the vane's oscillation frequency throughout the entire range of frequencies covered during the test, but over only a limited range of the trailing edge displacement amplitudes covered. More specifically, the value of the pressure coefficient was independent of increases in the vane's displacement amplitude above approximately 35 inner wall units of the boundary layer. Below this specific amplitude it varied as a function of the vane's trailing edge rms velocity. This height is close to the upper limit of the buffer layer. A parametric study was made to determine the variation of the maximum static pressure recovery as a function of the vane's oscillation frequency, for several ramp inlet velocities and a constant displacement amplitude of the vane's trailing edge. The results indicate that the phenomenon producing the optimum delay of separation may be Strouhal number dependent. Corona anemometer measurements obtained in the inner wall regions of the boundary layer for the excited case reveal a large range of unsteadiness in the local velocities. These measurements imply the existence of inflections in the profiles, which provide a mechanism for resulting inviscid flow instabilities to produce turbulence in the near wall region, thereby delaying separation of the boundary layer.

Double Dissociation of Amygdala and Hippocampal Contributions to Trace and Delay Fear Conditioning

PubMed Central

Raybuck, Jonathan D.; Lattal, K. Matthew

2011-01-01

A key finding in studies of the neurobiology of learning memory is that the amygdala is critically involved in Pavlovian fear conditioning. This is well established in delay-cued and contextual fear conditioning; however, surprisingly little is known of the role of the amygdala in trace conditioning. Trace fear conditioning, in which the CS and US are separated in time by a trace interval, requires the hippocampus and prefrontal cortex. It is possible that recruitment of cortical structures by trace conditioning alters the role of the amygdala compared to delay fear conditioning, where the CS and US overlap. To investigate this, we inactivated the amygdala of male C57BL/6 mice with GABA A agonist muscimol prior to 2-pairing trace or delay fear conditioning. Amygdala inactivation produced deficits in contextual and delay conditioning, but had no effect on trace conditioning. As controls, we demonstrate that dorsal hippocampal inactivation produced deficits in trace and contextual, but not delay fear conditioning. Further, pre- and post-training amygdala inactivation disrupted the contextual but the not cued component of trace conditioning, as did muscimol infusion prior to 1- or 4-pairing trace conditioning. These findings demonstrate that insertion of a temporal gap between the CS and US can generate amygdala-independent fear conditioning. We discuss the implications of this surprising finding for current models of the neural circuitry involved in fear conditioning. PMID:21283812

Delayed recall, hippocampal volume and Alzheimer neuropathology: findings from the Nun Study.

PubMed

Mortimer, J A; Gosche, K M; Riley, K P; Markesbery, W R; Snowdon, D A

2004-02-10

To examine the associations of hippocampal volume and the severity of neurofibrillary lesions determined at autopsy with delayed verbal recall performance evaluated an average of 1 year prior to death. Hippocampal volumes were computed using postmortem brain MRI from the first 56 scanned participants of the Nun Study. Quantitative neuropathologic studies included lesion counts, Braak staging, and determination of whether neuropathologic criteria for Alzheimer disease (AD) were met. Multiple regression was used to assess the association of hippocampal volume and neuropathologic lesions with the number of words (out of 10) recalled on the Consortium to Establish a Registry for Alzheimer's Disease Delayed Word Recall Test administered an average of 1 year prior to death. When entered separately, hippocampal volume, Braak stage, and the mean neurofibrillary tangle counts in the CA-1 region of the hippocampus and the subiculum were strongly associated with the number of words recalled after a delay, adjusting for age and education. When hippocampal volume was entered together with each neuropathologic index, only hippocampal volume retained a significant association with the delayed recall measure. The association between hippocampal volume and the number of words recalled was present in both demented and nondemented individuals as well as in those with and without substantial AD neurofibrillary pathology. The association of neurofibrillary tangles with delayed verbal recall may reflect associated hippocampal atrophy.

Spin-dependent delay time in ferromagnet/insulator/ferromagnet heterostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, ZhengWei; Zheng Shi, De; Lv, HouXiang

2014-07-07

We study theoretically spin-dependent group delay and dwell time in ferromagnet/insulator/ferromagnet (FM/I/FM) heterostructure. The results indicate that, when the electrons with different spin orientations tunnel through the FM/I/FM junction, the spin-up process and the spin-down process are separated on the time scales. As the self-interference delay has the spin-dependent features, the variations of spin-dependent dwell-time and spin-dependent group-delay time with the structure parameters appear different features, especially, in low incident energy range. These different features show up as that the group delay times for the spin-up electrons are always longer than those for spin-down electrons when the barrier height ormore » incident energy increase. In contrast, the dwell times for the spin-up electrons are longer (shorter) than those for spin-down electrons when the barrier heights (the incident energy) are under a certain value. When the barrier heights (the incident energy) exceed a certain value, the dwell times for the spin-up electrons turn out to be shorter (longer) than those for spin-down electrons. In addition, the group delay time and the dwell time for spin-up and down electrons also relies on the comparative direction of magnetization in two FM layers and tends to saturation with the thickness of the barrier.« less

An experimental study on the effects of rough hydrophobic surfaces on the flow around a circular cylinder

NASA Astrophysics Data System (ADS)

Kim, Nayoung; Kim, Hyunseok; Park, Hyungmin

2015-08-01

The present study investigates the effect that rough hydrophobic (or superhydrophobic) surfaces have on the flow separation and subsequent vortex structures in a turbulent wake behind a circular cylinder. The velocity fields were measured using two-dimensional particle image velocimetry in a water tunnel with Reynolds numbers of 0.7-2.3 × 104. The spray-coating of hydrophobic nanoparticles and roughened Teflon was used to produce the rough hydrophobic surfaces, and sandpapers with two different grit sizes were used to sand the Teflon into streamwise and spanwise directions, respectively, in order to examine the effect of the slip direction. The rough hydrophobic surface was found to enhance the turbulence in the flows above the circular cylinder and along the separating shear layers, resulting in a delay of the flow separation and early vortex roll-up in the wake. As a result, the size of the recirculation bubble in the wake was reduced by up to 40%, while the drag reduction of less than 10% is estimated from a wake survey. However, these effects are reversed as the Reynolds number increases. The surface texture normal to the flow direction (spanwise slip) was found to be more effective than that aligned to the flow (streamwise slip), supporting the suggested mechanism. In addition, the superhydrophobic surface is locally applied by varying the installation angle and that applied around the separation point is most effective, indicating that the rough hydrophobic surface directly affects the boundary layer at flow separation. In order to control the flow around a circular cylinder using rough hydrophobic surfaces, it is suggested to have a smaller roughness width, which can stably retain air pockets. In addition, a higher gas fraction and a more uniform distribution of the roughness size are helpful to enhance the performance such as the separation delay and drag reduction.

Enhancing BEM simulations of a stalled wind turbine using a 3D correction model

NASA Astrophysics Data System (ADS)

Bangga, Galih; Hutomo, Go; Syawitri, Taurista; Kusumadewi, Tri; Oktavia, Winda; Sabila, Ahmad; Setiadi, Herlambang; Faisal, Muhamad; Hendranata, Yongki; Lastomo, Dwi; Putra, Louis; Kristiadi, Stefanus; Bumi, Ilmi

2018-03-01

Nowadays wind turbine rotors are usually employed with pitch control mechanisms to avoid deep stall conditions. Despite that, wind turbines often operate under pitch fault situation causing massive flow separation to occur. Pure Blade Element Momentum (BEM) approaches are not designed for this situation and inaccurate load predictions are already expected. In the present studies, BEM predictions are improved through the inclusion of a stall delay model for a wind turbine rotor operating under pitch fault situation of -2.3° towards stall. The accuracy of the stall delay model is assessed by comparing the results with available Computational Fluid Dynamics (CFD) simulations data.

Fissile solution measurement apparatus

DOEpatents

Crane, T.W.; Collinsworth, P.R.

1984-06-11

An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.

Polyphenol content in white table grape (Vitis Vinifera) berries of cultivar Italia: interactive effect of irrigation, delayed harvest and storage.

PubMed

Capriotti, Anna Laura; Caruso, Giuseppe; Cavaliere, Chiara; Foglia, Patrizia; Laganà, Aldo; Samperi, Roberto

2012-01-01

Polyphenol concentrations were quantified by rapid resolution liquid chromatography/mass spectrometry in white table grape. The experimental vineyard was subjected to different kinds of water supply and supply rates. Samples from the same vineyards were also analysed after 6 weeks of storage in a refrigerator and after 6 weeks of delayed harvesting. Berry skins and seeds were analysed separately. A statistical treatment of the screening kind, namely the 2(k) full factorial design, was used for the interpretation of results. Storage, delayed harvesting and the different kinds of water supply appeared to be the variables most affecting grape polyphenol content. In some cases, results showed that polyphenol content diminished by more than 50% after 6 weeks if the grapes were stored in a refrigerator, or if a sprinkler was used for irrigation.

Emotion discourse, social cognition, and social skills in children with and without developmental delays.

PubMed

Fenning, Rachel M; Baker, Bruce L; Juvonen, Jaana

2011-01-01

This study examined parent-child emotion discourse, children's independent social information processing, and social skills outcomes in 146 families of 8-year-olds with and without developmental delays. Children's emergent social-cognitive understanding (internal state understanding, perspective taking, and causal reasoning and problem solving) was coded in the context of parent-child conversations about emotion, and children were interviewed separately to assess social problem solving. Mothers, fathers, and teachers reported on children's social skills. The proposed strengths-based model partially accounted for social skills differences between typically developing children and children with delays. A multigroup analysis of the model linking emotion discourse to social skills through children's prosocial problem solving suggested that processes operated similarly for the two groups. Implications for ecologically focused prevention and intervention are discussed. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Auditory cortex of newborn bats is prewired for echolocation.

PubMed

Kössl, Manfred; Voss, Cornelia; Mora, Emanuel C; Macias, Silvio; Foeller, Elisabeth; Vater, Marianne

2012-04-10

Neuronal computation of object distance from echo delay is an essential task that echolocating bats must master for spatial orientation and the capture of prey. In the dorsal auditory cortex of bats, neurons specifically respond to combinations of short frequency-modulated components of emitted call and delayed echo. These delay-tuned neurons are thought to serve in target range calculation. It is unknown whether neuronal correlates of active space perception are established by experience-dependent plasticity or by innate mechanisms. Here we demonstrate that in the first postnatal week, before onset of echolocation and flight, dorsal auditory cortex already contains functional circuits that calculate distance from the temporal separation of a simulated pulse and echo. This innate cortical implementation of a purely computational processing mechanism for sonar ranging should enhance survival of juvenile bats when they first engage in active echolocation behaviour and flight.

Longitudinal dynamics of twin electron bunches in the Linac Coherent Light Source

DOE PAGES

Zhang, Zhen; Ding, Yuantao; Marinelli, Agostino; ...

2015-03-02

The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We find that the wakefields in the accelerator structures play an important role in the twin-bunchmore » compression, and through analysis show that they can be used to extend the available time delay range. As a result, based on the theoretical model and simulations we propose several methods to achieve larger time delay.« less

Collagen matrix as an inlay in endoscopic skull base reconstruction.

PubMed

Oakley, G M; Christensen, J M; Winder, M; Jonker, B P; Davidson, A; Steel, T; Teo, C; Harvey, R J

2018-03-01

Multi-layer reconstruction has become standard in endoscopic skull base surgery. The inlay component used can vary among autografts, allografts, xenografts and synthetics, primarily based on surgeon preference. The short- and long-term outcomes of collagen matrix in skull base reconstruction are described. A case series of patients who underwent endoscopic skull base reconstruction with collagen matrix inlay were assessed. Immediate peri-operative outcomes (cerebrospinal fluid leak, meningitis, ventriculitis, intracranial bleeding, epistaxis, seizures) and delayed complications (delayed healing, meningoencephalocele, prolapse of reconstruction, delayed cerebrospinal fluid leak, ascending meningitis) were examined. Of 120 patients (51.0 ± 17.5 years, 41.7 per cent female), peri-operative complications totalled 12.7 per cent (cerebrospinal fluid leak, 3.3 per cent; meningitis, 3.3 per cent; other intracranial infections, 2.5 per cent; intracranial bleeding, 1.7 per cent; epistaxis, 1.7 per cent; and seizures, 0 per cent). Delayed complications did not occur in any patients. Collagen matrix is an effective inlay material. It provides robust long-term separation between sinus and cranial cavities, and avoids donor site morbidity, but carries additional cost.

Dynamical Behaviors in Complex-Valued Love Model With or Without Time Delays

NASA Astrophysics Data System (ADS)

Deng, Wei; Liao, Xiaofeng; Dong, Tao

2017-12-01

In this paper, a novel version of nonlinear model, i.e. a complex-valued love model with two time delays between two individuals in a love affair, has been proposed. A notable feature in this model is that we separate the emotion of one individual into real and imaginary parts to represent the variation and complexity of psychophysiological emotion in romantic relationship instead of just real domain, and make our model much closer to reality. This is because love is a complicated cognitive and social phenomenon, full of complexity, diversity and unpredictability, which refers to the coexistence of different aspects of feelings, states and attitudes ranging from joy and trust to sadness and disgust. By analyzing associated characteristic equation of linearized equations for our model, it is found that the Hopf bifurcation occurs when the sum of time delays passes through a sequence of critical value. Stability of bifurcating cyclic love dynamics is also derived by applying the normal form theory and the center manifold theorem. In addition, it is also shown that, for some appropriate chosen parameters, chaotic behaviors can appear even without time delay.

Working memory for conjunctions relies on the medial temporal lobe.

PubMed

Olson, Ingrid R; Page, Katie; Moore, Katherine Sledge; Chatterjee, Anjan; Verfaellie, Mieke

2006-04-26

A prominent theory of hippocampal function proposes that the hippocampus is importantly involved in relating or binding together separate pieces of information to form an episodic representation. This hypothesis has only been applied to studies of long-term memory because the paradigmatic view of the hippocampus is that it is not critical for short-term forms of memory. However, relational processing is important in many working memory tasks, especially tasks using visual stimuli. Here, we test the hypothesis that the medial temporal lobes are important for relational memory even over short delays. The task required patients with medial temporal lobe amnesia and controls to remember three objects, locations, or object-location conjunctions over 1 or 8 s delays. The results show that working memory for objects and locations was at normal levels, but that memory for conjunctions was severely impaired at 8 s delays. Additional analyses suggest that the hippocampus per se is critical for accurate conjunction working memory. We propose that the hippocampus is critically involved in memory for conjunctions at both short and long delays.

Working Memory for Conjunctions Relies on the Medial Temporal Lobe

PubMed Central

Olson, Ingrid R.; Page, Katie; Moore, Katherine Sledge; Chatterjee, Anjan; Verfaellie, Mieke

2006-01-01

A prominent theory of hippocampal function proposes that the hippocampus is importantly involved in relating or binding together separate pieces of information to form an episodic representation. This hypothesis has only been applied to studies of long-term memory because the paradigmatic view of the hippocampus is that it is not critical for short-term forms of memory. However, relational processing is important in many working memory tasks, especially tasks using visual stimuli. Here, we test the hypothesis that the medial temporal lobes are important for relational memory even over short delays. The task required patients with medial temporal lobe amnesia and controls to remember three objects, locations, or object-location conjunctions over 1 or 8 s delays. The results show that working memory for objects and locations was at normal levels, but that memory for conjunctions was severely impaired at 8 s delays. Additional analyses suggest that the hippocampus per se is critical for accurate conjunction working memory. We propose that the hippocampus is critically involved in memory for conjunctions at both short and long delays. PMID:16641239

Delayed Triplet-State Formation through Hybrid Charge Transfer Exciton at Copper Phthalocyanine/GaAs Heterojunction.

PubMed

Lim, Heeseon; Kwon, Hyuksang; Kim, Sang Kyu; Kim, Jeong Won

2017-10-05

Light absorption in organic molecules on an inorganic substrate and subsequent electron transfer to the substrate create so-called hybrid charge transfer exciton (HCTE). The relaxation process of the HCTE states largely determines charge separation efficiency or optoelectronic device performance. Here, the study on energy and time-dispersive behavior of photoelectrons at the hybrid interface of copper phthalocyanine (CuPc)/p-GaAs(001) upon light excitation of GaAs reveals a clear pathway for HCTE relaxation and delayed triplet-state formation. According to the ground-state energy level alignment at the interface, CuPc/p-GaAs(001) shows initially fast hole injection from GaAs to CuPc. Thus, the electrons in GaAs and holes in CuPc form an unusual HCTE state manifold. Subsequent electron transfer from GaAs to CuPc generates the formation of the triplet state in CuPc with a few picoseconds delay. Such two-step charge transfer causes delayed triplet-state formation without singlet excitation and subsequent intersystem crossing within the CuPc molecules.

Approximation-Based Adaptive Neural Tracking Control of Nonlinear MIMO Unknown Time-Varying Delay Systems With Full State Constraints.

PubMed

Li, Da-Peng; Li, Dong-Juan; Liu, Yan-Jun; Tong, Shaocheng; Chen, C L Philip

2017-10-01

This paper deals with the tracking control problem for a class of nonlinear multiple input multiple output unknown time-varying delay systems with full state constraints. To overcome the challenges which cause by the appearances of the unknown time-varying delays and full-state constraints simultaneously in the systems, an adaptive control method is presented for such systems for the first time. The appropriate Lyapunov-Krasovskii functions and a separation technique are employed to eliminate the effect of unknown time-varying delays. The barrier Lyapunov functions are employed to prevent the violation of the full state constraints. The singular problems are dealt with by introducing the signal function. Finally, it is proven that the proposed method can both guarantee the good tracking performance of the systems output, all states are remained in the constrained interval and all the closed-loop signals are bounded in the design process based on choosing appropriate design parameters. The practicability of the proposed control technique is demonstrated by a simulation study in this paper.

Ndj1, a telomere-associated protein, regulates centrosome separation in budding yeast meiosis.

PubMed

Li, Ping; Shao, Yize; Jin, Hui; Yu, Hong-Guo

2015-04-27

Yeast centrosomes (called spindle pole bodies [SPBs]) remain cohesive for hours during meiotic G2 when recombination takes place. In contrast, SPBs separate within minutes after duplication in vegetative cells. We report here that Ndj1, a previously known meiosis-specific telomere-associated protein, is required for protecting SPB cohesion. Ndj1 localizes to the SPB but dissociates from it ∼16 min before SPB separation. Without Ndj1, meiotic SPBs lost cohesion prematurely, whereas overproduction of Ndj1 delayed SPB separation. When produced ectopically in vegetative cells, Ndj1 caused SPB separation defects and cell lethality. Localization of Ndj1 to the SPB depended on the SUN domain protein Mps3, and removal of the N terminus of Mps3 allowed SPB separation and suppressed the lethality of NDJ1-expressing vegetative cells. Finally, we show that Ndj1 forms oligomeric complexes with Mps3, and that the Polo-like kinase Cdc5 regulates Ndj1 protein stability and SPB separation. These findings reveal the underlying mechanism that coordinates yeast centrosome dynamics with meiotic telomere movement and cell cycle progression. © 2015 Li et al.

Ndj1, a telomere-associated protein, regulates centrosome separation in budding yeast meiosis

PubMed Central

Li, Ping; Shao, Yize; Jin, Hui

2015-01-01

Yeast centrosomes (called spindle pole bodies [SPBs]) remain cohesive for hours during meiotic G2 when recombination takes place. In contrast, SPBs separate within minutes after duplication in vegetative cells. We report here that Ndj1, a previously known meiosis-specific telomere-associated protein, is required for protecting SPB cohesion. Ndj1 localizes to the SPB but dissociates from it ∼16 min before SPB separation. Without Ndj1, meiotic SPBs lost cohesion prematurely, whereas overproduction of Ndj1 delayed SPB separation. When produced ectopically in vegetative cells, Ndj1 caused SPB separation defects and cell lethality. Localization of Ndj1 to the SPB depended on the SUN domain protein Mps3, and removal of the N terminus of Mps3 allowed SPB separation and suppressed the lethality of NDJ1-expressing vegetative cells. Finally, we show that Ndj1 forms oligomeric complexes with Mps3, and that the Polo-like kinase Cdc5 regulates Ndj1 protein stability and SPB separation. These findings reveal the underlying mechanism that coordinates yeast centrosome dynamics with meiotic telomere movement and cell cycle progression. PMID:25897084

Application of ray-traced tropospheric slant delays to geodetic VLBI analysis

NASA Astrophysics Data System (ADS)

Hofmeister, Armin; Böhm, Johannes

2017-08-01

The correction of tropospheric influences via so-called path delays is critical for the analysis of observations from space geodetic techniques like the very long baseline interferometry (VLBI). In standard VLBI analysis, the a priori slant path delays are determined using the concept of zenith delays, mapping functions and gradients. The a priori use of ray-traced delays, i.e., tropospheric slant path delays determined with the technique of ray-tracing through the meteorological data of numerical weather models (NWM), serves as an alternative way of correcting the influences of the troposphere on the VLBI observations within the analysis. In the presented research, the application of ray-traced delays to the VLBI analysis of sessions in a time span of 16.5 years is investigated. Ray-traced delays have been determined with program RADIATE (see Hofmeister in Ph.D. thesis, Department of Geodesy and Geophysics, Faculty of Mathematics and Geoinformation, Technische Universität Wien. http://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-3444, 2016) utilizing meteorological data provided by NWM of the European Centre for Medium-Range Weather Forecasts (ECMWF). In comparison with a standard VLBI analysis, which includes the tropospheric gradient estimation, the application of the ray-traced delays to an analysis, which uses the same parameterization except for the a priori slant path delay handling and the used wet mapping factors for the zenith wet delay (ZWD) estimation, improves the baseline length repeatability (BLR) at 55.9% of the baselines at sub-mm level. If no tropospheric gradients are estimated within the compared analyses, 90.6% of all baselines benefit from the application of the ray-traced delays, which leads to an average improvement of the BLR of 1 mm. The effects of the ray-traced delays on the terrestrial reference frame are also investigated. A separate assessment of the RADIATE ray-traced delays is carried out by comparison to the ray-traced delays from the National Aeronautics and Space Administration Goddard Space Flight Center (NASA GSFC) (Eriksson and MacMillan in http://lacerta.gsfc.nasa.gov/tropodelays, 2016) with respect to the analysis performances in terms of BLR results. If tropospheric gradient estimation is included in the analysis, 51.3% of the baselines benefit from the RADIATE ray-traced delays at sub-mm difference level. If no tropospheric gradients are estimated within the analysis, the RADIATE ray-traced delays deliver a better BLR at 63% of the baselines compared to the NASA GSFC ray-traced delays.

Differential Acetylcholine Release in the Prefrontal Cortex and Hippocampus During Pavlovian Trace and Delay Conditioning

PubMed Central

Flesher, M. Melissa; Butt, Allen E.; Kinney-Hurd, Brandee L.

2011-01-01

Pavlovian trace conditioning critically depends on the medial prefrontal cortex (mPFC) and hippocampus (HPC), whereas delay conditioning does not depend on these brain structures. Given that the cholinergic basal forebrain system modulates activity in both the mPFC and HPC, it was reasoned that the level of acetylcholine (ACh) release in these regions would show distinct profiles during testing in trace and delay conditioning paradigms. To test this assumption, microdialysis probes were implanted unilaterally into the mPFC and HPC of rats that were pre-trained in appetitive trace and delay conditioning paradigms using different conditional stimuli in the two tasks. On the day of microdialysis testing, dialysate samples were collected during a quiet baseline interval before trials were initiated, and again during performance in separate blocks of trace and delay conditioning trials in each animal. ACh levels were quantified using high performance liquid chromatography and electrochemical detection techniques. Consistent with our hypothesis, results showed that ACh release in the mPFC was greater during trace conditioning than during delay conditioning. The level of ACh released during trace conditioning in the HPC was also greater than the levels observed during delay conditioning. While ACh efflux in both the mPFC and HPC selectively increased during trace conditioning, ACh levels in the mPFC during trace conditioning testing showed the greatest increases observed. These results demonstrate a dissociation in cholinergic activation of the mPFC and HPC during performance in trace but not delay appetitive conditioning, where this cholinergic activity may contribute to attentional mechanisms, adaptive response timing, or memory consolidation necessary for successful trace conditioning. PMID:21514394

Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis

PubMed Central

Hasler, W. L.; May, K. P.; Wilson, L. A.; Van Natta, M.; Parkman, H. P.; Pasricha, P. J.; Koch, K. L.; Abell, T. L.; McCallum, R. W.; Nguyen, L. A.; Snape, W. J.; Sarosiek, I.; Clarke, J. O.; Farrugia, G.; Calles-Escandon, J.; Grover, M.; Tonascia, J.; Lee, L. A.; Miriel, L.; Hamilton, F. A.

2018-01-01

Background Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing. Methods A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms. Key Results Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04). Conclusions & Inferences Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities. PMID:28872760

Parietal lobe critically supports successful paired immediate and single-item delayed memory for targets.

PubMed

Krumm, Sabine; Kivisaari, Sasa L; Monsch, Andreas U; Reinhardt, Julia; Ulmer, Stephan; Stippich, Christoph; Kressig, Reto W; Taylor, Kirsten I

2017-05-01

The parietal lobe is important for successful recognition memory, but its role is not yet fully understood. We investigated the parietal lobes' contribution to immediate paired-associate memory and delayed item-recognition memory separately for hits (targets) and correct rejections (distractors). We compared the behavioral performance of 56 patients with known parietal and medial temporal lobe dysfunction (i.e. early Alzheimer's Disease) to 56 healthy control participants in an immediate paired and delayed single item object memory task. Additionally, we performed voxel-based morphometry analyses to investigate the functional-neuroanatomic relationships between performance and voxel-based estimates of atrophy in whole-brain analyses. Behaviorally, all participants performed better identifying targets than rejecting distractors. The voxel-based morphometry analyses associated atrophy in the right ventral parietal cortex with fewer correct responses to familiar items (i.e. hits) in the immediate and delayed conditions. Additionally, medial temporal lobe integrity correlated with better performance in rejecting distractors, but not in identifying targets, in the immediate paired-associate task. Our findings suggest that the parietal lobe critically supports successful immediate and delayed target recognition memory, and that the ventral aspect of the parietal cortex and the medial temporal lobe may have complementary preferences for identifying targets and rejecting distractors, respectively, during recognition memory. Copyright © 2017. Published by Elsevier Inc.

Extracorporeal shockwave enhanced regeneration of fibrocartilage in a delayed tendon-bone insertion repair model.

PubMed

Chow, Dick Ho Kiu; Suen, Pui Kit; Huang, Le; Cheung, Wing-Hoi; Leung, Kwok-Sui; Ng, Chun; Shi, San Qiang; Wong, Margaret Wan Nar; Qin, Ling

2014-04-01

Fibrous tissue is often formed in delayed healing of tendon bone insertion (TBI) instead of fibrocartilage. Extracorporeal shockwave (ESW) provides mechanical cues and upregulates expression of fibrocartilage-related makers and cytokines. We hypothesized that ESW would accelerate fibrocartilage regeneration at the healing interface in a delayed TBI healing model. Partial patellectomy with shielding at the TBI interface was performed on 32 female New Zealand White Rabbits for establishing this delayed TBI healing model. The rabbits were separated into the control and ESW group for evaluations at postoperative week 8 and 12. Shielding was removed at week 4 and a single ESW treatment was applied at week 6. Fibrocartilage regeneration was evaluated histomorphologically and immunohistochemically. Vickers hardness of the TBI matrix was measured by micro-indentation. ESW group showed higher fibrocartilage area, thickness, and proteoglycan deposition than the control in week 8 and 12. ESW increased expression of SOX9 and collagen II significantly in week 8 and 12, respectively. ESW group showed a gradual transition of hardness from bone to fibrocartilage to tendon, and had a higher Vickers hardness than the control group at week 12. In conclusion, ESW enhanced fibrocartilage regeneration at the healing interface in a delayed TBI healing model. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Memory Impairment in Multiple Sclerosis is Due to a Core Deficit in Initial Learning

PubMed Central

DeLuca, John; Leavitt, Victoria M.; Chiaravalloti, Nancy; Wylie, Glenn

2013-01-01

Persons with multiple sclerosis (MS) suffer memory impairment, but research on the nature of MS-related memory problems is mixed. Some have argued for a core deficit in retrieval, while others have identified deficient initial learning as the core deficit. We used a selective reminding paradigm to determine whether deficient initial learning or delayed retrieval represents the primary memory deficit in 44 persons with MS. Brain atrophy was measured from high-resolution MRIs. Regression analyses examined the impact of brain atrophy on (a) initial learning and delayed retrieval separately, and then (b) delayed retrieval controlling for initial learning. Brain atrophy was negatively associated with both initial learning and delayed retrieval (ps < .01), but brain atrophy was unrelated to retrieval when controlling for initial learning (p > .05). In addition, brain atrophy was associated with inefficient learning across initial acquisition trials, and brain atrophy was unrelated to delayed recall among MS subjects who successfully acquired the word list (although such learning frequently required many exposures). Taken together, memory deficits in MS are a result of deficits in initial learning; moreover, initial learning mediates the relationship between brain atrophy and subsequent retrieval, thereby supporting the core learning-deficit hypothesis of memory impairment in MS. PMID:23832311

Temporal horizon: modulation by smoking status and gender

PubMed Central

Jones, Bryan A.; Landes, Reid D.; Yi, Richard; Bickel, Warren K.

2009-01-01

Recently, delay discounting has been argued to be conceptually consistent with the notion of temporal horizon (Bickel et al., 2008). Temporal horizon refers to the temporal distance over which behavioral events or objects can influence behavior. Here we examine the results on two putative measures of temporal horizon, future time perspective (FTP) and delay discounting, collected over three separate studies (n = 227), to determine the influence of smoking and gender on temporal horizon. By comparing the results on these temporal horizon measures we address our population of interest: women who smoke. One of the measures of FTP indicates that smoking women have a shorter temporal horizon than their nonsmoking counterparts. Additionally, the story completion measures of FTP are positively correlated with delay discounting. In contrast, results of delay discounting measures showed no difference between smoking women and nonsmoking women, while results of delay discounting measures indicated smoking men have a shorter temporal horizon than non-smoking men. Additionally, the results of the FTP story completion measure indicated that lower third income earners had a shortened temporal horizon compared to upper third income earners. A possible explanation for these results is explored, and the implications of the modulation of temporal horizon by gender and smoking are discussed. PMID:19446407

Localization suppression and fusion measure of the precedence effect in young children

NASA Astrophysics Data System (ADS)

Litovsky, Ruth; Godar, Shelly; Yu, Gongqiang

2004-05-01

This study investigated aspects of the precedence effect (PE) known as fusion and localization dominance in children 4-5 years of age. Stimuli were three, 25-ms noise bursts (2-ms rise/fall times) with 250-ms ISI. On PE conditions the lead stimulus was presented from one of six locations in azimuth, and the lag was at 0 deg. Lead-lag delays varied from 5 to 100 ms. Localization was measured using an identification paradigm. Fusion was measured separately whereby subjects reported whether a single auditory event or two auditory events were perceived. Children reported two sounds on 75% of trials (fusion threshold) at delays ranging from 15 to 35 ms. Below fusion thresholds, the localization of the lead was similar to that of single-source stimuli. Above fusion thresholds lead localization was significantly degraded, persisting out to 100 ms. Localization of the lag was poor at all delays on which it was reported as being heard. According to these results localization dominance (difficulty localizing the lag) in children persists at greater delays than fusion, which is consistent with findings obtained in adult subjects. The range of delays over which these effects are robust in children is longer than the range observed in adults.

Temporal Discontiguity Is neither Necessary nor Sufficient for Learning-Induced Effects on Adult Neurogenesis

PubMed Central

Leuner, Benedetta; Waddell, Jaylyn; Gould, Elizabeth; Shors, Tracey J.

2012-01-01

Some, but not all, types of learning and memory can influence neurogenesis in the adult hippocampus. Trace eyeblink conditioning has been shown to enhance the survival of new neurons, whereas delay eyeblink conditioning has no such effect. The key difference between the two training procedures is that the conditioning stimuli are separated in time during trace but not delay conditioning. These findings raise the question of whether temporal discontiguity is necessary for enhancing the survival of new neurons. Here we used two approaches to test this hypothesis. First, we examined the influence of a delay conditioning task in which the duration of the conditioned stimulus (CS) was increased nearly twofold, a procedure that critically engages the hippocampus. Although the CS and unconditioned stimulus are contiguous, this very long delay conditioning procedure increased the number of new neurons that survived. Second, we examined the influence of learning the trace conditioned response (CR) after having acquired the CR during delay conditioning, a procedure that renders trace conditioning hippocampal-independent. In this case, trace conditioning did not enhance the survival of new neurons. Together, these results demonstrate that associative learning increases the survival of new neurons in the adult hippocampus, regardless of temporal contiguity. PMID:17192426

Study of the GPS inter-frequency calibration of timing receivers

NASA Astrophysics Data System (ADS)

Defraigne, P.; Huang, W.; Bertrand, B.; Rovera, D.

