Ad libitum and restricted day and night sleep architecture.
Korompeli, Anna St; Muurlink, Olav; Gavala, Alexandra; Myrianthefs, Pavlos; Fildissis, Georgios; Baltopoulos, Georgios
2016-01-01
This study represents a first controlled comparison of restricted versus unrestricted sleep in both day and night sleep categories. A repeated measures study of a homogenous group of young women without sleep disorders (n=14) found that stage 1, 2, 3 and REM sleep, as well as sleep latency were not statistically different between day ad libitum sleep (DAL) and day interrupted (DI) sleep categories, while night interrupted (NI) and ad libitum (NAL) sleep showed strikingly different architecture. PMID:26734985
Soda Consumption During Ad Libitum Food Intake Predicts Weight Change
Bundrick, Sarah C.; Thearle, Marie S.; Venti, Colleen A.; Krakoff, Jonathan; Votruba, Susanne B.
2013-01-01
Soda consumption may contribute to weight gain over time. Objective data were used to determine whether soda consumption predicts weight gain or changes in glucose regulation over time. Subjects without diabetes (128 men, 75 women; mean age 34.3±8.9 years; mean body mass index [BMI] 32.5±7.4; mean percentage body fat 31.6%±8.6%) self-selected their food from an ad libitum vending machine system for 3 days. Mean daily energy intake was calculated from food weight. Energy consumed from soda was recorded as were food choices that were low in fat (<20%) or high in simple sugars (>30%). Food choices were expressed as percentage of daily energy intake. A subset of 85 subjects had measurement of follow-up weights and oral glucose tolerance (57 men, 28 women; mean follow-up time=2.5±2.1 years, range 6 months to 9.9 years). Energy consumed from soda was negatively related to age (r=–0.27, P=0.0001), and choosing low-fat foods (r=−0.35, P<0.0001), but positively associated with choosing solid foods high in simple sugars (r=0.45, P<0.0001) and overall average daily energy intake (r=0.46, P<0.0001). Energy intake from food alone did not differ between individuals who did and did not consume beverage calories (P=0.11). Total daily energy intake had no relationship with change in weight (P=0.29) or change in glucose regulation (P=0.38) over time. However, energy consumed from soda correlated with change in weight (r=0.21, P=0.04). This relationship was unchanged after adjusting for follow-up time and initial weight. Soda consumption is a marker for excess energy consumption and is associated with weight gain. PMID:24321742
Soda consumption during ad libitum food intake predicts weight change.
Bundrick, Sarah C; Thearle, Marie S; Venti, Colleen A; Krakoff, Jonathan; Votruba, Susanne B
2014-03-01
Soda consumption may contribute to weight gain over time. Objective data were used to determine whether soda consumption predicts weight gain or changes in glucose regulation over time. Subjects without diabetes (128 men, 75 women; mean age 34.3±8.9 years; mean body mass index 32.5±7.4; mean percentage body fat 31.6%±8.6%) self-selected their food from an ad libitum vending machine system for 3 days. Mean daily energy intake was calculated from food weight. Energy consumed from soda was recorded as were food choices that were low in fat (<20% of calories from fat) or high in simple sugars (>30%). Food choices were expressed as percentage of daily energy intake. A subset of 85 subjects had measurement of follow-up weights and oral glucose tolerance (57 men, 28 women; mean follow-up time=2.5±2.1 years, range 6 months to 9.9 years). Energy consumed from soda was negatively related to age (r=-0.27, P=0.0001) and choosing low-fat foods (r=-0.35, P<0.0001), but positively associated with choosing solid foods high in simple sugars (r=0.45, P<0.0001) and overall average daily energy intake (r=0.46, P<0.0001). Energy intake from food alone did not differ between individuals who did and did not consume beverage calories (P=0.11). Total daily energy intake had no relationship with change in weight (P=0.29) or change in glucose regulation (P=0.38) over time. However, energy consumed from soda correlated with change in weight (r=0.21, P=0.04). This relationship was unchanged after adjusting for follow-up time and initial weight. Soda consumption is a marker for excess energy consumption and is associated with weight gain. PMID:24321742
Ad Libitum Fluid Consumption via Self- or External Administration
Yeargin, Susan W.; Finn, Megan E.; Eberman, Lindsey E.; Gage, Matthew J.; McDermott, Brendon P.; Niemann, Andrew
2015-01-01
Context: During team athletic events, athletic trainers commonly provide fluids with water bottles. When a limited number of water bottles exist, various techniques are used to deliver fluids. Objective: To determine whether fluid delivered via water-bottle administration influenced fluid consumption and hydration status. Design: Crossover study. Setting: Outdoor field (22.2°C ± 3.5°C). Patients or Other Participants: Nineteen participants (14 men, 5 women, age = 30 ± 10 years, height = 176 ± 8 cm, mass = 72.5 ± 10 kg) were recruited from the university and local running clubs. Intervention(s): The independent variable was fluid delivery with 3 levels: self-administration with mouth-to-bottle direct contact (SA-DC), self-administration with no contact between mouth and bottle (SA-NC), and external administration with no contact between the mouth and the bottle (EA-NC). Participants warmed up for 10 minutes before completing 5 exercise stations, after which an ad libitum fluid break was given, for a total of 6 breaks. Main Outcome Measure(s): We measured the fluid variables of total volume consumed, total number of squirts, and average volume per squirt. Hydration status via urine osmolality and body-mass loss, and perceptual variables for thirst and fullness were recorded. We calculated repeated-measures analyses of variance to assess hydration status, fluid variables, and perceptual measures to analyze conditions across time. Results: The total volume consumed for EA-NC was lower than for SA-DC (P = .001) and SA-NC (P = .001). The total number of squirts for SA-DC was lower than for SA-NC (P = .009). The average volume per squirt for EA-NC was lower than for SA-DC (P = .020) and SA-NC (P = .009). Participants arrived (601.0 ± 21.3 mOsm/L) and remained (622.3 ± 38.3 mOsm/L) hydrated, with no difference between conditions (P = .544); however, the EA-NC condition lost more body mass than did the SA-DC condition (P = .001). There was no main effect for
Linden, Melissa A; Fletcher, Justin A; Meers, Grace M; Thyfault, John P; Laughlin, M Harold; Rector, R Scott
2016-09-01
Hyperphagic Otsuka Long-Evans Tokushima fatty (OLETF) rats develop obesity, insulin resistance, and nonalcoholic fatty liver disease (NAFLD), but lifestyle modifications, such as caloric restriction (CR), can prevent these conditions. We sought to determine if prior CR had protective effects on metabolic health and NAFLD development following a 4-wk return to ad libitum (AL) feeding. Four-week-old male OLETF rats (n = 8-10/group) were fed AL for 16 wk (O-AL), CR for 16 wk (O-CR; ∼70% kcal of O-AL), or CR for 12 wk followed by 4 wk of AL feeding (O-AL4wk). CR-induced benefit in prevention of NAFLD, including reduced hepatic steatosis, inflammation, and markers of Kupffer cell activation/number, was largely lost in AL4wk rats. These findings occurred in conjunction with a partial loss of CR-induced beneficial effects on obesity and serum triglycerides in O-AL4wk rats, but in the absence of changes in serum glucose or insulin. CR-induced increases in hepatic mitochondrial respiration remained significantly elevated (P < 0.01) in O-AL4wk compared with O-AL rats, while mitochondrial [1-(14)C]palmitate oxidation, citrate synthase activity, and β-hydroxyacyl-CoA dehydrogenase activity did not differ among OLETF groups. NAFLD development in O-AL4wk rats was accompanied by increases in the protein content of the de novo lipogenesis markers fatty acid synthase and stearoyl-CoA desaturase-1 and decreases in phosphorylated acetyl-CoA carboxylase (pACC)/ACC compared with O-CR rats (P < 0.05 for each). The beneficial effects of chronic CR on NAFLD development were largely lost with 4 wk of AL feeding in the hyperphagic OLETF rat, highlighting the importance of maintaining energy balance in the prevention of NAFLD. PMID:27445343
Allen, Scott; Miller, Kevin C.; Albrecht, Jay; Garden-Robinson, Julie; Blodgett-Salafia, Elizabeth
2013-01-01
Context: Adding sodium (Na+) to drinks improves rehydration and ad libitum fluid consumption. Clinicians (∼25%) use pickle juice (PJ) to treat cramping. Scientists warn against PJ ingestion, fearing it will cause rapid plasma volume restoration and thereby decrease thirst and delay rehydration. Advice about drinking PJ has been developed but never tested. Objective: To determine if drinking small volumes of PJ, hypertonic saline (HS), or deionized water (DIW) affects ad libitum DIW ingestion, plasma variables, or perceptual indicators. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Fifteen, euhydrated (urine specific gravity ≤ 1.01) men (age = 22 ± 2 years, height = 178 ± 6 cm, mass = 82.9 ± 8.4 kg). Intervention(s): Participants completed 3 testing days (≥72 hours between days). After a 30-minute rest, a blood sample was collected. Participants completed 60 minutes of hard exercise (temperature = 36 ± 2°C, relative humidity = 16 ± 1%). Postexercise, they rested for 30 minutes; had a blood sample collected; rated thirst, fullness, and nausea; and ingested 83 ± 8 mL of PJ, HS, or DIW. They rated drink palatability (100-mm visual analog scale) and were allowed to drink DIW ad libitum for 60 minutes. Blood samples and thirst, fullness, and nausea ratings (100-mm visual analog scales) were collected at 15, 30, 45, and 60 minutes posttreatment drink ingestion. Main Outcome Measure(s): Ad libitum DIW volume, percentage change in plasma volume, plasma osmolality (OSMp,) plasma sodium concentration ([Na+]p), and thirst, fullness, nausea, and palatability ratings. Results: Participants consumed more DIW ad libitum after HS (708.03 ± 371.03 mL) than after DIW (532.99 ± 337.14 mL, P < .05). Ad libitum DIW ingested after PJ (700.35 ± 366.15 mL) was similar to that after HS and DIW (P > .05). Plasma sodium concentration, OSMp, percentage change in plasma volume, thirst, fullness, and nausea did not differ among treatment drinks
Oral fluid cannabinoids in chronic frequent cannabis smokers during ad libitum cannabis smoking.