2018-02-01

When calibrating Global Positioning System (GPS) stations dedicated to timing, the hardware delays of P1 and P2, the P(Y)-codes on frequencies L1 and L2, are determined separately. In the international atomic time (TAI) network the GPS stations of the time laboratories are calibrated relatively against reference stations. This paper aims at determining the consistency between the P1 and P2 hardware delays (called dP1 and dP2) of these reference stations, and to look at the stability of the inter-signal hardware delays dP1-dP2 of all the stations in the network. The method consists of determining the dP1-dP2 directly from the GPS pseudorange measurements corrected for the frequency-dependent antenna phase center and the frequency-dependent ionosphere corrections, and then to compare these computed dP1-dP2 to the calibrated values. Our results show that the differences between the computed and calibrated dP1-dP2 are well inside the expected combined uncertainty of the two quantities. Furthermore, the consistency between the calibrated time transfer solution obtained from either single-frequency P1 or dual-frequency P3 for reference laboratories is shown to be about 1.0 ns, well inside the 2.1 ns uB uncertainty of a time transfer link based on GPS P3 or Precise Point Positioning. This demonstrates the good consistency between the P1 and P2 hardware delays of the reference stations used for calibration in the TAI network. The long-term stability of the inter-signal hardware delays is also analysed from the computed dP1-dP2. It is shown that only variations larger than 2 ns can be detected for a particular station, while variations of 200 ps can be detected when differentiating the results between two stations. Finally, we also show that in the differential calibration process as used in the TAI network, using the same antenna phase center or using different positions for L1 and L2 signals gives maximum differences of 200 ps on the hardware delays of the separate codes P1 and P2; however, the final impact on the P3 combination is less than 10 ps.

49 CFR 701.7 - Timing of responses to requests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... by a requester or by a group of requesters acting in concert constitute a single request that would... circumstances that may justify delay include: (i) The need to search for and collect the requested records from other facilities that are separate from Amtrak's headquarters offices. (ii) The need to search for...

40 CFR 355.40 - What information must I provide?

Code of Federal Regulations, 2010 CFR

2010-07-01

... retrieval of this information should not cause a delay in the notification on the emergency response. (1... 40 Protection of Environment 27 2010-07-01 2010-07-01 false What information must I provide? 355... Release Notification How to Comply § 355.40 What information must I provide? You must make two separate...

40 CFR 355.40 - What information must I provide?

Code of Federal Regulations, 2014 CFR

2014-07-01

... retrieval of this information should not cause a delay in the notification on the emergency response. (1... 40 Protection of Environment 28 2014-07-01 2014-07-01 false What information must I provide? 355... Release Notification How to Comply § 355.40 What information must I provide? You must make two separate...

40 CFR 355.40 - What information must I provide?

Code of Federal Regulations, 2011 CFR

2011-07-01

... retrieval of this information should not cause a delay in the notification on the emergency response. (1... 40 Protection of Environment 28 2011-07-01 2011-07-01 false What information must I provide? 355... Release Notification How to Comply § 355.40 What information must I provide? You must make two separate...

40 CFR 355.40 - What information must I provide?

Code of Federal Regulations, 2012 CFR

2012-07-01

... retrieval of this information should not cause a delay in the notification on the emergency response. (1... 40 Protection of Environment 29 2012-07-01 2012-07-01 false What information must I provide? 355... Release Notification How to Comply § 355.40 What information must I provide? You must make two separate...

40 CFR 355.40 - What information must I provide?

Code of Federal Regulations, 2013 CFR

2013-07-01

... retrieval of this information should not cause a delay in the notification on the emergency response. (1... 40 Protection of Environment 29 2013-07-01 2013-07-01 false What information must I provide? 355... Release Notification How to Comply § 355.40 What information must I provide? You must make two separate...

Marijuana Effects on Human Forgetting Functions

ERIC Educational Resources Information Center

Lane, Scott D.; Cherek, Don R.; Lieving, Lori M.; Tcheremissine, Oleg V.

2005-01-01

It has long been known that acute marijuana administration impairs working memory (e.g., the discrimination of stimuli separated by a delay). The determination of which of the individual components of memory are altered by marijuana is an unresolved problem. Previous human studies did not use test protocols that allowed for the determination of…

Double Dissociation of Pharmacologically Induced Deficits in Visual Recognition and Visual Discrimination Learning

ERIC Educational Resources Information Center

Turchi, Janita; Buffalari, Deanne; Mishkin, Mortimer

2008-01-01

Monkeys trained in either one-trial recognition at 8- to 10-min delays or multi-trial discrimination habits with 24-h intertrial intervals received systemic cholinergic and dopaminergic antagonists, scopolamine and haloperidol, respectively, in separate sessions. Recognition memory was impaired markedly by scopolamine but not at all by…

Analysis of sequencing and scheduling methods for arrival traffic

NASA Technical Reports Server (NTRS)

Neuman, Frank; Erzberger, Heinz

1990-01-01

The air traffic control subsystem that performs scheduling is discussed. The function of the scheduling algorithms is to plan automatically the most efficient landing order and to assign optimally spaced landing times to all arrivals. Several important scheduling algorithms are described and the statistical performance of the scheduling algorithms is examined. Scheduling brings order to an arrival sequence for aircraft. First-come-first-served scheduling (FCFS) establishes a fair order, based on estimated times of arrival, and determines proper separations. Because of the randomness of the traffic, gaps will remain in the scheduled sequence of aircraft. These gaps are filled, or partially filled, by time-advancing the leading aircraft after a gap while still preserving the FCFS order. Tightly scheduled groups of aircraft remain with a mix of heavy and large aircraft. Separation requirements differ for different types of aircraft trailing each other. Advantage is taken of this fact through mild reordering of the traffic, thus shortening the groups and reducing average delays. Actual delays for different samples with the same statistical parameters vary widely, especially for heavy traffic.

Is a bird in the hand worth two in the future? Intertemporal choice, attachment and theory of mind in school-aged children.

PubMed

Marchetti, Antonella; Castelli, Ilaria; Sanvito, Laura; Massaro, Davide

2014-01-01

Intertemporal choice is a decision-making dilemma related to outcomes of different entity located at different time points. Economic and psychological literature on this topic showed the phenomen of temporal discounting, i.e., the proclivity to devalue the outcome distant in time on the basis of the time delay necessary to obtain it. The goals of this research are to investigate two different components of intertemporal choice separately, namely time and outcome, in school-age children, and the possible link among such components and the security of attachment style and theory of mind. Ninety one children aged between 6 and 10 years performed two intertemporal choice tasks, first and second order false belief tasks and the Separation Anxiety Task in the Family and School versions. Results showed that the two components of intertemporal choice (waiting tolerance and sensitivity to delayed outcome) are stately interrelated; the quality of the attachment to the family caregiver affects the tolerance to waiting time and first order false belief understanding affects both the components of intertemporal choice.

Formation of Load Parameters of Destroyed Massife in Explosion of Multicharge Composition with Separation of its Parts by Profile Inert Interval

NASA Astrophysics Data System (ADS)

Paramonov, G. P.; Mysin, A. V.; Babkin, R. S.

2017-10-01

The paper introduces construction of multicharge composition with separation of parts by the profile inert interval. On the basis of the previous researches, the pulse-forming process at explosion of the borehole multicharge taking into account the offered design is considered. The physical model for definition of reflected wavelet taking into account an increment of radius of cross section of a charging cavity and the expiration of detonation products is offered. A technique is developed for numerical modeling of gas-dynamic processes in a borehole with a change in the axial channel of a profile inert interval caused by a high-temperature flow of gaseous products of an explosion. The authors obtained the dependence of the change in mean pressure on the borehole wall on time for each of the parts of the multicharge. To blast a series of charges of the proposed design, taking into account optimization of the stress fields of neighboring charges, the delay interval is determined for a short-delayed explosion.

Is a bird in the hand worth two in the future? Intertemporal choice, attachment and theory of mind in school-aged children

PubMed Central

Marchetti, Antonella; Castelli, Ilaria; Sanvito, Laura; Massaro, Davide

2014-01-01

Intertemporal choice is a decision-making dilemma related to outcomes of different entity located at different time points. Economic and psychological literature on this topic showed the phenomen of temporal discounting, i.e., the proclivity to devalue the outcome distant in time on the basis of the time delay necessary to obtain it. The goals of this research are to investigate two different components of intertemporal choice separately, namely time and outcome, in school-age children, and the possible link among such components and the security of attachment style and theory of mind. Ninety one children aged between 6 and 10 years performed two intertemporal choice tasks, first and second order false belief tasks and the Separation Anxiety Task in the Family and School versions. Results showed that the two components of intertemporal choice (waiting tolerance and sensitivity to delayed outcome) are stately interrelated; the quality of the attachment to the family caregiver affects the tolerance to waiting time and first order false belief understanding affects both the components of intertemporal choice. PMID:24904496

Hydrodynamic characteristics of sailfish and swordfish

NASA Astrophysics Data System (ADS)

Sagong, Woong; Jeon, Woo-Pyung; Choi, Haecheon

2009-11-01

The sailfish and swordfish are known as fastest sea animals, reaching their maximum speeds of more than 100km/h. Recently, Sagong et al. (2008, Phys. Fluids) investigated the role of V- shaped protrusions existing on the sailfish skin in the skin-friction reduction but those protrusions did not make a direct role in reducing drag. On the other hand, the long bill has been regarded as a device of reducing drag by separation delay through turbulence generation. In the present study, we investigate the hydrodynamic characteristics of sailfish and swordfish by installing the stuffed ones in a wind tunnel and measuring the drag on their bodies and boundary-layer velocities above the body surfaces. The drag coefficients of sailfish and swordfish are 0.0075 and 0.009 based on the free-stream velocity and wetted area, respectively. They are comparable to or smaller than those of other kinds of fish such as the dogfish, tuna and trout. Next, the role of bill on the drag is studied. The drag without bill or with an artificial short bill is lower than that with the original long bill, indicating that the bill does not reduce the drag at all. From the velocity measurement near the body surfaces, we found that flow separation does not occur even without bill, and thus the conjecture that the flow separation is delayed through turbulence generation by the bill is not valid.

Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

NASA Astrophysics Data System (ADS)

Trache, L.; Banu, A.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Jokinen, A.; Äysto, J.; Davinson, T.; Lotay, G.; Woods, P. J.; Pollacco, E.

2012-02-01

In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

Cherenkov and scintillation light separation on the CheSS experiment

NASA Astrophysics Data System (ADS)

Caravaca, Javier; Land, Benjamin; Descamps, Freija; Orebi Gann, Gabriel D.

2016-09-01

Separation of the scintillation and Cherenkov light produced in liquid scintillators enables outstanding capabilities for future particle detectors, the most relevant being: particle directionality information in a low energy threshold detector and improved particle identification. The CheSS experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in liquid scintillator using two techniques: based on the photon density and using the photon hit time information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by several ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WbLS) enhances the separation since it allows tuning of the Cherenkov/Scintillation ratio. Latest results on the separation for pure liquid scintillators and WbLS will be presented.

Orthodontic elastic separator-induced periodontal abscess: a case report.

PubMed

Becker, Talia; Neronov, Alex

2012-01-01

Aim. Orthodontic elastic bands were proposed as being the source of gingival abscesses that can rapidly lead to bone loss and teeth exfoliation. We report an adolescent, otherwise, healthy patient whose periodontal status was sound. Shortly after undergoing preparations for orthodontic treatment consisting of orthodontic separators, he presented with a periodontal abscess for which there was no apparent etiology. A non-orthoradial X-ray was inconclusive, but an appropriate one revealed a subgingival orthodontic separator as the cause of the abscess. Removal of the separator and thorough scaling led to complete resolution of the abscess, but there was already residual mild damage to the alveolar bone. Summary. Failure to use appropriate imaging to reveal the cause of gingival abscesses can result in the delay of implementing treatment and halting irreversible alveolar bone loss. An inflammatory process restricted to the gingiva and refractive to conventional therapy should raise the possibility of a foreign body etiology.

Orthodontic Elastic Separator-Induced Periodontal Abscess: A Case Report

PubMed Central

Becker, Talia; Neronov, Alex

2012-01-01

Aim. Orthodontic elastic bands were proposed as being the source of gingival abscesses that can rapidly lead to bone loss and teeth exfoliation. We report an adolescent, otherwise, healthy patient whose periodontal status was sound. Shortly after undergoing preparations for orthodontic treatment consisting of orthodontic separators, he presented with a periodontal abscess for which there was no apparent etiology. A non-orthoradial X-ray was inconclusive, but an appropriate one revealed a subgingival orthodontic separator as the cause of the abscess. Removal of the separator and thorough scaling led to complete resolution of the abscess, but there was already residual mild damage to the alveolar bone. Summary. Failure to use appropriate imaging to reveal the cause of gingival abscesses can result in the delay of implementing treatment and halting irreversible alveolar bone loss. An inflammatory process restricted to the gingiva and refractive to conventional therapy should raise the possibility of a foreign body etiology. PMID:22567456

Two-photon interference of temporally separated photons.

PubMed

Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

2016-10-06

We present experimental demonstrations of two-photon interference involving temporally separated photons within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-photon states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input photons; this state is composed of two temporally separated photons, which are in two different or the same spatial modes. We then observe two-photon interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-photon states simultaneously in a single interferometric setup. The observed two-photon interference fringes provide simultaneous observation of the interferometric properties of the single-photon and two-photon wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-photon states comprised of two temporally separated photons within the interferometer arms.

Proceedings of the 2010 National Toxicology Program Satellite Symposium

PubMed Central

Adams, E. Terence; Auerbach, Scott; Blackshear, Pamela E.; Bradley, Alys; Gruebbel, Margarita M.; Little, Peter B.; Malarkey, David; Maronpot, Robert; McKay, Jennifer S.; Miller, Rodney A.; Moore, Rebecca R.; Morrison, James P.; Nyska, Abraham; Ramot, Yuval; Rao, Deepa; Suttie, Andrew; Wells, Monique Y.; Willson, Gabrielle A.; Elmore, Susan A.

2011-01-01

The 2010 annual National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held in Chicago, Illinois, in advance of the scientific symposium sponsored jointly by the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP). The goal of the annual NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for voting or discussion. Some topics covered during the symposium included a comparison of rat and mouse hepatocholangiocarcinoma, a comparison of cholangiofibrosis and cholangiocarcinoma in rats, a mixed pancreatic neoplasm with acinar and islet cell components, an unusual preputial gland tumor, renal hyaline glomerulopathy in rats and mice, eosinophilic substance in the nasal septum of mice, INHAND nomenclature for proliferative and nonproliferative lesions of the CNS/PNS, retinal gliosis in a rat, fibroadnexal hamartoma in rats, intramural plaque in a mouse, a treatment-related chloracne-like lesion in mice, and an overview of mouse ovarian tumors. PMID:21177527

The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs.

PubMed

Brito, Erika H S; Fontenelle, Raquel O S; Brilhante, Raimunda S N; Cordeiro, Rossana A; Monteiro, André J; Sidrim, José J C; Rocha, Marcos F G

2009-11-01

The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp. Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03-16 microg/mL, 0.06 to >16 microg/mL and 0.5-64 microg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.

Flux analysis of cholesterol biosynthesis in vivo reveals multiple tissue and cell-type specific pathways

PubMed Central

Mitsche, Matthew A; McDonald, Jeffrey G; Hobbs, Helen H; Cohen, Jonathan C

2015-01-01

Two parallel pathways produce cholesterol: the Bloch and Kandutsch-Russell pathways. Here we used stable isotope labeling and isotopomer analysis to trace sterol flux through the two pathways in mice. Surprisingly, no tissue used the canonical K–R pathway. Rather, a hybrid pathway was identified that we call the modified K–R (MK–R) pathway. Proportional flux through the Bloch pathway varied from 8% in preputial gland to 97% in testes, and the tissue-specificity observed in vivo was retained in cultured cells. The distribution of sterol isotopomers in plasma mirrored that of liver. Sterol depletion in cultured cells increased flux through the Bloch pathway, whereas overexpression of 24-dehydrocholesterol reductase (DHCR24) enhanced usage of the MK–R pathway. Thus, relative use of the Bloch and MK–R pathways is highly variable, tissue-specific, flux dependent, and epigenetically fixed. Maintenance of two interdigitated pathways permits production of diverse bioactive sterols that can be regulated independently of cholesterol. DOI: http://dx.doi.org/10.7554/eLife.07999.001 PMID:26114596

[Congenital buried penis in the child: about a case].

PubMed

Rami, Mohamed; Bakkaly, Achraf El; Bouljrouf, Jaouad; Lafia, Toualouth; Bouhafs, Mohammed Amine; Belkacem, Rachid

2017-01-01

Congenital buried penis in the child is a congenital malformation where the penis appears small in size while all the parts of the organ are normal (the urethra, the erectile tissue and the glans penis). Our study aimed to describe our experience in the surgical treatment of this abnormality. We report the case of a 18-months old infant with bilateral hydrocele initially admitted to the Emergency Department and then referred to our Department. Clinical examination showed buried penis with tight foreskin and a dilation of the preputial reservoir due to urine. Surgical procedure included several steps: Z-shaped incision, pulling back of the foreskin of the penis, release of the adhesions surrounding the corpus cavernosum and ventral penile skin coverage using bladder catheter kept for a week to protect the wound healing. Aesthetic and functional result was satisfactory after 1-year follow-up. Congenital buried penis is a very debated subject in the literature. Our technique was simple and easily reproducible. Voiding difficulties and urinary infection are the main indications of this surgical procedure.

Distributed value representation in the medial prefrontal cortex during intertemporal choices.

PubMed

Wang, Qiang; Luo, Shan; Monterosso, John; Zhang, Jintao; Fang, Xiaoyi; Dong, Qi; Xue, Gui

2014-05-28

The ability to resist current temptations in favor of long-term benefits is a critical human capacity. Despite the extensive studies on the neural mechanisms of intertemporal choices, how the subjective value of immediate and delayed rewards is represented and compared in the brain remains to be elucidated. The present fMRI study addressed this question by simultaneously and independently manipulating the magnitude of immediate and delayed rewards in an intertemporal decision task, combined with univariate analysis and multiple voxel pattern analysis. We found that activities in the posterior portion of the dorsal medial prefrontal cortex (DmPFC) were modulated by the value of immediate options, whereas activities in the adjacent anterior DmPFC were modulated by the subjective value of delayed options. Brain signal change in the ventral mPFC was positively correlated with the "relative value" (the absolute difference of subjective value between two intertemporal alternatives). In contrast, the dorsal anterior cingulate cortex activity was negatively correlated with the relative value. These results suggest that immediate and delayed rewards are separately represented in the dorsal mPFC and compared in the ventral mPFC to guide decisions. The functional dissociation of posterior and anterior DmPFC in representing immediate and delayed reward is consistent with the general structural and functional architecture of the prefrontal cortex and may provide a neural basis for human's unique capacity to delayed gratification. Copyright © 2014 the authors 0270-6474/14/347522-09$15.00/0.

Characterization of Days Based On Analysis of National Airspace System Performance Metrics

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.; Musaffar, Bassam; Meyn, Larry A.; Quon, Leighton K.

2006-01-01

Days of operations in the National Airspace System can be described in term of traffic demand, runway conditions, equipment outages, and surface and enroute weather conditions. These causes manifest themselves in terms of departure delays, arrival delays, enroute delays and traffic flow management delays, Traffic flow management initiatives such as, ground stops, ground delay programs, miles-in-trail restrictions, rerouting and airborne holding are imposed to balance the air traffic demand with respect to the available capacity, In order to maintain operational efficiency of the National Airspace System, the Federal Aviation Administration (FAA) maintains delay sad other statistics in the Air Traffic Operations Network (OPSNET) and the Aviation System Performance Metrics (ASPM) databases. OPSNET data includes reportable delays of fifteen minutes ox more experienced by Instrument Flight Rule (IFR) flights. Numbers of aircraft affected by departure delays, enroute delays, arrival delays and traffic flow delays are recorded in the OPSNET data. ASPM data consist of number of actual departures, number of canceled departures, percentage of on time departures, percentage of on time gate arrivals, taxi-out delays. taxi-in delays, gate delays, arrival delays and block delays. Surface conditions at the major U.S. airports are classified in terms of Instrument Meteorological Condition (IMC) and Visual Meteorological Condition (VMC) as a function of the time of the day in the ASPM data. The main objective of this paper is to use OPSNET and ASPM data to classify the days in the datasets into few distinct groups, where each group is separated from the other groups in terms of a distance metric. The motivations for classifying the days are two-fold, 1) to enable selection of days of traffic with particular operational characteristics for concept evaluation using system-wide simulation systems such as the National Aeronautics and Space Administration's Airspace Concepts Evaluation Tool (ACES) and 2) to enable evaluation of a given day with respect to the characteristics of the classified groups. The first part of the paper is devoted to the analysis of major trends seen in the OPSNET and ASPM data. The second part of the paper is devoted to describing features or measures derived from the OPSNET and ASPM data that are suitable for characterizing days, and the classification algorithm used for grouping the days. Finally, the method for evaluating the characteristics of a given day with respect to the properties of the groups is described.

Numerical Analysis of the SCHOLAR Supersonic Combustor

NASA Technical Reports Server (NTRS)

Rodriguez, Carlos G.; Cutler, Andrew D.

2003-01-01

The SCHOLAR scramjet experiment is the subject of an ongoing numerical investigation. The facility nozzle and combustor were solved separate and sequentially, with the exit conditions of the former used as inlet conditions for the latter. A baseline configuration for the numerical model was compared with the available experimental data. It was found that ignition-delay was underpredicted and fuel-plume penetration overpredicted, while the pressure rise was close to experimental values. In addition, grid-convergence by means of grid-sequencing could not be established. The effects of the different turbulence parameters were quantified. It was found that it was not possible to simultaneously predict the three main parameters of this flow: pressure-rise, ignition-delay, and fuel-plume penetration.

Incorporating User Preferences Within an Optimal Traffic Flow Management Framework

NASA Technical Reports Server (NTRS)

Rios, Joseph Lucio; Sheth, Kapil S.; Guiterrez-Nolasco, Sebastian Armardo

2010-01-01

The effectiveness of future decision support tools for Traffic Flow Management in the National Airspace System will depend on two major factors: computational burden and collaboration. Previous research has focused separately on these two aspects without consideration of their interaction. In this paper, their explicit combination is examined. It is shown that when user preferences are incorporated with an optimal approach to scheduling, runtime is not adversely affected. A benefit-cost ratio is used to measure the influence of user preferences on an optimal solution. This metric shows user preferences can be accommodated without inordinately, negatively affecting the overall system delay. Specifically, incorporating user preferences will increase delays proportionally to increased user satisfaction.

Flow separation in a computational oscillating vocal fold model

NASA Astrophysics Data System (ADS)

Alipour, Fariborz; Scherer, Ronald C.

2004-09-01

A finite-volume computational model that solves the time-dependent glottal airflow within a forced-oscillation model of the glottis was employed to study glottal flow separation. Tracheal input velocity was independently controlled with a sinusoidally varying parabolic velocity profile. Control parameters included flow rate (Reynolds number), oscillation frequency and amplitude of the vocal folds, and the phase difference between the superior and inferior glottal margins. Results for static divergent glottal shapes suggest that velocity increase caused glottal separation to move downstream, but reduction in velocity increase and velocity decrease moved the separation upstream. At the fixed frequency, an increase of amplitude of the glottal walls moved the separation further downstream during glottal closing. Increase of Reynolds number caused the flow separation to move upstream in the glottis. The flow separation cross-sectional ratio ranged from approximately 1.1 to 1.9 (average of 1.47) for the divergent shapes. Results suggest that there may be a strong interaction of rate of change of airflow, inertia, and wall movement. Flow separation appeared to be ``delayed'' during the vibratory cycle, leading to movement of the separation point upstream of the glottal end only after a significant divergent angle was reached, and to persist upstream into the convergent phase of the cycle.

78 FR 57450 - Notice Rescinding a Notice of Intent To Prepare an Environmental Impact Statement for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-18

... allowed trains to run from one rail line to the other in order to accommodate intercity travel between... Pass and the Tri Valley area capable of supporting intercity and commuter rail passenger services. The... day, reducing travel times, and eliminating freight railroad delays by providing separate passenger...

Do Adults Show an Effect of Delayed First Language Acquisition When Calculating Scalar Implicatures?

ERIC Educational Resources Information Center

Davidson, Kathryn; Mayberry, Rachel I.

2015-01-01

Language acquisition involves learning not only grammatical rules and a lexicon but also what people are intending to convey with their utterances: the semantic/pragmatic component of language. In this article we separate the contributions of linguistic development and cognitive maturity to the acquisition of the semantic/pragmatic component of…

Tail Separation and Surface Impact Effects on the Underwater Trajectory of the JDAM

DTIC Science & Technology

2010-05-01

tow the very capable sled (with the MK-103 through MK- 106 installed) into shallow water, but is unable to work in low visibility or at night. The...delay depends on which types of targets the weapon is to attack. The explosive in the live weapon is PBXN -109, whereas the inert weapons have

Separation Dynamics of Controlled Internal Flow in an Adverse Pressure Gradient

NASA Astrophysics Data System (ADS)

Peterson, C. J.; Vukasinovic, B.; Glezer, A.

2017-11-01

The effects of fluidic actuation on the dynamic evolution of aggressive internal flow separation is investigated at speeds up to M = 0.4 within a constant-width diffuser branching off of a primary flow duct. It is shown that a spanwise array of fluidic actuators upstream of the separation actively controls the flow constriction (and losses) within the diffuser and consequently the local pressure gradient at its entrance. The effectiveness of the actuation, as may be measured by the increased flow rate that is diverted through the diffuser, scales with its flow rate coefficient. In the presence of actuation (0.7% mass fraction), the mass flow rate in the primary duct increases by 10% while the fraction of the diverted mass flow rate in the diffuser increases by more than 45%. The flow dynamics near separation in the absence and presence of actuation are characterized using high speed particle image velocimetry and analyzed using proper orthogonal and spectral decompositions. In particular, the spectral contents of the incipient boundary layer separation are compared in the absence and presence of actuation with emphasis on the changes in local dynamics near separation as the characteristic cross stream scale of the boundary layer increases with separation delay.

Vortical flow management for improved configuration aerodynamics: Recent experiences

NASA Technical Reports Server (NTRS)

Rao, D. M.

1983-01-01

Recent progress in vortex-control applications for alleviating the adverse consequences of three dimensional separation and vortical interactions on slender body/swept wing configurations is reported. Examples include helical separation trip to alleviate the side force due to forebody vortex asymmetry; hinged strakes to avoid vortex breakdown effects; compartmentation of swept leading edge separation to delay the pitch-up instability; under wing vortex trip and vortex trip and vortex flaps for drag reduction at high lift; and an apex-flap trimmer to fully utilize the lift capability of trailing-edge flaps for take off and landing of delta wings. Experimental results on generic wind-tunnel models are presented to illustrate the vortex-management concepts involved and to indicate their potential for enhancing the subsonic aerodynamics of supersonic-cruise type vehicles.

Proton acceleration by a pair of successive ultraintense femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Ferri, J.; Senje, L.; Dalui, M.; Svensson, K.; Aurand, B.; Hansson, M.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Gremillet, L.; Siminos, E.; DuBois, T. C.; Yi, L.; Martins, J. L.; Fülöp, T.

2018-04-01

We investigate the target normal sheath acceleration of protons in thin aluminum targets irradiated at a relativistic intensity by two time-separated ultrashort (35 fs) laser pulses. When the full-energy laser pulse is temporally split into two identical half-energy pulses, and using target thicknesses of 3 and 6 μm, we observe experimentally that the second half-pulse boosts the maximum energy and charge of the proton beam produced by the first half-pulse for time delays below ˜0.6-1 ps. Using two-dimensional particle-in-cell simulations, we examine the variation of the proton energy spectra with respect to the time-delay between the two pulses. We demonstrate that the expansion of the target front surface caused by the first pulse significantly enhances the hot-electron generation by the second pulse arriving after a few hundreds of fs time delay. This enhancement, however, does not suffice to further accelerate the fastest protons driven by the first pulse once three-dimensional quenching effects have set in. This implies a limit to the maximum time delay that leads to proton energy enhancement, which we theoretically determine.

Monaural Sound Localization Based on Reflective Structure and Homomorphic Deconvolution

PubMed Central

Park, Yeonseok; Choi, Anthony

2017-01-01

The asymmetric structure around the receiver provides a particular time delay for the specific incoming propagation. This paper designs a monaural sound localization system based on the reflective structure around the microphone. The reflective plates are placed to present the direction-wise time delay, which is naturally processed by convolutional operation with a sound source. The received signal is separated for estimating the dominant time delay by using homomorphic deconvolution, which utilizes the real cepstrum and inverse cepstrum sequentially to derive the propagation response’s autocorrelation. Once the localization system accurately estimates the information, the time delay model computes the corresponding reflection for localization. Because of the structure limitation, two stages of the localization process perform the estimation procedure as range and angle. The software toolchain from propagation physics and algorithm simulation realizes the optimal 3D-printed structure. The acoustic experiments in the anechoic chamber denote that 79.0% of the study range data from the isotropic signal is properly detected by the response value, and 87.5% of the specific direction data from the study range signal is properly estimated by the response time. The product of both rates shows the overall hit rate to be 69.1%. PMID:28946625

Pregnancy rates of beef cattle are not affected by Campylobacter fetus subsp. venerealis real-time PCR-positive breeding sires in New Zealand.

PubMed

Sanhueza, J M; Heuer, C; Jackson, R; Hughes, P; Anderson, P; Kelly, K; Walker, G

2014-09-01

Campylobacter fetus subspecies venerealis (C. fetus venerealis) is the causal agent of bovine genital campylobacteriosis, a venereal disease that is asymptomatic in bulls but responsible for reproductive wastage in female cattle. In New Zealand, a commercial real-time PCR assay was introduced in 2007 to identify the DNA of this pathogen in preputial scrapings; however, concerns were raised about the specificity of the test following anecdotal reports of a high number of test-positive bulls with no apparent relationship to reproductive performance. The objective of this study, therefore, was to examine the association between real-time PCR assay results from beef breeding bulls and pregnancy rates in beef herds using these bulls. Veterinarians from four veterinary practices selected beef cattle herds with relatively high and low pregnancy rates between December 2008 and February 2009. Preputial scrapings were collected from bulls used for mating in those herds. Samples were tested using the real-time PCR assay under consideration. Bivariable and multivariable analyses were used to assess the relationship between pregnancy rates in each mob (15-month-old heifers, 27-month-old heifers and mixed-age cows) and the percentage of real-time PCR-positive bulls in each mob. Sixty-four (28.8%) of 222 bulls tested positive, 130 (58.6%) tested negative, and 28 (12.6%) returned an inconclusive result to the real-time PCR assay. The percentage of bulls testing real-time PCR-positive in these mobs was not associated with pregnancy rates (p=0.757) after controlling for mob, average body condition score of cows, cow to bull ratio, length of the mating period, and farm. Real-time PCR assay results were not associated with pregnancy rates, suggesting that the specificity of the real-time PCR assay was too low to be used to reliably detect C. fetus venerealis. This study adds to a growing body of evidence indicating that C. fetus venerealis strains are either absent from, or present at clinically insignificant levels of endemicity among, beef breeding herds in New Zealand. The real-time PCR assay that was assessed in this study should not be used for the detection of C. fetus venerealis in bulls or for investigations of low conception rates in cattle in New Zealand. During the course of this survey, sequencing analysis of an apparent C. fetus venerealis isolate from the intestines of a Friesian bull turned out to be Campylobacter hyointestinalis. As a consequence, this real-time PCR assay for C. fetus venerealis is no longer being offered by diagnostic laboratories in New Zealand.

CORRECTING FOR INTERSTELLAR SCATTERING DELAY IN HIGH-PRECISION PULSAR TIMING: SIMULATION RESULTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palliyaguru, Nipuni; McLaughlin, Maura; Stinebring, Daniel

2015-12-20

Light travel time changes due to gravitational waves (GWs) may be detected within the next decade through precision timing of millisecond pulsars. Removal of frequency-dependent interstellar medium (ISM) delays due to dispersion and scattering is a key issue in the detection process. Current timing algorithms routinely correct pulse times of arrival (TOAs) for time-variable delays due to cold plasma dispersion. However, none of the major pulsar timing groups correct for delays due to scattering from multi-path propagation in the ISM. Scattering introduces a frequency-dependent phase change in the signal that results in pulse broadening and arrival time delays. Any methodmore » to correct the TOA for interstellar propagation effects must be based on multi-frequency measurements that can effectively separate dispersion and scattering delay terms from frequency-independent perturbations such as those due to a GW. Cyclic spectroscopy, first described in an astronomical context by Demorest (2011), is a potentially powerful tool to assist in this multi-frequency decomposition. As a step toward a more comprehensive ISM propagation delay correction, we demonstrate through a simulation that we can accurately recover impulse response functions (IRFs), such as those that would be introduced by multi-path scattering, with a realistic signal-to-noise ratio (S/N). We demonstrate that timing precision is improved when scatter-corrected TOAs are used, under the assumptions of a high S/N and highly scattered signal. We also show that the effect of pulse-to-pulse “jitter” is not a serious problem for IRF reconstruction, at least for jitter levels comparable to those observed in several bright pulsars.« less

Effects of the NMDA receptor antagonists dizocilpine and Ro 63-1908 on delay-discounting and risky decision-making in a gambling task.

PubMed

Higgins, Guy A; Silenieks, Leo B; MacMillan, Cam; Zeeb, Fiona D; Thevarkunnel, Sandy

2018-04-22

Previous studies demonstrated that NMDA receptor antagonists such as dizocilpine (MK801) and the GluN2B NMDA antagonist Ro 63-1908 promote impulsive action (motor impulsivity). The effects of these treatments on impulsive choice and decision-making is less well characterized. Two experiments were undertaken. In the first experiment, given evidence for delay order as a factor in choice selection, the effect of dizocilpine was examined in a delay discounting task with separate groups of male Long-Evans rats trained to a schedule of either ascending (i.e. 0-40 s), or descending delays (i.e. 40-0 s). Under the ascending-delay schedule, dizocilpine (0.03-0.06 mg/kg SC) reduced discounting, yet on the descending-delay schedule discounting was increased. Subgrouping rats according to discounting rate under vehicle pretreatment were consistent with a treatment-induced choice perseveration. In a second experiment, male Long-Evans rats were trained to a gambling task (rGT). Neither dizocilpine (0.01-0.06 mg/kg SC) nor Ro 63-1908 (0.1-1 mg/kg SC) shifted choice from the advantageous to the disadvantageous options. However dizocilpine, and marginally Ro 63-1908, increased choice of the least risky, but suboptimal option. This effect was most evident in rats that initially preferred the disadvantageous options. Consistent with previous studies, both treatments increased measures of motor impulsivity. These results demonstrate that dizocilpine has effects on discounting dependent on delay order and likely reflective of perseveration. On the rGT task, neither dizocilpine nor Ro 63-1908 promoted risky choice, yet both NMDA receptor antagonists increased impulsive action. Copyright © 2018 Elsevier B.V. All rights reserved.

Parents with doubts about vaccines: which vaccines and reasons why.

PubMed

Gust, Deborah A; Darling, Natalie; Kennedy, Allison; Schwartz, Ben

2008-10-01

The goals were (1) to obtain national estimates of the proportions of parents with indicators of vaccine doubt, (2) to identify factors associated with those parents, compared with parents reporting no vaccine doubt indicators, (3) to identify the specific vaccines that prompted doubt and the reasons why, and (4) to describe the main reasons parents changed their minds about delaying or refusing a vaccine for their child. Data were from the National Immunization Survey (2003-2004). Groups included parents who ever got a vaccination for their child although they were not sure it was the best thing to do ("unsure"), delayed a vaccination for their child ("delayed"), or decided not to have their child get a vaccination ("refused"). A total of 3924 interviews were completed. Response rates were 57.9% in 2003 and 65.0% in 2004. Twenty-eight percent of parents responded yes to ever experiencing >or=1 of the outcome measures listed above. In separate analyses for each outcome measure, vaccine safety concern was a predictor for unsure, refused, and delayed parents. The largest proportions of unsure and refused parents chose varicella vaccine as the vaccine prompting their concern, whereas delayed parents most often reported "not a specific vaccine" as the vaccine prompting their concern. Most parents who delayed vaccines for their child did so for reasons related to their child's illness, unlike the unsure and refused parents. The largest proportion of parents who changed their minds about delaying or not getting a vaccination for their child listed "information or assurances from health care provider" as the main reason. Parents who exhibit doubts about immunizations are not all the same. This research suggests encouraging children's health care providers to solicit questions about vaccines, to establish a trusting relationship, and to provide appropriate educational materials to parents.

Rap system of stress stimulation can promote bone union after lower tibial bone fracture: a clinical research.

PubMed

Yao, Jian-fei; Shen, Jia-zuo; Li, Da-kun; Lin, Da-sheng; Li, Lin; Li, Qiang; Qi, Peng; Lian, Ke-jian; Ding, Zhen-qi

2012-01-01

Lower tibial bone fracture may easily cause bone delayed union or nonunion because of lacking of dynamic mechanical load. Research Group would design a new instrument as Rap System of Stress Stimulation (RSSS) to provide dynamic mechanical load which would promote lower tibial bone union postoperatively. This clinical research was conducted from January 2008 to December 2010, 92 patients(male 61/female 31, age 16-70 years, mean 36.3 years) who suffered lower tibial bone closed fracture were given intramedullary nail fixation and randomly averagely separated into experimental group and control group(according to the successively order when patients went for the admission procedure). Then researchers analysed the clinical healing time, full weight bearing time, VAS (Visual Analogue Scales) score and callus growth score of Lane-Sandhu in 3,6,12 months postoperatively. The delayed union and nonunion rates were compared at 6 and 12 months separately. All the 92 patients had been followed up (mean 14 months). Clinical bone healing time in experimental group was 88.78±8.80 days but control group was 107.91±9.03 days. Full weight bearing time in experimental group was 94.07±9.81 days but control group was 113.24±13.37 days respectively (P<0.05). The delayed union rate in 6 months was 4.3% in experimental group but 10.9% in control group(P<0.05). The nonunion rate in 12 months was 6.5% in experimental group but 19.6% in control group(P<0.05). In 3, 6, 12 months postoperatively, VAS score and Lane-Sandhu score in experimental group had more significantly difference than them in control group. RSSS can intermittently provide dynamic mechanical load and stimulate callus formation, promote lower tibial bone union, reduce bone delayed union or nonunion rate. It is an adjuvant therapy for promoting bone union after lower tibial bone fracture.

Intestinal electrical stimulation improves delayed gastric emptying and vomiting induced by duodenal distension in dogs.

PubMed

Xu, J; Chen, J D Z

2008-03-01

The aim of this study was to investigate the effects of short-pulse intestinal electrical stimulation (IES) on duodenal distention-induced delayed gastric emptying and vomiting in dogs and its possible mechanisms. The study was performed in 12 dogs with jejunal electrodes and a duodenal cannula in three separate experiments to investigate the effects of IES on duodenal distension (DD)-induced delayed gastric emptying and discomfort signs, vagal efferent activity, and jejunal tone. We found that: (i) IES significantly accelerated gastric emptying of liquid delayed by distension (18.05 +/- 4.06%vs. 7.18 +/- 1.99%, P = 0.036 at 60 min). (ii) IES significantly reduced vomiting and discomfort/pain induced by distension. The average signs score was 15.33 +/- 1.37 during distension which decreased to 6.50 +/- 0.91 (P = 0.0002) with IES. (iii) IES did not change vagal afferent activity, which was assessed by the spectral analysis of the heart rate variability. (iv) IES decreased jejunal tone. In conclusion, IES with parameters commonly used in gastric electrical stimulation for nausea and vomiting associated with gastroparesis improves DD-induced delayed gastric emptying and prevents DD-induced vomiting and discomfort signs. Further studies are warranted to investigate the therapeutic potential of IES for gastrointestinal symptoms associated with disturbances in motility and sensory function in small intestine.

Space Flight Middleware: Remote AMS over DTN for Delay-Tolerant Messaging

NASA Technical Reports Server (NTRS)

Burleigh, Scott

2011-01-01

This paper describes a technique for implementing scalable, reliable, multi-source multipoint data distribution in space flight communications -- Delay-Tolerant Reliable Multicast (DTRM) -- that is fully supported by the "Remote AMS" (RAMS) protocol of the Asynchronous Message Service (AMS) proposed for standardization within the Consultative Committee for Space Data Systems (CCSDS). The DTRM architecture enables applications to easily "publish" messages that will be reliably and efficiently delivered to an arbitrary number of "subscribing" applications residing anywhere in the space network, whether in the same subnet or in a subnet on a remote planet or vehicle separated by many light minutes of interplanetary space. The architecture comprises multiple levels of protocol, each included for a specific purpose and allocated specific responsibilities: "application AMS" traffic performs end-system data introduction and delivery subject to access control; underlying "remote AMS" directs this application traffic to populations of recipients at remote locations in a multicast distribution tree, enabling the architecture to scale up to large networks; further underlying Delay-Tolerant Networking (DTN) Bundle Protocol (BP) advances RAMS protocol data units through the distribution tree using delay-tolerant storeand- forward methods; and further underlying reliable "convergence-layer" protocols ensure successful data transfer over each segment of the end-to-end route. The result is scalable, reliable, delay-tolerant multi-source multicast that is largely self-configuring.

Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit.

PubMed

Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

2017-06-21

Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I ) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model architecture, allows the feasibility of a range of imaging protocols to be investigated via simulation in a straight-forward manner for a wide range of possible scenarios. The hope is that the ease of utilising this approach during feasibility studies and in practice removes any perceived technical barrier to performing dual-tracer imaging.

Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit

NASA Astrophysics Data System (ADS)

Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

2017-06-01

Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model architecture, allows the feasibility of a range of imaging protocols to be investigated via simulation in a straight-forward manner for a wide range of possible scenarios. The hope is that the ease of utilising this approach during feasibility studies and in practice removes any perceived technical barrier to performing dual-tracer imaging.

General Relativistic Theory of the VLBI Time Delay in the Gravitational Field of Moving Bodies

NASA Technical Reports Server (NTRS)

Kopeikin, Sergei

2003-01-01

The general relativistic theory of the gravitational VLBI experiment conducted on September 8, 2002 by Fomalont and Kopeikin is explained. Equations of radio waves (light) propagating from the quasar to the observer are integrated in the time-dependent gravitational field of the solar system by making use of either retarded or advanced solutions of the Einstein field equations. This mathematical technique separates explicitly the effects associated with the propagation of gravity from those associated with light in the integral expression for the relativistic VLBI time delay of light. We prove that the relativistic correction to the Shapiro time delay, discovered by Kopeikin (ApJ, 556, L1, 2001), changes sign if one retains direction of the light propagation but replaces the retarded for the advanced solution of the Einstein equations. Hence, this correction is associated with the propagation of gravity. The VLBI observation measured its speed, and that the retarded solution is the correct one.

Theoretical investigations of quantum correlations in NMR multiple-pulse spin-locking experiments

NASA Astrophysics Data System (ADS)

Gerasev, S. A.; Fedorova, A. V.; Fel'dman, E. B.; Kuznetsova, E. I.

2018-04-01

Quantum correlations are investigated theoretically in a two-spin system with the dipole-dipole interactions in the NMR multiple-pulse spin-locking experiments. We consider two schemes of the multiple-pulse spin-locking. The first scheme consists of π /2-pulses only and the delays between the pulses can differ. The second scheme contains φ-pulses (0<φ <π ) and has equal delays between them. We calculate entanglement for both schemes for an initial separable state. We show that entanglement is absent for the first scheme at equal delays between π /2-pulses at arbitrary temperatures. Entanglement emerges after several periods of the pulse sequence in the second scheme at φ =π /4 at milliKelvin temperatures. The necessary number of the periods increases with increasing temperature. We demonstrate the dependence of entanglement on the number of the periods of the multiple-pulse sequence. Quantum discord is obtained for the first scheme of the multiple-pulse spin-locking experiment at different temperatures.

Cigarette smokers show steeper discounting of both food and cigarettes than money.

PubMed

Odum, Amy L; Baumann, Ana A L

2007-12-01

People with drug addiction show steeper discounting of drugs of abuse than money. One suggestion is that this effect is related to withdrawal processes in drug dependence. We investigated whether it could be related to the fact that drugs are directly consumable, whereas money is not. We determined whether regular cigarette smokers discount food (another consumable outcome) less steeply than cigarettes, both of which were predicted to be discounted more steeply than money. Cigarette smokers (N=20) indicated preferences for immediate and delayed outcomes in a titration procedure that determined indifference points at various delays. In three separate conditions, the choices involved food, cigarettes, or money. The value of the delayed option was always US$ 10 or US$ 10 worth of the outcome. Cigarette smokers discounted both cigarettes and food more steeply than money. Most importantly, cigarettes and food were discounted to a similar degree. Cigarettes may be steeply discounted in part due to their consumable nature, rather than solely due to withdrawal-related processes.

Don't wait to incubate: immediate versus delayed incubation in divergent thinking.

PubMed

Gilhooly, Kenneth J; Georgiou, George J; Garrison, Jane; Reston, Jon D; Sirota, Miroslav

2012-08-01

Previous evidence for the effectiveness of immediate incubation in divergent creative tasks has been weak, because earlier studies exhibited a range of methodological problems. This issue is theoretically important, as a demonstration of the effects of immediate incubation would strengthen the case for the involvement of unconscious work in incubation effects. For the present experiment, we used a creative divergent-thinking task (alternative uses) in which separate experimental groups had incubation periods that were either delayed or immediate and that consisted of either spatial or verbal tasks. Control groups were tested without incubation periods, and we carried out checks for intermittent conscious work on the target task during the incubation periods. The results showed significant incubation effects that were stronger for immediate than for delayed incubation. Performance was not different between the verbal and spatial incubation conditions, and we found no evidence for intermittent conscious working during the incubation periods. These results support a role for unconscious work in creative divergent thinking, particularly in the case of immediate incubation.

The VLBI time delay function for synchronous orbits

NASA Technical Reports Server (NTRS)

Rosenbaum, B.

1972-01-01

The VLBI is a satellite tracking technique that to date was applied largely to the tracking of synchronous orbits. These orbits are favorable for VLBI in that the remote satellite range allows continuous viewing from widely separated stations. The primary observable, geometric time delay is the time difference for signal propagation between satellite and baseline terminals. Extraordinary accuracy in angular position data on the satellite can be obtained by observation from baselines of continental dimensions. In satellite tracking though the common objective is to derive orbital elements. A question arises as to how the baseline vector bears on the accuracy of determining the elements. Our approach to this question is to derive an analytic expression for the time delay function in terms of Kepler elements and station coordinates. The analysis, which is for simplicity based on elliptic motion, shows that the resolution for the inclination of the orbital plane depends on the magnitude of the baseline polar component and the resolution for in-plane elements depends on the magnitude of a projected equatorial baseline component.

Psychological Delaying Model of Bicycle Passing Events on Physically Separated Bicycle Roadways in China*

NASA Astrophysics Data System (ADS)

Zhao, De; Wang, Wei; Li, Zhibin; Shan, Xiaonian; Sun, Xin

Bicycle facilities are quite common in China but there are not enough quantitative methods to evaluate the Level of Service (LOS) of bicycle roadways. The number of passing events, which considers the interactions between bicyclists, has been proved to be a proper indicator for evaluating bicycle LOS under the special traffic and roadway conditions in China. The primary objective of this study is to propose a model considering the delay effects of passing events and rider's overtaking motivation. Field data was collected on South Zhongshan Road and Huaihai Road in Nanjing city of China with 639 bicyclists investigated. Then a new mathematical model was built to evaluate those effects through probability and regression analyses. It was found that the delay effect of passing events and rider's overtaking motivation are significant influencing factors which cannot be omitted. Correlation test shows the fitted relationship is greater between the model prediction and field data comparing with the previous model.

Terminal Area Productivity Airport Wind Analysis and Chicago O'Hare Model Description

NASA Technical Reports Server (NTRS)

Hemm, Robert; Shapiro, Gerald

1998-01-01

This paper describes two results from a continuing effort to provide accurate cost-benefit analyses of the NASA Terminal Area Productivity (TAP) program technologies. Previous tasks have developed airport capacity and delay models and completed preliminary cost benefit estimates for TAP technologies at 10 U.S. airports. This task covers two improvements to the capacity and delay models. The first improvement is the completion of a detailed model set for the Chicago O'Hare (ORD) airport. Previous analyses used a more general model to estimate the benefits for ORD. This paper contains a description of the model details with results corresponding to current conditions. The second improvement is the development of specific wind speed and direction criteria for use in the delay models to predict when the Aircraft Vortex Spacing System (AVOSS) will allow use of reduced landing separations. This paper includes a description of the criteria and an estimate of AVOSS utility for 10 airports based on analysis of 35 years of weather data.

Efficient high-performance ultrasound beamforming using oversampling

NASA Astrophysics Data System (ADS)

Freeman, Steven R.; Quick, Marshall K.; Morin, Marc A.; Anderson, R. C.; Desilets, Charles S.; Linnenbrink, Thomas E.; O'Donnell, Matthew

1998-05-01

High-performance and efficient beamforming circuitry is very important in large channel count clinical ultrasound systems. Current state-of-the-art digital systems using multi-bit analog to digital converters (A/Ds) have matured to provide exquisite image quality with moderate levels of integration. A simplified oversampling beamforming architecture has been proposed that may a low integration of delta-sigma A/Ds onto the same chip as digital delay and processing circuitry to form a monolithic ultrasound beamformer. Such a beamformer may enable low-power handheld scanners for high-end systems with very large channel count arrays. This paper presents an oversampling beamformer architecture that generates high-quality images using very simple; digitization, delay, and summing circuits. Additional performance may be obtained with this oversampled system for narrow bandwidth excitations by mixing the RF signal down in frequency to a range where the electronic signal to nose ratio of the delta-sigma A/D is optimized. An oversampled transmit beamformer uses the same delay circuits as receive and eliminates the need for separate transmit function generators.

Solar corona electron density distribution

NASA Astrophysics Data System (ADS)

Esposito, P. B.; Edenhofer, P.; Lueneburg, E.

1980-07-01

The paper discusses the three and one-half months of single-frequency time delay data which were acquired from the Helios 2 spacecraft around the time of its solar occultation. The excess time delay due to integrated effect of free electrons along the signal's ray path could be separated and modeled following the determination of the spacecraft trajectory. An average solar corona and equatorial electron density profile during solar minimum were deduced from the time delay measurements acquired within 5-60 solar radii of the sun. As a point of reference at 10 solar radii from the sun, an average electron density was 4500 el/cu cm. However, an asymmetry was found in the electron density as the ray path moved from the west to east solar limb. This may be related to the fact that during entry into occultation the heliographic latitude of the ray path was about 6 deg, while during exit it was 7 deg. The Helios density model is compared with similar models deduced from different experimental techniques.

Blind source separation based on time-frequency morphological characteristics for rigid acoustic scattering by underwater objects

NASA Astrophysics Data System (ADS)

Yang, Yang; Li, Xiukun

2016-06-01

Separation of the components of rigid acoustic scattering by underwater objects is essential in obtaining the structural characteristics of such objects. To overcome the problem of rigid structures appearing to have the same spectral structure in the time domain, time-frequency Blind Source Separation (BSS) can be used in combination with image morphology to separate the rigid scattering components of different objects. Based on a highlight model, the separation of the rigid scattering structure of objects with time-frequency distribution is deduced. Using a morphological filter, different characteristics in a Wigner-Ville Distribution (WVD) observed for single auto term and cross terms can be simplified to remove any cross-term interference. By selecting time and frequency points of the auto terms signal, the accuracy of BSS can be improved. An experimental simulation has been used, with changes in the pulse width of the transmitted signal, the relative amplitude and the time delay parameter, in order to analyzing the feasibility of this new method. Simulation results show that the new method is not only able to separate rigid scattering components, but can also separate the components when elastic scattering and rigid scattering exist at the same time. Experimental results confirm that the new method can be used in separating the rigid scattering structure of underwater objects.

Zero-Extra-Dose PET Delayed Imaging with Data-Driven Attenuation Correction Estimation.

PubMed

Pang, Lifang; Zhu, Wentao; Dong, Yun; Lv, Yang; Shi, Hongcheng

2018-05-08

Delayed positron emission tomography (PET) imaging may improve sensitivity and specificity in lesion detection. We proposed a PET data-driven method to estimate the attenuation map (AM) for the delayed scan without an additional x-ray computed tomography (CT). An emission-attenuation-scatter joint estimation framework was developed. Several practical issues for clinical datasets were addressed. Particularly, the unknown scatter correction was incorporated in the joint estimation algorithm. The scaling problem was solved using prior information from the early CT scan. Fourteen patient datasets were added to evaluate the method. These patients went through two separate PET/CT scans. The delayed CT-based AM served as ground truth for the delayed scan. Standard uptake values (SUVmean and SUVmax) of lesion and normal tissue regions of interests (ROIs) in the early and delayed phase and the respective %DSUV (percentage change of SUVmean at two different time points) were analyzed, all with estimated and the true AM. Three radiologists participated in lesion detection tasks with images reconstructed with both AMs and rated scores for detectability. The mean relative difference of SUVmean in lesion and normal liver tissue were 3.30 and 6.69 %. The average lesion-to-background contrast (detectability) with delayed PET images using CT AM was 60 % higher than that of the earlier PET image, and was 64 % higher when using the data-based AM. %DSUV for lesions and liver backgrounds with CT-based AM were - 0.058 ± 0.25 and - 0.33 ± 0.08 while with data-based AM were - 0.00 ± 0.26 and - 0.28 ± 0.08. Only slight significance difference was found between using CT-based AM and using the data-based AM reconstruction delay phase on %DSUV of lesion. The scores associated with the two AMs matched well consistently. Our method may be used in delayed PET imaging, which allows no secondary CT radiation in delayed phase. The quantitative analysis for lesion detection purpose could be ensured.

Planned Variation in Preanalytical Conditions to Evaluate Biospecimen Stability in the National Children’s Study (NCS)

PubMed Central

Mechanic, Leah; Mendez, Armando; Merrill, Lori; Rogers, John; Layton, Marnie; Todd, Deborah; Varanasi, Arti; O’Brien, Barbara; Meyer, William A.; Zhang, Ming; Schleicher, Rosemary L.; Moye, Jack

2014-01-01

BACKGROUND Preanalytical conditions encountered during collection, processing, and storage of biospecimens may influence laboratory results. The National Children’s Study (NCS) is a planned prospective cohort study of 100,000 families to examine the influence of a wide variety of exposures on child health. In developing biospecimen collection, processing, and storage procedures for the NCS, we identified several analytes of different biochemical categories for which it was unclear to what extent deviations from NCS procedures could influence measurement results. METHODS A pilot study was performed to examine effects of preanalytic sample handling conditions (delays in centrifugation, freezing delays, delays in separation from cells, additive delay, and tube type) on concentrations of eight different analytes. 2,825 measurements were made to assess 15 unique combinations of analyte and handling conditions in blood collected from 151 women of childbearing age (≥20 individuals per handling condition). RESULTS The majority of analytes were stable under the conditions evaluated. However, levels of plasma interleukin-6 and serum insulin were decreased in response to sample centrifugation delays of up to 5.5 hours post collection (P<0.0001). In addition, delays in freezing centrifuged plasma samples (comparing 24, 48 and 72 hours to immediate freezing) resulted in increased levels of adrenocorticotropic hormone (P=0.0014). CONCLUSIONS Determining stability of proposed analytes in response to preanalytical conditions and handling helps to ensure high-quality specimens for study now and in the future. The results inform development of procedures, plans for measurement of analytes, and interpretation of laboratory results. PMID:23924524

Factors affecting breast cancer treatment delay in Turkey: a study from Turkish Federation of Breast Diseases Societies

PubMed Central

Boylu, Sukru; Ok, Engin; Canturk, Nuh Zafer; Celik, Varol; Kapkac, Murat; Girgin, Sadullah; Tireli, Mustafa; Ihtiyar, Enver; Demircan, Orhan; Baskan, Mazhar Semih; Koyuncu, Ayhan; Tasdelen, Ismet; Dumanli, Esra; Ozdener, Fatih; Zaborek, Piotr

2015-01-01

Background: One of the most important factors in breast cancer (BC) mortality is treatment delay. The primary goal of this survey was to identify factors affecting the total delay time (TDT) in Turkish BC patients. Methods: A total of 1031 patients with BC were surveyed using a uniform questionnaire. The time between discovering the first symptom and signing up for the first medical visit (patient delay time; PDT) and the time between the first medical visit and the start of therapy (system delay time; SDT) were modelled separately with multilevel regression. Results: The mean PDT, SDT and TDT were 4.8, 10.5 and 13.8 weeks, respectively. In all, 42% of the patients had a TDT >12 weeks. Longer PDT was significantly correlated with disregarding symptoms and having age of between 30 and 39 years. Shorter PDT was characteristic of patients who: had stronger self-examination habits, received more support from family and friends and had at least secondary education. Predictors of longer SDT included disregard of symptoms, distrust in success of therapy and medical system and having PDT in excess of 4 weeks. Shorter SDT was linked to the age of >60 years. Patients who were diagnosed during a periodic check-up or opportunistic mammography displayed shorter SDT compared with those who had symptomatic BC and their first medical examination was by a surgeon. Conclusion: TDT in Turkey is long and remains a major problem. Delays can be reduced by increasing BC awareness, implementing organized population-based screening programmes and founding cancer centres. PMID:25096257

Effect of leading-edge load constraints on the design and performance of supersonic wings

NASA Technical Reports Server (NTRS)

Darden, C. M.

1985-01-01

A theoretical and experimental investigation was conducted to assess the effect of leading-edge load constraints on supersonic wing design and performance. In the effort to delay flow separation and the formation of leading-edge vortices, two constrained, linear-theory optimization approaches were used to limit the loadings on the leading edge of a variable-sweep planform design. Experimental force and moment tests were made on two constrained camber wings, a flat uncambered wing, and an optimum design with no constraints. Results indicate that vortex strength and separation regions were mildest on the severely and moderately constrained wings.

Acute Middle East Respiratory Syndrome Coronavirus Infection in Livestock Dromedaries, Dubai, 2014

PubMed Central

Corman, Victor M.; Wong, Emily Y.M.; Tsang, Alan K.L.; Muth, Doreen; Lau, Susanna K. P.; Khazanehdari, Kamal; Zirkel, Florian; Ali, Mansoor; Nagy, Peter; Juhasz, Jutka; Wernery, Renate; Joseph, Sunitha; Syriac, Ginu; Elizabeth, Shyna K.; Patteril, Nissy Annie Georgy; Woo, Patrick C. Y.; Drosten, Christian

2015-01-01

Camels carry Middle East respiratory syndrome coronavirus, but little is known about infection age or prevalence. We studied >800 dromedaries of all ages and 15 mother–calf pairs. This syndrome constitutes an acute, epidemic, and time-limited infection in camels <4 years of age, particularly calves. Delayed social separation of calves might reduce human infection risk. PMID:25989145

Immediacy Bias in Emotion Perception: Current Emotions Seem More Intense than Previous Emotions

ERIC Educational Resources Information Center

Van Boven, Leaf; White, Katherine; Huber, Michaela

2009-01-01

People tend to perceive immediate emotions as more intense than previous emotions. This "immediacy bias" in emotion perception occurred for exposure to emotional but not neutral stimuli (Study 1), when emotional stimuli were separated by both shorter (2 s; Studies 1 and 2) and longer (20 min; Studies 3, 4, and 5) delays, and for emotional…

Ventral Lateral Geniculate Input to the Medial Pons Is Necessary for Visual Eyeblink Conditioning in Rats

ERIC Educational Resources Information Center

Halverson, Hunter E.; Freeman, John H.

2010-01-01

The conditioned stimulus (CS) pathway that is necessary for visual delay eyeblink conditioning was investigated in the current study. Rats were initially given eyeblink conditioning with stimulation of the ventral nucleus of the lateral geniculate (LGNv) as the CS followed by conditioning with light and tone CSs in separate training phases.…

Differential effects of cognitive load on emotion: Emotion maintenance versus passive experience.

PubMed

DeFraine, William C

2016-06-01

Two separate lines of research have examined the effects of cognitive load on emotional processing with similar tasks but seemingly contradictory results. Some research has shown that the emotions elicited by passive viewing of emotional images are reduced by subsequent cognitive load. Other research has shown that such emotions are not reduced by cognitive load if the emotions are actively maintained. The present study sought to compare and resolve these 2 lines of research. Participants either passively viewed negative emotional images or maintained the emotions elicited by the images, and after a delay rated the intensity of the emotion they were feeling. Half of trials included a math task during the delay to induce cognitive load, and the other half did not. Results showed that cognitive load reduced the intensity of negative emotions during passive-viewing of emotional images but not during emotion maintenance. The present study replicates the findings of both lines of research, and shows that the key factor is whether or not emotions are actively maintained. Also, in the context of previous emotion maintenance research, the present results support the theoretical idea of a separable emotion maintenance process. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Spectral Separation of the Turbofan Engine Coherent Combustion Noise Component

NASA Technical Reports Server (NTRS)

Miles, Jeffrey Hilton

2008-01-01

The core noise components of a dual spool turbofan engine (Honeywell TECH977) were separated by the use of a coherence function. A source location technique based on adjusting the time delay between the combustor pressure sensor signal and the far-field microphone signal to maximize the coherence and remove as much variation of the phase angle with frequency as possible was used. While adjusting the time delay to maximize the coherence and minimize the cross spectrum phase angle variation with frequency, the discovery was made that for the 130 microphone a 90.027 ms time shift worked best for the frequency band from 0 to 200 Hz while a 86.975 ms time shift worked best for the frequency band from 200 to 400 Hz. Since the 0 to 200 Hz band signal took more time to travel the same distance, it is slower than the 200 to 400 Hz band signal. This suggests the 0 to 200 Hz coherent cross spectral density band is partly due to indirect combustion noise attributed to hot spots interacting with the turbine. The signal in the 200 to 400 Hz frequency band is attributed mostly to direct combustion noise.

β -decay of very neutron-rich Pd and Ag nuclei

NASA Astrophysics Data System (ADS)

Smith, Karl; S323 / S410 Collaboration

2013-10-01

The astrophysical origin of about half of the elements heavier than iron have been attributed to the rapid neutron capture process. The modeling of such a process requires not only the correct astrophysical conditions but also reliable nuclear physics. The properties of neutron-rich nuclei in the region just below the N = 82 shell closure are of particular interest as they are responsible for the A = 130 peak in the solar abundance pattern. An experiment to investigate half-lives and β-delayed neutron emission branching ratios of very neutron-rich Pd and Ag isotopes was performed at the GSI projectile FRagment Separator (FRS). The FRS was used to separate products from in-flight fission of a 900 MeV/u 238U beam. Ions of interest were then implanted in the Silicon IMplantation detector and Beta Absorber (SIMBA) array. The high pixelation of the implantation detectors allowed for time-position correlation of the order of several seconds between implants and decays. Neutrons emitted during the decay were detected by the BEta deLayEd Neutron detector (BELEN) which surrounded the SIMBA array. Resulting analysis of half-lives and neutron emission branching ratios including a time-dependent background will be presented.

Improvement of a patient's circadian rhythm sleep disorders by aripiprazole was associated with stabilization of his bipolar illness.

PubMed

Tashiro, Tetsuo

2017-04-01

Splitting of the behavioural activity phase has been found in nocturnal rodents with suprachiasmatic nucleus (SCN) coupling disorder. A similar phenomenon was observed in the sleep phase in the diurnal human discussed here, suggesting that there are so-called evening and morning oscillators in the SCN of humans. The present case suffered from bipolar disorder refractory to various treatments, and various circadian rhythm sleep disorders, such as delayed sleep phase, polyphasic sleep, separation of the sleep bout resembling splitting and circabidian rhythm (48 h), were found during prolonged depressive episodes with hypersomnia. Separation of sleep into evening and morning components and delayed sleep-offset (24.69-h cycle) developed when lowering and stopping the dose of aripiprazole (APZ). However, resumption of APZ improved these symptoms in 2 weeks, accompanied by improvement in the patient's depressive state. Administration of APZ may improve various circadian rhythm sleep disorders, as well as improve and prevent manic-depressive episodes, via augmentation of coupling in the SCN network. © 2017 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

Observation of β-delayed two-proton emission in the decay of 22Si

DOE PAGES

Xu, X. X.; Lin, C. J.; Sun, L. J.; ...

2017-01-19

The decay of the lightest nucleus with Tz=-3, 22Si, was studied by a silicon array. A charged-particle group at 5600 (70) keV in the decay-energy spectrum was identified experimentally as β-delayed two-proton emission from the isobaric analog state (IAS) of 22Al. Experimental results of the IAS fed by a superallowed Fermi transition were compared with our large-scale shell-model calculations. The ground-state mass of 22Si was obtained indirectly in the experiment for the first time. Two-proton separation energy for 22Si is deduced to be -108 (125) keV, which indicates that it is a very marginal candidate for two-proton ground-state emission.

Observation of β-delayed two-proton emission in the decay of 22Si

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, X. X.; Lin, C. J.; Sun, L. J.

The decay of the lightest nucleus with Tz=-3, 22Si, was studied by a silicon array. A charged-particle group at 5600 (70) keV in the decay-energy spectrum was identified experimentally as β-delayed two-proton emission from the isobaric analog state (IAS) of 22Al. Experimental results of the IAS fed by a superallowed Fermi transition were compared with our large-scale shell-model calculations. The ground-state mass of 22Si was obtained indirectly in the experiment for the first time. Two-proton separation energy for 22Si is deduced to be -108 (125) keV, which indicates that it is a very marginal candidate for two-proton ground-state emission.

Self-Powered Neutron Detector Qualification for Absolute On-Line In-Pile Neutron Flux Measurements in BR2

NASA Astrophysics Data System (ADS)

Vermeeren, L.; Wéber, M.

2003-06-01

A set of ten Self-Powered Neutron Detectors with Co, Rh and Ag emitters has been irradiated in several channels of the BR2 research reactor at SCK•CEN aiming at a comparison of their performance as thermal neutron flux detectors under various conditions. To allow for a correct interpretation of their signals, all detector sensitivity contributions (prompt and delayed) were calculated using a dedicated Monte Carlo model. The various contributions were also measured separately; the agreement between calculated and experimental data, including data from activation dosimetry, was excellent. Detailed neutron flux profiles were obtained from the SPND data, after correction for the finite detector lengths and for the slow response of delayed SPNDs.

Asynchronous sampled-data approach for event-triggered systems

NASA Astrophysics Data System (ADS)

Mahmoud, Magdi S.; Memon, Azhar M.

2017-11-01

While aperiodically triggered network control systems save a considerable amount of communication bandwidth, they also pose challenges such as coupling between control and event-condition design, optimisation of the available resources such as control, communication and computation power, and time-delays due to computation and communication network. With this motivation, the paper presents separate designs of control and event-triggering mechanism, thus simplifying the overall analysis, asynchronous linear quadratic Gaussian controller which tackles delays and aperiodic nature of transmissions, and a novel event mechanism which compares the cost of the aperiodic system against a reference periodic implementation. The proposed scheme is simulated on a linearised wind turbine model for pitch angle control and the results show significant improvement against the periodic counterpart.

Spectrometer employing optical fiber time delays for frequency resolution

DOEpatents

Schuss, Jack J.; Johnson, Larry C.

1979-01-01

This invention provides different length glass fibers for providing a broad range of optical time delays for short incident chromatic light pulses for the selective spatial and frequency analysis of the light with a single light detector. To this end, the frequencies of the incident light are orientated and matched with the different length fibers by dispersing the separate frequencies in space according to the respective fiber locations and lengths at the input terminal of the glass fibers. This makes the different length fibers useful in the field of plasma physics. To this end the short light pulses can be scattered by a plasma and then passed through the fibers for analyzing and diagnosing the plasma while it varies rapidly with time.