Lee, Dayong; Vandrey, Ryan; Mendu, Damodara R; Murray, Jeannie A; Barnes, Allan J; Huestis, Marilyn A
2015-06-01
Oral fluid (OF) offers a simple, non-invasive, directly observable sample collection for clinical and forensic drug testing. Given that chronic cannabis smokers often engage in drug administration multiple times daily, evaluating OF cannabinoid pharmacokinetics during ad libitum smoking is important for practical development of analytical methods and informed interpretation of test results. Eleven cannabis smokers resided in a closed research unit for 51 days, and underwent four, 5-day oral delta-9-tetrahydrocannabinol (THC) treatments. Each medication period was separated by 9 days of ad libitum cannabis smoking from 12:00 to 23:00 h daily. Ten OF samples were collected from 9:00-22:00 h on each of the last ad libitum smoking days (Study Days 4, 18, 32, and 46). As the number of cannabis cigarettes smoked increased over the study days, OF THC, cannabinol (CBN), and 11-nor-9-carboxy-THC (THCCOOH) also increased with a significant effect of time since last smoking (Δtime; range, 0.0-17.4 h) and ≥88% detection rates; concentrations on Day 4 were significantly lower than those on Days 32 and 46 but not Day 18. Within 30 min of smoking, median THC, CBN, and THCCOOH concentrations were 689 µg/L, 116 µg/L, and 147 ng/L, respectively, decreasing to 19.4 µg/L, 2.4 µg/L, and 87.6 ng/L after 10 h. Cannabidiol and 11-hydroxy-THC showed overall lower detection rates of 29 and 8.6%, respectively. Cannabinoid disposition in OF was highly influenced by Δtime and composition of smoked cannabis. Furthermore, cannabinoid OF concentrations increased over ad libitum smoking days, in parallel with increased cannabis self-administration, possibly reflecting development of increased cannabis tolerance. PMID:25220020
Reproducibility of ad libitum energy intake with the use of a computerized vending machine system123
Votruba, Susanne B; Franks, Paul W; Krakoff, Jonathan; Salbe, Arline D
2010-01-01
Background: Accurate assessment of energy intake is difficult but critical for the evaluation of eating behavior and intervention effects. Consequently, methods to assess ad libitum energy intake under controlled conditions have been developed. Objective: Our objective was to evaluate the reproducibility of ad libitum energy intake with the use of a computerized vending machine system. Design: Twelve individuals (mean ± SD: 36 ± 8 y old; 41 ± 8% body fat) consumed a weight-maintaining diet for 3 d; subsequently, they self-selected all food with the use of a computerized vending machine system for an additional 3 d. Mean daily energy intake was calculated from the actual weight of foods consumed and expressed as a percentage of weight-maintenance energy needs (%WMEN). Subjects repeated the study multiple times during 2 y. The within-person reproducibility of energy intake was determined through the calculation of the intraclass correlation coefficients (ICCs) between visits. Results: Daily energy intake for all subjects was 5020 ± 1753 kcal during visit 1 and 4855 ± 1615 kcal during visit 2. There were no significant associations between energy intake and body weight, body mass index, or percentage body fat while subjects used the vending machines, which indicates that intake was not driven by body size or need. Despite overconsumption (%WMEN = 181 ± 57%), the reproducibility of intake between visits, whether expressed as daily energy intake (ICC = 0.90), %WMEN (ICC = 0.86), weight of food consumed (ICC = 0.87), or fat intake (g/d; ICC = 0.87), was highly significant (P < 0.0001). Conclusion: Although ad libitum energy intake exceeded %WMEN, the within-person reliability of this intake across multiple visits was high, which makes this a reproducible method for the measurement of ad libitum intake in subjects who reside in a research unit. This trial was registered at clinicaltrials.gov as NCT00342732. PMID:19923376
Brisk walking reduces ad libitum snacking in regular chocolate eaters during a workplace simulation.
Oh, Hwajung; Taylor, Adrian H
2012-02-01
Workplace snacking can contribute to obesity. Exercise reduces chocolate cravings but effects on chocolate consumption are unknown. This study investigated the effect of brief exercise on ad libitum consumption during breaks in a computerised task. Seventy-eight regular chocolate eaters, age: 24.90±8.15 years, BMI: 23.56±3.78 kg/m(2) abstained for 2 days. They were randomly assigned to one of four conditions, in a 2 × 2 factorial design, involving either a 15 min brisk walk or quiet rest, and then computerised Stroop tasks with low or high demanding conditions, in three 180 s blocks with a 90 s interval. Throughout, a pre-weighed bowl of chocolates was available for ad libitum eating. A two-way ANOVA revealed no interaction effect of exercise and stress on total chocolate consumption, or main effect of stress, but a main effect of exercise [F(1, 74)=7.12, p<.01]. Mean (SD) chocolate consumption was less (t(73.5)=2.69, 95% CI for difference 3.4-22.9, ES=0.61) for the exercise (15.6 g) than control (28.8 g) group. Exercise also increased affective activation, but there was no mediating effect of change in affect on chocolate consumption. A brief walk may help to reduce ad libitum snacking in regular chocolate eaters. PMID:22100187
Fertility of sows fed ad libitum with a high fibre diet during pregnancy.
Peltoniemi, O A T; Tast, A; Heinonen, M; Oravainen, J; Munsterhjelm, C; Hälli, O; Oliviero, C; Hämeenoja, P; Virolainen, J V
2010-12-01
The effect of ad libitum (ADLIB) feeding strategy on the fertility of the group housed sow was studied in a prospective field trial during 1.5 years. All study animals farrowed under standard farrowing circumstances in crates, and they were provided with an ad libitum feeding throughout the 30-day lactation. After weaning, animals were randomly allocated to one of the two dry sow feeding strategies (AD LIB or CONT). After oestrus detection in groups, they were artificially inseminated and moved into pregnancy pens with partially slatted floor, in groups of 40 sows each. The ADLIB sows (n = 447) were loose housed and provided with ad libitum access to 7.7 MJ/kg feed high in fibre from two feeders per group. The control sows (n = 479; CONT) were also loose housed and given a standard dry sow feed in feeding stalls once a day (2.5 kg/day. The energy content of the feed was 9.3 MJ/kg NE). The feeding strategy (ADLIB vs CONT) had no effect on pregnancy rate (85.8 vs 90.9, p > 0.05), weaning to oestrus interval (7.7 vs 7.3 days, p > 0.05), piglets born alive (11.5 ± 3.5 vs 11.6 ± 3.3, p > 0.05), stillborn piglets (1.2 ± 1.8 vs 0.9 ± 1.5, p > 0.05) nor on progesterone concentration (p > 0.05). CONT sows weaned more piglets (9.7 ± 2.2 vs 9.4 ± 2.0, p < 0.01), whereas the piglets of AD LIB sows were heavier at weaning (8.8 ± 0.9 vs 8.0 ± 1.3 kg, p < 0.05). In conclusion, ad libitum feeding with a high in fibre diet during pregnancy did not affect the reproductive performance. PMID:19497024
Jeusette, I; Detilleux, J; Cuvelier, C; Istasse, L; Diez, M
2004-04-01
The aim of this study was (i) to evaluate the effect of ovariectomy on daily energy requirement in Beagle dogs, and (ii) to evaluate the effects of ad libitum feeding with a high energy diet on energy consumption, body weight gain and blood metabolites in these spayed dogs. Four young adult female Beagle dogs were used. Ovariectomy induced a significant decrease of daily energy requirement in dogs. Ad libitum feeding, initiated 6 months after spaying, induced a significant increase in consumption in spayed dogs. This overconsumption was greatest during the first month of ad libitum feeding but continued for the entire 4 months of this period. When fed ad libitum, dogs gained excess body weight without significant effect on plasma cholesterol, triglycerides, glucose and insulin, at short term. These data suggest that energy intake should be strictly controlled to avoid excess weight gain in spayed dogs. PMID:15059235
Effect of exercise on cigarette cravings and ad libitum smoking following concurrent stressors.
Fong, Angela J; De Jesus, Stefanie; Bray, Steven R; Prapavessis, Harry
2014-10-01
The health consequences of smoking are well documented, yet quit rates are modest. While exercise has supported decreased cravings and withdrawal symptoms in temporarily abstinent smokers, it has yet to be applied when smokers are experiencing concurrent stressors. This study examined the effect of an acute bout of moderate intensity exercise on cravings (primary outcome) and ad libitum smoking (secondary outcome) following concurrent stressors (i.e., temporary abstinence and environmental manipulation-Stroop cognitive task+cue-elicited smoking stimuli). Twenty-five smokers (>10cig/day; Mean age=37.4years) were randomized into either exercise (n=12) or passive sitting conditions. A repeated measure (RM) ANOVA showed that psychological withdrawal symptoms (a measure of distress) were significantly exacerbated after temporary abstinence and then again after the environmental manipulation for all participants (p<.0001, η(2)=.50). Furthermore, a treatment by time RM ANOVA revealed decreases in psychological withdrawal symptoms for only the exercise condition (p<.001, η(2)=.42). A treatment by time RM ANOVA also revealed craving reductions for only the exercise condition (p<.0001, η(2)=.82). Exercise had no effect on ad libitum smoking. This is the first study to use a lab-based scenario with high ecological validity to show that an acute bout of exercise can reduce cravings following concurrent stressors. Future work is now needed where momentary assessment is used in people's natural environment to examine changes in cigarette cravings following acute bouts of exercise. PMID:24971700
Ad-libitum drinking and performance during a 40-km cycling time trial in the heat.
Berkulo, Meriam A R; Bol, Susan; Levels, Koen; Lamberts, Robert P; Daanen, Hein A M; Noakes, Timothy D
2016-01-01
The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and two 40-km cycling TTs hypohydrated. During one hypohydrated trial no fluid was ingested (HYPO), during the other trial ad-libitum water ingestion was allowed (FLUID). Ambient temperature was 35.2 ± 0.2 °C, relative humidity 51 ± 3% and airflow 7 m·s(-1). Body mass (BM) was determined at the start of the test, and before and after the TT. During the TT, power output, heart rate (HR), gastrointestinal temperature, mean skin temperature, rating of perceived exertion (RPE), thermal sensation, thermal comfort and thirst sensation were measured. Prior to the start of the TT, BM was 1.2% lower in HYPO and FLUID compared to EU. During the TT, BM loss in FLUID was lower compared to EU and HYPO (1.0 ± 0.8%, 2.7 ± 0.2% and 2.6 ± 0.3%, respectively). Hydration status had no effect on power output (EU: 223 ± 32 W, HYPO: 217 ± 39 W, FLUID: 224 ± 35 W), HR, gastrointestinal temperature, mean skin temperature, RPE, thermal sensation and thermal comfort. Thirst sensation was higher in HYPO than in EU and FLUID. It was concluded that hypohydration did not adversely affect performance during a 40-km cycling TT in the heat. Therefore, whether or not participants consumed fluid during exercise did not influence their TT performance. PMID:25675355
Alterations in energy balance from an exercise intervention with ad libitum food intake.