Microfluidic chip for peptide analysis with an integrated HPLC column, sample enrichment column, and nanoelectrospray tip.

PubMed

Yin, Hongfeng; Killeen, Kevin; Brennen, Reid; Sobek, Dan; Werlich, Mark; van de Goor, Tom

2005-01-15

Current nano-LC/MS systems require the use of an enrichment column, a separation column, a nanospray tip, and the fittings needed to connect these parts together. In this paper, we present a microfabricated approach to nano-LC, which integrates these components on a single LC chip, eliminating the need for conventional LC connections. The chip was fabricated by laminating polyimide films with laser-ablated channels, ports, and frit structures. The enrichment and separation columns were packed using conventional reversed-phase chromatography particles. A face-seal rotary valve provided a means for switching between sample loading and separation configurations with minimum dead and delay volumes while allowing high-pressure operation. The LC chip and valve assembly were mounted within a custom electrospray source on an ion-trap mass spectrometer. The overall system performance was demonstrated through reversed-phase gradient separations of tryptic protein digests at flow rates between 100 and 400 nL/min. Microfluidic integration of the nano-LC components enabled separations with subfemtomole detection sensitivity, minimal carryover, and robust and stable electrospray throughout the LC solvent gradient.

Autonomic functioning in mothers with interpersonal violence-related posttraumatic stress disorder in response to separation-reunion.

PubMed

Schechter, Daniel S; Moser, Dominik A; McCaw, Jaime E; Myers, Michael M

2014-05-01

This study characterizes autonomic nervous system activity reactive to separation-reunion among mothers with Interpersonal Violence-Related Posttraumatic Stress Disorder (IPV-PTSD). Heart-rate (HR) and high frequency heart-rate-variability (HF-HRV) were measured in 17 IPV-PTSD-mothers, 22 sub-threshold-mothers, and 15 non-PTSD mother-controls while interacting with their toddlers (12-48 months). Analyses showed IPV-PTSD-mothers having generally lower HR than other groups. All groups showed negative correlations between changes in HR and HF-HRV from sitting- to standing-baseline. During initial separation, controls no longer showed a negative relationship between HR and HF-HRV. But by the second reunion, the negative relationship reappeared. IPV-PTSD- and sub-threshold-mothers retained negative HR/HF-HRV correlations during the initial separation, but stopped showing them by the second reunion. Results support that mother-controls showed a pattern of autonomic regulation suggestive of hypervigilance during initial separation that resolved by the time of re-exposure. PTSD-mothers showed delayed onset of this pattern only upon re-exposure, and were perhaps exhibiting defensive avoidance or numbing during the initial separation/reunion. © 2013 Wiley Periodicals, Inc.

Flowfield dynamics in blunt fin-induced shock wave/turbulent boundary layer interactions

NASA Technical Reports Server (NTRS)

Dolling, David S.; Brusniak, Leon

1994-01-01

Fluctuating wall pressure measurements have been made on centerline upstream of a blunt fin in a Mach 5 turbulent boundary layer. By examining the ensemble averaged wall pressure distributions for different separation shock foot positions, it has been shown that local fluctuating wall pressure measurements are due to a distinct pressure distribution, Rho(sub i), which undergoes a stretching and flattening effect as its upstream boundary translates aperiodically between the upstream influence and separation lines. The locations of the maxima and minima in the wall pressure standard deviation can be accurately predicted using this distribution, providing quantitative confirmation of the model. This model also explains the observed cross-correlations and ensemble average measurements within the interaction. Using the Rho(sub i) model, wall pressure signals from under the separated flow region were used to reproduce the position-time history of the separation shock foot. Further, the negative time delay peak in the cross-correlation between the predicted and actual shock foot histories suggests that the separated region fluctuations precede shock foot motion. The unsteady behavior of the primary horseshoe vortex and its relation to the unsteady separation shock are described.

Estimating Controller Intervention Probabilities for Optimized Profile Descent Arrivals

NASA Technical Reports Server (NTRS)

Meyn, Larry A.; Erzberger, Heinz; Huynh, Phu V.

2011-01-01

Simulations of arrival traffic at Dallas/Fort-Worth and Denver airports were conducted to evaluate incorporating scheduling and separation constraints into advisories that define continuous descent approaches. The goal was to reduce the number of controller interventions required to ensure flights maintain minimum separation distances of 5 nmi horizontally and 1000 ft vertically. It was shown that simply incorporating arrival meter fix crossing-time constraints into the advisory generation could eliminate over half of the all predicted separation violations and more than 80% of the predicted violations between two arrival flights. Predicted separation violations between arrivals and non-arrivals were 32% of all predicted separation violations at Denver and 41% at Dallas/Fort-Worth. A probabilistic analysis of meter fix crossing-time errors is included which shows that some controller interventions will still be required even when the predicted crossing-times of the advisories are set to add a 1 or 2 nmi buffer above the minimum in-trail separation of 5 nmi. The 2 nmi buffer was shown to increase average flight delays by up to 30 sec when compared to the 1 nmi buffer, but it only resulted in a maximum decrease in average arrival throughput of one flight per hour.

Liquid-chromatographic separation and on-line bioluminescence detection of creatine kinase isoenzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bostick, W.D.; Denton, M.S.; Dinsmore, S.R.

1980-01-01

Isoenzymes of creatine kinase were separated by anion-exchange chromatography, with use of an elution gradient containing lithium acetate (0.1 to 0.6 mol/L). A stream splitter was used to divert a 5% side stream of column effluent, which was subsequently mixed with the reagents necessary for bioluminescence assay of the separated isoenzymes. The use of the stream splitter greatly decreased the rate of consumption of reagent and, when combined with a peristaltic pumping system, permitted independent control of the side-stream flow rate. Thus both the residence interval in a delay coil in which the ATP reaction product is formed and themore » bioluminescence emission was monitored in a flow-through fluorometer without use of an external light source or filters. Separation and detection of the isoenzymes of creatine kinase were rapid, sensitive, and highly selective. The incremental decrease of bioluminescence response owing to inhibition by the ions in the eluent was less than 31% across the entire gradient.« less

Two-photon interference of temporally separated photons

PubMed Central

Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

2016-01-01

We present experimental demonstrations of two-photon interference involving temporally separated photons within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-photon states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input photons; this state is composed of two temporally separated photons, which are in two different or the same spatial modes. We then observe two-photon interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-photon states simultaneously in a single interferometric setup. The observed two-photon interference fringes provide simultaneous observation of the interferometric properties of the single-photon and two-photon wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-photon states comprised of two temporally separated photons within the interferometer arms. PMID:27708380

Fast gradient separation by very high pressure liquid chromatography: reproducibility of analytical data and influence of delay between successive runs.

PubMed

Stankovicha, Joseph J; Gritti, Fabrice; Beaver, Lois Ann; Stevensona, Paul G; Guiochon, Georges

2013-11-29

Five methods were used to implement fast gradient separations: constant flow rate, constant column-wall temperature, constant inlet pressure at moderate and high pressures (controlled by a pressure controller),and programmed flow constant pressure. For programmed flow constant pressure, the flow rates and gradient compositions are controlled using input into the method instead of the pressure controller. Minor fluctuations in the inlet pressure do not affect the mobile phase flow rate in programmed flow. There producibilities of the retention times, the response factors, and the eluted band width of six successive separations of the same sample (9 components) were measured with different equilibration times between 0 and 15 min. The influence of the length of the equilibration time on these reproducibilities is discussed. The results show that the average column temperature may increase from one separation to the next and that this contributes to fluctuation of the results.

A Mixed Integer Linear Program for Airport Departure Scheduling

NASA Technical Reports Server (NTRS)

Gupta, Gautam; Jung, Yoon Chul

2009-01-01

Aircraft departing from an airport are subject to numerous constraints while scheduling departure times. These constraints include wake-separation constraints for successive departures, miles-in-trail separation for aircraft bound for the same departure fixes, and time-window or prioritization constraints for individual flights. Besides these, emissions as well as increased fuel consumption due to inefficient scheduling need to be included. Addressing all the above constraints in a single framework while allowing for resequencing of the aircraft using runway queues is critical to the implementation of the Next Generation Air Transport System (NextGen) concepts. Prior work on airport departure scheduling has addressed some of the above. However, existing methods use pre-determined runway queues, and schedule aircraft from these departure queues. The source of such pre-determined queues is not explicit, and could potentially be a subjective controller input. Determining runway queues and scheduling within the same framework would potentially result in better scheduling. This paper presents a mixed integer linear program (MILP) for the departure-scheduling problem. The program takes as input the incoming sequence of aircraft for departure from a runway, along with their earliest departure times and an optional prioritization scheme based on time-window of departure for each aircraft. The program then assigns these aircraft to the available departure queues and schedules departure times, explicitly considering wake separation and departure fix restrictions to minimize total delay for all aircraft. The approach is generalized and can be used in a variety of situations, and allows for aircraft prioritization based on operational as well as environmental considerations. We present the MILP in the paper, along with benefits over the first-come-first-serve (FCFS) scheme for numerous randomized problems based on real-world settings. The MILP results in substantially reduced delays as compared to FCFS, and the magnitude of the savings depends on the queue and departure fix structure. The MILP assumes deterministic aircraft arrival times at the runway queues. However, due to taxi time uncertainty, aircraft might arrive either earlier or later than these deterministic times. Thus, to incorporate this uncertainty, we present a method for using the MILP with "overlap discounted rolling planning horizon". The approach is based on valuing near-term decision results more than future ones. We develop a model of taxitime uncertainty based on real-world data, and then compare the baseline FCFS delays with delays using the above MILP in a simple rolling-horizon method and in the overlap discounted scheme.

Azathioprine pharmacokinetics after intravenous, oral, delayed release oral and rectal foam administration.

PubMed Central

Van Os, E C; Zins, B J; Sandborn, W J; Mays, D C; Tremaine, W J; Mahoney, D W; Zinsmeister, A R; Lipsky, J J

1996-01-01

BACKGROUND: 6-Mercaptopurine and its prodrug azathioprine are effective medications for refractory inflammatory bowel disease. However, use of these drugs has been limited by concerns about their toxicity. Colonic delivery of azathioprine may reduce its systemic bioavailability and limit toxicity. AIM: To determine the bioavailability of 6-mercaptopurine after administration of azathioprine via three colonic delivery formulations. METHODS: Twenty four healthy human subjects each received 50 mg of azathioprine by one of four delivery formulations (each n = 6): oral; delayed release oral; hydrophobic rectal foam; and hydrophilic rectal foam. All subjects also received a 50 mg dose of intravenous azathioprine during a separate study period. Plasma concentrations of 6-mercaptopurine were determined by high pressure liquid chromatography. RESULTS: The bioavailabilities of 6-mercaptopurine after colonic azathioprine administration via delayed release oral, hydrophobic rectal foam, and hydrophilic rectal foam (7%, 5%, 1%; respectively) were significantly lower than the bioavailability of 6-mercaptopurine after oral azathioprine administration (47%) by Wilcoxon rank sum pairwise comparison. CONCLUSIONS: Azathioprine delivered to the colon by delayed release oral and rectal foam formulations considerably reduced systemic 6-mercaptopurine bioavailability. The therapeutic potential of these colonic delivery methods, which can potentially limit toxicity by local delivery of high doses of azathioprine, should be investigated in patients with inflammatory bowel disease. PMID:8881811

Delayed visual maturation in infants: a disorder of figure-ground separation?

PubMed

Harris, C M; Kriss, A; Shawkat, F; Taylor, D; Russell-Eggitt, I

1996-01-01

Delayed visual maturation (DVM) is characterised by visual unresponsiveness in early infancy, which subsequently improves spontaneously to normal levels. We studied the optokinetic response and recorded pattern reversal VEPs in six infants with DVM (aged 2-4 months) when they were at the stage of complete visual unresponsiveness. Although no saccades or visual tracking with the eyes or head could be elicited to visual objects, a normal full-field rapid buildup OKN response occurred when viewing biocularly or during monocular stimulation in the temporo-nasal direction of the viewing eye. Almost no monocular OKN could be elicited in the naso-temporal direction, which was significantly poorer than normal age-matched infants. No OKN quick phases were missed, and there were no other signs of "ocular motor apraxia." VEPs were normal in amplitude and latency for age. It appears, therefore, that infants with DVM are delayed in orienting to local regions of the visual field, but can respond to full-field motion. The presence of normal OKN quick-phases and slow-phases suggests normal brain stem function, and the presence of normal pattern VEPs suggests a normal retino-geniculo-striate pathway. These oculomotor and electrophysiological findings suggest delayed development of extra-striate cortical structures, possibly involving either an abnormality in figure-ground segregation or in attentional pathways.

Geometric mean IELT and premature ejaculation: appropriate statistics to avoid overestimation of treatment efficacy.

PubMed

Waldinger, Marcel D; Zwinderman, Aeilko H; Olivier, Berend; Schweitzer, Dave H

2008-02-01

The intravaginal ejaculation latency time (IELT) behaves in a skewed manner and needs the appropriate statistics for correct interpretation of treatment results. To explain the rightful use of geometrical mean IELT values and the fold increase of the geometric mean IELT because of the positively skewed IELT distribution. Linking theoretical arguments to the outcome of several selective serotonin reuptake inhibitor and modern antidepressant study results. Geometric mean IELT and fold increase of geometrical mean IELT. Log-transforming each separate IELT measurement of each individual man is the basis for the calculation of the geometric mean IELT. A drug-induced positively skewed IELT distribution necessitates the calculation of the geometric mean IELTs at baseline and during drug treatment. In a positively skewed IELT distribution, the use of the "arithmetic" mean IELT risks an overestimation of the drug-induced ejaculation delay as the mean IELT is always higher than the geometric mean IELT. Strong ejaculation-delaying drugs give rise to a strong positively skewed IELT distribution, whereas weak ejaculation-delaying drugs give rise to (much) less skewed IELT distributions. Ejaculation delay is expressed in fold increase of the geometric mean IELT. Drug-induced ejaculatory performance discloses a positively skewed IELT distribution, requiring the use of the geometric mean IELT and the fold increase of the geometric mean IELT.

Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth.

PubMed

Kanazawa, H; Kawai, M; Niwa, F; Hasegawa, T; Iwanaga, K; Ohata, K; Tamaki, A; Heike, T

2014-06-01

Physical growth in neurologically healthy preterm infants affects motor development. This study investigated the separate relationships between muscle and fat in infancy and later motor development and physical growth. Muscle thickness and subcutaneous fat thickness of the anterior thigh were measured using ultrasound images obtained from neurologically healthy preterm infants at birth, 3, 6, 12 and 18 months' corrected age. We also obtained the Pediatric Evaluation of Disability Inventory and Alberta Infant Motor Scale scores at 18 months' corrected age to assess motor ability and motor delay. Thirty preterm infants completed the study protocol. There was a significant positive correlation between motor ability and increments in subcutaneous fat thickness during the first 3 and 6 months' corrected age (r = 0.48 and 0.40, p < 0.05, respectively), but not between motor ability and muscle thickness growth in any of the periods. A secondary, logistic regression analysis showed that increments in subcutaneous fat thickness during the first 3 months were a protective factor for motor delay. Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Immediate newborn care practices delay thermoregulation and breastfeeding initiation

PubMed Central

Sobel, Howard L; Silvestre, Maria Asuncion A; Mantaring, Jacinto Blas V; Oliveros, Yolanda E; Nyunt-U, Soe

2011-01-01

Aim A deadly nosocomial outbreak in a Philippine hospital drew nationwide attention to neonatal sepsis. Together with specific infection control measures, interventions that protect newborns against infection-related mortality include drying, skin-to-skin contact, delayed cord clamping, breastfeeding initiation and delayed bathing. This evaluation characterized hospital care in the first hours of life with the intent to drive policy change, strategic planning and hospital reform. Methods Trained physicians observed 481 consecutive deliveries in 51 hospitals using a standardized tool to record practices and timing of immediate newborn care procedures. Results Drying, weighing, eye care and vitamin K injections were performed in more than 90% of newborns. Only 9.6% were allowed skin-to-skin contact. Interventions were inappropriately sequenced, e.g. immediate cord clamping (median 12 sec), delayed drying (96.5%) and early bathing (90.0%). While 68.2% were put to the breast, they were separated two minutes later. Unnecessary suctioning was performed in 94.9%. Doctors trained in neonatal resuscitation were 2.5 (1.1–5.7) times more likely to unnecessarily suction vigorous newborns. Two per cent died and 5.7% developed sepsis/pneumonia. Conclusions This minute-by-minute observational assessment revealed that performance and timing of immediate newborn care interventions are below WHO standards and deprive newborns of basic protections against infection and death. PMID:21375583

Analysis of delay reducing and fuel saving sequencing and spacing algorithms for arrival traffic

NASA Technical Reports Server (NTRS)

Neuman, Frank; Erzberger, Heinz

1991-01-01

The air traffic control subsystem that performs sequencing and spacing is discussed. The function of the sequencing and spacing algorithms is to automatically plan the most efficient landing order and to assign optimally spaced landing times to all arrivals. Several algorithms are described and their statistical performance is examined. Sequencing brings order to an arrival sequence for aircraft. First-come-first-served sequencing (FCFS) establishes a fair order, based on estimated times of arrival, and determines proper separations. Because of the randomness of the arriving traffic, gaps will remain in the sequence of aircraft. Delays are reduced by time-advancing the leading aircraft of each group while still preserving the FCFS order. Tightly spaced groups of aircraft remain with a mix of heavy and large aircraft. Spacing requirements differ for different types of aircraft trailing each other. Traffic is reordered slightly to take advantage of this spacing criterion, thus shortening the groups and reducing average delays. For heavy traffic, delays for different traffic samples vary widely, even when the same set of statistical parameters is used to produce each sample. This report supersedes NASA TM-102795 on the same subject. It includes a new method of time-advance as well as an efficient method of sequencing and spacing for two dependent runways.

Puberty is delayed in male mice with dextran sodium sulfate colitis out of proportion to changes in food intake, body weight, and serum levels of leptin.

PubMed

Deboer, Mark D; Li, Yongli

2011-01-01

In boys, inflammatory bowel disease often results in delayed puberty associated with decreased bone mineral density and decreased linear growth. Our goal was to investigate whether pubertal timing and levels of leptin differed between prepubertal male mice with colitis and food-restricted (FR) mice maintained at a similar weight. We induced colitis in 32-d-old male mice using dextran sodium sulfate (DSS), resulting in 10 d of worsening colitis. We followed up these mice for separation of the prepuce from the glans penis as a marker of pubertal progression. Compared with free-feeding control mice, DSS and FR mice had significantly lower weight on d 7-10 of treatment. DSS mice had later puberty than control and FR mice. DSS mice also had smaller testes, lower FSH levels, increased systemic cytokines, and increased colonic inflammation by histology. Leptin levels were similar between DSS and FR mice, whereas both had decreases in leptin compared with controls. We conclude that DSS colitis causes delayed puberty in sexually immature male mice beyond what is seen among FR mice of similar weight, food intake, and leptin levels. These experiments provide support for the hypothesis that pubertal delay in colitis is influenced by factors beyond poor weight gain alone.

Obesity and Prader-Willi Syndrome Affect Heart Rate Recovery from Dynamic Resistance Exercise in Youth.

PubMed

Castner, Diobel M; Clark, Susan J; Judelson, Daniel A; Rubin, Daniela A

2016-01-15

Following exercise, heart rate decline is initially driven by parasympathetic reactivation and later by sympathetic withdrawal. Obesity delays endurance exercise heart rate recovery (HRR) in both children and adults. Young people with Prader-Willi Syndrome (PWS), a congenital cause for obesity, have shown a slower 60-s endurance exercise HRR compared to lean and obese children, suggesting compromised regulation. This study further evaluated effects of obesity and PWS on resistance exercise HRR at 30 and 60 s in children. PWS (8-18 years) and lean and obese controls (8-11 years) completed a weighted step-up protocol (six sets x 10 reps per leg, separated by one-minute rest), standardized using participant stature and lean body mass. HRR was evaluated by calculated HRR value (HRRV = difference between HR at test termination and 30 (HRRV30) and 60 (HRRV60) s post-exercise). PWS and obese had a smaller HRRV30 than lean ( p < 0.01 for both). Additionally, PWS had a smaller HRRV60 than lean and obese ( p = 0.01 for both). Obesity appears to delay early parasympathetic reactivation, which occurs within 30 s following resistance exercise. However, the continued HRR delay at 60 s in PWS may be explained by either blunted parasympathetic nervous system reactivation, delayed sympathetic withdrawal and/or poor cardiovascular fitness.

Methylphenidate significantly improves declarative memory functioning of adults with ADHD.

PubMed

Verster, Joris C; Bekker, Evelijne M; Kooij, J J Sandra; Buitelaar, Jan K; Verbaten, Marinus N; Volkerts, Edmund R; Olivier, Berend

2010-10-01

Declarative memory deficits are common in untreated adults with attention-deficit hyperactivity disorder (ADHD), but limited evidence exists to support improvement after treatment with methylphenidate. The objective of this study was to examine the effects of methylphenidate on memory functioning of adults with ADHD. Eighteen adults with ADHD who were clinical responders to methylphenidate participated in this randomized crossover trial. After 3 days of no treatment, patients received in random order either their usual methylphenidate dose (mean: 14.7 mg; range: 10-30 mg) or placebo, separated by a 6-7-day washout period. Patients performed an immediate word recall test 1 h after treatment administration. Three hours after intake, patients performed the second part of the memory test (delayed word recall and a recognition test). Delayed recognition and immediate recall was similar on treatment and on placebo. Delayed word recall was significantly better in the methylphenidate than in the placebo condition (F (1, 17) = 7.0, p <  0.017). A significant correlation was found between prestudy CES-D depression scores and difference scores on delayed recall (r = 0.602, p <  0.008). Methylphenidate improves declarative memory functioning in patients with ADHD. New studies should further examine whether subclinical depressive symptoms mediate the effect of methylphenidate on declarative memory.

Singer's preferred acoustic condition in performance in an opera house and self-perception of the singer's voice

NASA Astrophysics Data System (ADS)

Noson, Dennis; Kato, Kosuke; Ando, Yoichi

2004-05-01

Solo singers have been shown to over estimate the relative sound pressure level of a delayed, external reproduction of their own voice, singing single syllables, which, in turn, appears to influence the preferred delay of simulated stage reflections [Noson, Ph.D. thesis, Kobe University, 2003]. Bone conduction is thought to be one factor separating singer versus instrumental performer judgments of stage acoustics. Using a parameter derived from the vocal signal autocorrelation function (ACF envelope), the changes in singer preference for delayed reflections is primarily explained by the ACF parameter, rather than internal bone conduction. An auditory model of a singer's preferred reflection delay is proposed, combining the effects of acoustical environment (reflection amplitude), bone conduction, and performer vocal overestimate, which may be applied to the acoustic design of reflecting elements in both upstage and forestage environments of opera stages. For example, soloists who characteristically underestimate external voice levels (or overestimate their own voice) should be provided shorter distances to reflective panels-irrespective of their singing style. Adjustable elements can be deployed to adapt opera houses intended for bel canto style performances to other styles. Additional examples will also be discussed. a)Now at Kumamoto Univ., Kumamoto, Japan. b)Now at: 1-10-27 Yamano Kami, Kumamoto, Japan.

UAS Air Traffic Controller Acceptability Study. 2; Evaluating Detect and Avoid Technology and Communication Delays in Simulation

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2015-01-01

This study evaluated the effects of communications delays and winds on air traffic controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between Unmanned Aircraft Systems (UAS) and manned aircraft in a simulation of the Dallas-Ft. Worth (DFW) airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from Detect and Avoid (DAA) self-separation algorithms (Stratway+) displayed on the Multi-Aircraft Control System. This guidance consisted of amber "bands" on the heading scale of the UAS navigation display indicating headings that would result in a loss of well clear between the UAS and nearby traffic. Winds tested were successfully handled by the DAA algorithms and did not affect the controller acceptability ratings of the HMDs. Voice communications delays for the UAS were also tested and included one-way delay times of 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS. Information from this study will also be of value to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 - Minimum Performance Standards for UAS.

Prospection and emotional memory: how expectation affects emotional memory formation following sleep and wake

PubMed Central

Cunningham, Tony J.; Chambers, Alexis M.; Payne, Jessica D.

2014-01-01

Successful prospective memory is necessarily driven by an expectation that encoded information will be relevant in the future, leading to its preferential placement in memory storage. Like expectation, emotional salience is another type of cue that benefits human memory formation. Although separate lines of research suggest that both emotional information and information explicitly expected to be important in the future benefit memory consolidation, it is unknown how expectation affects the processing of emotional information and whether sleep, which is known to maximize memory consolidation, plays a critical role. The purpose of this study was to investigate how expectation would impact the consolidation of emotionally salient content, and whether this impact would differ across delays of sleep and wake. Participants encoded scenes containing an emotionally charged negative or neutral foreground object placed on a plausible neutral background. After encoding, half of the participants were informed they would later be tested on the scenes (expected condition), while the other half received no information about the test (unexpected condition). At recognition, following a 12-h delay of sleep or wakefulness, the scene components (objects and backgrounds) were presented separately and one at a time, and participants were asked to determine if each component was old or new. Results revealed a greater disparity for memory of negative objects over their paired neutral backgrounds for both the sleep and wake groups when the memory test was expected compared to when it was unexpected, while neutral memory remained unchanged. Analyzing each group separately, the wake group showed a threefold increase in the magnitude of this object/background trade-off for emotional scenes when the memory test was expected compared to when it was unexpected, while those who slept performed similarly across conditions. These results suggest that emotional salience and expectation cues interact to benefit emotional memory consolidation during a delay of wakefulness. The sleeping brain, however, may automatically tag emotionally salient information as important, such that explicit instruction of an upcoming memory test does not further improve memory performance. PMID:25136328

Compound earthquakes on a bimaterial interface and implications for rupture mechanics

NASA Astrophysics Data System (ADS)

Wang, E.; Rubin, A. M.

2012-12-01

Earthquake ruptures on the San Andreas are affected by the material contrast across the fault. Previous observations of microearthquakes in the northern creeping section have found strong signals of asymmetry in both rupture directivity (preferential propagation to the SE; Wang & Rubin, 2011), and aftershock asymmetry (many more to the NW, on timescales from 10 to 1000 s; Rubin & Gillard, 2000; Rubin, 2002). To understand the aftershock asymmetry, Rubin & Ampuero [2007] simulated slip-weakening ruptures on a bimaterial interface and observed differences in the timescales for the two edges to experience their peak stress after being slowed by barriers. While the barrier on the "positive" side (SE in the case of the San Andreas fault) reached the peak stress almost instantaneously, the "negative" side (NW) has to wait for the arrival of the P-wave stopping phase from the opposite end. For a 100 m main event the delay between the two potential ruptures is 20 ms, which may be long enough for the secondary rupture to be observed as a distinct subevent. A second possible source of subevent asymmetry is that when slowed by barriers, a significant tensile stress pulse propagates in the positive but not the negative direction. The events in the region where previous asymmetries were found have high spatial density and similar focal mechanisms, which makes it possible to use an Empirical Green's Function's method to do a comprehensive search. About 200 candidate compound events were identified in an 8300-event catalog from 1984 to 2009. Most delays between the two subevents cluster around the shear-wave transit time over the subevent separation, although with considerable scatter. For subevents separated by 0.7 to 2 estimated mainshock radii (the same spatial separation found by Rubin [2002] to maximize the longer-term aftershock asymmetry), about twice as many second events occurred on the SE (positive) side of the first, and the origin time delays also tend to be shorter for SE aftershocks. One interpretation is that these subevents represent the events "missing" from the aftershock population because they became part of the mainshock.

Column-coupling strategies for multidimensional electrophoretic separation techniques.

PubMed

Kler, Pablo A; Sydes, Daniel; Huhn, Carolin

2015-01-01

Multidimensional electrophoretic separations represent one of the most common strategies for dealing with the analysis of complex samples. In recent years we have been witnessing the explosive growth of separation techniques for the analysis of complex samples in applications ranging from life sciences to industry. In this sense, electrophoretic separations offer several strategic advantages such as excellent separation efficiency, different methods with a broad range of separation mechanisms, and low liquid consumption generating less waste effluents and lower costs per analysis, among others. Despite their impressive separation efficiency, multidimensional electrophoretic separations present some drawbacks that have delayed their extensive use: the volumes of the columns, and consequently of the injected sample, are significantly smaller compared to other analytical techniques, thus the coupling interfaces between two separations components must be very efficient in terms of providing geometrical precision with low dead volume. Likewise, very sensitive detection systems are required. Additionally, in electrophoretic separation techniques, the surface properties of the columns play a fundamental role for electroosmosis as well as the unwanted adsorption of proteins or other complex biomolecules. In this sense the requirements for an efficient coupling for electrophoretic separation techniques involve several aspects related to microfluidics and physicochemical interactions of the electrolyte solutions and the solid capillary walls. It is interesting to see how these multidimensional electrophoretic separation techniques have been used jointly with different detection techniques, for intermediate detection as well as for final identification and quantification, particularly important in the case of mass spectrometry. In this work we present a critical review about the different strategies for coupling two or more electrophoretic separation techniques and the different intermediate and final detection methods implemented for such separations.

Impact of Glucose Measurement Processing Delays on Clinical Accuracy and Relevance

PubMed Central

Jangam, Sujit R.; Hayter, Gary; Dunn, Timothy C.

2013-01-01

Background In a hospital setting, glucose is often measured from venous blood in the clinical laboratory. However, laboratory glucose measurements are typically not available in real time. In practice, turn-around times for laboratory measurements can be minutes to hours. This analysis assesses the impact of turn-around time on the effective clinical accuracy of laboratory measurements. Methods Data obtained from an earlier study with 58 subjects with type 1 diabetes mellitus (T1DM) were used for this analysis. In the study, glucose measurements using a YSI glucose analyzer were obtained from venous blood samples every 15 min while the subjects were at the health care facility. To simulate delayed laboratory results, each YSI glucose value from a subject was paired with one from a later time point (from the same subject) separated by 15, 30, 45, and 60 min. To assess the clinical accuracy of a delayed YSI result relative to a real-time result, the percentage of YSI pairs that meet the International Organization for Standardization (ISO) 15197:2003(E) standard for glucose measurement accuracy (±15 mg/dl for blood glucose < 75 mg/dl, ±20% for blood glucose ≥ 75 mg/dl) was calculated. Results It was observed that delays of 15 min or more reduce clinical accuracy below the ISO 15197:2003(E) recommendation of 95%. The accuracy was less than 65% for delays of 60 min. Conclusion This analysis suggests that processing delays in glucose measurements reduce the clinical relevance of results in patients with T1DM and may similarly degrade the clinical value of measurements in other patient populations. PMID:23759399

Retrieval practice improves memory in survivors of severe traumatic brain injury.

PubMed

Sumowski, James F; Coyne, Julia; Cohen, Amanda; Deluca, John

2014-02-01

To investigate whether retrieval practice (RP) improves delayed recall after short and long delays in survivors of severe traumatic brain injury (TBI) relative to massed restudy (MR) and spaced restudy (SR). 3(learning condition: MR, SR, RP)×2(delayed recall: 30min, 1wk) within-subject experiment. Nonprofit medical rehabilitation research center. Memory-impaired (<5th percentile) survivors of severe TBI (N=10). During RP, patients are quizzed on to-be-learned information shortly after it is presented, such that patients practice retrieval. MR consists of repeated restudy (ie, cramming). SR consists of restudy trials separated in time (ie, distributed learning). Forty-eight verbal paired associates (VPAs) were equally divided across 3 learning conditions (16 per condition). Delayed recall for one half of the VPAs was assessed after 30 minutes (8 per condition) and for the other half after 1 week (8 per condition). There was a large effect of learning condition after the short delay (P<.001, η(2)=.72), with much better recall of VPAs studied through RP (46.3%) relative to MR (12.5%) and SR (15.0%). This large effect of learning condition remained after the long delay (P=.001, η(2)=.56), as patients recalled 11.3% of the VPAs studied through RP, but nothing through MR (0.0%) and only 1.3% through SR. That is, RP was essentially the only learning condition to result in successful recall after 1 week, with most patients recalling at least 1 VPA. The robust effect of RP among TBI survivors with severe memory impairment engenders confidence that this strategy would work outside the laboratory to improve memory in real-life settings. Future randomized controlled trials of RP training are needed. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Working memory encoding delays top-down attention to visual cortex.

PubMed

Scalf, Paige E; Dux, Paul E; Marois, René

2011-09-01

The encoding of information from one event into working memory can delay high-level, central decision-making processes for subsequent events [e.g., Jolicoeur, P., & Dell'Acqua, R. The demonstration of short-term consolidation. Cognitive Psychology, 36, 138-202, 1998, doi:10.1006/cogp.1998.0684]. Working memory, however, is also believed to interfere with the deployment of top-down attention [de Fockert, J. W., Rees, G., Frith, C. D., & Lavie, N. The role of working memory in visual selective attention. Science, 291, 1803-1806, 2001, doi:10.1126/science.1056496]. It is, therefore, possible that, in addition to delaying central processes, the engagement of working memory encoding (WME) also postpones perceptual processing as well. Here, we tested this hypothesis with time-resolved fMRI by assessing whether WME serially postpones the action of top-down attention on low-level sensory signals. In three experiments, participants viewed a skeletal rapid serial visual presentation sequence that contained two target items (T1 and T2) separated by either a short (550 msec) or long (1450 msec) SOA. During single-target runs, participants attended and responded only to T1, whereas in dual-target runs, participants attended and responded to both targets. To determine whether T1 processing delayed top-down attentional enhancement of T2, we examined T2 BOLD response in visual cortex by subtracting the single-task waveforms from the dual-task waveforms for each SOA. When the WME demands of T1 were high (Experiments 1 and 3), T2 BOLD response was delayed at the short SOA relative to the long SOA. This was not the case when T1 encoding demands were low (Experiment 2). We conclude that encoding of a stimulus into working memory delays the deployment of attention to subsequent target representations in visual cortex.

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745*

NASA Technical Reports Server (NTRS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Hakon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found T(sub AB) = 47.7 +/- 6.0 days and T(sub AC) = 722 +/- 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are T(sub AD) = 502+/- 68 days, T( sub AE) = 611 +/- 75 days, and T(sub AF) = 415 +/- 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.

LENS MODEL AND TIME DELAY PREDICTIONS FOR THE SEXTUPLY LENSED QUASAR SDSS J2222+2745

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharon, Keren; Johnson, Traci L.; Paterno-Mahler, Rachel

2017-01-20

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image ofmore » the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τ {sub AB} = 47.7 ± 6.0 days and τ {sub AC} = −722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τ {sub AD} = 502 ± 68 days, τ {sub AE} = 611 ± 75 days, and τ {sub AF} = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift , indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.« less

Single generation cycles and delayed feedback cycles are not separate phenomena.

PubMed

Pfaff, T; Brechtel, A; Drossel, B; Guill, C

2014-12-01

We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations. Copyright © 2014 Elsevier Inc. All rights reserved.

Nonnegative Matrix Factorization for identification of unknown number of sources emitting delayed signals

PubMed Central

Iliev, Filip L.; Stanev, Valentin G.; Vesselinov, Velimir V.

2018-01-01

Factor analysis is broadly used as a powerful unsupervised machine learning tool for reconstruction of hidden features in recorded mixtures of signals. In the case of a linear approximation, the mixtures can be decomposed by a variety of model-free Blind Source Separation (BSS) algorithms. Most of the available BSS algorithms consider an instantaneous mixing of signals, while the case when the mixtures are linear combinations of signals with delays is less explored. Especially difficult is the case when the number of sources of the signals with delays is unknown and has to be determined from the data as well. To address this problem, in this paper, we present a new method based on Nonnegative Matrix Factorization (NMF) that is capable of identifying: (a) the unknown number of the sources, (b) the delays and speed of propagation of the signals, and (c) the locations of the sources. Our method can be used to decompose records of mixtures of signals with delays emitted by an unknown number of sources in a nondispersive medium, based only on recorded data. This is the case, for example, when electromagnetic signals from multiple antennas are received asynchronously; or mixtures of acoustic or seismic signals recorded by sensors located at different positions; or when a shift in frequency is induced by the Doppler effect. By applying our method to synthetic datasets, we demonstrate its ability to identify the unknown number of sources as well as the waveforms, the delays, and the strengths of the signals. Using Bayesian analysis, we also evaluate estimation uncertainties and identify the region of likelihood where the positions of the sources can be found. PMID:29518126

Impact of glucose measurement processing delays on clinical accuracy and relevance.

PubMed

Jangam, Sujit R; Hayter, Gary; Dunn, Timothy C

2013-05-01

In a hospital setting, glucose is often measured from venous blood in the clinical laboratory. However, laboratory glucose measurements are typically not available in real time. In practice, turn-around times for laboratory measurements can be minutes to hours. This analysis assesses the impact of turn-around time on the effective clinical accuracy of laboratory measurements. Data obtained from an earlier study with 58 subjects with type 1 diabetes mellitus (T1DM) were used for this analysis. In the study, glucose measurements using a YSI glucose analyzer were obtained from venous blood samples every 15 min while the subjects were at the health care facility. To simulate delayed laboratory results, each YSI glucose value from a subject was paired with one from a later time point (from the same subject) separated by 15, 30, 45, and 60 min. To assess the clinical accuracy of a delayed YSI result relative to a real-time result, the percentage of YSI pairs that meet the International Organization for Standardization (ISO) 15197:2003(E) standard for glucose measurement accuracy (±15 mg/dl for blood glucose < 75 mg/dl, ±20% for blood glucose ≥ 75 mg/dl) was calculated. It was observed that delays of 15 min or more reduce clinical accuracy below the ISO 15197:2003(E) recommendation of 95%. The accuracy was less than 65% for delays of 60 min. This analysis suggests that processing delays in glucose measurements reduce the clinical relevance of results in patients with T1DM and may similarly degrade the clinical value of measurements in other patient populations. © 2013 Diabetes Technology Society.

Comparison of Low-Dose Higher-Relaxivity and Standard-Dose Lower-Relaxivity Contrast Media for Delayed-Enhancement MRI: A Blinded Randomized Crossover Study.

PubMed

Cheong, Benjamin Y C; Duran, Cihan; Preventza, Ourania A; Muthupillai, Raja

2015-09-01

The gadolinium-based MRI contrast agent gadobenate dimeglumine has nearly twice the MR relaxivity of gadopentetate dimeglumine at 1.5 T. The purpose of this study was to determine whether a lower dose (0.1 mmol/kg) of gadobenate dimeglumine can be used to obtain delayed-enhancement MR images comparable to those obtained with a standard dose (0.2 mmol/kg) of gadopentetate dimeglumine. In this blinded randomized crossover study, 20 patients with known myocardial infarction underwent two separate delayed-enhancement MRI examinations after receiving 0.1 mmol/kg gadobenate dimeglumine and 0.2 mmol/kg gadopentetate dimeglumine (random administration). The conspicuity of lesion enhancement 5, 10, and 20 minutes after contrast administration was quantified as relative enhancement ratio (RER). With either gadolinium-based contrast agent, damaged myocardium had higher signal intensity than normal remote myocardium (RER > 4) on delayed-enhancement MR images, and the blood RER declined over time after contrast administration. The blood RER was not significantly higher for gadobenate dimeglumine than for gadopentetate dimeglumine at 5 and 10 minutes. Nevertheless, there was a larger reduction in blood RER for gadobenate dimeglumine than for gadopentetate dimeglumine between 5 and 10 minutes and between 10 and 20 minutes. The volumes of enhancement were similar for gadobenate dimeglumine (13.6 ± 8.8 cm(3)) and gadopentetate dimeglumine (13.5 ± 8.9 cm(3)) (p = 0.98). The mean difference in Bland-Altman analysis for delayed-enhancement volume between the agents was 0.1 cm(3). Qualitatively and quantitatively, delayed-enhancement MR images of ischemic myocardium obtained with 0.1 mmol/kg gadobenate dimeglumine are comparable to those obtained with 0.2 mmol/kg gadopentetate dimeglumine 5, 10, and 20 minutes after contrast administration.

Nonnegative Matrix Factorization for identification of unknown number of sources emitting delayed signals.

PubMed

Iliev, Filip L; Stanev, Valentin G; Vesselinov, Velimir V; Alexandrov, Boian S

2018-01-01

Factor analysis is broadly used as a powerful unsupervised machine learning tool for reconstruction of hidden features in recorded mixtures of signals. In the case of a linear approximation, the mixtures can be decomposed by a variety of model-free Blind Source Separation (BSS) algorithms. Most of the available BSS algorithms consider an instantaneous mixing of signals, while the case when the mixtures are linear combinations of signals with delays is less explored. Especially difficult is the case when the number of sources of the signals with delays is unknown and has to be determined from the data as well. To address this problem, in this paper, we present a new method based on Nonnegative Matrix Factorization (NMF) that is capable of identifying: (a) the unknown number of the sources, (b) the delays and speed of propagation of the signals, and (c) the locations of the sources. Our method can be used to decompose records of mixtures of signals with delays emitted by an unknown number of sources in a nondispersive medium, based only on recorded data. This is the case, for example, when electromagnetic signals from multiple antennas are received asynchronously; or mixtures of acoustic or seismic signals recorded by sensors located at different positions; or when a shift in frequency is induced by the Doppler effect. By applying our method to synthetic datasets, we demonstrate its ability to identify the unknown number of sources as well as the waveforms, the delays, and the strengths of the signals. Using Bayesian analysis, we also evaluate estimation uncertainties and identify the region of likelihood where the positions of the sources can be found.

Factors affecting breast cancer treatment delay in Turkey: a study from Turkish Federation of Breast Diseases Societies.

PubMed

Ozmen, Vahit; Boylu, Sukru; Ok, Engin; Canturk, Nuh Zafer; Celik, Varol; Kapkac, Murat; Girgin, Sadullah; Tireli, Mustafa; Ihtiyar, Enver; Demircan, Orhan; Baskan, Mazhar Semih; Koyuncu, Ayhan; Tasdelen, Ismet; Dumanli, Esra; Ozdener, Fatih; Zaborek, Piotr

2015-02-01

One of the most important factors in breast cancer (BC) mortality is treatment delay. The primary goal of this survey was to identify factors affecting the total delay time (TDT) in Turkish BC patients. A total of 1031 patients with BC were surveyed using a uniform questionnaire. The time between discovering the first symptom and signing up for the first medical visit (patient delay time; PDT) and the time between the first medical visit and the start of therapy (system delay time; SDT) were modelled separately with multilevel regression. The mean PDT, SDT and TDT were 4.8, 10.5 and 13.8 weeks, respectively. In all, 42% of the patients had a TDT >12 weeks. Longer PDT was significantly correlated with disregarding symptoms and having age of between 30 and 39 years. Shorter PDT was characteristic of patients who: had stronger self-examination habits, received more support from family and friends and had at least secondary education. Predictors of longer SDT included disregard of symptoms, distrust in success of therapy and medical system and having PDT in excess of 4 weeks. Shorter SDT was linked to the age of >60 years. Patients who were diagnosed during a periodic check-up or opportunistic mammography displayed shorter SDT compared with those who had symptomatic BC and their first medical examination was by a surgeon. TDT in Turkey is long and remains a major problem. Delays can be reduced by increasing BC awareness, implementing organized population-based screening programmes and founding cancer centres. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association.

The TRIUMF nuclear structure program and TIGRESS

NASA Astrophysics Data System (ADS)

Garrett, P. E.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Chakrawarthy, R. S.; Churchman, R.; Cline, D.; Cooper, R. J.; Cross, D.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T.; Finlay, P.; Gagnon, K.; Gallant, A. T.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Hackman, G.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Kulp, W. D.; Leach, K. G.; Lee, G.; Leslie, J. R.; Maharaj, R.; Martin, J.-P.; Mattoon, C.; Mills, W. J.; Morton, A. C.; Nelson, L.; Newman, O.; Nolan, P. J.; Padilla-Rodal, E.; Pearson, C. J.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Ruiz, C.; Sarazin, F.; Schumaker, M. A.; Scraggs, D. P.; Strange, M. D.; Subramanian, M.; Svensson, C. E.; Waddington, J. C.; Wan, J.; Whitbeck, A.; Williams, S. J.; Wood, J. L.; Wong, J. C.; Wu, C. Y.; Zganjar, E. F.

2007-08-01

The isotope separator and accelerator (ISAC) facility located at the TRIUMF laboratory in Vancouver, Canada, is one of the world's most advanced isotope separator on-line-type radioactive ion beam facilities. An extensive γ-ray spectroscopy programme at ISAC is centred around two major research facilities: (i) the 8π γ-ray spectrometer for β-delayed γ-ray spectroscopy experiments with the low-energy beams from ISAC-I, and (ii) the next generation TRIUMF-ISAC gamma-ray escape suppressed spectrometer (TIGRESS) for in-beam experiments with the accelerated radioactive-ion beams. An overview of these facilities and recent results from the diverse programme of nuclear structure and fundamental interaction studies they support is presented.

A Translational Polarization Rotator

NASA Technical Reports Server (NTRS)

Chuss, David T.; Wollack, Edward J.; Pisano, Giampaolo; Ackiss, Sheridan; U-Yen, Kongpop; Ng, Ming wah

2012-01-01

We explore a free-space polarization modulator in which a variable phase introduction between right- and left-handed circular polarization components is used to rotate the linear polarization of the outgoing beam relative to that of the incoming beam. In this device, the polarization states are separated by a circular polarizer that consists of a quarter-wave plate in combination with a wire grid. A movable mirror is positioned behind and parallel to the circular polarizer. As the polarizer-mirror distance is separated, an incident liear polarization will be rotated through an angle that is proportional to the introduced phase delay. We demonstrate a prototype device that modulates Stokes Q and U over a 20% bandwidth.

Simulations of the Richtmyer-Meshkov Instability in a two-shock vertical shock tube

NASA Astrophysics Data System (ADS)

Ferguson, Kevin; Olson, Britton; Jacobs, Jeffrey

2017-11-01

Simulations of the Richtmyer-Meshkov Instability (RMI) in a new two-shock vertical shock tube configuration are presented. The simulations are performed using the ARES code at Lawrence-Livermore National Laboratory (LLNL). Two M=1.2 shock waves travel in opposing directions and impact an initially stationary interface formed by sulfur hexaflouride (SF6) and air. The delay between the two shocks is controlled to achieve a prescribed temporal separation in shock wave arrival time. Initial interface perturbations and diffusion profiles are generated in keeping with previously gathered experimental data. The effect of varying the inter-shock delay and initial perturbation structure on instability growth and mixing parameters is examined. Information on the design, construction, and testing of a new two-shock vertical shock tube are also presented.

Play and Joint Attention of Children with Autism in the Preschool Special Education Classroom

PubMed Central

Kasari, Connie

2014-01-01

The purpose of this study was to examine play and joint attention in children with autism (n=27) as compared to children with other developmental delays (n=28) in public preschool special education classrooms. The participants were observed in their classroom environment for 2 h over 3 separate days. Results show that children with autism spent more of their time unengaged and less time engaged in symbolic play and joint attention behaviors as compared to children with other developmental delays. Additionally, teachers seldom focused directly on symbolic play and joint attention in their teaching. These findings suggest the importance of educating teachers to target play and joint attention skills in their preschool special education classes, specifically for children with autism. PMID:22350340

Tissue characterization with ballistic photons: counting scattering and/or absorption centres

NASA Astrophysics Data System (ADS)

Corral, F.; Strojnik, M.; Paez, G.

2015-03-01

We describe a new method to separate ballistic from the scattered photons for optical tissue characterization. It is based on the hypothesis that the scattered photons acquire a phase delay. The photons passing through the sample without scattering or absorption preserve their coherence so they may participate in interference. We implement a Mach-Zehnder experimental setup where the ballistic photons pass through the sample with the delay caused uniquely by the sample indices of refraction. We incorporate a movable mirror on the piezoelectric actuator in the sample arm to detect the amplitude of the modulation term. We present the theory that predicts the path-integrated (or total) concentration of the scattering and absorption centres. The proposed technique may characterize samples with transmission attenuation of ballistic photons by a factor of 10-14.

Dissociating parafoveal preview benefit and parafovea-on-fovea effects during reading: A combined eye tracking and EEG study.

PubMed

Niefind, Florian; Dimigen, Olaf

2016-12-01

During reading, the parafoveal processing of an upcoming word n+1 can influence word recognition in two ways: It can affect fixation behavior during the preceding fixation on word n (parafovea-on-fovea effect, POF), and it can facilitate subsequent foveal processing once word n+1 is fixated (preview benefit). While preview benefits are established, evidence for POF effects is mixed. Recently, it has been suggested that POF effects exist, but have a delayed impact on saccade planning and thus coincide with preview benefits measured on word n+1. We combined eye movement and EEG recordings to investigate and separate neural correlates of POF and preview benefit effects. Participants read lists of nouns either in a boundary paradigm or the RSVP-with-flankers paradigm, while we recorded fixation- or event-related potentials (FRPs/ERPs), respectively. The validity and lexical frequency of the word shown as preview for the upcoming word n+1 were orthogonally manipulated. Analyses focused on the first fixation on word n+1. Preview validity (correct vs. incorrect preview) strongly modulated fixation times and electrophysiological N1 amplitudes, replicating previous findings. Importantly, gaze durations and FRPs measured on word n+1 were also affected by the frequency of the word shown as preview, with low-frequency previews eliciting a sustained, N400-like centroparietal negativity. Results support the idea that POF effects exist but affect word recognition with a delay. Lastly, once word n+1 was fixated, its frequency also modulated N1 amplitudes in ERPs and FRPs. Taken together, we separated immediate and delayed effects of parafoveal processing on brain correlates of word recognition. © 2016 Society for Psychophysiological Research.

Observational selection biases in time-delay strong lensing and their impact on cosmography

NASA Astrophysics Data System (ADS)

Collett, Thomas E.; Cunnington, Steven D.

2016-11-01

Inferring cosmological parameters from time-delay strong lenses requires a significant investment of telescope time; it is therefore tempting to focus on the systems with the brightest sources, the highest image multiplicities and the widest image separations. We investigate if this selection bias can influence the properties of the lenses studied and the cosmological parameters inferred. Using an ellipsoidal power-law deflector population, we build a sample of double- and quadruple-image systems. Assuming reasonable thresholds on image separation and flux, based on current lens monitoring campaigns, we find that the typical density profile slopes of monitorable lenses are significantly shallower than the input ensemble. From a sample of quads, we find that this selection function can introduce a 3.5 per cent bias on the inferred time-delay distances if the properties of the input ensemble are (incorrectly) used as priors on the lens model. This bias remains at the 2.4 per cent level when high-resolution imaging of the quasar host is used to precisely infer the properties of individual lenses. We also investigate if the lines of sight for monitorable strong lenses are biased. The expectation value for the line-of-sight convergence is increased by 0.009 (0.004) for quads (doubles) implying a 0.9 per cent (0.4 per cent) bias on H0. We therefore conclude that whilst the properties of typical quasar lenses and their lines of sight do deviate from the global population, the total magnitude of this effect is likely to be a subdominant effect for current analyses, but has the potential to be a major systematic for samples of ˜25 or more lenses.

Laboratory diagnosis of gestational diabetes: An in silico investigation into the effects of pre-analytical processing on the diagnostic sensitivity and specificity of the oral glucose tolerance test.

PubMed

Mansell, Erin; Lunt, Helen; Docherty, Paul

2017-06-01

Delayed separation of red cells from plasma causes pre analytical glucose loss, which in turn results in an under-diagnosis of GDM (gestational diabetes) based on the OGTT (oral glucose tolerance test). In silico investigations may help laboratory decision making, when exploring pragmatic improvements to sample processing. Late pregnancy 0, 1 and 2h 75g OGTT values were obtained from two distinct populations of pregnant women: 1. Values derived from the HAPO (Hyperglycemia and Adverse Pregnancy Outcome) Study and 2. New Zealand women identified as at higher risk of GDM by their caregivers, undergoing OGTT during routine antenatal care. In both populations studied, in silico modelling focussed on the effects of pre-analytical delays in plasma separation, when using fluoride collection tubes. Using a model that 'batched' samples from the three OGTT collection times, diagnostic sensitivity was estimated as follows: 66.1% for HAPO research population and 48.4% for the 1305 women receiving routine antenatal care. If samples were not batched, but processed shortly after each blood sample was collected, then sensitivity increased to 81%. Exploration of a range of clinical and laboratory scenarios using in silico modelling, showed that delaying the processing of pregnancy OGTT samples, using batched sample collection into fluoride tubes, causes unacceptable loss of GDM diagnostic sensitivity across two distinct population groups. This modelling approach will hopefully provide information that helps with final decision making around improved laboratory processing techniques. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Power reduction and the radial limit of stall delay in revolving wings of different aspect ratio

PubMed Central

Kruyt, Jan W.; van Heijst, GertJan F.; Altshuler, Douglas L.; Lentink, David

2015-01-01

Airplanes and helicopters use high aspect ratio wings to reduce the power required to fly, but must operate at low angle of attack to prevent flow separation and stall. Animals capable of slow sustained flight, such as hummingbirds, have low aspect ratio wings and flap their wings at high angle of attack without stalling. Instead, they generate an attached vortex along the leading edge of the wing that elevates lift. Previous studies have demonstrated that this vortex and high lift can be reproduced by revolving the animal wing at the same angle of attack. How do flapping and revolving animal wings delay stall and reduce power? It has been hypothesized that stall delay derives from having a short radial distance between the shoulder joint and wing tip, measured in chord lengths. This non-dimensional measure of wing length represents the relative magnitude of inertial forces versus rotational accelerations operating in the boundary layer of revolving and flapping wings. Here we show for a suite of aspect ratios, which represent both animal and aircraft wings, that the attachment of the leading edge vortex on a revolving wing is determined by wing aspect ratio, defined with respect to the centre of revolution. At high angle of attack, the vortex remains attached when the local radius is shorter than four chord lengths and separates outboard on higher aspect ratio wings. This radial stall limit explains why revolving high aspect ratio wings (of helicopters) require less power compared with low aspect ratio wings (of hummingbirds) at low angle of attack and vice versa at high angle of attack. PMID:25788539

Fine mapping analysis confirms and strengthens linkage of four chromosomal regions in familial hypospadias

PubMed Central

Söderhäll, Cilla; Körberg, Izabella Baranowska; Thai, Hanh T T; Cao, Jia; Chen, Yougen; Zhang, Xufeng; Shulu, Zu; van der Zanden, Loes F M; van Rooij, Iris A L M; Frisén, Louise; Roeleveld, Nel; Markljung, Ellen; Kockum, Ingrid; Nordenskjöld, Agneta

2015-01-01

Hypospadias is a common male genital malformation and is regarded as a complex disease affected by multiple genetic as well as environmental factors. In a previous genome-wide scan for familial hypospadias, we reported suggestive linkage in nine chromosomal regions. We have extended this analysis by including new families and additional markers using non-parametric linkage. The fine mapping analysis displayed an increased LOD score on chromosome 8q24.1 and 10p15 in altogether 82 families. On chromosome 10p15, with the highest LOD score, we further studied AKR1C2, AKR1C3 and AKR1C4 involved in steroid metabolism, as well as KLF6 expressed in preputial tissue from hypospadias patients. Mutation analysis of the AKR1C3 gene showed a new mutation, c.643G>A (p.(Ala215Thr)), in a boy with penile hypospadias. This mutation is predicted to have an impact on protein function and structure and was not found in controls. Altogether, we homed in on four chromosomal regions likely to harbor genes for hypospadias. Future studies will aim for studying regulatory sequence variants in these regions. PMID:24986825

Characterization of a novel papillomavirus species (ZcPV1) from two California sea lions (Zalophus californianus).

PubMed

Rivera, Rebecca; Robles-Sikisaka, Refugio; Hoffman, Elizabeth M; Stacy, Brian A; Jensen, Eric D; Nollens, Hendrik H; Wellehan, James F X

2012-03-23

A seven-year old California sea lion (Zalophus californianus) presented with focally extensive, bilaterally symmetric, proliferative axillary skin lesions and preputial lesions. A second California sea lion in the same population presented with similar proliferative lesions on the underside of the tail. Histopathology revealed epidermal hyperplasia with severe hyperkeratosis, with proliferating keratinocytes forming broad, branching pegs that extended into the dermis. Pan-papillomaviral consensus PCR was used to obtain initial E1 sequence template and the complete genome was determined using a combination of rolling circle amplification and specific-primer PCR. Analysis revealed a novel papillomavirus, Zalophus californianus papillomavirus 1 (ZcPV1), with seven open reading frames encoding five early proteins (E6, E7, E1, E2 and E4) and two late proteins (L1 and L2). Phylogenetic analysis revealed that (ZcPV1) is most closely related to Equine papillomavirus 1 (EcPV1) in the genus Zetapapillomavirus, and Canine papillomaviruses 3 and 4 (CPV3, CPV4) in the genus Chipapillomavirus. The lesions regressed without intervention over a period of several months. Copyright © 2011 Elsevier B.V. All rights reserved.

Novel genotype of Tritrichomonas foetus from cattle in Southern Africa.

PubMed

Casteriano, Andrea; Molini, Umberto; Kandjumbwa, Kornelia; Khaiseb, Siegfried; Frey, Caroline F; Šlapeta, Jan

2016-12-01

Bovine trichomonosis caused by Tritrichomonas foetus is a significant reproductive disease of cattle. Preputial samples were collected using sheath washing technique in bulls in Namibia. Thirty-six trichomonad cultures were characterized using the TaqMan-probe commercial real-time polymerase chain reaction (PCR) diagnostic assay (VetMAX™-Gold Trich Detection Kit) and CYBR real-time PCR assay based on TFR3/4 primers. Diagnostic real-time PCRs and DNA sequencing of the internal transcribed region confirmed presence of T. foetus in 35 out of 36 samples. Multilocus genotyping using cysteine proteases (CP1, CP2, CP4, CP5, CP6, CP7, CP8, CP9) and malate dehydrogenase (MDH1) gene sequences demonstrate that the T. foetus in Namibia are genetically distinct from those characterized elsewhere. We report the discovery of a novel genotype of T. foetus in Namibian cattle, distinct from other T. foetus genotypes in Europe, South and North America and Australia. We suggest recognition of a 'Southern African' genotype of T. foetus. Identification of the new genotype of T. foetus demonstrates the need for wider global sampling to fully understand the diversity and origin of T. foetus causing disease in cattle or cats.

Identification of a parametric, discrete-time model of ankle stiffness.

PubMed

Guarin, Diego L; Jalaleddini, Kian; Kearney, Robert E

2013-01-01

Dynamic ankle joint stiffness defines the relationship between the position of the ankle and the torque acting about it and can be separated into intrinsic and reflex components. Under stationary conditions, intrinsic stiffness can described by a linear second order system while reflex stiffness is described by Hammerstein system whose input is delayed velocity. Given that reflex and intrinsic torque cannot be measured separately, there has been much interest in the development of system identification techniques to separate them analytically. To date, most methods have been nonparametric and as a result there is no direct link between the estimated parameters and those of the stiffness model. This paper presents a novel algorithm for identification of a discrete-time model of ankle stiffness. Through simulations we show that the algorithm gives unbiased results even in the presence of large, non-white noise. Application of the method to experimental data demonstrates that it produces results consistent with previous findings.

Method of steering the gain of a multiple antenna global positioning system receiver

NASA Astrophysics Data System (ADS)

Evans, Alan G.; Hermann, Bruce R.

1992-06-01

A method for steering the gain of a multiple antenna Global Positioning System (GPS) receiver toward a plurality of a GPS satellites simultaneously is provided. The GPS signals of a known wavelength are processed digitally for a particular instant in time. A range difference or propagation delay between each antenna for GPS signals received from each satellite is first resolved. The range difference consists of a fractional wavelength difference and an integer wavelength difference. The fractional wavelength difference is determined by each antenna's tracking loop. The integer wavelength difference is based upon the known wavelength and separation between each antenna with respect to each satellite position. The range difference is then used to digitally delay the GPS signals at each antenna with respect to a reference antenna. The signal at the reference antenna is then summed with the digitally delayed signals to generate a composite antenna gain. The method searches for the correct number of integer wavelengths to maximize the composite gain. The range differences are also used to determine the attitude of the array.

Trapped ventricle after laser ablation of a subependymal giant cell astrocytoma complicated by intraventricular gadolinium extravasation: case report.

PubMed

Karsy, Michael; Patel, Daxa M; Bollo, Robert J

2018-05-01

Magnetic resonance imaging-guided stereotactic laser ablation of intracranial targets, including brain tumors, has expanded dramatically over the past decade, but there have been few reports of complications, especially those occurring in a delayed fashion. Laser ablation of subependymal giant cell astrocytomas (SEGAs) is an attractive alternative to maintenance immunotherapy in some children with tuberous sclerosis complex (TSC); however, the effect of treatment on disease progression and the nature and frequency of potential complications remains largely unknown. The authors report the case of a 5-year-old boy with TSC who underwent stereotactic laser ablation of a SEGA at the right foramen of Monro on 2 separate occasions. After the second ablation, immediate posttreatment MRI revealed gadolinium extravasation from the tumor into the lateral ventricle. Nine months later, the patient presented with papilledema and delayed obstructive hydrocephalus secondary to intraventricular adhesions causing a trapped right lateral ventricle. This was successfully treated with endoscopic septostomy. The authors discuss the potential cause and clinical management of a delayed complication not previously reported after a relatively novel surgical therapy.

Antibody-immobilized column for quick cell separation based on cell rolling.

PubMed

Mahara, Atsushi; Yamaoka, Tetsuji

2010-01-01

Cell separation using methodological standards that ensure high purity is a very important step in cell transplantation for regenerative medicine and for stem cell research. A separation protocol using magnetic beads has been widely used for cell separation to isolate negative and positive cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a cell depends on its developmental stage and differentiation ability. Rapid and label-free separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized cell-rolling column, that can separate cells depending on the CD34 density of the cell surfaces. Various conditions for the cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative cell lines, the cell separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative cells on antibody-immobilized microfluidic device. Cell separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated cells in each fraction were analyzed using a cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that cells with a given surface marker density can be continuously separated using the cell rolling column.

Delayed Gastric Emptying is Associated with Early and Long-Term Hyperglycemia in Type 1 Diabetes Mellitus

PubMed Central

Bharucha, Adil E.; Batey-Schaefer, Barbara; Cleary, Patricia A.; Murray, Joseph A.; Cowie, Catherine; Lorenzi, Gayle; Driscoll, Marsha; Harth, Judy; Larkin, Mary; Christofi, Marielle; Bayless, Margaret; Wimmergren, Nyra; Herman, William; Whitehouse, Fred; Jones, Kim; Kruger, Davida; Martin, Cathy; Ziegler, Georgia; Zinsmeister, Alan R.; Nathan, David M.

2015-01-01

Background and Aims After the Diabetes Control and Complications Trial (DCCT), the Epidemiology of Diabetes Interventions and Complications (EDIC) study continued to demonstrate persistent benefit of prior intensive therapy on neuropathy, retinopathy, and nephropathy in type 1 diabetes mellitus (DM)., The relationship between control of glycemia and gastric emptying (GE) is unclear. Methods We assessed GE with a 13C-spirulina breath test and symptoms in 78 participants with type 1 diabetes at year 20 of EDIC. The relationship between delayed GE and HbA1c, complications of DM, and gastrointestinal symptoms were evaluated. Results GE was normal (37 participants, 50%), delayed (35 participants, 47%), or rapid (2 participants, 3%). The latest mean HbA1c was 7.7%. In univariate analyses, delayed GE was associated with greater DCCT baseline HbA1c and duration of DM prior to DCCT (P ≤ 0.04), greater mean HbA1c over an average of 27 years of follow up (during DCCT-EDIC, P = 0.01), lower R-R variability during deep breathing (P=0.03) and severe nephropathy (P=0.05) and a greater composite upper gastrointestinal symptom score (P<0.05). In multivariate models, retinopathy was the only complication of DM associated with delayed GE. Separately, DCCT baseline HbA1c (OR 1.6, 95% CI 1.1–2.3) and duration of DM (OR 1.2, 95%CI 1.01–1.3) prior to DCCT entry and mean HbA1c during DCCT-EDIC (OR 2.2, 95%CI 1.04–4.5) were independently associated with delayed GE. Conclusions In the DCCT/EDIC study, delayed GE was remarkably common and associated with gastrointestinal symptoms and with measures of early and long-term hyperglycemia. ClinicalTrials.gov numbers NCT00360815 and NCT00360893. PMID:25980755

Enhancement of the NMSU Channel Error Simulator to Provide User-Selectable Link Delays

NASA Technical Reports Server (NTRS)

Horan, Stephen; Wang, Ru-Hai

2000-01-01

This is the third in a continuing series of reports describing the development of the Space-to-Ground Link Simulator (SGLS) to be used for testing data transfers under simulated space channel conditions. The SGLS is based upon Virtual Instrument (VI) software techniques for managing the error generation, link data rate configuration, and, now, selection of the link delay value. In this report we detail the changes that needed to be made to the SGLS VI configuration to permit link delays to be added to the basic error generation and link data rate control capabilities. This was accomplished by modifying the rate-splitting VIs to include a buffer the hold the incoming data for the duration selected by the user to emulate the channel link delay. In sample tests of this configuration, the TCP/IP(sub ftp) service and the SCPS(sub fp) service were used to transmit 10-KB data files using both symmetric (both forward and return links set to 115200 bps) and unsymmetric (forward link set at 2400 bps and a return link set at 115200 bps) link configurations. Transmission times were recorded at bit error rates of 0 through 10(exp -5) to give an indication of the link performance. In these tests. we noted separate timings for the protocol setup time to initiate the file transfer and the variation in the actual file transfer time caused by channel errors. Both protocols showed similar performance to that seen earlier for the symmetric and unsymmetric channels. This time, the delays in establishing the file protocol also showed that these delays could double the transmission time and need to be accounted for in mission planning. Both protocols also showed a difficulty in transmitting large data files over large link delays. In these tests, there was no clear favorite between the TCP/IP(sub ftp) and the SCPS(sub fp). Based upon these tests, further testing is recommended to extend the results to different file transfer configurations.

Identifying Anomalies in Gravitational Lens Time Delays

NASA Astrophysics Data System (ADS)

Congdon, Arthur B.; Keeton, C. R.; Nordgren, C. E.

2009-05-01

Gravitational lensing has become a powerful probe of cold dark matter substructure. Earlier work using anomalous flux ratios in four-image quasar lenses has shown that lensing is sensitive to substructure which raises the exciting prospect of constraining the mass function and spatial distribution of dark matter satellites in galaxies. We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxies with tidal shear. We can then identify outliers as "time-delay anomalies." We find evidence for anomalies in close image pairs in the cusp lenses RX J1131-1231 and B1422+231. The anomalies in RX J1131-1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time-delay anomalies in larger-separation image pairs in four additional lenses. We suggest that these anomalies are caused by some combination of substructure and a complex lens environment. Our work argues for a large sample of strong lenses with precisely-measured time delays. The first of these objectives will be readily achievable as the next generation of optical and radio telescopes come online, while the second will require a dedicated one-meter class space-based observatory. Meeting these goals will make it possible to examine the properties of dark matter on sub-galactic scales, which is essential for distinguishing among the various dark matter candidates from particle physics. Part of this work was funded by NSF grant AST-0747311. ABC is currently supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, administered by Oak Ridge Associated Universities through a contract with NASA.