Melzer, Katarina; Renaud, Anne; Zurbuchen, Stefanie; Tschopp, Céline; Lehmann, Jan; Malatesta, Davide; Ruch, Nicole; Schutz, Yves; Kayser, Bengt; Mäder, Urs
2016-01-01
Better understanding is needed regarding the effects of exercise alone, without any imposed dietary regimens, as a single tool for body-weight regulation. Thus, we evaluated the effects of an 8-week increase in activity energy expenditure (AEE) on ad libitum energy intake (EI), body mass and composition in healthy participants with baseline physical activity levels (PAL) in line with international recommendations. Forty-six male adults (BMI = 19·7-29·3 kg/m(2)) participated in an intervention group, and ten (BMI = 21·0-28·4 kg/m(2)) in a control group. Anthropometric measures, cardiorespiratory fitness, EI, AEE and exercise intensity were recorded at baseline and during the 1st, 5th and 8th intervention weeks, and movement was recorded throughout. Body composition was measured at the beginning and at the end of the study, and resting energy expenditure was measured after the study. The intervention group increased PAL from 1·74 (se 0·03) to 1·93 (se 0·03) (P < 0·0001) and cardiorespiratory fitness from 41·4 (se 0·9) to 45·7 (se 1·1) ml O2/kg per min (P = 0·001) while decreasing body mass (-1·36 (se 0·2) kg; P = 0·001) through adipose tissue mass loss (ATM) (-1·61 (se 0·2) kg; P = 0·0001) compared with baseline. The control group did not show any significant changes in activity, body mass or ATM. EI was unchanged in both groups. The results indicate that in normal-weight and overweight men, increasing PAL from 1·7 to 1·9 while keeping EI ad libitum over an 8-week period produces a prolonged negative energy balance. Replication using a longer period (and/or more intense increase in PAL) is needed to investigate if and at what body composition the increase in AEE is met by an equivalent increase in EI. PMID:27066256
Japur, Camila Cremonezi; Diez-Garcia, Rosa Wanda; de Oliveira Penaforte, Fernanda Rodrigues; de Sá, Marcos Felipe Silva
2014-02-11
Obese women with polycystic ovary syndrome (PCOS) may have impairment in the regulation of food intake associated with ghrelin and insulin. In order to compare postprandial ghrelin and insulin responses to an ad libitum meal, we assessed 30 obese women with PCOS and 23 obese women without PCOS (control group). Blood samples were taken under fasting conditions, preprandially, and 15, 45, 75, and 135 minutes after the beginning of an ad libitum meal and ghrelin and insulin concentrations were analyzed. Insulin resistance (IR) was classified using basal insulin, quantitative insulin sensitivity check index, and homeostasis model assessment index. Mean ad libitum food intake was similar between the groups (468 ± 150 vs 444 ± 165 g, P = .60). The IR was found in 56.6% in PCOS group compared with 30.4% in the control group (P < .01). The postprandial ghrelin response was similar in both the groups but the insulin area under the curve (AUC) tend to be greater in the PCOS group (12807 ± 8149.4 vs 8654.4 ± 7232.3 μIU/mL/min; P = .057). The ghrelin AUC was negatively correlated with the insulin AUC (r = -.5138; P = .01) only in the control group. The imbalance in the feedback mechanisms between insulin and ghrelin, present in obese women, especially those with IR, may affect food intake throughout the day and that could be a mechanism for the development of obesity in PCOS. PMID:24520086
Picavet, Patrick; Haziza, Christelle; Lama, Nicola; Weitkunat, Rolf
2016-01-01
Introduction: We aimed to compare the pharmacokinetics of nicotine between the heat-not-burn Tobacco Heating System 2.1 (THS 2.1) and combustible cigarettes (CCs). We also examined whether the subjective urge to smoke was associated with the pharmacokinetics of nicotine. Methods: This open-label, randomized, two-period, two-sequence crossover study conducted in 28 healthy smokers assessed the pharmacokinetics of nicotine after single and ad libitum use of the THS 2.1 or CCs. During the 7-day confinement period, blood samples were drawn for pharmacokinetic analysis. Subjective effects related to THS 2.1 or CC use were assessed using the Questionnaire of Smoking Urges (QSU-Brief). Results: The nicotine delivery rate was similar with the THS 2.1 and CCs after single and ad libitum use. The time to the maximum nicotine concentration was 8 minutes after single use of the THS 2.1 and CCs. The time to the peak concentration following ad libitum use was similar between the THS 2.1 and CCs. The maximum plasma nicotine concentration after single use of the THS 2.1 was 8.4ng/mL, 70.3% of that obtained with CCs. A transient reduction from baseline in the urge to smoke of 40% was observed 15 minutes after the single use of both the THS 2.1 and CCs. The mean QSU-Brief total scores following single and ad libitum use were similar for the THS 2.1 and CCs. Conclusions: These results suggest that the THS 2.1 effectively delivers nicotine and achieves similar pharmacokinetic profiles to CCs. The THS 2.1 also reduced the urge to smoke similarly to CCs. Implications: Reducing exposure to toxicants and safer delivery of nicotine are among the strategies that may reduce the harm of smoking-related diseases. In the present study, we investigated the pharmacokinetics of nicotine and their effects on the urge to smoke using the THS 2.1. It was developed to replicate the ritual of smoking as closely as possible by providing nicotine in a way that mimics CC smoking, but limits pyrolysis and
Devant, M; Quintana, B; Aris, A; Bach, A
2015-10-01
The objectives of this study were to evaluate the effects of high-moisture corn (HMC), either whole or ground, fed separately from concentrate and straw on feeding behavior, rumen fermentation, whole tract digestibility, and nitrogen balance. Twenty-four Holstein heifers (199 ± 5.5 kg BW and 157 ± 6.9 d age) housed in individual pens were assigned to 3 treatments: 1) whole (unprocessed) HMC fed along with concentrate and barley straw, all fed separately and ad libitum (WHMC); 2) HMC ground through a 0.4-cm screen before ensiling and fed along with concentrate and barley straw, all fed separately and ad libitum (GHMC); and 3) a concentrate composed of mainly corn meal, ground through a roller mill with screen openings of 6 mm, and barley straw, both fed separately and ad libitum (Control). Concentrate, HMC, and straw were offered separately ad libitum in a free-choice situation and consumption was recorded daily and BW was recorded weekly. Apparent nutrient digestibility and N balance were determined at the beginning, middle, and end of the study. At the same time points, rumen fluid was collected through rumenocentesis to determine rumen pH and VFA concentrations. Feeding behavior was monitored throughout the study. Animals were harvested after 134 d and HCW, rumen and cecum wall lesions, and liver abscesses were recorded. Treatment did not affect total DMI, feed efficiency, ADG, final BW, and carcass weight or classification. Concentrate consumption (6.6 ± 0.35 kg/d) of Control heifers was greater ( < 0.001) than that of GHMC (4.1 ± 0.35 kg/d) and WHMC heifers (2.8 ± 0.35 kg/d), and GHMC heifers consumed less ( < 0.001) HMC than WHMC heifers (2.3 ± 0.31 and 4.2 ± 0.31 kg/d, respectively). Dietary treatments did not affect rumination, self-grooming, nonnutritive oral behaviors, and rumen pH. However, rumen acetate to propionate ratio decreased when heifers received HMC (1.77 ± 0.276) compared with when heifers received the Control (2.82 ± 0.276). Total
Lee, C; Araujo, R C; Koenig, K M; Beauchemin, K A
2015-05-01
A slow-release form of nitrate (encapsulated nitrate [EN]) was investigated for effects on risk of toxicity, feed consumption rates, and feed sorting behavior in 2 experiments. In Exp. 1, 5 beef heifers (806 ± 72 kg BW) were fed once daily at 75% of ad libitum intake. Supplementary EN (85.6% DM; 71.4% NO3(-) on a DM basis) was increased by 1% every 4 d from 0 to 1.0, 2.0, 2.9, 3.9, 4.8, and 5.8% of dietary DM (from 10.3 to 15.6% CP and 0.11 to 4.8% total NO3(-)). During the study, a heifer was removed due to nitrate poisoning with 59% blood methemoglobin (MetHb; % of total hemoglobin) at 2.9% EN and another due to refusal to eat the 2% EN diet. When dietary EN increased from 0 to 5.8%, DMI (8.8 to 7.6 kg/d; P < 0.001) and feed consumption from 0 to 3 h were decreased (70.3 to 48.6% of total feed offered on an as-is basis; P = 0.001) and feed consumption from 12 to 24 h was increased (0.6 to 22.6%; P < 0.001). Blood MetHb at 1% EN was negligible (<1.5% of total hemoglobin). However, MetHb levels were greater (average 9.8 vs. 3.1% and maximum 23.6 vs. 13.6% at 3 h) at 2.0 and 2.9% EN than at 3.9, 4.8, and 5.8% EN. In Exp. 2, 8 beef heifers (451 ± 21 kg BW) were used in a replicated 4 × 4 Latin square design and fed for ad libitum intake, once daily, diets containing 0, 1, 2, and 3% EN (isonitrogenous, 12.7% CP, and 0.15 to 2.5% total NO3(-) in dietary DM). Each period consisted of 14 d for adaption and 14 d for sampling followed by a 7-d washout. During adaptation, EN was provided to heifers in a stepwise manner (an increase by 1% every 4 d). In Exp. 2 with ad libitum feeding, feed consumption rates were not different (41.8% of total feed consumed from 0 to 3 h; P = 0.56) among EN levels, but DMI tended to decrease linearly (0 to 3% EN; 10.4 to 10.1 kg/d; P = 0.06) and feed was sorted (linear, P < 0.05) against concentrates (containing EN) with EN inclusion. Potential toxicity of nitrate based on blood MetHb was not observed (all samples <2.0% of total hemoglobin
Thearle, Marie S.; Krakoff, Jonathan; Votruba, Susanne B.