Delaying first birth: an analysis of household survey data from rural Southern Tanzania.

PubMed

Sedekia, Yovitha; Nathan, Rose; Church, Kathryn; Temu, Silas; Hanson, Claudia; Schellenberg, Joanna; Marchant, Tanya

2017-01-31

Currently, family planning metrics derived from nationally-representative household surveys such as the Demographic and Health Surveys (DHS) categorise women into those desiring to space or limit (permanently stop) births, or according to their age in the case of young women. This conceptualisation potentially ignores a large and growing group of young women who desire to delay a first birth. This study uses household survey data to investigate the characteristics and needs for family planning of women who want to delay their first birth. The research was conducted in two rural districts in southern Tanzania (Tandahimba and Newala), and nested within the Expanded Quality Management Using Information Power (EQUIP) study. Data were collected as part of a repeated cross sectional household survey conducted between September 2013 and April 2014. The socio-demographic characteristics, including parity, contraceptive practices and fertility intentions of 2128 women aged 13-49 were analysed. The association between women's life stages of reproduction (delayers of first birth, spacers of subsequent pregnancies and limiters of future birth) and selected contraceptive outcomes (current use, unmet need and demand for modern contraceptives) was assessed using the point estimates and 95% confidence intervals for each indicator, adjusted for the survey design. Overall, four percent of women surveyed were categorised as 'delayers of first birth', i.e. sexually active but not started childbearing. Among this group, the majority were younger than 20 years old (82%) and unmarried (88%). Fifty-nine percent were currently using a modern method of contraception and injectables dominated their contraceptive use. Unmet need for contraception was higher among delayers (41%; 95% CI 32-51) and limiters (41%; 95% CI 35-47) compared to spacers (19%; 95% CI 17-22). Delayers of first birth have very high unmet needs for modern contraceptives and they should be routinely and separately categorised and measured within nationally-representative surveys such as Demographic and Health Survey and Multiple Indicator Cluster surveys. Acknowledging their unique needs could help catalyse a programmatic response.

Robotic Anesthesia – A Vision for the Future of Anesthesia

PubMed Central

Hemmerling, Thomas M; Taddei, Riccardo; Wehbe, Mohamad; Morse, Joshua; Cyr, Shantale; Zaouter, Cedrick

2011-01-01

Summary This narrative review describes a rationale for robotic anesthesia. It offers a first classification of robotic anesthesia by separating it into pharmacological robots and robots for aiding or replacing manual gestures. Developments in closed loop anesthesia are outlined. First attempts to perform manual tasks using robots are described. A critical analysis of the delayed development and introduction of robots in anesthesia is delivered. PMID:23905028

Temperature and strain rate dependent behavior of polymer separator for Li-ion batteries

DOE PAGES

Kalnaus, Sergiy; Wang, Yanli; Li, Jianlin; ...

2018-03-07

Safe performance of advanced Li-ion batteries relies on integrity of the separator membrane which prevents contact between electrodes of opposite polarity. Current work provides detailed study of mechanical behavior of such membrane. Temperature and strain rate sensitivity of the triple-layer polypropylene (PP)/polyethylene (PE)/polypropylene (PP) porous separator for Li-ion batteries was studied experimentally under controlled temperatures of up to 120° (393 K), and strain rates (from 1∙10-4s-1 to 0.1s-1). Digital image correlation was used to study strain localization in separator under load. The results show significant dependence of mechanical properties on temperature, with the yield stress decreasing by 30% and elasticmore » modulus decreasing by a factor of two when the temperature is increased from 20 °C to 50 °C. The strain rate strengthening also decreased with higher temperatures while the temperature softening remained independent of the applied strain rate. Application of temperature creates long lasting changes in mechanical behavior of separator as was revealed by performing experiments after the annealing. Such delayed effect of temperature application appears to have directional dependence. The results demonstrate complex behavior of polymer separator which needs to be considered in proper safety assessments of Li-ion batteries.« less

Temperature and strain rate dependent behavior of polymer separator for Li-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalnaus, Sergiy; Wang, Yanli; Li, Jianlin

Safe performance of advanced Li-ion batteries relies on integrity of the separator membrane which prevents contact between electrodes of opposite polarity. Current work provides detailed study of mechanical behavior of such membrane. Temperature and strain rate sensitivity of the triple-layer polypropylene (PP)/polyethylene (PE)/polypropylene (PP) porous separator for Li-ion batteries was studied experimentally under controlled temperatures of up to 120° (393 K), and strain rates (from 1∙10-4s-1 to 0.1s-1). Digital image correlation was used to study strain localization in separator under load. The results show significant dependence of mechanical properties on temperature, with the yield stress decreasing by 30% and elasticmore » modulus decreasing by a factor of two when the temperature is increased from 20 °C to 50 °C. The strain rate strengthening also decreased with higher temperatures while the temperature softening remained independent of the applied strain rate. Application of temperature creates long lasting changes in mechanical behavior of separator as was revealed by performing experiments after the annealing. Such delayed effect of temperature application appears to have directional dependence. The results demonstrate complex behavior of polymer separator which needs to be considered in proper safety assessments of Li-ion batteries.« less

Sex and strategy use matters for pattern separation, adult neurogenesis, and immediate early gene expression in the hippocampus.

PubMed

Yagi, Shunya; Chow, Carmen; Lieblich, Stephanie E; Galea, Liisa A M

2016-01-01

Adult neurogenesis in the dentate gyrus (DG) plays a crucial role for pattern separation, and there are sex differences in the regulation of neurogenesis. Although sex differences, favoring males, in spatial navigation have been reported, it is not known whether there are sex differences in pattern separation. The current study was designed to determine whether there are sex differences in the ability for separating similar or distinct patterns, learning strategy choice, adult neurogenesis, and immediate early gene (IEG) expression in the DG in response to pattern separation training. Male and female Sprague-Dawley rats received a single injection of the DNA synthesis marker, bromodeoxyuridine (BrdU), and were tested for the ability of separating spatial patterns in a spatial pattern separation version of delayed nonmatching to place task using the eight-arm radial arm maze. Twenty-seven days following BrdU injection, rats received a probe trial to determine whether they were idiothetic or spatial strategy users. We found that male spatial strategy users outperformed female spatial strategy users only when separating similar, but not distinct, patterns. Furthermore, male spatial strategy users had greater neurogenesis in response to pattern separation training than all other groups. Interestingly, neurogenesis was positively correlated with performance on similar pattern trials during pattern separation in female spatial strategy users but negatively correlated with performance in male idiothetic strategy users. These results suggest that the survival of new neurons may play an important positive role for pattern separation of similar patterns in females. Furthermore, we found sex and strategy differences in IEG expression in the CA1 and CA3 regions in response to pattern separation. These findings emphasize the importance of studying biological sex on hippocampal function and neural plasticity. © 2015 Wiley Periodicals, Inc.

Overcoming phase 1 delays: the critical component of obstetric fistula prevention programs in resource-poor countries

PubMed Central

2012-01-01

Background An obstetric fistula is a traumatic childbirth injury that occurs when labor is obstructed and delivery is delayed. Prolonged obstructed labor leads to the destruction of the tissues that normally separate the bladder from the vagina and creates a passageway (fistula) through which urine leaks continuously. Women with a fistula become social outcasts. Universal high-quality maternity care has eliminated the obstetric fistula in wealthy countries, but millions of women in resource-poor nations still experience prolonged labor and tens of thousands of new fistula sufferers are added to the millions of pre-existing cases each year. This article discusses fistula prevention in developing countries, focusing on the factors which delay treatment of prolonged labor. Discussion Obstetric fistulas can be prevented through contraception, avoiding obstructed labor, or improving outcomes for women who develop obstructed labor. Contraception is of little use to women who are already pregnant and there is no reliable screening test to predict obstruction in advance of labor. Improving the outcome of obstructed labor depends on prompt diagnosis and timely intervention (usually by cesarean section). Because obstetric fistulas are caused by tissue compression, the time interval from obstruction to delivery is critical. This time interval is often extended by delays in deciding to seek care, delays in arriving at a hospital, and delays in accessing treatment after arrival. Communities can reasonably demand that governments and healthcare institutions improve the second (transportation) and third (treatment) phases of delay. Initial delays in seeking hospital care are caused by failure to recognize that labor is prolonged, confusion concerning what should be done (often the result of competing therapeutic pathways), lack of women’s agency, unfamiliarity with and fear of hospitals and the treatments they offer (especially surgery), and economic constraints on access to care. Summary Women in resource-poor countries will use institutional obstetric care when the services provided are valued more than the competing choices offered by a pluralistic medical system. The key to obstetric fistula prevention is competent obstetrical care delivered respectfully, promptly, and at affordable cost. The utilization of these services is driven largely by trust. PMID:22809234

Visualization of Surface Flow on a Prolate Spheroid Model Suspended by Magnetic Suspension and Balance System

NASA Astrophysics Data System (ADS)

Ambo, Takumi; Nakamura, Yuki; Ochiai, Taku; Nonomura, Taku; Asai, Keisuke

2017-11-01

In this study, the surface flow on a 6:1 prolate spheroid model was visualized by oil flow method in the magnetic suspension and balance system (MSBS). The MSBS is a support-free system for wind-tunnel test in that a model is levitated by magnetic force. In this experiment, the 0.3-m MSBS was installed in the low-speed wind tunnel. The Reynolds number was 0.5 million and the angle of attack was set 0 and 5 degrees. In addition to free-levitation tests, a thin rod simulating disturbance of a support system was placed on the model surface and the influence of support interference was evaluated. The obtained results indicate that complicated separation patterns are present even at zero angle of attack. At α = 5°, separation pattern becomes more complicated than that at α = 0° and the streamlines form a highly three-dimensional structure. A characteristic pattern of open separation is observed and a focal point is formed at the end of the separation line. In evaluation of the support interference, the separation is delayed in the downstream of the rod, suggesting that the change of separation pattern is caused by the transition of laminar boundary layer behind the rod. These results indicate that one must take particular care to the support interference in studying three-dimensional separation on a prolate spheroid.

Astrometria diferencial de precision con VLBI el triangulo de Draco (y estudios de SN1993J)

NASA Astrophysics Data System (ADS)

Ros, E.

1997-11-01

The Very Long Baseline Interferometry (VLBI) technique provides unprecedented resolutions in astronomy. In this PhD we show progress in the study of high precision phase-delay differential astrometry through observations of the radio source triangle formed by the BL-Lac objects 1803+784 and 2007+777, and the QSO 1928+738, in the Northern constellation of Draco (the Dragon), from observations carried out on 20/21 November 1991 with an intercontinental interferometric array simultaneously at the frequencies of 2.3 and 8.4 GHz. We have determined the angular separations among the three radio sources with submilliarcsecond accuracy from a weighted least squares analysis of the differential phase delay from the three celestial bodies. Our present work introduces important advances with respect to previous astrometric studies, carried out over radio source pairs separated by smaller angular distances. We have consistently modeled the parameters involved in an astrometric VLBI observation, in order to reproduce the differential phase observed for radio sources separated by almost 7o on the sky. We have demonstrated the possibility of phase-connection over these angular distances at 8.4 GHz, even at an epoch of a maximum in the solar activity. After the phase-connection we have corrected the effects of the extended structure of the radio source and of the ionosphere. This last correction is one of the main technical achievements of this thesis: it is possible to remove the ionospheric contribution with independent measurements of the ionosphere total electron content obtained at Global Positioning Systems (GPS) sites the VLBI observing stations. The triangular geometry introduces constraints in parameter space that allow a better estimation of the angular separations among the radio sources. It is possible to test the consistency of the astrometric results through the Sky-Closure, defined as the circular sum of the angular separations of the three radio sources, determined pairwise and independently. In our case it is consistent with zero, and verifies satisfactorily the data process followed. The comparison of the measurements of the separations of the pair 1928+738/2007+777 (1991 data) with previous measurements (data from 1985 and 1988), carried out with the same technique, allows us to register adequately the absolute position of 1928+738 relative to 2007+777. We estimate the proper motion of components in 1928+738, and also identify the position of the radio source core. We confirm the superluminal motion of the components of 1928+738. The comparison of our results with those obtained by Eubanks (USNO) from group delay measurements (without structure correction) show the incorrectness of the latter. We also include succinctly in this PhD my colaboration in the work on the radio supernova SN 1993J, in galaxy M81. We have discovered a shell-like structure of the radio emission of SN 1993J which exploded on March 1993. We have also elaborated a movie of its evolution, by monitoring the shell structure for different epochs, and determined the deceleration of its expansion.

Short-Latency, Goal-Directed Movements of the Pinnae to Sounds That Produce Auditory Spatial Illusions

PubMed Central

McClaine, Elizabeth M.; Yin, Tom C. T.

2010-01-01

The precedence effect (PE) is an auditory spatial illusion whereby two identical sounds presented from two separate locations with a delay between them are perceived as a fused single sound source whose position depends on the value of the delay. By training cats using operant conditioning to look at sound sources, we have previously shown that cats experience the PE similarly to humans. For delays less than ±400 μs, cats exhibit summing localization, the perception of a “phantom” sound located between the sources. Consistent with localization dominance, for delays from 400 μs to ∼10 ms, cats orient toward the leading source location only, with little influence of the lagging source. Finally, echo threshold was reached for delays >10 ms, where cats first began to orient to the lagging source. It has been hypothesized by some that the neural mechanisms that produce facets of the PE, such as localization dominance and echo threshold, must likely occur at cortical levels. To test this hypothesis, we measured both pinnae position, which were not under any behavioral constraint, and eye position in cats and found that the pinnae orientations to stimuli that produce each of the three phases of the PE illusion was similar to the gaze responses. Although both eye and pinnae movements behaved in a manner that reflected the PE, because the pinnae moved with strikingly short latencies (∼30 ms), these data suggest a subcortical basis for the PE and that the cortex is not likely to be directly involved. PMID:19889848

Short-latency, goal-directed movements of the pinnae to sounds that produce auditory spatial illusions.

PubMed

Tollin, Daniel J; McClaine, Elizabeth M; Yin, Tom C T

2010-01-01

The precedence effect (PE) is an auditory spatial illusion whereby two identical sounds presented from two separate locations with a delay between them are perceived as a fused single sound source whose position depends on the value of the delay. By training cats using operant conditioning to look at sound sources, we have previously shown that cats experience the PE similarly to humans. For delays less than +/-400 mus, cats exhibit summing localization, the perception of a "phantom" sound located between the sources. Consistent with localization dominance, for delays from 400 mus to approximately 10 ms, cats orient toward the leading source location only, with little influence of the lagging source. Finally, echo threshold was reached for delays >10 ms, where cats first began to orient to the lagging source. It has been hypothesized by some that the neural mechanisms that produce facets of the PE, such as localization dominance and echo threshold, must likely occur at cortical levels. To test this hypothesis, we measured both pinnae position, which were not under any behavioral constraint, and eye position in cats and found that the pinnae orientations to stimuli that produce each of the three phases of the PE illusion was similar to the gaze responses. Although both eye and pinnae movements behaved in a manner that reflected the PE, because the pinnae moved with strikingly short latencies ( approximately 30 ms), these data suggest a subcortical basis for the PE and that the cortex is not likely to be directly involved.

Vaccination Confidence and Parental Refusal/Delay of Early Childhood Vaccines.

PubMed

Gilkey, Melissa B; McRee, Annie-Laurie; Magnus, Brooke E; Reiter, Paul L; Dempsey, Amanda F; Brewer, Noel T

2016-01-01

To support efforts to address parental hesitancy towards early childhood vaccination, we sought to validate the Vaccination Confidence Scale using data from a large, population-based sample of U.S. parents. We used weighted data from 9,354 parents who completed the 2011 National Immunization Survey. Parents reported on the immunization history of a 19- to 35-month-old child in their households. Healthcare providers then verified children's vaccination status for vaccines including measles, mumps, and rubella (MMR), varicella, and seasonal flu. We used separate multivariable logistic regression models to assess associations between parents' mean scores on the 8-item Vaccination Confidence Scale and vaccine refusal, vaccine delay, and vaccination status. A substantial minority of parents reported a history of vaccine refusal (15%) or delay (27%). Vaccination confidence was negatively associated with refusal of any vaccine (odds ratio [OR] = 0.58, 95% confidence interval [CI], 0.54-0.63) as well as refusal of MMR, varicella, and flu vaccines specifically. Negative associations between vaccination confidence and measures of vaccine delay were more moderate, including delay of any vaccine (OR = 0.81, 95% CI, 0.76-0.86). Vaccination confidence was positively associated with having received vaccines, including MMR (OR = 1.53, 95% CI, 1.40-1.68), varicella (OR = 1.54, 95% CI, 1.42-1.66), and flu vaccines (OR = 1.32, 95% CI, 1.23-1.42). Vaccination confidence was consistently associated with early childhood vaccination behavior across multiple vaccine types. Our findings support expanding the application of the Vaccination Confidence Scale to measure vaccination beliefs among parents of young children.

VRX-03011, a novel 5-HT4 agonist, enhances memory and hippocampal acetylcholine efflux.

PubMed

Mohler, Eric G; Shacham, Sharon; Noiman, Silvia; Lezoualc'h, Frank; Robert, Sylvain; Gastineau, Monique; Rutkowski, Joseph; Marantz, Yael; Dumuis, Aline; Bockaert, Joel; Gold, Paul E; Ragozzino, Michael E

2007-09-01

Recent evidence suggests that 5-hydroxytryptamine (5-HT)(4) receptor activity enhances cognition and provides neuroprotection. Here we report the effects of VRX-03011, a novel partial 5-HT(4) agonist, that is both potent (K(i) approximately 30 nM) and highly selective (K(i) > 5 microM for all other 5-HT receptors tested). In separate experiments, rats received VRX-03011 (0.1-10 mg/kg i.p.) 30 min prior to spontaneous alternation testing in a no-delay or a 30-s delay condition. VRX-03011 (1, 5 and 10 mg/kg, but not 0.1 mg/kg) significantly enhanced delayed spontaneous alternation performance while none of the doses enhanced performance in the no-delay test. VRX-03011 (1 and 5 mg/kg) concomitantly enhanced hippocampal acetylcholine output and delayed spontaneous alternation scores compared to that of vehicle controls, but had no effect on hippocampal acetylcholine release under a resting condition. Moreover, suboptimal doses of VRX-03011 and the acetylcholinesterase inhibitor galanthamine combined to enhance memory. VRX-03011 also regulated amyloid precursor protein (APP) metabolism by inducing a concentration-dependent increase in the non-amyloidogenic soluble form of APP (sAPPalpha) with an EC(50) approximately 1--10 nM. VRX-03011 had no effect on contractile properties in guinea pig ileum or colon preparations with an EC(50) > 10 microM and did not alter rat intestinal transit at doses up to 10 mg/kg. These findings suggest that VRX-03011 may represent a novel treatment for Alzheimer's disease that reduces cognitive impairments and provides neuroprotection without gastrointestinal side effects.

The effect of force feedback delay on stiffness perception and grip force modulation during tool-mediated interaction with elastic force fields

PubMed Central

Karniel, Amir; Nisky, Ilana

2015-01-01

During interaction with objects, we form an internal representation of their mechanical properties. This representation is used for perception and for guiding actions, such as in precision grip, where grip force is modulated with the predicted load forces. In this study, we explored the relationship between grip force adjustment and perception of stiffness during interaction with linear elastic force fields. In a forced-choice paradigm, participants probed pairs of virtual force fields while grasping a force sensor that was attached to a haptic device. For each pair, they were asked which field had higher level of stiffness. In half of the pairs, the force feedback of one of the fields was delayed. Participants underestimated the stiffness of the delayed field relatively to the nondelayed, but their grip force characteristics were similar in both conditions. We analyzed the magnitude of the grip force and the lag between the grip force and the load force in the exploratory probing movements within each trial. Right before answering which force field had higher level of stiffness, both magnitude and lag were similar between delayed and nondelayed force fields. These results suggest that an accurate internal representation of environment stiffness and time delay was used for adjusting the grip force. However, this representation did not help in eliminating the bias in stiffness perception. We argue that during performance of a perceptual task that is based on proprioceptive feedback, separate neural mechanisms are responsible for perception and action-related computations in the brain. PMID:25717155

Trace conditioning in insects—keep the trace!

PubMed Central

Dylla, Kristina V.; Galili, Dana S.; Szyszka, Paul; Lüdke, Alja

2013-01-01

Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS) and an unconditioned stimulus (US) following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination—a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase (Rut-AC), which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning. PMID:23986710

Methylphenidate does not improve interference control during a working memory task in young patients with attention-deficit hyperactivity disorder.

PubMed

Prehn-Kristensen, Alexander; Krauel, Kerstin; Hinrichs, Hermann; Fischer, Jochen; Malecki, Ulrike; Schuetze, Hartmut; Wolff, Stephan; Jansen, Olav; Duezel, Emrah; Baving, Lioba

2011-05-04

Patients with attention-deficit/hyperactivity disorder (ADHD) show deficits in working memory (WM) which may be related to prefrontal dysfunction. Methylphenidate (MPH) can restore WM deficits in ADHD by enhancing prefrontal activity. At the same time, changes in striatal activation could cause ADHD patients to be more interference-sensitive during working memory tasks. However, it is unclear whether MPH reduces WM distractibility in ADHD. In this fMRI study, 12 ADHD patients and 12 healthy controls participated on two separate days in a delayed-match-to-sample test. During the delay interval, a distractor stimulus was presented in half of the trials. Children and adolescents with ADHD received MPH only on one of the two sessions. Behavioral data analyses revealed that MPH normalized WM in ADHD. However, MPH did not improve WM performance when a distractor was presented during the delay interval. Functional images showed that MPH enhanced prefrontal activity during the delay in ADHD patients when no distractor was present. If the delay was interrupted by a distractor, only healthy controls showed activation of the caudate. In patients with ADHD, however, in line with behavioral data, MPH did not enhance caudate activity. In healthy youth, caudate activity is involved in interference control allowing the successful maintenance of information in working memory even in the presence of distraction. Our findings suggest that interference control, linked to caudate activity, is not adequately enhanced by MPH in ADHD. Copyright © 2011 Elsevier B.V. All rights reserved.

The effect of force feedback delay on stiffness perception and grip force modulation during tool-mediated interaction with elastic force fields.

PubMed

Leib, Raz; Karniel, Amir; Nisky, Ilana

2015-05-01

During interaction with objects, we form an internal representation of their mechanical properties. This representation is used for perception and for guiding actions, such as in precision grip, where grip force is modulated with the predicted load forces. In this study, we explored the relationship between grip force adjustment and perception of stiffness during interaction with linear elastic force fields. In a forced-choice paradigm, participants probed pairs of virtual force fields while grasping a force sensor that was attached to a haptic device. For each pair, they were asked which field had higher level of stiffness. In half of the pairs, the force feedback of one of the fields was delayed. Participants underestimated the stiffness of the delayed field relatively to the nondelayed, but their grip force characteristics were similar in both conditions. We analyzed the magnitude of the grip force and the lag between the grip force and the load force in the exploratory probing movements within each trial. Right before answering which force field had higher level of stiffness, both magnitude and lag were similar between delayed and nondelayed force fields. These results suggest that an accurate internal representation of environment stiffness and time delay was used for adjusting the grip force. However, this representation did not help in eliminating the bias in stiffness perception. We argue that during performance of a perceptual task that is based on proprioceptive feedback, separate neural mechanisms are responsible for perception and action-related computations in the brain. Copyright © 2015 the American Physiological Society.

Neurotoxic lesions of the dorsal and ventral hippocampus impair acquisition and expression of trace-conditioned fear-potentiated startle in rats.

PubMed

Trivedi, Mehul A; Coover, Gary D

2006-04-03

Pavlovian delay conditioning, in which a conditioned stimulus (CS) and unconditioned stimulus (US) co-terminate, is thought to reflect non-declarative memory. In contrast, trace conditioning, in which the CS and US are temporally separate, is thought to reflect declarative memory. Hippocampal lesions impair acquisition and expression of trace conditioning measured by the conditioned freezing and eyeblink responses, while having little effect on the acquisition of delay conditioning. Recent evidence suggests that lesions of the ventral hippocampus (VH) impair conditioned fear under conditions in which dorsal hippocampal (DH) lesions have little effect. In the present study, we examined the time-course of fear expression after delay and trace conditioning using the fear-potentiated startle (FPS) reflex, and the effects of pre- and post-training lesions to the VH and DH on trace-conditioned FPS. We found that both delay- and trace-conditioned rats displayed significant FPS near the end of the CS relative to the unpaired control group. In contrast, trace-conditioned rats displayed significant FPS throughout the duration of the trace interval, whereas FPS decayed rapidly to baseline after CS offset in delay-conditioned rats. In experiment 2, both DH and VH lesions were found to significantly reduce the overall magnitude of FPS compared to the control group, however, no differences were found between the DH and VH groups. These findings support a role for both the DH and VH in trace fear conditioning, and suggest that the greater effect of VH lesions on conditioned fear might be specific to certain measures of fear.

Obesity and Prader-Willi Syndrome Affect Heart Rate Recovery from Dynamic Resistance Exercise in Youth

PubMed Central

Castner, Diobel M.; Clark, Susan J.; Judelson, Daniel A.; Rubin, Daniela A.

2016-01-01

Following exercise, heart rate decline is initially driven by parasympathetic reactivation and later by sympathetic withdrawal. Obesity delays endurance exercise heart rate recovery (HRR) in both children and adults. Young people with Prader-Willi Syndrome (PWS), a congenital cause for obesity, have shown a slower 60-s endurance exercise HRR compared to lean and obese children, suggesting compromised regulation. This study further evaluated effects of obesity and PWS on resistance exercise HRR at 30 and 60 s in children. PWS (8–18 years) and lean and obese controls (8–11 years) completed a weighted step-up protocol (six sets x 10 reps per leg, separated by one-minute rest), standardized using participant stature and lean body mass. HRR was evaluated by calculated HRR value (HRRV = difference between HR at test termination and 30 (HRRV30) and 60 (HRRV60) s post-exercise). PWS and obese had a smaller HRRV30 than lean (p < 0.01 for both). Additionally, PWS had a smaller HRRV60 than lean and obese (p = 0.01 for both). Obesity appears to delay early parasympathetic reactivation, which occurs within 30 s following resistance exercise. However, the continued HRR delay at 60 s in PWS may be explained by either blunted parasympathetic nervous system reactivation, delayed sympathetic withdrawal and/or poor cardiovascular fitness. PMID:28933384

The 7q11.23 Microduplication Syndrome: A Clinical Report with Review of Literature

PubMed Central

Abbas, Elham; Cox, Devin M.; Smith, Teri; Butler, Merlin G.

2016-01-01

We report a 14-year-old adolescent girl with selective mutism (SM) and a 7q11.23 microduplication detected by chromosomal microarray (CMA) analysis and reviewed the literature from 18 published clinical reports. Our patient had specific phobias, SM, extreme anxiety, obesity, cutis marmorata, and a round appearing face with a short neck and over folded ears. We reviewed the published clinical, cognitive, behavioral, and cytogenetic findings grouped by speech and language delay, growth and development, craniofacial, clinical, and behavior and cognitive features due to the 7q11.23 microduplication. This microduplication syndrome is characterized by speech delay (91%), social anxiety (42%), attention deficit hyperactivity disorder (ADHD, 37%), autism spectrum disorder (29%), and separation anxiety (13%). Other findings include abnormal brain imaging (80%), congenital heart and vascular defects (54%), and mild intellectual disability (38%). We then compared the phenotype with Williams–Beuren syndrome (WBS) which is due to a deletion of the same chromosome region. Both syndromes have abnormal brain imaging, hypotonia, delayed motor development, joint laxity, mild intellectual disability, ADHD, autism, and poor visuospatial skills but opposite or dissimilar findings regarding speech and behavioral patterns, cardiovascular problems, and social interaction. Those with WBS are prone to have hyperverbal speech, lack of stranger anxiety, and supravalvular aortic stenosis while those with the 7q11.23 microduplication have speech delay, SM, social anxiety, and are prone to aortic dilatation. PMID:27617154

Integrating across Episodes: Investigating the Long-term Accessibility of Self-derived Knowledge in 4-Year-Old Children

PubMed Central

Varga, Nicole L.; Stewart, Rebekah A.; Bauer, Patricia J.

2016-01-01

Semantic memory, defined as our store of knowledge about the world, provides representational support for all of our higher order cognitive functions. As such, it is crucial that the contents of semantic memory remain accessible over time. Although memory for knowledge learned through direct observation has been previously investigated, we know very little about the retention of knowledge derived through integration of information acquired across separate learning episodes. The present research investigated cross-episode integration in 4-year-old children. Participants were presented with novel facts via distinct story episodes and tested for knowledge extension through cross-episode integration, as well as for retention of the information over a 1-week delay. In Experiment 1, children retained the self-derived knowledge over the delay, though performance was primarily evidenced in a forced-choice format. In Experiment 2, we sought to facilitate the accessibility and robustness of self-derived knowledge by providing a verbal reminder after the delay. The accessibility of self-derived knowledge increased, irrespective of whether participants successfully demonstrated knowledge of the integration facts during the first visit. The results suggest knowledge extended through integration remains accessible after delays, even in a population in which this learning process is less robust. The findings also demonstrate the facilitative effect of reminders on the accessibility and further extension of knowledge over extended time periods. PMID:26774259

Interrelationships between Marijuana Demand and Discounting of Delayed Rewards: Convergence in Behavioral Economic Methods

PubMed Central

Aston, Elizabeth R.; Metrik, Jane; Amlung, Michael; Kahler, Christopher W.; MacKillop, James

2016-01-01

Background Distinct behavioral economic domains, including high perceived drug value (demand) and delay discounting (DD), have been implicated in the initiation of drug use and the progression to dependence. However, it is unclear whether frequent marijuana users conform to a “reinforcer pathology” addiction model wherein marijuana demand and DD jointly increase risk for problematic marijuana use and cannabis dependence (CD). Methods Participants (n=88, 34% female, 14% cannabis dependent) completed a marijuana purchase task at baseline. A delay discounting task was completed following placebo marijuana cigarette (0% THC) administration during a separate experimental session. Results Marijuana demand and DD were quantified using area under the curve (AUC). In multiple regression models, demand uniquely predicted frequency of marijuana use while DD did not. In contrast, DD uniquely predicted CD symptom count while demand did not. There were no significant interactions between demand and DD in either model. Conclusions These findings suggest that frequent marijuana users exhibit key constituents of the reinforcer pathology model: high marijuana demand and steep discounting of delayed rewards. However, demand and DD appear to be independent rather than synergistic risk factors for elevated marijuana use and risk for progression to CD. Findings also provide support for using AUC as a singular marijuana demand metric, particularly when also examining other behavioral economic constructs that apply similar statistical approaches, such as DD, to support analytic methodological convergence. PMID:27810657

The 7q11.23 Microduplication Syndrome: A Clinical Report with Review of Literature.

PubMed

Abbas, Elham; Cox, Devin M; Smith, Teri; Butler, Merlin G

2016-09-01

We report a 14-year-old adolescent girl with selective mutism (SM) and a 7q11.23 microduplication detected by chromosomal microarray (CMA) analysis and reviewed the literature from 18 published clinical reports. Our patient had specific phobias, SM, extreme anxiety, obesity, cutis marmorata, and a round appearing face with a short neck and over folded ears. We reviewed the published clinical, cognitive, behavioral, and cytogenetic findings grouped by speech and language delay, growth and development, craniofacial, clinical, and behavior and cognitive features due to the 7q11.23 microduplication. This microduplication syndrome is characterized by speech delay (91%), social anxiety (42%), attention deficit hyperactivity disorder (ADHD, 37%), autism spectrum disorder (29%), and separation anxiety (13%). Other findings include abnormal brain imaging (80%), congenital heart and vascular defects (54%), and mild intellectual disability (38%). We then compared the phenotype with Williams-Beuren syndrome (WBS) which is due to a deletion of the same chromosome region. Both syndromes have abnormal brain imaging, hypotonia, delayed motor development, joint laxity, mild intellectual disability, ADHD, autism, and poor visuospatial skills but opposite or dissimilar findings regarding speech and behavioral patterns, cardiovascular problems, and social interaction. Those with WBS are prone to have hyperverbal speech, lack of stranger anxiety, and supravalvular aortic stenosis while those with the 7q11.23 microduplication have speech delay, SM, social anxiety, and are prone to aortic dilatation.

RXTE Observation of Cygnus X-1: III. Implications for Compton Corona and ADAF Models. Report 3; Implications for Compton Corona and ADAF Models

NASA Technical Reports Server (NTRS)

Nowak, Michael A.; Wilms, Joern; Vaughan, Brian A.; Dove, James B.; Begelman, Mitchell C.

1999-01-01

We have recently shown that a 'sphere + disk' geometry Compton corona model provides a good description of Rossi X-ray Timing Explorer (RXTE) observations of the hard/low state of Cygnus X-1. Separately, we have analyzed the temporal data provided by RXTE. In this paper we consider the implications of this timing analysis for our best-fit 'sphere + disk' Comptonization models. We focus our attention on the observed Fourier frequency-dependent time delays between hard and soft photons. We consider whether the observed time delays are: created in the disk but are merely reprocessed by the corona; created by differences between the hard and soft photon diffusion times in coronae with extremely large radii; or are due to 'propagation' of disturbances through the corona. We find that the time delays are most likely created directly within the corona; however, it is currently uncertain which specific model is the most likely explanation. Models that posit a large coronal radius [or equivalently, a large Advection Dominated Accretion Flow (ADAF) region] do not fully address all the details of the observed spectrum. The Compton corona models that do address the full spectrum do not contain dynamical information. We show, however, that simple phenomenological propagation models for the observed time delays for these latter models imply extremely slow characteristic propagation speeds within the coronal region.

Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

NASA Astrophysics Data System (ADS)

Konki, J.; Khuyagbaatar, J.; Uusitalo, J.; Greenlees, P. T.; Auranen, K.; Badran, H.; Block, M.; Briselet, R.; Cox, D. M.; Dasgupta, M.; Di Nitto, A.; Düllmann, Ch. E.; Grahn, T.; Hauschild, K.; Herzán, A.; Herzberg, R.-D.; Heßberger, F. P.; Hinde, D. J.; Julin, R.; Juutinen, S.; Jäger, E.; Kindler, B.; Krier, J.; Leino, M.; Lommel, B.; Lopez-Martens, A.; Luong, D. H.; Mallaburn, M.; Nishio, K.; Pakarinen, J.; Papadakis, P.; Partanen, J.; Peura, P.; Rahkila, P.; Rezynkina, K.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Stolze, S.; Sulignano, B.; Theisen, Ch.; Ward, A.; Yakushev, A.; Yakusheva, V.

2017-01-01

The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion-evaporation reaction 209Bi(34S,3n)240Es. Half-lives of 6 (2)s and 22-6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα = 8.19 (3)MeV and 8.09 (3)MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16 (6) and 0.04 (2) were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

Understanding light scattering by a coated sphere part 2: time domain analysis.

PubMed

Laven, Philip; Lock, James A

2012-08-01

Numerical computations were made of scattering of an incident electromagnetic pulse by a coated sphere that is large compared to the dominant wavelength of the incident light. The scattered intensity was plotted as a function of the scattering angle and delay time of the scattered pulse. For fixed core and coating radii, the Debye series terms that most strongly contribute to the scattered intensity in different regions of scattering angle-delay time space were identified and analyzed. For a fixed overall radius and an increasing core radius, the first-order rainbow was observed to evolve into three separate components. The original component faded away, while the two new components eventually merged together. The behavior of surface waves generated by grazing incidence at the core/coating and coating/exterior interfaces was also examined and discussed.

Geodesic curve-of-sight formulae for the cosmic microwave background: a unified treatment of redshift, time delay, and lensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, Ryo; Naruko, Atsushi; Hiramatsu, Takashi

2014-10-01

In this paper, we introduce a new approach to a treatment of the gravitational effects (redshift, time delay and lensing) on the observed cosmic microwave background (CMB) anisotropies based on the Boltzmann equation. From the Liouville's theorem in curved spacetime, the intensity of photons is conserved along a photon geodesic when non-gravitational scatterings are absent. Motivated by this fact, we derive a second-order line-of-sight formula by integrating the Boltzmann equation along a perturbed geodesic (curve) instead of a background geodesic (line). In this approach, the separation of the gravitational and intrinsic effects are manifest. This approach can be considered asmore » a generalization of the remapping approach of CMB lensing, where all the gravitational effects can be treated on the same footing.« less

Study of isomeric states in 198,200,202,206Pb and 206Hg populated in fragmentation reactions

NASA Astrophysics Data System (ADS)

Lalović, N.; Rudolph, D.; Podolyák, Zs; Sarmiento, L. G.; Simpson, E. C.; Alexander, T.; Cortés, M. L.; Gerl, J.; Golubev, P.; Ameil, F.; Arici, T.; Bauer, Ch; Bazzacco, D.; Bentley, M. A.; Boutachkov, P.; Bowry, M.; Fahlander, C.; Gadea, A.; Gellanki, J.; Givechev, A.; Goel, N.; Górska, M.; Gottardo, A.; Gregor, E.; Guastalla, G.; Habermann, T.; Hackstein, M.; Jungclaus, A.; Kojouharov, I.; Kumar, R.; Kurz, N.; Lettmann, M.; Lizarazo, C.; Louchart, C.; Merchán, E.; Michelagnoli, C.; Moeller, Th; Moschner, K.; Patel, Z.; Pietralla, N.; Pietri, S.; Ralet, D.; Reese, M.; Regan, P. H.; Reiter, P.; Schaffner, H.; Singh, P.; Stahl, C.; Stegmann, R.; Stezowski, O.; Taprogge, J.; Thöle, P.; Wendt, A.; Wieland, O.; Wilson, E.; Wood, R.; Wollersheim, H.-J.; Birkenbach, B.; Bruyneel, B.; Burrows, I.; Clément, E.; Désesquelles, P.; Domingo-Pardo, C.; Eberth, J.; González, V.; Hess, H.; Jolie, J.; Judson, D. S.; Menegazzo, R.; Mengoni, D.; Napoli, D. R.; Pullia, A.; Quintana, B.; Rainovski, G.; Salsac, M. D.; Sanchis, E.; Simpson, J.; Valiente Dóbon, J. J.; AGATA Collaboration

2018-03-01

Isomeric states in isotopes in the vicinity of doubly-magic 208Pb were populated following reactions of a relativistic 208Pb primary beam impinging on a 9Be fragmentation target. Secondary beams of 198,200,202,206Pb and 206Hg were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed γ rays were detected with the Advanced Gamma Tracking Array (AGATA). Decay schemes were re-evaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei 206Pb/206Hg was found to differ from the population of multi neutron-hole isomeric states in 198,200,202Pb.

Practical guide for implementing hybrid PET/MR clinical service: lessons learned from our experience

PubMed Central

Parikh, Nainesh; Friedman, Kent P.; Shah, Shetal N.; Chandarana, Hersh

2015-01-01

Positron emission tomography (PET) and magnetic resonance imaging, until recently, have been performed on separate PET and MR systems with varying temporal delay between the two acquisitions. The interpretation of these two separately acquired studies requires cognitive fusion by radiologists/nuclear medicine physicians or dedicated and challenging post-processing. Recent advances in hardware and software with introduction of hybrid PET/MR systems have made it possible to acquire the PET and MR images simultaneously or near simultaneously. This review article serves as a road-map for clinical implementation of hybrid PET/MR systems and briefly discusses hardware systems, the personnel needs, safety and quality issues, and reimbursement topics based on experience at NYU Langone Medical Center and Cleveland Clinic. PMID:25985966

Draft Registration Implementation. Report Together with Dissenting Individual, Additional, and Separate Views. House of Representatives, Committee on Education and Labor, Ninety-eighth Congress, First Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and Labor.

A report on a bill to delay the effective date for the denial of federal aid to students who have failed to comply with draft registration requirements is presented. The bill also directs the Comptroller General to conduct an ongoing study of the effectiveness of the Department of Defense Authorization Act of 1983 (Solomon/Hayakawa amendment) in…

Seaworthy Quantum Key Distribution Design and Validation (SEAKEY)

DTIC Science & Technology

2015-11-12

polarization control and the CV state and the LO state are separated at a polarizing beam splitter . The CV state is delayed relative to the LO state, and... splitter or loss imperfections. We have identified a number of risks associated with implementing this design . The two most critical risks are: • The...Contractor Address: 10 Moulton Street, Cambridge, MA 02138 Title of the Project: Seaworthy Quantum Key Distribution Design and Validation (SEAKEY

Strategically Planning Avionics Laboratory’s Facilities for the Future

DTIC Science & Technology

1993-09-01

Goldsboro Road Bethesda, Maryland 20817-5886 93 12 22 02 DISCLAIMII NOTICE THIS DOCUMENT IS BEST QUALITY AVAILABLE. THE COPY FURNISHLD TO DTIC CONTAINED A...Avionics Laboratory establish a multiyear strategy for improving its facility utilization nearly 7 years ago. That plan, which is still being implemented...experi- mental data transmission delays caused when on-line equipment is separated by as much as a mile. The plan - now nearly 7 years old - initiated

Post-traumatic stress symptoms are associated with better performance on a delayed match-to-position task

PubMed Central

2018-01-01

Many individuals with posttraumatic stress disorder (PTSD) report experiencing frequent intrusive memories of the original traumatic event (e.g., flashbacks). These memories can be triggered by situations or stimuli that reflect aspects of the trauma and may reflect basic processes in learning and memory, such as generalization. It is possible that, through increased generalization, non-threatening stimuli that once evoked normal memories become associated with traumatic memories. Previous research has reported increased generalization in PTSD, but the role of visual discrimination processes has not been examined. To investigate visual discrimination in PTSD, 143 participants (Veterans and civilians) self-assessed for symptom severity were grouped according to the presence of severe PTSD symptoms (PTSS) vs. few/no symptoms (noPTSS). Participants were given a visual match-to-sample pattern separation task that varied trials by spatial separation (Low, Medium, High) and temporal delays (5, 10, 20, 30 s). Unexpectedly, the PTSS group demonstrated better discrimination performance than the noPTSS group at the most difficult spatial trials (Low spatial separation). Further assessment of accuracy and reaction time using diffusion drift modeling indicated that the better performance by the PTSS group on the hardest trials was not explained by slower reaction times, but rather a faster accumulation of evidence during decision making in conjunction with a reduced threshold, indicating a tendency in the PTSS group to decide quickly rather than waiting for additional evidence to support the decision. This result supports the need for future studies examining the precise role of discrimination and generalization in PTSD, and how these cognitive processes might contribute to expression and maintenance of PTSD symptoms. PMID:29736339

Multi-time resolution analysis of speech: evidence from psychophysics

PubMed Central

Chait, Maria; Greenberg, Steven; Arai, Takayuki; Simon, Jonathan Z.; Poeppel, David

2015-01-01

How speech signals are analyzed and represented remains a foundational challenge both for cognitive science and neuroscience. A growing body of research, employing various behavioral and neurobiological experimental techniques, now points to the perceptual relevance of both phoneme-sized (10–40 Hz modulation frequency) and syllable-sized (2–10 Hz modulation frequency) units in speech processing. However, it is not clear how information associated with such different time scales interacts in a manner relevant for speech perception. We report behavioral experiments on speech intelligibility employing a stimulus that allows us to investigate how distinct temporal modulations in speech are treated separately and whether they are combined. We created sentences in which the slow (~4 Hz; Slow) and rapid (~33 Hz; Shigh) modulations—corresponding to ~250 and ~30 ms, the average duration of syllables and certain phonetic properties, respectively—were selectively extracted. Although Slow and Shigh have low intelligibility when presented separately, dichotic presentation of Shigh with Slow results in supra-additive performance, suggesting a synergistic relationship between low- and high-modulation frequencies. A second experiment desynchronized presentation of the Slow and Shigh signals. Desynchronizing signals relative to one another had no impact on intelligibility when delays were less than ~45 ms. Longer delays resulted in a steep intelligibility decline, providing further evidence of integration or binding of information within restricted temporal windows. Our data suggest that human speech perception uses multi-time resolution processing. Signals are concurrently analyzed on at least two separate time scales, the intermediate representations of these analyses are integrated, and the resulting bound percept has significant consequences for speech intelligibility—a view compatible with recent insights from neuroscience implicating multi-timescale auditory processing. PMID:26136650

SDSS J2222+2745: A GRAVITATIONALLY LENSED SEXTUPLE QUASAR WITH A MAXIMUM IMAGE SEPARATION OF 15.''1 DISCOVERED IN THE SLOAN GIANT ARCS SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahle, H.; Groeneboom, N.; Gladders, M. D.

2013-08-20

We report the discovery of a unique gravitational lens system, SDSS J2222+2745, producing five spectroscopically confirmed images of a z{sub s} = 2.82 quasar lensed by a foreground galaxy cluster at z{sub l} = 0.49. We also present photometric and spectroscopic evidence for a sixth lensed image of the same quasar. The maximum separation between the quasar images is 15.''1. Both the large image separations and the high image multiplicity are in themselves rare among known lensed quasars, and observing the combination of these two factors is an exceptionally unlikely occurrence in present data sets. This is only the thirdmore » known case of a quasar lensed by a cluster, and the only one with six images. The lens system was discovered in the course of the Sloan Giant Arcs Survey, in which we identify candidate lenses in the Sloan Digital Sky Survey and target these for follow-up and verification with the 2.56 m Nordic Optical Telescope. Multi-band photometry obtained over multiple epochs from 2011 September to 2012 September reveals significant variability at the {approx}10%-30% level in some of the quasar images, indicating that measurements of the relative time delay between quasar images will be feasible. In this lens system, we also identify a bright (g = 21.5) giant arc corresponding to a strongly lensed background galaxy at z{sub s} = 2.30. We fit parametric models of the lens system, constrained by the redshift and positions of the quasar images and the redshift and position of the giant arc. The predicted time delays between different pairs of quasar images range from {approx}100 days to {approx}6 yr.« less

Long-term Study of the Solar Filaments from the Synoptic Maps as Derived from {{\\rm{H}}}_{\\alpha } Spectroheliograms of the Kodaikanal Observatory

NASA Astrophysics Data System (ADS)

Chatterjee, Subhamoy; Hegde, Manjunath; Banerjee, Dipankar; Ravindra, B.

2017-11-01

The century long (1914-2007) {{{H}}}α (656.28 nm) spectroheliograms from the Kodaikanal Solar Observatory (KSO) have been recently digitized. Using these newly calibrated, processed images we study the evolution of dark elongated on-disk structures called filaments, which are potential representatives of magnetic activities on the Sun. To our knowledge, this is the oldest uniform digitized data set with daily images available today in {{{H}}}α . We generate Carrington maps for the entire time duration and try to find the correlations with maps of the same Carrington rotation from the Ca II K KSO data. Filaments are segmented from the Carrington maps using a semi-automated technique and are studied individually to extract their centroids and tilts. We plot the time-latitude distribution of the filament centroids, producing a butterfly diagram which clearly shows the presence of poleward migration. We separate polar filaments for each cycle and try to estimate the delay between the polar filament number cycle and the sunspot number cycle peaks. We correlate this delay with the delay between polar reversal and sunspot number maxima. This provides new insight on the role of polar filaments on polar reversal.

Testing the performance of superhydrophobic aluminum surfaces.

PubMed

Ruiz-Cabello, F Javier Montes; Ibáñez-Ibáñez, Pablo F; Gómez-Lopera, J Francisco; Martínez-Aroza, José; Cabrerizo-Vílchez, Miguel; Rodríguez-Valverde, Miguel A

2017-12-15

The analysis of wetting properties of superhydrophobic surfaces may be a difficult task due to the restless behavior of drops on this type of surfaces and the limitations of goniometry for high contact angles. A method to validate the performance of superhydrophobic surfaces, rather than standard goniometry, is required. In this work, we used bouncing drop dynamics as a useful tool to predict the water repellency of different superhydrophobic surfaces. From bouncing drop experiments conducted over a wide range of superhydrophobic surfaces, we found that those surfaces with a proper roughness degree and homogeneous chemical composition showed higher water-repellency. We also conducted a drop condensation study at saturating conditions aimed to determine whether there is direct correlation between water repellency and condensation delay. We found that the drop condensation process is strongly related to the surface topography, as well as the intrinsic wettability. The condensation is promoted on rough surfaces but it is delayed on intrinsically hydrophobic surfaces. However, the differences found in condensation delay between the superhydrophobic surfaces explored in this study cannot be justified by their chemical homogeneity nor their efficiency as water repellent surfaces, separately. Copyright © 2017 Elsevier Inc. All rights reserved.

Synchronization of discrete-time neural networks with delays and Markov jump topologies based on tracker information.

PubMed

Yang, Xinsong; Feng, Zhiguo; Feng, Jianwen; Cao, Jinde

2017-01-01

In this paper, synchronization in an array of discrete-time neural networks (DTNNs) with time-varying delays coupled by Markov jump topologies is considered. It is assumed that the switching information can be collected by a tracker with a certain probability and transmitted from the tracker to controller precisely. Then the controller selects suitable control gains based on the received switching information to synchronize the network. This new control scheme makes full use of received information and overcomes the shortcomings of mode-dependent and mode-independent control schemes. Moreover, the proposed control method includes both the mode-dependent and mode-independent control techniques as special cases. By using linear matrix inequality (LMI) method and designing new Lyapunov functionals, delay-dependent conditions are derived to guarantee that the DTNNs with Markov jump topologies to be asymptotically synchronized. Compared with existing results on Markov systems which are obtained by separately using mode-dependent and mode-independent methods, our result has great flexibility in practical applications. Numerical simulations are finally given to demonstrate the effectiveness of the theoretical results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spindle checkpoint–independent inhibition of mitotic chromosome segregation by Drosophila Mps1

PubMed Central

Althoff, Friederike; Karess, Roger E.; Lehner, Christian F.

2012-01-01

Monopolar spindle 1 (Mps1) is essential for the spindle assembly checkpoint (SAC), which prevents anaphase onset in the presence of misaligned chromosomes. Moreover, Mps1 kinase contributes in a SAC-independent manner to the correction of erroneous initial attachments of chromosomes to the spindle. Our characterization of the Drosophila homologue reveals yet another SAC-independent role. As in yeast, modest overexpression of Drosophila Mps1 is sufficient to delay progression through mitosis during metaphase, even though chromosome congression and metaphase alignment do not appear to be affected. This delay in metaphase depends on the SAC component Mad2. Although Mps1 overexpression in mad2 mutants no longer causes a metaphase delay, it perturbs anaphase. Sister kinetochores barely move apart toward spindle poles. However, kinetochore movements can be restored experimentally by separase-independent resolution of sister chromatid cohesion. We propose therefore that Mps1 inhibits sister chromatid separation in a SAC-independent manner. Moreover, we report unexpected results concerning the requirement of Mps1 dimerization and kinase activity for its kinetochore localization in Drosophila. These findings further expand Mps1's significance for faithful mitotic chromosome segregation and emphasize the importance of its careful regulation. PMID:22553353

Spindle checkpoint-independent inhibition of mitotic chromosome segregation by Drosophila Mps1.

PubMed

Althoff, Friederike; Karess, Roger E; Lehner, Christian F

2012-06-01

Monopolar spindle 1 (Mps1) is essential for the spindle assembly checkpoint (SAC), which prevents anaphase onset in the presence of misaligned chromosomes. Moreover, Mps1 kinase contributes in a SAC-independent manner to the correction of erroneous initial attachments of chromosomes to the spindle. Our characterization of the Drosophila homologue reveals yet another SAC-independent role. As in yeast, modest overexpression of Drosophila Mps1 is sufficient to delay progression through mitosis during metaphase, even though chromosome congression and metaphase alignment do not appear to be affected. This delay in metaphase depends on the SAC component Mad2. Although Mps1 overexpression in mad2 mutants no longer causes a metaphase delay, it perturbs anaphase. Sister kinetochores barely move apart toward spindle poles. However, kinetochore movements can be restored experimentally by separase-independent resolution of sister chromatid cohesion. We propose therefore that Mps1 inhibits sister chromatid separation in a SAC-independent manner. Moreover, we report unexpected results concerning the requirement of Mps1 dimerization and kinase activity for its kinetochore localization in Drosophila. These findings further expand Mps1's significance for faithful mitotic chromosome segregation and emphasize the importance of its careful regulation.

Investigation of the Air Quality Change Effect on Gnss Signals

NASA Astrophysics Data System (ADS)

Gurbuz, G.; Gormus, K. S.; Altan, U.

2017-11-01

Air pollution is the most important environmental problem in Zonguldak city center. Since bituminous coal is used for domestic heating in houses and generating electricity in thermal power plants, particulate matter (PM10) is the leading air pollutant. Previous studies have shown that the water vapor in the troposphere is responsible for the tropospheric zenith delay in Global Navigation Satellite System (GNSS) measurements. In this study, data obtained from the ZONG GNSS station from Türkiye Ulusal Sabit GNSS Ağı (TUSAGA-Active network) in the central district of Zonguldak province, processed with GIPSY-OASIS II and GAMIT/GlobK software using the VMF1 mapping function, which is developed previously and considered to be the most accurate model. The resulting values were examined separately in terms of software. The meteorological parameters obtained from the Turkish State Meteorological Service and the air pollution values obtained from the Ministry of Environment and Urban Planning were analyzed and the zenith delay values were compared. When wet zenith delays of different days with different amounts of PM10 concentrations were examined in succession and under the same meteorological conditions, differences in the range of 20-40 mm on ZTD were observed.

Electrocardiogram classification using delay differential equations

NASA Astrophysics Data System (ADS)

Lainscsek, Claudia; Sejnowski, Terrence J.

2013-06-01

Time series analysis with nonlinear delay differential equations (DDEs) reveals nonlinear as well as spectral properties of the underlying dynamical system. Here, global DDE models were used to analyze 5 min data segments of electrocardiographic (ECG) recordings in order to capture distinguishing features for different heart conditions such as normal heart beat, congestive heart failure, and atrial fibrillation. The number of terms and delays in the model as well as the order of nonlinearity of the model have to be selected that are the most discriminative. The DDE model form that best separates the three classes of data was chosen by exhaustive search up to third order polynomials. Such an approach can provide deep insight into the nature of the data since linear terms of a DDE correspond to the main time-scales in the signal and the nonlinear terms in the DDE are related to nonlinear couplings between the harmonic signal parts. The DDEs were able to detect atrial fibrillation with an accuracy of 72%, congestive heart failure with an accuracy of 88%, and normal heart beat with an accuracy of 97% from 5 min of ECG, a much shorter time interval than required to achieve comparable performance with other methods.

Eye-movements intervening between two successive sounds disrupt comparisons of auditory location

PubMed Central

Pavani, Francesco; Husain, Masud; Driver, Jon

2008-01-01

Summary Many studies have investigated how saccades may affect the internal representation of visual locations across eye-movements. Here we studied instead whether eye-movements can affect auditory spatial cognition. In two experiments, participants judged the relative azimuth (same/different) of two successive sounds presented from a horizontal array of loudspeakers, separated by a 2.5 secs delay. Eye-position was either held constant throughout the trial (being directed in a fixed manner to the far left or right of the loudspeaker array), or had to be shifted to the opposite side of the array during the retention delay between the two sounds, after the first sound but before the second. Loudspeakers were either visible (Experiment1) or occluded from sight (Experiment 2). In both cases, shifting eye-position during the silent delay-period affected auditory performance in the successive auditory comparison task, even though the auditory inputs to be judged were equivalent. Sensitivity (d′) for the auditory discrimination was disrupted, specifically when the second sound shifted in the opposite direction to the intervening eye-movement with respect to the first sound. These results indicate that eye-movements affect internal representation of auditory location. PMID:18566808

Eye-movements intervening between two successive sounds disrupt comparisons of auditory location.

PubMed

Pavani, Francesco; Husain, Masud; Driver, Jon

2008-08-01

Many studies have investigated how saccades may affect the internal representation of visual locations across eye-movements. Here, we studied, instead, whether eye-movements can affect auditory spatial cognition. In two experiments, participants judged the relative azimuth (same/different) of two successive sounds presented from a horizontal array of loudspeakers, separated by a 2.5-s delay. Eye-position was either held constant throughout the trial (being directed in a fixed manner to the far left or right of the loudspeaker array) or had to be shifted to the opposite side of the array during the retention delay between the two sounds, after the first sound but before the second. Loudspeakers were either visible (Experiment 1) or occluded from sight (Experiment 2). In both cases, shifting eye-position during the silent delay-period affected auditory performance in thn the successive auditory comparison task, even though the auditory inputs to be judged were equivalent. Sensitivity (d') for the auditory discrimination was disrupted, specifically when the second sound shifted in the opposite direction to the intervening eye-movement with respect to the first sound. These results indicate that eye-movements affect internal representation of auditory location.

LIGHT EXPOSURE AMONG ADOLESCENTS WITH DELAYED SLEEP PHASE DISORDER: A PROSPECTIVE COHORT STUDY

PubMed Central

Auger, R. Robert; Burgess, Helen J.; Dierkhising, Ross A.; Sharma, Ruchi G.; Slocumb, Nancy L.

2012-01-01

Our study objective was to compare light exposure and sleep parameters between adolescents with delayed sleep phase disorder (n=16, 15.3 ± 1.8 years) and unaffected controls (n=22, 13.7 ± 2.4 years) using a prospective cohort design. Participants wore wrist actigraphs with photosensors for 14 days. Mean hourly lux levels from 20:00-05:00 h and 05:00-14:00 h were examined, in addition to the 9-hour intervals prior to sleep onset and after sleep offset. Sleep parameters were compared separately, and were also included as covariates within models that analyzed associations with specified light intervals. Additional covariates included group and school night status. Adolescent subjects with delayed sleep phase disorder received more evening (p<0.02, 22:00-02:00 h) and less morning light (p<0.05, 08:00-09:00 h and 10:00-12:00 h) than controls, but had less pre-sleep exposure with adjustments for the time of sleep onset (p<0.03, fifth-seventh hours prior to onset hour). No differences were identified with respect to the sleep offset interval. Increased total sleep time and later sleep offset times were associated with decreased evening (p<0.001 and p=0.02, respectively) and morning (p=0.01 and p<0.001, respectively) exposure, and later sleep onset times were associated with increased evening exposure (p<0.001). Increased total sleep time also correlated with increased exposure during the 9 hours before sleep-onset (p=0.01), and a later sleep onset time corresponded with decreased exposure during the same interval (p<0.001). Outcomes persisted regardless of school night status. In conclusion, light exposure interpretation requires adjustments for sleep timing among adolescents with delayed sleep phase disorder. Pre- and post-sleep exposure do not appear to contribute directly to phase delays. Sensitivity to morning light may be reduced among adolescents with delayed sleep phase disorder. PMID:22080736

Optimizing MRI Logistics: Prospective Analysis of Performance, Efficiency, and Patient Throughput.

PubMed

Beker, Kevin; Garces-Descovich, Alejandro; Mangosing, Jason; Cabral-Goncalves, Ines; Hallett, Donna; Mortele, Koenraad J

2017-10-01

The objective of this study is to optimize MRI logistics through evaluation of MRI workflow and analysis of performance, efficiency, and patient throughput in a tertiary care academic center. For 2 weeks, workflow data from two outpatient MRI scanners were prospectively collected and stratified by value added to the process (i.e., value-added time, business value-added time, or non-value-added time). Two separate time cycles were measured: the actual MRI process cycle as well as the complete length of patient stay in the department. In addition, the impact and frequency of delays across all observations were measured. A total of 305 MRI examinations were evaluated, including body (34.1%), neurologic (28.9%), musculoskeletal (21.0%), and breast examinations (16.1%). The MRI process cycle lasted a mean of 50.97 ± 24.4 (SD) minutes per examination; the mean non-value-added time was 13.21 ± 18.77 minutes (25.87% of the total process cycle time). The mean length-of-stay cycle was 83.51 ± 33.63 minutes; the mean non-value-added time was 24.33 ± 24.84 minutes (29.14% of the total patient stay). The delay with the highest frequency (5.57%) was IV or port placement, which had a mean delay of 22.82 minutes. The delay with the greatest impact on time was MRI arthrography for which joint injection of contrast medium was necessary but was not accounted for in the schedule (mean delay, 42.2 minutes; frequency, 1.64%). Of 305 patients, 34 (11.15%) did not arrive at or before their scheduled time. Non-value-added time represents approximately one-third of the total MRI process cycle and patient length of stay. Identifying specific delays may expedite the application of targeted improvement strategies, potentially increasing revenue, efficiency, and overall patient satisfaction.

Effect of a single intraoperative high-dose ATG-Fresenius on delayed graft function in donation after cardiac-death donor renal allograft recipients: a randomized study.

PubMed

van den Hoogen, Martijn W F; Kho, Marcia M L; Abrahams, Alferso C; van Zuilen, Arjan D; Sanders, Jan-Stephan; van Dijk, Marja; Hilbrands, Luuk B; Weimar, Willem; Hoitsma, Andries J

2013-04-01

Reducing the incidence of delayed graft function after transplant with donation after cardiac death donor renal allografts would facilitate managing recipients during their first weeks after a transplant. To reduce this incidence, in most studies, induction therapy with depleting anti-T-lymphocyte antibodies is coupled with a reduction of the dosage of the calcineurin inhibitor. The separate effect of anti-T-cell therapy on the incidence and duration of delayed graft function is therefore difficult to assess. We performed a randomized study to evaluate the effect of a single intraoperative high-dose of anti-T-lymphocyte immunoglobulin (ATG)-Fresenius (9 mg/kg body weight) on the incidence of delayed graft function. Eligible adult recipients of a first donation after cardiac death donor renal allograft were randomly assigned to ATG-Fresenius or no induction therapy. Maintenance immunosuppression consisted of tacrolimus, in an unadjusted dose, mycophenolate mofetil, and steroids. The study was prematurely terminated because of a lower-than-anticipated inclusion rate. Baseline characteristics were comparable in the ATG-Fresenius group (n=28) and the control group (n=24). Twenty-two patients in the ATG-Fresenius group (79%) had delayed graft function, compared with 13 in the control group (54%; P = .06). Allograft and patient survival were comparable in both groups. Serious adverse events occurred more frequently in the ATG-Fresenius group than they did in the control group (57% vs 29%; P < .05). Intraoperative administration of a single high-dose of ATG-Fresenius in donation after cardiac death donor renal allograft recipients, followed by triple immunosuppression with an unadjusted tacrolimus dose, seems ineffective to reduce the incidence of delayed graft function. Moreover, this was associated with a higher rate of serious adverse events (EudraCT-number, 2007-000210-36.).

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745

NASA Astrophysics Data System (ADS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Håkon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τAB = 47.7 ± 6.0 days and τAC = -722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τAD = 502 ± 68 days, τAE = 611 ± 75 days, and τAF = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-13337.

A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes.

PubMed

García-Berro, Enrique; Torres, Santiago; Althaus, Leandro G; Renedo, Isabel; Lorén-Aguilar, Pablo; Córsico, Alejandro H; Rohrmann, René D; Salaris, Maurizio; Isern, Jordi

2010-05-13

NGC 6791 is a well studied open cluster that it is so close to us that can be imaged down to very faint luminosities. The main-sequence turn-off age ( approximately 8 Gyr) and the age derived from the termination of the white dwarf cooling sequence ( approximately 6 Gyr) are very different. One possible explanation is that as white dwarfs cool, one of the ashes of helium burning, (22)Ne, sinks in the deep interior of these stars. At lower temperatures, white dwarfs are expected to crystallize and phase separation of the main constituents of the core of a typical white dwarf ((12)C and (16)O) is expected to occur. This sequence of events is expected to introduce long delays in the cooling times, but has not hitherto been proven. Here we report that, as theoretically anticipated, physical separation processes occur in the cores of white dwarfs, resolving the age discrepancy for NGC 6791.

Active Control of Separation From the Flap of a Supercritical Airfoil

NASA Technical Reports Server (NTRS)

Melton, LaTunia Pack; Yao, Chung-Sheng; Seifert, Avi

2006-01-01

Zero-mass-flux periodic excitation was applied at several regions on a simplified high-lift system to delay the occurrence of flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control at several locations on the deflected trailing edge flap. High frequency (F(+) approximately equal to 10) and low frequency amplitude modulation (F(+) sub AM approximately equal to 1) of the high frequency excitation were used for control. It was noted that the same performance gains were obtained with amplitude modulation and required only 30% of the momentum input required by pure sine excitation.

Active Control of Separation From the Flap of a Supercritical Airfoil

NASA Technical Reports Server (NTRS)

Melton, La Tunia Pack; Yao, Chung-Sheng; Seifert, Avi

2003-01-01

Active flow control in the form of periodic zero-mass-flux excitation was applied at several regions on the leading edge and trailing edge flaps of a simplified high-lift system t o delay flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control at several locations on the deflected trailing edge flap. High frequency (F(+) approx.= 10) and low frequency amplitude modulation (F(+)AM approx.= 1) of the high frequency excitation were used for control. Preliminary efforts to combine leading and trailing edge flap excitations are also reported.

Vaccination Confidence and Parental Refusal/Delay of Early Childhood Vaccines

PubMed Central

Gilkey, Melissa B.; McRee, Annie-Laurie; Magnus, Brooke E.; Reiter, Paul L.; Dempsey, Amanda F.; Brewer, Noel T.

2016-01-01

Objective To support efforts to address parental hesitancy towards early childhood vaccination, we sought to validate the Vaccination Confidence Scale using data from a large, population-based sample of U.S. parents. Methods We used weighted data from 9,354 parents who completed the 2011 National Immunization Survey. Parents reported on the immunization history of a 19- to 35-month-old child in their households. Healthcare providers then verified children’s vaccination status for vaccines including measles, mumps, and rubella (MMR), varicella, and seasonal flu. We used separate multivariable logistic regression models to assess associations between parents’ mean scores on the 8-item Vaccination Confidence Scale and vaccine refusal, vaccine delay, and vaccination status. Results A substantial minority of parents reported a history of vaccine refusal (15%) or delay (27%). Vaccination confidence was negatively associated with refusal of any vaccine (odds ratio [OR] = 0.58, 95% confidence interval [CI], 0.54–0.63) as well as refusal of MMR, varicella, and flu vaccines specifically. Negative associations between vaccination confidence and measures of vaccine delay were more moderate, including delay of any vaccine (OR = 0.81, 95% CI, 0.76–0.86). Vaccination confidence was positively associated with having received vaccines, including MMR (OR = 1.53, 95% CI, 1.40–1.68), varicella (OR = 1.54, 95% CI, 1.42–1.66), and flu vaccines (OR = 1.32, 95% CI, 1.23–1.42). Conclusions Vaccination confidence was consistently associated with early childhood vaccination behavior across multiple vaccine types. Our findings support expanding the application of the Vaccination Confidence Scale to measure vaccination beliefs among parents of young children. PMID:27391098

Impact of patient navigation in eliminating economic disparities in cancer care.