2015-01-01
Context: Body fat-free mass (FFM), energy expenditure (EE), and respiratory quotient (RQ) are known predictors of daily food intake. Because FFM largely determines EE, it is unclear whether body composition per se or the underlying metabolism drives dietary intake. Objective: The objective of the study was to test whether 24-hour measures of EE and RQ and their components influence ad libitum food intake independently of FFM. Design and Participants: One hundred seven healthy individuals (62 males/45 females, 84 Native Americans/23 whites; age 33 ± 8 y; body mass index 33 ± 8 kg/m2; body fat 31% ± 8%) had 24-hour measures of EE in a whole-room indirect calorimeter during energy balance, followed by 3 days of ad libitum food intake using computerized vending machine systems. Body composition was estimated by dual-energy x-ray absorptiometry. Main Outcome Measures: FFM, 24-hour EE, RQ, spontaneous physical activity, sleeping EE (sleeping metabolic rate), awake and fed thermogenesis, and ad libitum food intake (INTAKE) were measured. Results: Higher 24-hour RQ (P < .001, partial R2 = 16%) and EE (P = .01, partial R2 = 7%), but not FFM (P = .65), were independent predictors of INTAKE. Mediation analysis demonstrated that 24-hour EE is responsible for 80% of the FFM effect on INTAKE (44.5 ± 16.9 kcal ingested per kilogram of FFM, P= .01), whereas the unique effect due to solely FFM was negligible (10.6 ± 23.2, P = .65). Spontaneous physical activity (r = 0.33, P = .001), but not sleeping metabolic rate (P = .71), positively predicted INTAKE, whereas higher awake and fed thermogenesis determined greater INTAKE only in subjects with a body mass index of 29 kg/m2 or less (r = 0.44, P = .01). Conclusions: EE and RQ, rather than FFM, independently determine INTAKE, suggesting that competitive energy-sensing mechanisms driven by the preferential macronutrient oxidation and total energy demands may regulate food intake. PMID:26086330
Snack food intake in ad libitum fed rats is triggered by the combination of fat and carbohydrates.
Hoch, Tobias; Pischetsrieder, Monika; Hess, Andreas
2014-01-01
Snack food like potato chips substantially contributes to energy intake in humans. In contrast to basic food, snacks are consumed additionally to other meals and may thereby lead to non-homeostatic energy intake. Snack food is also frequently associated with hedonic hyperphagia, a food intake independent from hunger. Analysis of brain activity patterns by manganese-enhanced MRI has previously revealed that the intake of potato chips in ad libitum fed rats strongly activates the reward system of the rat brain, which may lead to hedonic hyperphagia. The purpose of the present study was to develop a two-choice preference test to identify molecular determinants of snack food triggering extra food intake in ad libitum fed rats. Different kinds of test food were presented three times a day for 10 min each time. To minimize the influence of organoleptic properties, each test food was applied in a homogenous mixture with standard chow. Food intake as well as food intake-related locomotor activity were analyzed to evaluate the effects induced by the test foods in the two-choice preference test. In summary, fat (F), carbohydrates (CH), and a mixture of fat and carbohydrates (FCH) led to a higher food intake compared to standard chow. Notably, potato chip test food (PC) was highly significantly preferred over standard chow (STD) and also over their single main macronutrients F and CH. Only FCH induced an intake comparable to PC. Despite its low energy density, fat-free potato chip test food (ffPC) was also significantly preferred over STD and CH, but not over F, FCH, and PC. Thus, it can be concluded that the combination of fat and carbohydrates is a major molecular determinant of potato chips triggering hedonic hyperphagia. The applied two-choice preference test will facilitate future studies on stimulating and suppressive effects of other food components on non-homeostatic food intake. PMID:24744741
Influence of a high-protein diet on energy balance in obese cats allowed ad libitum access to food.
Wei, A; Fascetti, A J; Liu, K J; Villaverde, C; Green, A S; Manzanilla, E G; Havel, P J; Ramsey, J J
2011-06-01
The influence of a high-protein [HP, 47% of metabolizable energy (ME)] diet on energy balance was evaluated in obese cats allowed ad libitum access to food. Energy intake, body weight, body composition, energy expenditure, and concentrations of hormones and metabolites associated with carbohydrate and lipid metabolism (glucose, insulin, free fatty acids, triglycerides and leptin) were measured in cats after consuming either a moderate protein (MP, 27% of ME) or HP diet for 4 months. Indirect respiration calorimetry showed that resting and total energy expenditure (kJ/day) adjusted for either body weight or lean body mass was increased in cats consuming the HP in relation to MP diets. However, voluntary energy intake also was increased in the HP treatment and, thus, there was no difference in body weight between animals consuming the two diets. Body composition measurements using deuterium oxide dilution showed that dietary protein content did not alter amounts of either lean body mass or fat mass. No significant differences (p > 0.05) were observed between the two treatment groups for blood glucose, free fatty acid or leptin concentrations, although there was a trend (p = 0.054) towards an increase of serum insulin concentrations in the cats eating the HP diet. This study showed that short-term ad libitum feeding of an HP diet did not reduce food intake or promote weight loss in obese cats. However, energy expenditure was increased in the HP diet group and it is possible that this effect of HP might help promote weight loss when energy intake is restricted. PMID:21039925
Effects of ad libitum ingestion of monosodium glutamate on weight gain in C57BL6/J mice.
Ren, Xueying; Ferreira, Jozélia G; Yeckel, Catherine W; Kondoh, Takashi; de Araujo, Ivan E
2011-01-01
Although the umami compound monosodium glutamate (MSG) is a widely used flavor enhancer, controversy still persists regarding the effects of MSG intake on body weight. It has been claimed, in particular, that chronic MSG intake may result in excessive body weight gain and obesity. In this study we assessed the effects of chronic (16 weeks) ad libitum MSG on body weight and metabolism of C57BL6/J mice. Adult male mice were divided in four experimental groups and fed with either a low-fat (LF) or high-fat (HF) diet and with either two bottles of plain water or one bottle containing 1% MSG and another one containing water according to a factorial design. Mice were monitored weekly for body weight and food/fluid intake for 15 weeks. At the end of the experiments, the circulating levels of leptin, insulin, total protein, total cholesterol, triglyceride, blood urea nitrogen, and non-esterified fatty acids were also analyzed. Our results show that MSG intake did not influence body weight in either LF or HF groups. Interestingly, although animals overall displayed strong preferences for MSG against water, preferences were relatively higher in LF compared to HF group. Consistent with the body weight data, while significant differences in leptin, insulin, total cholesterol, and non-esterified fatty acids were found between HF and LF groups, such an effect was not influenced by MSG intake. Finally, indirect calorimetry measurements revealed similar energy expenditure levels between animals being presented water only and MSG only. In summary, our data does not support the notion that ad libitum MSG intake should trigger the development of obesity or other metabolic abnormalities. PMID:21389726
Snack food intake in ad libitum fed rats is triggered by the combination of fat and carbohydrates
Hoch, Tobias; Pischetsrieder, Monika; Hess, Andreas
2014-01-01
Snack food like potato chips substantially contributes to energy intake in humans. In contrast to basic food, snacks are consumed additionally to other meals and may thereby lead to non-homeostatic energy intake. Snack food is also frequently associated with hedonic hyperphagia, a food intake independent from hunger. Analysis of brain activity patterns by manganese-enhanced MRI has previously revealed that the intake of potato chips in ad libitum fed rats strongly activates the reward system of the rat brain, which may lead to hedonic hyperphagia. The purpose of the present study was to develop a two-choice preference test to identify molecular determinants of snack food triggering extra food intake in ad libitum fed rats. Different kinds of test food were presented three times a day for 10 min each time. To minimize the influence of organoleptic properties, each test food was applied in a homogenous mixture with standard chow. Food intake as well as food intake-related locomotor activity were analyzed to evaluate the effects induced by the test foods in the two-choice preference test. In summary, fat (F), carbohydrates (CH), and a mixture of fat and carbohydrates (FCH) led to a higher food intake compared to standard chow. Notably, potato chip test food (PC) was highly significantly preferred over standard chow (STD) and also over their single main macronutrients F and CH. Only FCH induced an intake comparable to PC. Despite its low energy density, fat-free potato chip test food (ffPC) was also significantly preferred over STD and CH, but not over F, FCH, and PC. Thus, it can be concluded that the combination of fat and carbohydrates is a major molecular determinant of potato chips triggering hedonic hyperphagia. The applied two-choice preference test will facilitate future studies on stimulating and suppressive effects of other food components on non-homeostatic food intake. PMID:24744741
Souza da Silva, C; Bosch, G; Bolhuis, J E; Stappers, L J N; van Hees, H M J; Gerrits, W J J; Kemp, B
2014-12-01
This study assessed the long-term effects of feeding diets containing either a gelling fibre (alginate (ALG)), or a fermentable fibre (resistant starch (RS)), or both, on feeding patterns, behaviour and growth performance of growing pigs fed ad libitum for 12 weeks. The experiment was set up as a 2×2 factorial arrangement: inclusion of ALG (yes or no) and inclusion of RS (yes or no) in the control diet, resulting in four dietary treatments, that is, ALG-RS- (control), ALG+RS-, ALG-RS+, and ALG+RS+. Both ALG and RS were exchanged for pregelatinized potato starch. A total of 240 pigs in 40 pens were used. From all visits to an electronic feeding station, feed intake and detailed feeding patterns were calculated. Apparent total tract digestibility of energy, dry matter (DM), and CP was determined in week 6. Pigs' postures and behaviours were scored from live observations in weeks 7 and 12. Dietary treatments did not affect final BW and average daily gain (ADG). ALG reduced energy and DM digestibility (P<0.01). Moreover, ALG increased average daily DM intake, and reduced backfat thickness and carcass gain : digestible energy (DE) intake (P<0.05). RS increased feed intake per meal, meal duration (P<0.05) and inter-meal intervals (P=0.05), and reduced the number of meals per day (P<0.01), but did not affect daily DM intake. Moreover, RS reduced energy, DM and CP digestibility (P<0.01). Average daily DE intake was reduced (P<0.05), and gain : DE intake tended to be increased (P=0.07), whereas carcass gain : DE intake was not affected by RS. In week 12, ALG+RS- increased standing and walking, aggressive, feeder-directed, and drinking behaviours compared with ALG+RS+ (ALG×RS interaction, P<0.05), with ALG-RS- and ALG-RS+ in between. No other ALG×RS interactions were found. In conclusion, pigs fed ALG compensated for the reduced dietary DE content by increasing their feed intake, achieving similar DE intake and ADG as control pigs. Backfat thickness and carcass efficiency
Sprinkle, J E; Ferrell, C L; Holloway, J W; Warrington, B G; Greene, L W; Wu, G; Stuth, J W
1998-03-01
We compared fat distribution and lipoprotein lipase (LPL) activity in steers differing in adaptability to the subtropics. Steers were fed a grain diet (3.13 Mcal ME/kg DM) at limited (150 kcal ME x kg[-.75] x d[-1]; .23 kg ADG) or ad libitum levels for 140 d, then slaughtered. Sixteen British- (8 Angus, 8 Hereford; S), 16 Boran- (R), 16 Brahman- (B), and 16 Tuli- (T) cross steers from MARC III composite cows were used. Adipose tissue samples from perirenal, omental, and subcutaneous depots were analyzed for LPL activity. Carcass measurements including omental, external, and seam fat trim from 1/ 2 of the carcass were measured. Subcutaneous fat had greater (P < .05) LPL activity than fat from the other depots. Generally, there were no differences (P > .05) in fat distribution for steers fed at limited levels. Means for ADG, slaughter weights, carcass weights, yield grades, and carcass lipid weights for S and B fed for ad libitum intake were greater (P < .05) than those for T and R. Marbling was greatest (P < .05) for S and did not differ (P > .05) for the other breeds with ad libitum intake. Factor analysis of fat depots for animals with ad libitum intake indicated that Bos taurus cattle differing in adaptation to heat deposited fat differently; S deposited greater (P < .05) proportions of carcass fat and T deposited greater (P < .05) proportions of internal fat. It seems that accumulation of internal fat is detrimental for ADG for Bos taurus cattle. PMID:9535321
Hedemann, Mette Skou; Damgaard, Birthe Marie
2012-12-01
Metabolite profiling may elucidate changes in metabolic pathways under various physiological or nutritional conditions. In the present study two groups of female mink characterised as having a high (16 mink) or low (14 mink) residual feed intake were investigated during restrictive and ad libitum feeding. Blood samples were collected three times during the experimental period; during restrictive feeding, and four days and three weeks after the change to ad libitum feeding. Plasma samples were subjected to liquid chromatography mass spectrometry non-targeted metabolomics. Subjecting data to principal component analysis showed that there was no grouping of the data according to the residual feed intake. In contrast, data were clearly grouped according to feeding level. Identification of the metabolites responsible for this grouping showed that the plasma level of metabolites related to mobilisation of energy was high during restrictive feeding, e.g. betaine, carnitine, and creatine. During ad libitum feeding the plasma level of metabolites that can be characterised as biomarkers of meat intake (creatinine, carnosine, 1- and 3 methylhistidine) was high. The plasma level of lysophosphatidylcholine species was highest after four days of ad libitum feeding suggesting a short term imbalance in the transport or metabolism of these metabolites when changing the feeding level. PMID:23123310
Marks, Kristin A; Marvyn, Phillip M; Henao, Juan J Aristizabal; Bradley, Ryan M; Stark, Ken D; Duncan, Robin E
2016-06-01
Data are presented on the fatty acyl composition of phospholipid from retroperitoneal white adipose tissue of female mice that were either given ad libitum access to food or fasted for 16 h overnight prior to sacrifice. Our data show that total adipose phospholipid concentrations were more than 2-fold higher in the fasted animals compared with the fed animals (33.48±7.40 versus 16.57±4.43 μg phospholipid fatty acids/100 mg tissue). Concentrations of several individual phospholipid fatty acyl species, including palmitic acid (16:0), vaccenic acid (18:1n-7), linoleic acid (18:2n-6), dihomo-gamma-linolenic acid (20:3n-6), arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), as well as total phospholipid saturated fatty acids, n-6 polyunsaturated fatty acids and n-3 polyunsaturated fatty acids, were significantly higher in adipose tissue from the fasted animals compared with the fed animals. However, when the relative abundance of phospholipid fatty acyl species was analyzed, only 20:4n-6 was specifically enriched (by ~2.5-fold) in adipose phospholipid with fasting. PMID:27014729
Litherland, N B; Weich, W D; Hansen, W P; Linn, J G
2012-12-01
The objectives of this study were to investigate the effects of forage source [wheat straw (WS) or orchardgrass hay (OG)] and total amount of diet dry matter fed [ad libitum or restricted to 70% of predicted dry matter intake (DMI)] prepartum on postpartum performance. The study design was a 2×2 factorial design with 10 cows per treatment. Treatments were WS total mixed ration (TMR) ad libitum, OG TMR ad libitum, WS TMR restricted, and OG TMR restricted. The WS TMR (dry matter basis) contained 30% WS, 20.7% corn silage, 10.0% alfalfa hay, 18.2% ground corn, 16.8% soybean meal, and 4.3% molasses mineral mix (14.7% CP, 1.5 Mcal/kg of net energy for lactation, 37.0% neutral detergent fiber). The OG TMR contained 30% OG, 46.2% corn silage, 10.0% alfalfa hay, 9.5% soybean meal, and 4.3% molasses (14.2% CP, 1.5 Mcal/kg of net energy for lactation, 41.0% neutral detergent fiber). Cows received 1 lactation diet after calving (17.7% CP, 1.6 Mcal/kg of net energy for lactation, 27.3% neutral detergent fiber). Total diet DMI prepartum was higher for ad libitum than for restricted as designed, but forage source had no effect on DMI. Total tract apparent digestibilities of DM and NDF were greater for OG than for WS. Postpartum DMI expressed as a percentage of body weight for the first week of lactation was higher for ad libitum than for restricted diets. Postpartum DMI during the first 30 d of lactation was higher for OG than for WS, but no effect was observed for the amount fed prepartum. Milk yield during the first week of lactation was higher for OG than for WS; however, during the first 30 d, 3.5% fat-corrected milk yield and yield of milk fat were highest for OG TMR restricted and WS TMR ad libitum. Prepartum treatments had a limited effect on pre- and postpartum lipid metabolism; however, cows fed WS TMR ad libitum had the highest postpartum β-hydroxybutyrate. Eating behavior was observed by 10-min video scans of 24-h video surveillance for 5d pre- and postpartum
2012-01-01
Background An association between fluid intake and limb swelling has been described for 100-km ultra-marathoners. We investigated a potential development of peripheral oedemata in Ironman triathletes competing over 3.8 km swimming, 180 km cycling and 42.2 km running. Methods In 15 male Ironman triathletes, fluid intake, changes in body mass, fat mass, skeletal muscle mass, limb volumes and skinfold thickness were measured. Changes in renal function, parameters of skeletal muscle damage, hematologic parameters and osmolality in both serum and urine were determined. Skinfold thicknesses at hands and feet were measured using LIPOMETER® and changes of limb volumes were measured using plethysmography. Results The athletes consumed a total of 8.6 ± 4.4 L of fluids, equal to 0.79 ± 0.43 L/h. Body mass, skeletal muscle mass and the volume of the lower leg decreased (p <0.05), fat mass, skinfold thicknesses and the volume of the arm remained unchanged (p >0.05). The decrease in skeletal muscle mass was associated with the decrease in body mass (p <0.05). The decrease in the lower leg volume was unrelated to fluid intake (p >0.05). Haemoglobin, haematocrit and serum sodium remained unchanged (p >0.05). Osmolality in serum and urine increased (p <0.05). The change in body mass was related to post-race serum sodium concentration ([Na+]) (r = −0.52, p <0.05) and post-race serum osmolality (r = −0.60, p <0.05). Conclusions In these Ironman triathletes, ad libitum fluid intake maintained plasma [Na+] and plasma osmolality and led to no peripheral oedemata. The volume of the lower leg decreased and the decrease was unrelated to fluid intake. Future studies may investigate ultra-triathletes competing in a Triple Iron triathlon over 11.4 km swimming, 540 km cycling and 126.6 km running to find an association between fluid intake and the development of peripheral oedemata. PMID:22937792
Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D
2015-06-01
Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR
Corner-Thomas, R. A.; Back, P. J.; Kenyon, P. R.; Hickson, R. E.; Ridler, A. L.; Stafford, K. J.; Morris, S. T.
2015-01-01
The present study evaluated the effect of controlled ryegrass-white clover herbage availability from day 128 until day 142 of pregnancy in comparison to unrestricted availability, on the performance of twin-bearing ewes of varying body condition score (BCS; 2.0, 2.5, or 3.0) and their lambs. It was hypothesised that under conditions of controlled herbage availability, the performance of lambs born to ewes with a greater BCS would be greater than those born to ewes with a lower BCS. During the period that the nutritional regimens were imposed, the pre- and post-grazing herbage masses of the Control regimen (1,070±69 and 801±30 kg dry matter [DM]/ha) were lower than the ad libitum regimen (1,784±69 and 1,333±33 kg DM/ha; p<0.05). The average herbage masses during lactation were 1,410±31 kg DM/ha. Nutritional regimen had no effect on ewe live weight, BCS and back fat depth or on lamb live weight, indices of colostrum uptake, maximal heat production, total litter weight weaned or survival to weaning (p>0.05). The difference in ewe BCSs and back fats observed among body condition groups was maintained throughout pregnancy (p<0.05). At weaning, ewes from the BCS2.0 group had lower BCS and live weight (2.4±0.2, 74.3±2.6 kg) than both the BCS2.5 (2.6±0.2, 78.6±2.4 kg) and BCS3.0 ewes (2.7±0.2, 79.0±2.6 kg; p<0.05), which did not differ (p>0.05). Ewe BCS group had no effect on lamb live weight at birth or weaning or on maximal heat production (p>0.05). Serum gamma glutamyl transferase concentrations of lambs born to BCS3.0 ewes were higher within 36 hours of birth than lambs born to BCS2.0 ewes and BCS2.5 ewes (51.8±1.9 vs 46.5±1.9 and 45.6±1.9 IU/mL, respectively [p<0.05]). There was, however, no effect of ewe body condition on lamb plasma glucose concentration (p>0.05). Lamb survival was the only lamb parameter that showed an interaction between ewe nutritional regimen and ewe BCS whereby survival of lambs born to BCS2.5 and BCS3.0 ewes differed but only
Lyons, Donald E.; Roby, Daniel D.