PubMed

Rodday, Angie Mae; Parsons, Susan K; Snyder, Frederick; Simon, Melissa A; Llanos, Adana A M; Warren-Mears, Victoria; Dudley, Donald; Lee, Ji-Hyun; Patierno, Steven R; Markossian, Talar W; Sanders, Mechelle; Whitley, Elizabeth M; Freund, Karen M

2015-11-15

Patient navigation may reduce cancer disparities associated with socioeconomic status (SES) and household factors. This study examined whether these factors were associated with delays in diagnostic resolution among patients with cancer screening abnormalities and whether patient navigation ameliorated these delays. This study analyzed data from 5 of 10 centers of the National Cancer Institute's Patient Navigation Research Program, which collected SES and household data on employment, income, education, housing, marital status, and household composition. The primary outcome was the time to diagnostic resolution after a cancer screening abnormality. Separate adjusted Cox proportional hazard models were fit for each SES and household factor, and an interaction between that factor and the intervention status was included. Among the 3777 participants (1968 in the control arm and 1809 in the navigation intervention arm), 91% were women, and the mean age was 44 years; 43% were Hispanic, 28% were white, and 27% were African American. Within the control arm, the unemployed experienced a longer time to resolution than those employed full-time (hazard ratio [HR], 0.85; P = .02). Renters (HR, 0.81; P = .02) and those with other (ie, unstable) housing (HR, 0.60; P < .001) had delays in comparison with homeowners. Never married (HR, 0.70; P < .001) and previously married participants (HR, 0.85; P = .03) had a longer time to care than married participants. There were no differences in the time to diagnostic resolution with any of these variables within the navigation intervention arm. Delays in diagnostic resolution exist by employment, housing type, and marital status. Patient navigation eliminated these disparities in the study sample. These findings demonstrate the value of providing patient navigation to patients at high risk for delays in cancer care. © 2015 American Cancer Society.

Lateralized delay period activity marks the focus of spatial attention in working memory: evidence from somatosensory event-related brain potentials.

PubMed

Katus, Tobias; Eimer, Martin

2015-04-29

The short-term retention of sensory information in working memory (WM) is known to be associated with a sustained enhancement of neural activity. What remains controversial is whether this neural trace indicates the sustained storage of information or the allocation of attention. To evaluate the storage and attention accounts, we examined sustained tactile contralateral delay activity (tCDA component) of the event-related potential. The tCDA manifests over somatosensory cortex contralateral to task-relevant tactile information during stimulus retention. Two tactile sample sets (S1, S2) were presented sequentially, separated by 1.5 s. Each set comprised two stimuli, one per hand. Human participants memorized the location of one task-relevant stimulus per sample set and judged whether one of these locations was stimulated again at memory test. The two relevant pulses were unpredictably located on the same hand (stay trials) or on different hands (shift trials). Initially, tCDA components emerged contralateral to the relevant S1 pulse. Sequential loading of WM enhanced the tCDA after S2 was presented on stay trials. On shift trials, the tCDA's polarity reversed after S2 presentation, resulting in delay activity that was now contralateral to the task-relevant S2 pulse. The disappearance of a lateralized neural trace for the relevant S1 pulse did not impair memory accuracy for this stimulus on shift trials. These results contradict the storage account and suggest that delay period activity indicates the sustained engagement of an attention-based rehearsal mechanism. In conclusion, somatosensory delay period activity marks the current focus of attention in tactile WM. Copyright © 2015 the authors 0270-6474/15/356689-07$15.00/0.

The Cost Implications in Ontario, Alberta, and British Columbia of Early Versus Delayed External Cephalic Version in the Early External Cephalic Version 2 (EECV2) Trial.

PubMed

Ahmed, Rashid J; Gafni, Amiram; Hutton, Eileen K

2016-03-01

According to the Early External Cephalic Version (EECV2) Trial, planning external cephalic version (ECV) early in pregnancy results in fewer breech presentations at delivery compared with delayed external cephalic version. A Cochrane review conducted after the EECV2 Trial identified an increase in preterm birth associated with early ECV. We examined whether a policy of routine early ECV (i.e., before 37 weeks' gestation) is more or less costly than a policy of delayed ECV. We undertook this analysis from the perspective of a third-party payer (Ministry of Health). We applied data, using resources reported in the EECV2 Trial, to the Canadian context using 10 hospital unit costs and 17 physician service/procedure unit costs. The data were derived from the provincial health insurance plan schedule of medical benefits in three Canadian provinces (Ontario, Alberta, and British Columbia). The difference in mean total costs between study groups was tested for each province separately. We found that planning early ECV results in higher costs than planning delayed ECV. The mean costs of all physician services/procedures and hospital units for planned ECV compared with delayed ECV were $7997.32 versus $7263.04 in Ontario (P < 0.001), $8162.82 versus $7410.55 in Alberta (P < 0.001), and $8178.92 versus $7417.04 in British Columbia (P < 0.001), respectively. From the perspective of overall cost, our analyses do not support a policy of routinely planning ECV before 37 weeks' gestation. Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

Topographic Organization for Delayed Saccades in Human Posterior Parietal Cortex

PubMed Central

Schluppeck, Denis; Glimcher, Paul; Heeger, David J.

2008-01-01

Posterior parietal cortex (PPC) is thought to play a critical role in decision making, sensory attention, motor intention, and/or working memory. Research on the PPC in non-human primates has focused on the lateral intraparietal area (LIP) in the intraparietal sulcus (IPS). Neurons in LIP respond after the onset of visual targets, just before saccades to those targets, and during the delay period in between. To study the function of posterior parietal cortex in humans, it will be crucial to have a routine and reliable method for localizing specific parietal areas in individual subjects. Here, we show that human PPC contains at least two topographically organized regions, which are candidates for the human homologue of LIP. We mapped the topographic organization of human PPC for delayed (memory guided) saccades using fMRI. Subjects were instructed to fixate centrally while a peripheral target was briefly presented. After a further 3-s delay, subjects made a saccade to the remembered target location followed by a saccade back to fixation and a 1-s inter-trial interval. Targets appeared at successive locations “around the clock” (same eccentricity, ≈30° angular steps), to produce a traveling wave of activity in areas that are topographically organized. PPC exhibited topographic organization for delayed saccades. We defined two areas in each hemisphere that contained topographic maps of the contralateral visual field. These two areas were immediately rostral to V7 as defined by standard retinotopic mapping. The two areas were separated from each other and from V7 by reversals in visual field orientation. However, we leave open the possibility that these two areas will be further subdivided in future studies. Our results demonstrate that topographic maps tile the cortex continuously from V1 well into PPC. PMID:15817644

Comparative Shock-Tube Study of Autoignition and Plasma-Assisted Ignition of C2-Hydrocarbons

NASA Astrophysics Data System (ADS)

Kosarev, Ilya; Kindysheva, Svetlana; Plastinin, Eugeny; Aleksandrov, Nikolay; Starikovskiy, Andrey

2015-09-01

The dynamics of pulsed picosecond and nanosecond discharge development in liquid water, ethanol and hexane Using a shock tube with a discharge cell, ignition delay time was measured in a lean (φ = 0.5) C2H6:O2:Ar mixture and in lean (φ = 0.5) and stoichiometric C2H4:O2:Ar mixtures with a high-voltage nanosecond discharge and without it. The measured results were compared with the measurements made previously with the same setup for C2H6-, C2H5OH- and C2H2-containing mixtures. It was shown that the effect of plasma on ignition is almost the same for C2H6, C2H4 and C2H5OH. The reduction in time is smaller for C2H2, the fuel that is well ignited even without the discharge. Autoignition delay time was independent of the stoichiometric ratio for C2H6 and C2H4, whereas this time in stoichiometric C2H2- and C2H5OH-containing mixtures was noticeably shorter than that in the lean mixtures. Ignition after the discharge was not affected by a change in the stoichiometric ratio for C2H2 and C2H4, whereas the plasma-assisted ignition delay time for C2H6 and C2H5OH decreased as the equivalence ratio changed from 1 to 0.5. Ignition delay time was calculated in C2-hydrocarbon-containing mixtures under study by simulating separately discharge and ignition processes. Good agreement was obtained between new measurements and calculated ignition delay times.

[Neurodevelopmental Outcomes of Very Preterm or Very Low Birth Weigth Infants: Comparison of Monochorionic and Dichorionic Twins with Singletons].

PubMed

Taborda, Adelaide; Oliveira, Guiomar

2016-11-01

Twins are associated with a delayed development and cerebral palsy. The purpose of this work was to compare the neurologic morbidity in very preterm or very low birth weight dichorionic and monochorionic twins with singletons. We conducted a retrospective cohort study of livebirths lowest through 32 weeks of gestation or very low weight infants admitted to Neonatal Intensive Care Unit of a level III hospital, between 2006 and 2010. Development was evaluated with the Growing Skills II Scale at 24 months of age. Cerebral palsy was defined by predetermined criteria by Surveillance of Cerebral Palsy in Europe. Infants were analyzed as twins and singletons cohort. Within the twin category the infants were further separated as dichorionic and monochorionic and were compared with singletons infants. Logistic regression models were used to control for demographic and clinical factors. The cohort of infants who were assessed for neurodevelopmental impaired, consisted of 194 singletons infants and 89 twins (50 dichorionic; 39 monochorionic). Monochorionic twins, when compared with the singletons, showed an increased risk of severe developmental delay in these areas: locomotion (adjusted OR 12.2) language (adjusted OR 6.5) and autonomy (adjusted OR 7.2). Cerebral palsy was diagnosed in 4.1% of singleton infants and 15.4% of monochorionic twins. The adjusted risk of severe developmental delay and cerebral palsy in monochorionic twins was 3.6 and 4.2, respectively. This work showed higher rate of moderate and severe neurodevelopment delay including cerebral palsy in monochorionic twins compared to singletons infants. Analysis by groups stratified according to gestational age and comparison of monochorionic and dichorionic twins displayed the role of chorionicity for these neurodevelopmental disorders. In our sample the monochorionic twins are associated with an independent risk of neurodevelopmental delay.

The impact of patient navigation in eliminating economic disparities in cancer care

PubMed Central

Rodday, Angie Mae; Parsons, Susan K.; Snyder, Frederick; Simon, Melissa A.; Llanos, Adana A.M.; Warren-Mears, Victoria; Dudley, Donald; Lee, Ji-Hyun; Patierno, Steve R.; Markossian, Talar W.; Sanders, Mechelle; Whitley, Elizabeth; Freund, Karen M.

2015-01-01

Background Patient navigation may reduce cancer disparities associated with socioeconomic status (SES) and household factors. We examined whether these factors were associated with delays in diagnostic resolution among patients with cancer screening abnormalities and whether patient navigation ameliorated these delays. Methods We analyzed data from five of ten centers from the NCI Patient Navigation Research Program that collected SES and household data on employment, income, education, housing, marital status, and household composition. The primary outcome was time to diagnostic resolution following a cancer screening abnormality. We fit separate adjusted Cox proportional hazard models for each SES and household factor and included an interaction between that factor and intervention status. Results Among 3777 participants (n=1968 control, n=1809 navigation intervention), 91% were women, with a mean age of 44 years, and 43% were Hispanic, 28% White, and 27% African American. Within the control arm, the unemployed experienced longer time to resolution than the full-time employed (HR=0.85, p=0.02). Renters (HR=0.81, p=0.02) and those with other (i.e., unstable) housing (HR=0.60, p<0.001) had delays compared to homeowners. Never married (HR=0.70, p<0.001) and previously married participants (HR=0.85, p=0.03) had longer time to care than married participants. There were no differences in time to diagnostic resolution by any of these variables within the navigation intervention arm. Conclusions Delays in diagnostic resolution exist by employment, housing type, and marital status. Patient navigation eliminated these disparities in our study sample. Our findings demonstrate the value of providing patient navigation to patients at high risk for delays in cancer care. PMID:26348120

Assessment of langatate material constants and temperature coefficients using SAW delay line measurements.

PubMed

Sturtevant, Blake T; Pereira da Cunha, Mauricio

2010-03-01

This paper reports on the assessment of langatate (LGT) acoustic material constants and temperature coefficients by surface acoustic wave (SAW) delay line measurements up to 130 degrees C. Based upon a full set of material constants recently reported by the authors, 7 orientations in the LGT plane with Euler angles (90 degrees, 23 degrees, Psi) were identified for testing. Each of the 7 selected orientations exhibited calculated coupling coefficients (K(2)) between 0.2% and 0.75% and also showed a large range of predicted temperature coefficient of delay (TCD) values around room temperature. Additionally, methods for estimating the uncertainty in predicted SAW propagation properties were developed and applied to SAW phase velocity and temperature coefficient of delay calculations. Starting from a purchased LGT boule, the SAW wafers used in this work were aligned, cut, ground, and polished at University of Maine facilities, followed by device fabrication and testing. Using repeated measurements of 2 devices on separate wafers for each of the 7 orientations, the room temperature SAW phase velocities were extracted with a precision of 0.1% and found to be in agreement with the predicted values. The normalized frequency change and the temperature coefficient of delay for all 7 orientations agreed with predictions within the uncertainty of the measurement and the predictions over the entire 120 degrees C temperature range measured. Two orientations, with Euler angles (90 degrees, 23 degrees, 123 degrees) and (90 degrees, 23 degrees, 119 degrees), were found to have high predicted coupling for LGT (K(2) > 0.5%) and were shown experimentally to exhibit temperature compensation in the vicinity of room temperature, with turnover temperatures at 50 and 60 degrees C, respectively.

Contribution of delayed rectifier potassium currents to the electrical activity of murine colonic smooth muscle

PubMed Central

Koh, S D; Ward, S M; Dick, G M; Epperson, A; Bonner, H P; Sanders, K M; Horowitz, B; Kenyon, J L

1999-01-01

We used intracellular microelectrodes to record the membrane potential (Vm) of intact murine colonic smooth muscle. Electrical activity consisted of spike complexes separated by quiescent periods (Vm≈−60 mV). The spike complexes consisted of about a dozen action potentials of approximately 30 mV amplitude. Tetraethylammonium (TEA, 1–10 mM) had little effect on the quiescent periods but increased the amplitude of the action potential spikes. 4-Aminopyridine (4-AP, ⋧ 5 mM) caused continuous spiking.Voltage clamp of isolated myocytes identified delayed rectifier K+ currents that activated rapidly (time to half-maximum current, 11.5 ms at 0 mV) and inactivated in two phases (τf = 96 ms, τs = 1.5 s at 0 mV). The half-activation voltage of the permeability was −27 mV, with significant activation at −50 mV.TEA (10 mM) reduced the outward current at potentials positive to 0 mV. 4-AP (5 mM) reduced the early current but increased outward current at later times (100–500 ms) consistent with block of resting channels relieved by depolarization. 4-AP inhibited outward current at potentials negative to −20 mV, potentials where TEA had no effect.Qualitative PCR amplification of mRNA identified transcripts encoding delayed rectifier K+ channel subunits Kv1.6, Kv4.1, Kv4.2, Kv4.3 and the Kvβ1.1 subunit in murine colon myocytes. mRNA encoding Kv 1.4 was not detected.We find that TEA-sensitive delayed rectifier currents are important determinants of action potential amplitude but not rhythmicity. Delayed rectifier currents sensitive to 4-AP are important determinants of rhythmicity but not action potential amplitude. PMID:10050014

Distribution of a Generic Mission Planning and Scheduling Toolkit for Astronomical Spacecraft

NASA Technical Reports Server (NTRS)

Kleiner, Steven C.

1998-01-01

This 2-year report describes the progress made to date on the project to package and distribute the planning and scheduling toolkit for the SWAS astronomical spacecraft. SWAS was scheduled to be launched on a Pegasus XL vehicle in fall 1995. Three separate failures in the launch vehicle have delayed the SWAS launch. The researchers have used this time to continue developing scheduling algorithms and GUI design. SWAS is expected to be launched this year.

On the unity of children’s phonological error patterns: Distinguishing symptoms from the problem

PubMed Central

Dinnsen, Daniel A.

2012-01-01

This article compares the claims of rule- and constraint-based accounts of three seemingly distinct error patterns, namely, Deaffrication, Consonant Harmony and Assibilation, in the sound system of a child with a phonological delay. It is argued that these error patterns are not separate problems, but rather are symptoms of a larger conspiracy to avoid word-initial coronal stops. The clinical implications of these findings are also considered. PMID:21787147

Low jitter, low inductance solid dielectric switches.

PubMed

Guenther, A H; Strickland, D M; Bettis, J R

1979-11-01

It has been shown that the use of graded solid dielectric sandwiches in laser-triggered spark gaps (LTS) can lead to highly desirable multichannel operations while maintaining the low delay and jitter performance characteristics of LTS. As many as ten separate breakdown channels were observed when small circular or hexagonal aluminum inserts were inserted between two Mylar dielectric sheets stressed at 4.1 kV/mil. A reduction in rise time was noted for these multichannel switching events.

The absence or temporal offset of visual feedback does not influence adaptation to novel movement dynamics.

PubMed

McKenna, Erin; Bray, Laurence C Jayet; Zhou, Weiwei; Joiner, Wilsaan M

2017-10-01

Delays in transmitting and processing sensory information require correctly associating delayed feedback to issued motor commands for accurate error compensation. The flexibility of this alignment between motor signals and feedback has been demonstrated for movement recalibration to visual manipulations, but the alignment dependence for adapting movement dynamics is largely unknown. Here we examined the effect of visual feedback manipulations on force-field adaptation. Three subject groups used a manipulandum while experiencing a lag in the corresponding cursor motion (0, 75, or 150 ms). When the offset was applied at the start of the session (continuous condition), adaptation was not significantly different between groups. However, these similarities may be due to acclimation to the offset before motor adaptation. We tested additional subjects who experienced the same delays concurrent with the introduction of the perturbation (abrupt condition). In this case adaptation was statistically indistinguishable from the continuous condition, indicating that acclimation to feedback delay was not a factor. In addition, end-point errors were not significantly different across the delay or onset conditions, but end-point correction (e.g., deceleration duration) was influenced by the temporal offset. As an additional control, we tested a group of subjects who performed without visual feedback and found comparable movement adaptation results. These results suggest that visual feedback manipulation (absence or temporal misalignment) does not affect adaptation to novel dynamics, independent of both acclimation and perceptual awareness. These findings could have implications for modeling how the motor system adjusts to errors despite concurrent delays in sensory feedback information. NEW & NOTEWORTHY A temporal offset between movement and distorted visual feedback (e.g., visuomotor rotation) influences the subsequent motor recalibration, but the effects of this offset for altered movement dynamics are largely unknown. Here we examined the influence of 1 ) delayed and 2 ) removed visual feedback on the adaptation to novel movement dynamics. These results contribute to understanding of the control strategies that compensate for movement errors when there is a temporal separation between motion state and sensory information. Copyright © 2017 the American Physiological Society.

Two-Component Structure of the Radio Source 0014+813 from VLBI Observations within the CONT14 Program

NASA Astrophysics Data System (ADS)

Titov, O. A.; Lopez, Yu. R.

2018-03-01

We consider a method of reconstructing the structure delay of extended radio sources without constructing their radio images. The residuals derived after the adjustment of geodetic VLBI observations are used for this purpose. We show that the simplest model of a radio source consisting of two point components can be represented by four parameters (the angular separation of the components, the mutual orientation relative to the poleward direction, the flux-density ratio, and the spectral index difference) that are determined for each baseline of a multi-baseline VLBI network. The efficiency of this approach is demonstrated by estimating the coordinates of the radio source 0014+813 observed during the two-week CONT14 program organized by the International VLBI Service (IVS) in May 2014. Large systematic deviations have been detected in the residuals of the observations for the radio source 0014+813. The averaged characteristics of the radio structure of 0014+813 at a frequency of 8.4 GHz can be calculated from these deviations. Our modeling using four parameters has confirmed that the source consists of two components at an angular separation of 0.5 mas in the north-south direction. Using the structure delay when adjusting the CONT14 observations leads to a correction of the average declination estimate for the radio source 0014+813 by 0.070 mas.

Sports teams as complex adaptive systems: manipulating player numbers shapes behaviours during football small-sided games.

PubMed

Silva, Pedro; Vilar, Luís; Davids, Keith; Araújo, Duarte; Garganta, Júlio

2016-01-01

Small-sided and conditioned games (SSCGs) in sport have been modelled as complex adaptive systems. Research has shown that the relative space per player (RSP) formulated in SSCGs can impact on emergent tactical behaviours. In this study we adopted a systems orientation to analyse how different RSP values, obtained through manipulations of player numbers, influenced four measures of interpersonal coordination observed during performance in SSCGs. For this purpose we calculated positional data (GPS 15 Hz) from ten U-15 football players performing in three SSCGs varying in player numbers (3v3, 4v4 and 5v5). Key measures of SSCG system behaviours included values of (1) players' dispersion, (2) teams' separateness, (3) coupling strength and time delays between participants' emerging movements, respectively. Results showed that values of participants' dispersion increased, but the teams' separateness remained identical across treatments. Coupling strength and time delay also showed consistent values across SSCGs. These results exemplified how complex adaptive systems, like football teams, can harness inherent degeneracy to maintain similar team spatial-temporal relations with opponents through changes in inter-individual coordination modes (i.e., players' dispersion). The results imply that different team behaviours might emerge at different ratios of field dimension/player numbers. Therefore, sport pedagogists should carefully evaluate the effects of changing RSP in SSCGs as a way of promoting increased or decreased pressure on players.

Laser-Ranging Transponders for Science Investigations of the Moon and Mars

NASA Technical Reports Server (NTRS)

Hemmati, Hamid; Chen, Yijiang; Bimbaum, Kevin

2012-01-01

An active laser was developed ranging in real-time with two terminals, emulating interplanetary distances, and with submillimeter accuracy. In order to overcome the limitations to ranging accuracy from jitters and delay drifts within the transponders, architecture was proposed based on asynchronous paired one-way ranging with local references. A portion of the transmitted light is directed, via a reference path, to the local detector. This allows for compensation of any jitter in the timing of the emitted laser pulse. The same detector is used to measure the time of the received pulses emitted from the remote terminal. This approach removes any change in the delay caused by the detector or its electronics. Two separate terminals using commercial off-the-shelf hardware were built to emulate active laser ranging over interplanetary distances. The communication link for the command to start recording pulse arrival times and data transfer from one terminal to the other was achieved using a standard wireless link, emulating free space laser communication. The deviation is well below the goal of 1-mm precision. This leaves enough margin to achieve 1-mm precision when including the fluctuations due to atmospheric turbulence while ranging to Mars through the Earth s atmosphere. The two terminals are mounted on translation stages, which can be moved freely on rails to yield a wide range of distances with fine adjustment. The two terminals were separated by approximately 16 meters.

Time-of-flight dependency on transducer separation distance in a reflective-path guided-wave ultrasonic flow meter at zero flow conditions.

PubMed

Aanes, Magne; Kippersund, Remi Andre; Lohne, Kjetil Daae; Frøysa, Kjell-Eivind; Lunde, Per

2017-08-01

Transit-time flow meters based on guided ultrasonic wave propagation in the pipe spool have several advantages compared to traditional inline ultrasonic flow metering. The extended interrogation field, obtained by continuous leakage from guided waves traveling in the pipe wall, increases robustness toward entrained particles or gas in the flow. In reflective-path guided-wave ultrasonic flow meters (GW-UFMs), the flow equations are derived from signals propagating solely in the pipe wall and from signals passing twice through the fluid. In addition to the time-of-flight (TOF) through the fluid, the fluid path experiences an additional time delay upon reflection at the opposite pipe wall due to specular and non-specular reflections. The present work investigates the influence of these reflections on the TOF in a reflective-path GW-UFM as a function of transducer separation distance at zero flow conditions. Two models are used to describe the signal propagation through the system: (i) a transient full-wave finite element model, and (ii) a combined plane-wave and ray-tracing model. The study shows that a range-dependent time delay is associated with the reflection of the fluid path, introducing transmitter-receiver distance dependence. Based on these results, the applicability of the flow equations derived using model (ii) is discussed.

Short stature in genetic syndromes: Selected issues.

PubMed

Łaczmańska, Izabela; Kuliczkowska-Płaksej, Justyna; Stembalska, Agnieszka

2018-03-14

Short stature, which is defined as height below 2 standard deviations of the mean height for the age and sex, is one of the most frequent reasons for medical consultations in children. Short stature may occur due to a constitutional delay in growth, familial short stature or chronic diseases, including many genetic syndromes, metabolic and endocrine disorders. In this article the authors provide a mini-review of the most frequent genetic syndromes associated with short stature that should be taken into account in the differential diagnosis process. Syndromes caused by chromosomal aberrations and gene mutations were divided into 2 main groups: syndromes that are associated with intrauterine growth retardation (IUGR) and those in which IUGR does not occur in the natural history of the patient. The authors described the most important anomalies in each syndrome. Metabolic diseases and skeletal dysplasias were omitted, as they are major separate groups of diseases involving growth delay.

Background Noise Reduction Using Adaptive Noise Cancellation Determined by the Cross-Correlation

NASA Technical Reports Server (NTRS)

Spalt, Taylor B.; Brooks, Thomas F.; Fuller, Christopher R.

2012-01-01

Background noise due to flow in wind tunnels contaminates desired data by decreasing the Signal-to-Noise Ratio. The use of Adaptive Noise Cancellation to remove background noise at measurement microphones is compromised when the reference sensor measures both background and desired noise. The technique proposed modifies the classical processing configuration based on the cross-correlation between the reference and primary microphone. Background noise attenuation is achieved using a cross-correlation sample width that encompasses only the background noise and a matched delay for the adaptive processing. A present limitation of the method is that a minimum time delay between the background noise and desired signal must exist in order for the correlated parts of the desired signal to be separated from the background noise in the crosscorrelation. A simulation yields primary signal recovery which can be predicted from the coherence of the background noise between the channels. Results are compared with two existing methods.

Highly Efficient Thermally Activated Delayed Fluorescence from an Excited-State Intramolecular Proton Transfer System

PubMed Central

2017-01-01

Thermally activated delayed fluorescence (TADF) materials have shown great potential for highly efficient organic light-emitting diodes (OLEDs). While the current molecular design of TADF materials primarily focuses on combining donor and acceptor units, we present a novel system based on the use of excited-state intramolecular proton transfer (ESIPT) to achieve efficient TADF without relying on the well-established donor–acceptor scheme. In an appropriately designed acridone-based compound with intramolecular hydrogen bonding, ESIPT leads to separation of the highest occupied and lowest unoccupied molecular orbitals, resulting in TADF emission with a photoluminescence quantum yield of nearly 60%. High external electroluminescence quantum efficiencies of up to 14% in OLEDs using this emitter prove that efficient triplet harvesting is possible with ESIPT-based TADF materials. This work will expand and accelerate the development of a wide variety of TADF materials for high performance OLEDs. PMID:28776019

Go When You Know: Chimpanzees’ Confidence Movements Reflect Their Responses in a Computerized Memory Task

PubMed Central

Beran, Michael J.; Perdue, Bonnie M.; Futch, Sara E.; Smith, J. David; Evans, Theodore A.; Parrish, Audrey E.

2015-01-01

Three chimpanzees performed a computerized memory task in which auditory feedback about the accuracy of each response was delayed. The delivery of food rewards for correct responses was also delayed and occurred in a separate location from the response. Crucially, if the chimpanzees did not move to the reward-delivery site before food was dispensed, the reward was lost and could not be recovered. Chimpanzees were significantly more likely to move to the dispenser on trials they had completed correctly than on those they had completed incorrectly, and these movements occurred before any external feedback about the outcome of their responses. Thus, chimpanzees moved (or not) on the basis of their confidence in their responses, and these confidence movements aligned closely with objective task performance. These untrained, spontaneous confidence judgments demonstrated that chimpanzees monitored their own states of knowing and not knowing and adjusted their behavior accordingly. PMID:26057831

Advanced Gouy phase high harmonics interferometer

NASA Astrophysics Data System (ADS)

Mustary, M. H.; Laban, D. E.; Wood, J. B. O.; Palmer, A. J.; Holdsworth, J.; Litvinyuk, I. V.; Sang, R. T.

2018-05-01

We describe an extreme ultraviolet (XUV) interferometric technique that can resolve ∼100 zeptoseconds (10‑21 s) delay between high harmonic emissions from two successive sources separated spatially along the laser propagation in a single Gaussian beam focus. Several improvements on our earlier work have been implemented in the advanced interferometer. In this paper, we report on the design, characterization and optimization of the advanced Gouy phase interferometer. Temporal coherence for both atomic argon and molecular hydrogen gases has been observed for several harmonic orders. It has been shown that phase shift of XUV pulses mainly originates from the emission time delay due to the Gouy phase in the laser focus and the observed interference is independent of the generating medium. This interferometer can be a useful tool for measuring the relative phase shift between any two gas species and for studying ultrafast dynamics of their electronic and nuclear motion.

Semantic effects in naming perceptual identification but not in delayed naming: implications for models and tasks.

PubMed

Wurm, Lee H; Seaman, Sean R

2008-03-01

Previous research has demonstrated that the subjective danger and usefulness of words affect lexical decision times. Usually, an interaction is found: Increasing danger predicts faster reaction times (RTs) for words low on usefulness, but increasing danger predicts slower RTs for words high on usefulness. The authors show the same interaction with immediate auditory naming. The interaction disappeared with a delayed auditory naming control experiment, suggesting that it has a perceptual basis. In an attempt to separate input (signal to ear) from output (brain to muscle) processes in word recognition, the authors ran 2 auditory perceptual identification experiments. The interaction was again significant, but performance was best for words high on both danger and usefulness. This suggests that initial demonstrations of the interaction were reflecting an output approach/withdraw response conflict induced by stimuli that are both dangerous and useful. The interaction cannot be characterized as a tradeoff of speed versus accuracy.

Fourier transform of delayed fluorescence as an indicator of herbicide concentration.

PubMed

Guo, Ya; Tan, Jinglu

2014-12-21

It is well known that delayed fluorescence (DF) from Photosystem II (PSII) of plant leaves can be potentially used to sense herbicide pollution and evaluate the effect of herbicides on plant leaves. The research of using DF as a measure of herbicides in the literature was mainly conducted in time domain and qualitative correlation was often obtained. Fourier transform is often used to analyze signals. Viewing DF signal in frequency domain through Fourier transform may allow separation of signal components and provide a quantitative method for sensing herbicides. However, there is a lack of an attempt to use Fourier transform of DF as an indicator of herbicide. In this work, the relationship between the Fourier transform of DF and herbicide concentration was theoretically modelled and analyzed, which immediately yielded a quantitative method to measure herbicide concentration in frequency domain. Experiments were performed to validate the developed method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simulating the Response of a New Beta Delayed Proton Detector

NASA Astrophysics Data System (ADS)

Roosa, Michael; Friedman, Moshe; Wrede, Christopher

2017-09-01

To better understand reactions of astrophysical importance, such as 15O(α, γ)19Ne and 30P(p, γ)31S, a new gas filled detector of β-delayed charged particles has been designed and built for use at the National Superconducting Cyclotron Laboratory. The detector has separate drift and proportional amplification regions provided by a flex-board field cage and a Micromegas structure, respectively. We have developed a simulation to model the response of this detector using Magboltz and Garfield++ which calculate the electron transport and amplification through the two regions. The simulation provides information that is useful for understanding the microscopic function of the detector and will help optimize its operation. This work is supported by the U.S. National Science Foundation under Award Nos. PHY-1102511 and PHY- 1565546 and the U.S. Department of Energy, Office of Science, under Award No. DE-SC0016052.

Two-color field enhancement at an STM junction for spatiotemporally resolved photoemission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Xiang; Jin, Wencan; Yang, Hao

Here, we report measurements and numerical simulations of ultrafast laser-excited carrier flow across a scanning tunneling microscope (STM) junction. The current from a nanoscopic tungsten tip across a ~1 nm vacuum gap to a silver surface is driven by a two-color excitation scheme that uses an optical delay-modulation technique to extract the two-color signal from background contributions. The role of optical field enhancements in driving the current is investigated using density functional theory and full three-dimensional finite-difference time-domain computations. We find that simulated field-enhanced two-photon photoemission (2PPE) currents are in excellent agreement with the observed exponential decay of the two-colormore » photoexcited current with increasing tip–surface separation, as well as its optical-delay dependence. The results suggest an approach to 2PPE with simultaneous subpicosecond temporal and nanometer spatial resolution.« less

RSR' pattern and the risk of mortality in men and women free of cardiovascular disease.

PubMed

O'Neal, Wesley T; Qureshi, Waqas; Li, Yabing; Soliman, Elsayed Z

2015-01-01

This study included 6,398 participants (mean age 55 ± 0.34 years; 54% female; 49% white; 22% black; 24% Mexican; 4.3% other) free of clinical cardiovascular disease (CVD) and major ECG abnormalities. Cox regression was used to examine the association between the RSR' (incomplete right bundle branch block (RBBB) or right ventricular conduction delay) pattern and CVD and all-cause mortalities. The RSR' pattern was not associated with an increased risk of CVD (HR=1.10; 95%CI=0.63, 1.91) mortality or all-cause (HR=0.95; 95%CI=0.66, 1.35) mortality. The results were similar when the RSR' pattern was further separated into incomplete RBBB and right ventricular conduction delay. In conclusion, the RSR' pattern is a benign finding in older adults free of clinical CVD. Copyright © 2015 Elsevier Inc. All rights reserved.

Autogenerator of beams of charged particles

DOEpatents

Adler, Richard J.; Mazarakis, Michael G.; Miller, Robert B.; Shope, Steven L.; Smith, David L.

1986-01-01

An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.