2011-01-01
For seabirds raising young under conditions of limited food availability, reducing chick provisioning and chick growth rates are the primary means available to avoid abandonment of a breeding effort. For most seabirds, however, baseline data characterizing chick growth and development under known feeding conditions are unavailable, so it is difficult to evaluate chick nutritional status as it relates to foraging conditions near breeding colonies. To address this need, we examined the growth and development of young Caspian Terns (Hydroprogne caspia), a cosmopolitan, generalist piscivore, reared in captivity and fed ad libitum and restricted (ca. one-third lower caloric intake) diets. Ad libitum-fed chicks grew at similar rates and achieved a similar size at fledging as previously documented for chicks in the wild and had energetic demands that closely matched allometric predictions. We identified three general characteristics of food-restricted Caspian Tern chicks compared to ad libitum chicks: (1) lower age-specific body mass, (2) lower age-specific skeletal and feather size, such as wing chord length, and (3) heightened levels of corticosterone in blood, both for baseline levels and in response to acute stress. Effects of diet restriction on feather growth (10-11% slower growth in diet-restricted chicks) were less pronounced than effects on structural growth (37-52% slower growth) and body mass (24% lower at fledging age), apparently due to preferential allocation of food resources to maintain plumage growth. Our results suggest that measurements of chick body mass and feather development (e.g., wing chord or primary length) or measurement of corticosterone levels in the blood would allow useful evaluation of the nutritional status of chicks reared in the wild and of food availability in the foraging range of adults. Such evaluations could also inform demography studies (e.g., predict future recruitment) and assist in evaluating designated piscivorous waterbird
Knechtle, Beat; Senn, Oliver; Imoberdorf, Reinhard; Joleska, Irena; Wirth, Andrea; Knechtle, Patrizia; Rosemann, Thomas
2010-01-01
We investigated in 11 female ultra-runners during a 100 km ultra-run, the association between fluid intake and prevalence of exercise-associated hyponatremia in a cross-sectional study. Athletes drank ad libitum and recorded their fluid intake. They competed at 8.0 (1.0) km/h and finished within 762 (91) min. Fluid intake was 4.1 (1.3) L during the race, equal to 0.3 (0.1) L/h. Body mass decreased by 1.5 kg (p< 0.01); pre race body mass was related to speed in the race (r = -0.78, p< 0.05); and change (Delta) in body mass was not associated with speed in the race. Change in body mass was positively (r = 0.70; p< 0.05), and Delta urinary specific gravity negatively (r = -0.67; p< 0.05), correlated to Delta percent total body water. Changes in body mass were not related to fluid intake during the race. Fluid intake was not correlated to running speed and showed no association with either Delta percent total body water nor Delta [Na] in plasma. Fluid intake showed no relationship with both Delta haematocrit and Delta plasma volume. No exercise-associated hyponatremia occurred. Female ultra- runners consuming fluids ad libitum during the race experienced no fluid overload, and ad libitum drinking protects against exercise-associated hyponatremia. The reported higher incidence of exercise-associated hyponatremia in women is not really a gender effect but due to women being more prone to overdrink. PMID:20199991
Chowdhury, Enhad A; Richardson, Judith D; Tsintzas, Kostas; Thompson, Dylan; Betts, James A
2015-07-14
Breakfast omission is associated with obesity and CVD/diabetes, but the acute effects of extended morning fasting upon subsequent energy intake and metabolic/hormonal responses have received less attention. In a randomised cross-over design, thirty-five lean men (n 14) and women (n 21) extended their overnight fast or ingested a typical carbohydrate-rich breakfast in quantities relative to RMR (i.e. 1963 (sd 238) kJ), before an ad libitum lunch 3 h later. Blood samples were obtained hourly throughout the day until 3 h post-lunch, with subjective appetite measures assessed. Lunch intake was greater following extended fasting (640 (sd 1042) kJ, P< 0.01) but incompletely compensated for the omitted breakfast, with total intake lower than the breakfast trial (3887 (sd 1326) v. 5213 (sd 1590) kJ, P< 0.001). Systemic concentrations of peptide tyrosine-tyrosine and leptin were greater during the afternoon following breakfast (both P< 0.05) but neither acylated/total ghrelin concentrations were suppressed by the ad libitum lunch in the breakfast trial, remaining greater than the morning fasting trial throughout the afternoon (all P< 0.05). Insulin concentrations were greater during the afternoon in the morning fasting trial (all P< 0.01). There were no differences between trials in subjective appetite during the afternoon. In conclusion, morning fasting caused incomplete energy compensation at an ad libitum lunch. Breakfast increased some anorectic hormones during the afternoon but paradoxically abolished ghrelin suppression by the second meal. Extending morning fasting until lunch altered subsequent metabolic and hormonal responses but without greater appetite during the afternoon. The present study clarifies the impact of acute breakfast omission and adds novel insights into second-meal metabolism. PMID:26004166
Doyon, Caroline Y; Tremblay, Angelo; Rioux, Laurie-Eve; Rhéaume, Caroline; Cianflone, Katherine; Poursharifi, Pegah; Turgeon, Sylvie L
2015-10-01
The objective of the study was to assess the impact of protein composition and/or fibre enrichment of yogurt on appetite sensations and subsequent energy intake. In this double-blind crossover study, 20 healthy men (aged 32.4 ± 9.1 years) were submitted to 5 randomized testing sessions, during which they had to consume 5 isocaloric and isonproteinemic yogurt snacks (120-g servings, ∼230 kJ, ∼4.5 g protein) differing by their casein-to-whey protein ratio (C:W) or dietary fibre content: (i) control C:W = 2.8:1; (ii) high whey (HW) C:W = 1.5:1, and fibre-enriched formulations using control; (iii) 2.4 g of inulin; (iv) 1.9 g of inulin and 0.5 g of β-glucan (+IN-βG); and (v) 0.5 g of β-glucan. Appetite sensations were assessed using 150-mm visual analog scales. Plasma variables (glucose, insulin, ghrelin) were measured at 30-min intervals post-yogurt consumption for 2 h. Finally, energy intakes during ad libitum lunches offered 2 h after yogurt snacks were recorded. None of the yogurts impacted appetite sensations. Ad libitum energy intake was significantly different only between HW and control yogurts (-812 kJ; p = 0.03). Regarding post-yogurt plasma variables, a significant difference was found only between ghrelin area under the curve of the +IN-βG and the HW yogurts (-15 510 pmol/L per 120 min, p = 0.04). In conclusion, although appetite sensations were not influenced by variations in yogurts' protein compositions, a reduced energy intake was observed during the ad libitum lunch after the HW yogurt that may be attributable to its lower C:W. Surprisingly, the fibre enrichments studied did not exert effect on appetite sensations and energy intake. PMID:26394259
Allsop, Susan; Dodd-Reynolds, Caroline J; Green, Benjamin P; Debuse, Dorothée; Rumbold, Penny L S
2015-12-28
The present study examined the acute effects of active gaming on energy intake (EI) and appetite responses in 8-11-year-old boys in a school-based setting. Using a randomised cross-over design, twenty-one boys completed four individual 90-min gaming bouts, each separated by 1 week. The gaming bouts were (1) seated gaming, no food or drink; (2) active gaming, no food or drink; (3) seated gaming with food and drink offered ad libitum; and (4) active gaming with food and drink offered ad libitum. In the two gaming bouts during which foods and drinks were offered, EI was measured. Appetite sensations - hunger, prospective food consumption and fullness - were recorded using visual analogue scales during all gaming bouts at 30-min intervals and at two 15-min intervals post gaming. In the two bouts with food and drink, no significant differences were found in acute EI (MJ) (P=0·238). Significant differences were detected in appetite sensations for hunger, prospective food consumption and fullness between the four gaming bouts at various time points. The relative EI calculated for the two gaming bouts with food and drink (active gaming 1·42 (sem 0·28) MJ; seated gaming 2·12 (sem 0·25) MJ) was not statistically different. Acute EI in response to active gaming was no different from seated gaming, and appetite sensations were influenced by whether food was made available during the 90-min gaming bouts. PMID:26435259
NASA Astrophysics Data System (ADS)
Möseneder, Jutta M.
2002-01-01
In der randomisierten, multizentrischen DASH-Studie (Dietary Approaches to Stop Hy-pertension), die unter kontrollierten Bedingungen stattfand, führte eine fettreduzierte Mischkost, reich an Obst, Gemüse und Milchprodukten, bei Borderline-Hypertonikern zu einer signifikanten Blutdrucksenkung. Während der Studienphase wurden Körpermasse, Natrium-Aufnahme sowie Alkoholzufuhr aufgrund der bekannten Einflussnahme auf den Blutdruck konstant gehalten. In der eigenen Pilot-Studie sollte untersucht werden, ob das Ergebnis der DASH-Studie (i) mit deutschen Hypertonikern und (ii) unter habituellen Ernährungs- und Lebensbedingungen mit regelmäßig durchgeführter Ernährungsberatung und ad libitum Verzehr anstelle des streng kontrollierten Studienansatzes bestätigt werden kann. Eine Konstanz der Körpermasse, der Natrium-Urinausscheidung (unter diesem Studienansatz valider als die Aufnahme) und des Alkoholkonsums wurde vorausgesetzt. Die Studienpopulation setzte sich aus 53 übergewichtigen Probanden mit einer nicht medikamentös therapierten Borderline-Hypertonie und ohne Stoffwechselerkrankungen zusammen. Die Studienteilnehmer wurden randomisiert entweder der Idealgruppe mit einer fettarmen Kost reich an Milchprodukten, Obst und Gemüse (ähnlich der DASH-Idealgruppe) oder der Kontrollgruppe mit habitueller Ernährungsweise zugeteilt. Über einen Zeitraum von fünf Wochen wurde den Probanden etwa 50% ihres täglichen Lebensmittelbedarfes entsprechend ihrer Gruppenzugehörigkeit kostenfrei zur Verfügung gestellt. Gelegenheitsblutdruckmessungen und 24h-Blutdruckmessungen, Ernährungs- und Aktivitätsprotokolle, Blut- und Urinproben sowie anthropometrische Messungen wurden vor, während und fünf Wochen nach der Interventionsphase durchgeführt. Die Ergebnisse zeigen, dass in der Idealgruppe keine signifikante Blutdrucksenkung beobachtet werden konnte. Dies lässt sich durch die Tatsache erklären, dass die Lebens-mittel- und Nährstoffaufnahme der deutschen
NASA Astrophysics Data System (ADS)
Möseneder, Jutta M.
2002-01-01
In der randomisierten, multizentrischen DASH-Studie (Dietary Approaches to Stop Hy-pertension), die unter kontrollierten Bedingungen stattfand, führte eine fettreduzierte Mischkost, reich an Obst, Gemüse und Milchprodukten, bei Borderline-Hypertonikern zu einer signifikanten Blutdrucksenkung. Während der Studienphase wurden Körpermasse, Natrium-Aufnahme sowie Alkoholzufuhr aufgrund der bekannten Einflussnahme auf den Blutdruck konstant gehalten. In der eigenen Pilot-Studie sollte untersucht werden, ob das Ergebnis der DASH-Studie (i) mit deutschen Hypertonikern und (ii) unter habituellen Ernährungs- und Lebensbedingungen mit regelmäßig durchgeführter Ernährungsberatung und ad libitum Verzehr anstelle des streng kontrollierten Studienansatzes bestätigt werden kann. Eine Konstanz der Körpermasse, der Natrium-Urinausscheidung (unter diesem Studienansatz valider als die Aufnahme) und des Alkoholkonsums wurde vorausgesetzt. Die Studienpopulation setzte sich aus 53 übergewichtigen Probanden mit einer nicht medikamentös therapierten Borderline-Hypertonie und ohne Stoffwechselerkrankungen zusammen. Die Studienteilnehmer wurden randomisiert entweder der Idealgruppe mit einer fettarmen Kost reich an Milchprodukten, Obst und Gemüse (ähnlich der DASH-Idealgruppe) oder der Kontrollgruppe mit habitueller Ernährungsweise zugeteilt. Über einen Zeitraum von fünf Wochen wurde den Probanden etwa 50% ihres täglichen Lebensmittelbedarfes entsprechend ihrer Gruppenzugehörigkeit kostenfrei zur Verfügung gestellt. Gelegenheitsblutdruckmessungen und 24h-Blutdruckmessungen, Ernährungs- und Aktivitätsprotokolle, Blut- und Urinproben sowie anthropometrische Messungen wurden vor, während und fünf Wochen nach der Interventionsphase durchgeführt. Die Ergebnisse zeigen, dass in der Idealgruppe keine signifikante Blutdrucksenkung beobachtet werden konnte. Dies lässt sich durch die Tatsache erklären, dass die Lebens-mittel- und Nährstoffaufnahme der deutschen
Pereira, A B D; Utsumi, S A; Dorich, C D; Brito, A F
2015-12-01
The objective of this study was to use spot short-term measurements of CH4 (QCH4) and CO2 (QCO2) integrated with backward dietary energy partition calculations to estimate dry matter intake (DMI) in lactating dairy cows. Twelve multiparous cows averaging 173±37d in milk and 4 primiparous cows averaging 179±27d in milk were blocked by days in milk, parity, and DMI (as a percentage of body weight) and, within each block, randomly assigned to 1 of 2 treatments: ad libitum intake (AL) or restricted intake (RI=90% DMI) according to a crossover design. Each experimental period lasted 22d with 14d for treatments adaptation and 8d for data and sample collection. Diets contained (dry matter basis): 40% corn silage, 12% grass-legume haylage, and 48% concentrate. Spot short-term gas measurements were taken in 5-min sampling periods from 15 cows (1 cow refused sampling) using a portable, automated, open-circuit gas quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) with intervals of 12h between the 2daily samples. Sampling points were advanced 2h from a day to the next to yield 16 gas samples per cow over 8d to account for diurnal variation in QCH4 and QCO2. The following equations were used sequentially to estimate DMI: (1) heat production (MJ/d)=(4.96 + 16.07 ÷ respiratory quotient) × QCO2; respiratory quotient=0.95; (2) metabolizable energy intake (MJ/d)=(heat production + milk energy) ± tissue energy balance; (3) digestible energy (DE) intake (MJ/d)=metabolizable energy + CH4 energy + urinary energy; (4) gross energy (GE) intake (MJ/d)=DE + [(DE ÷ in vitro true dry matter digestibility) - DE]; and (5) DMI (kg/d)=GE intake estimated ÷ diet GE concentration. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) and Fit Model procedure in JMP (α=0.05; SAS Institute Inc.). Cows significantly differed in DMI measured (23.8 vs. 22.4kg/d for AL and RI, respectively). Dry matter intake estimated using QCH4 and QCO2 coupled with
Baguley, Brenton; Zilujko, Jessica; Leveritt, Michael D; Desbrow, Ben; Irwin, Christopher
2016-08-01
The aim of this study was to compare the effect of ad libitum intake of a milk-based liquid meal supplement against a carbohydrate-electrolyte sports drink following exercise induced fluid loss. Seven male participants (age 22.3 ± 3.4 years, height 179.3 ± 7.9 cm, body mass 74.3 ± 7.3 kg; mean ± SD) completed 4 separate trials and lost 1.89 ± 0.44% body mass through moderate intensity exercise in the laboratory. After exercise, participants consumed ad libitum over 2 h a milk-based liquid meal supplement (Sustagen Sport) on two of the trials (S1, S2) or a carbohydrate-electrolyte sports drink (Powerade) on two of the trials (P1, P2), with an additional 1 hr observational period. Measures of body mass, urine output, gastrointestinal tolerance and palatability were collected throughout the recovery period. Participants consumed significantly more Powerade than Sustagen Sport over the 2 h rehydration period (P1 = 2225 ± 888 ml, P2 = 2602 ± 1119 mL, S1 = 1375 ± 711 mL, S2 = 1447 ± 857 ml). Total urine output on both Sustagen trails was significantly lower than the second Powerade trial (P2 = 1447 ± 656 ml, S1 = 153 ± 62 ml, S2 = 182 ± 118 mL; p < .05) and trended toward being lower compared with the first Powerade trial (P1 = 1057 ± 699 ml vs. S1, p = .067 and vs. S2, p = .061). No significant differences in net fluid balance were observed between any of the drinks at the conclusion of each trial (P1 = -0.50 ±0. 46 kg, P2 = -0.40 ± 0.35 kg, S1 = -0.61 ± 0.74 kg, S2 = -0.45 ± 0.58 kg). Gastrointestinal tolerance and beverage palatability measures indicated Powerade to be preferred as a rehydration beverage. Ad libitum milk-based liquid meal supplement results in similar net fluid balance as a carbohydrate-electrolyte sports drink after exercise induced fluid loss. PMID:26693643
Tucker, Amy J; Heap, Sarah; Ingram, Jessica; Law, Marron; Wright, Amanda J
2016-04-01
Reproducibility and validity testing of appetite ratings and energy intakes are needed in experimental and natural settings. Eighteen healthy young women ate a standardized breakfast for 8 days. Days 1 and 8, they rated their appetite (Hunger, Fullness, Desire to Eat, Prospective Food Consumption (PFC)) over a 3.5 h period using visual analogue scales, consumed an ad libitum lunch, left the research center and recorded food intake for the remainder of the day. Days 2-7, participants rated their at-home Hunger at 0 and 30 min post-breakfast and recorded food intake for the day. Total area under the curve (AUC) over the 180 min period before lunch, and energy intakes were calculated. Reproducibility of satiety measures between days was evaluated using coefficients of repeatability (CR), coefficients of variation (CV) and intra-class coefficients (ri). Correlation analysis was used to examine validity between satiety measures. AUCs for Hunger, Desire to Eat and PFC (ri = 0.73-0.78), ad libitum energy intakes (ri = 0.81) and total day energy intakes (ri = 0.48) were reproducible; fasted ratings were not. Average AUCs for Hunger, Desire to Eat and PFC, Desire to Eat at nadir and PFC at fasting, nadir and 180 min were correlated to total day energy intakes (r = 0.50-0.77, P < 0.05), but no ratings were correlated to lunch consumption. At-home Hunger ratings were weakly reproducible but not correlated to reported total energy intakes. Satiety ratings did not concur with next meal intake but PFC ratings may be useful predictors of intake. Overall, this study adds to the limited satiety research on women and challenges the accepted measures of satiety in an experimental setting. PMID:26763471
Drouilhet, L; Achard, C S; Zemb, O; Molette, C; Gidenne, T; Larzul, C; Ruesche, J; Tircazes, A; Segura, M; Bouchez, T; Theau-Clément, M; Joly, T; Balmisse, E; Garreau, H; Gilbert, H
2016-01-01
To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding (-20% of voluntary intake). The first objective of this study was to evaluate, after 9 generations of selection, the direct and correlated responses to selection on production traits in the 2 lines for traits recorded during growth. Second, applying the 2 feeding conditions used for selection to both selected lines plus the control unselected line (generation 0, G0) in a 2 × 3 factorial trial, the line performances were compared and the gut microbiota of the lines was characterized. The correlated responses in feed conversion ratio (FCR) were remarkably equivalent in both selected lines (-2.74 genetic σ) but correlated responses in other traits were notably different. In the ConsoResidual line, selection for decreased RFI resulted in a small negative correlated response in BW at 63 d old (BW63) and in a null response in ADG. In the ADGrestrict line, on the contrary, the correlated response in BW63 was substantial (+1.59 σ). The 2 selected lines had a FCR reduced by 0.2 point compared with the G0 line, and the same difference was found in both feeding regimens ( < 0.001). Indeed, selection on ADG would lead to heavier animals with no significant reduction of feed costs, whereas selection on RFI leads to lower feed costs and no increase of animal BW under ad libitum feeding. Altogether, our results do not suggest any genotype × environment interaction in the response to feeding regimens. The intestinal microbial communities from efficient rabbits differed from their unselected counterparts in terms of fermentation end products and microbial phylotypes, suggesting a central role of these microbes in the better feed efficiency of the rabbits. PMID:26812310
Lin, Zhi; Liao, Wenhua; Yang, Yuanyuan; Gao, Zhiling; Ma, Wenqi; Wang, Dianwu; Cao, Yufeng; Li, Jianguo; Cai, Zhenjiang
2015-04-01
Accurately quantifying methane (CH4) and nitrous oxide (N2O) emissions from beef operations in China is necessary to evaluate the contribution of beef cattle to greenhouse gas budgets at the national and global level. Methane and N2O emissions from two intensive beef feedlots in the North China Plain, one with a restricted feeding strategy and high manure collection frequency and the other with an ad libitum feeding strategy and low manure collection frequency, were quantified in the fall and spring seasons using an inverse dispersion technique. The diel pattern of CH4 from the beef feedlot with an ad libitum feed strategy (single peak during a day) differed from that under a restricted feeding condition (multiple peaks during a day), but little difference in the diel pattern of N2O emissions between two feeding strategies was observed. The two-season average CH4 emission rates of the two intensive feedlots were 230 and 198gCH4animal(-1)d(-1) and accounted for 6.7% and 6.8% of the gross energy intake, respectively, indicating little impact of the feeding strategy and manure collection frequency on the CH4 conversion factor at the feedlot level. However, the average N2O emission rates (21.2g N2Oanimal(-1)d(-1)) and conversion factor (8.5%) of the feedlot with low manure collection frequency were approximately 131% and 174% greater, respectively, than the feedlot under high frequency conditions, which had a N2O emission rate and conversion factor of 9.2g N2Oanimal(-1)d(-1) and 3.1%, respectively, indicating that increasing manure collection frequency played an important role in reducing N2O emissions from beef feedlots. In addition, comparison indicated that China's beef and dairy cattle in feedlots appeared to have similar CH4 conversion factors. PMID:25769128
Boddicker, N; Gabler, N K; Spurlock, M E; Nettleton, D; Dekkers, J C M
2011-08-01
Residual feed intake (RFI), defined as the difference between observed and expected feed intake based on growth and backfat, has been used to investigate genetic variation in feed efficiency in cattle, poultry and pigs. However, little is known about the biological basis of differences in RFI in pigs. To this end, the objective of this study was to evaluate the fifth generation of a line of pigs selected for reduced RFI against a randomly selected Control line for performance, carcass and chemical carcass composition and overall efficiency. Here, emphasis was on the early grower phase. A total of 100 barrows, 50 from each line, were paired by age and weight (22.6 ± 3.9 kg) and randomly assigned to one of four feeding treatments in 11 replicates: ad libitum (Ad), 75% of Ad (Ad75), 55% of Ad (Ad55) and weight stasis (WS), which involved weekly adjustments in intake to keep body weight (BW) constant for each pig. Pigs were individually penned (group housing was used for selection) and were on treatment for 6 weeks. Initial BW did not significantly differ between the lines (P > 0.17). Under Ad feeding, the low RFI pigs consumed 8% less feed compared with Control line pigs (P < 0.06), had less carcass fat (P < 0.05), but with no significant difference in growth rate (P > 0.85). Under restricted feeding, low RFI pigs under the Ad75 treatment had a greater rate of gain while consuming the same amount of feed as Control pigs. Despite the greater gain, no significant line differences in carcass composition or carcass traits were observed. For the WS treatment, low RFI pigs had similar BW (P > 0.37) with no significant difference in feed consumption (P > 0.32). Overall, selection for reduced RFI has decreased feed intake, with limited differences in growth rate but reduced carcass fat, as seen under Ad feeding. Collectively, results indicate that the effects of selection for low RFI are evident during the early grower stage, which allows for greater savings to the producer
Lin, Zhi; Liao, Wenhua; Yang, Yuanyuan; Gao, Zhiling; Ma, Wenqi; Wang, Dianwu; Cao, Yufeng; Li, Jianguo; Cai, Zhenjiang
2015-04-15
Accurately quantifying methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions from beef operations in China is necessary to evaluate the contribution of beef cattle to greenhouse gas budgets at the national and global level. Methane and N{sub 2}O emissions from two intensive beef feedlots in the North China Plain, one with a restricted feeding strategy and high manure collection frequency and the other with an ad libitum feeding strategy and low manure collection frequency, were quantified in the fall and spring seasons using an inverse dispersion technique. The diel pattern of CH{sub 4} from the beef feedlot with an ad libitum feed strategy (single peak during a day) differed from that under a restricted feeding condition (multiple peaks during a day), but little difference in the diel pattern of N{sub 2}O emissions between two feeding strategies was observed. The two-season average CH{sub 4} emission rates of the two intensive feedlots were 230 and 198 g CH{sub 4} animal{sup −1} d{sup −1} and accounted for 6.7% and 6.8% of the gross energy intake, respectively, indicating little impact of the feeding strategy and manure collection frequency on the CH{sub 4} conversion factor at the feedlot level. However, the average N{sub 2}O emission rates (21.2 g N{sub 2}O animal{sup −1} d{sup −1}) and conversion factor (8.5%) of the feedlot with low manure collection frequency were approximately 131% and 174% greater, respectively, than the feedlot under high frequency conditions, which had a N{sub 2}O emission rate and conversion factor of 9.2 g N{sub 2}O animal{sup −1} d{sup −1} and 3.1%, respectively, indicating that increasing manure collection frequency played an important role in reducing N{sub 2}O emissions from beef feedlots. In addition, comparison indicated that China’s beef and dairy cattle in feedlots appeared to have similar CH{sub 4} conversion factors. - Highlights: • CH{sub 4} and N{sub 2}O emissions from China’s beef feedlots were
Selim, S; Kokkonen, T; Taponen, J; Vanhatalo, A; Elo, K
2015-08-01
Prepartal energy overfeeding may predispose cows to a state of increased insulin resistance with greater lipolysis after parturition. The aim of the study was to evaluate the effects of prepartal overfeeding in terms of abundant grass silage ration on the liver and subcutaneous adipose tissue (SAT) gene expression around parturition. Sixteen multiparous Finnish Ayrshire dairy cows were fed ad libitum either grass silage [high energy, HE; 144 MJ/d of metabolizable energy (ME) intake, n=8] or a mixture of grass silage, wheat straw, and rapeseed meal [55:40:5 (CON), 109 MJ/d of ME, n=8] during the dry period (58.2±4.89 d, mean ± standard deviation). Tissue biopsies and blood samples were collected at -14 (±4.98), 1, and 7 d relative to the actual parturition date. The HE cows had greater total dry matter intake, ME intake, and ME balance during the dry period than the CON cows. Compared with CON, the increases in body weight and body condition score were greater in HE during the dry period. Milk yield during the first 2 wk of lactation was not different between the groups. Plasma glucose, nonesterified fatty acids, insulin, glucagon, and β-hydroxybutyrate did not differ between the groups during the transition period. Dietary treatment did not affect hepatic triglyceride content; however, a delayed increase in hepatic total lipid content was observed in the HE cows at d 1 postpartum. Hepatic cytosolic phosphoenolpyruvate carboxykinase 1 mRNA expression was lower in HE than in CON at d 1 and 7 postpartum. Adiponectin receptor 1 and 2 mRNA abundance tended to be lower in SAT of HE than CON. Lower lipoprotein lipase, leptin, and stearoyl-coenzyme A desaturase mRNA abundances were observed at d 7 postpartum in SAT of the HE cows compared with the CON cows. We concluded that prepartal ad libitum feeding of grass silage may decrease insulin sensitivity and lipogenesis in SAT during peripartal period and may attenuate the increase of hepatic gluconeogenic capacity from
Molette, C; Gilbert, H; Larzul, C; Balmisse, E; Ruesche, J; Manse, H; Tircazes, A; Theau-Clément, M; Joly, T; Gidenne, T; Garreau, H; Drouilhet, L
2016-01-01
To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding. The aim of the present study was to evaluate the impact on carcass and meat quality of the genetic selections. This comparison was performed using 2 different feeding strategies corresponding to the selection design. Carcass and meat quality traits were recorded for the 3 lines (ConsoResidual, ADGrestrict, and an unselected control [generation 0 {G0}]) in the 2 feeding systems (ad libitum and restricted) for 163 animals. Concerning the line effect, the BW at 63 d old was higher for the ADGrestrict line compared with the G0 and ConsoResidual lines ( < 0.0001). There was no line effect on the gastrointestinal tract. The rabbits did not exhibit a different carcass yield but showed different carcass traits. Indeed, the ConsoResidual rabbits had a higher hind leg yield ( < 0.0001) but no difference in the meat-to-bone ratio of the hind leg. On the contrary, the ADGrestrict line had a higher proportion of forelegs plus thoracic cage ( = 0.03). We also found lower perirenal ( < 0.0001) and scapular fat yields ( < 0.0001) in ConsoResidual rabbits. The ADGrestrict line had an intermediate perirenal fat yield compared with the other 2 lines. The G0 line always exhibited higher fat yields. Concerning meat quality, the ConsoResidual rabbits showed a lower ultimate pH ( < 0.0001) and higher water loss (drip and cooking loss; < 0.002) compared with the G0 and ADGrestrict rabbits. The feeding level had a strong effect on the gastrointestinal tract ( = 0.0004) and the carcass yield ( = 0.001). The latter was decreased in restricted rabbits. The effects of feeding strategy on meat quality were detrimental in the case of restricted feeding. Even if the ultimate pH was slightly higher in restricted rabbits ( = 0.0002), the carcass
Sayer, R. Drew; Amankwaah, Akua F.; Tamer, Gregory G.; Chen, Ningning; Wright, Amy J.; Tregellas, Jason R.; Cornier, Marc-Andre; Kareken, David A.; Talavage, Thomas M.; McCrory, Megan A.; Campbell, Wayne W.
2016-01-01
Increasing either protein or fiber at mealtimes has relatively modest effects on ingestive behavior. Whether protein and fiber have additive or interactive effects on ingestive behavior is not known. Fifteen overweight adults (5 female, 10 male; BMI: 27.1 ± 0.2 kg/m2; aged 26 ± 1 year) consumed four breakfast meals in a randomized crossover manner (normal protein (12 g) + normal fiber (2 g), normal protein (12 g) + high fiber (8 g), high protein (25 g) + normal fiber (2 g), high protein (25 g) + high fiber (8 g)). The amount of protein and fiber consumed at breakfast did not influence postprandial appetite or ad libitum energy intake at lunch. In the fasting-state, visual food stimuli elicited significant responses in the bilateral insula and amygdala and left orbitofrontal cortex. Contrary to our hypotheses, postprandial right insula responses were lower after consuming normal protein vs. high protein breakfasts. Postprandial responses in other a priori brain regions were not significantly influenced by protein or fiber intake at breakfast. In conclusion, these data do not support increasing dietary protein and fiber at breakfast as effective strategies for modulating neural reward processing and acute ingestive behavior in overweight adults. PMID:26742068
Sayer, R Drew; Amankwaah, Akua F; Tamer, Gregory G; Chen, Ningning; Wright, Amy J; Tregellas, Jason R; Cornier, Marc-Andre; Kareken, David A; Talavage, Thomas M; McCrory, Megan A; Campbell, Wayne W
2016-01-01
Increasing either protein or fiber at mealtimes has relatively modest effects on ingestive behavior. Whether protein and fiber have additive or interactive effects on ingestive behavior is not known. Fifteen overweight adults (5 female, 10 male; BMI: 27.1 ± 0.2 kg/m²; aged 26 ± 1 year) consumed four breakfast meals in a randomized crossover manner (normal protein (12 g) + normal fiber (2 g), normal protein (12 g) + high fiber (8 g), high protein (25 g) + normal fiber (2 g), high protein (25 g) + high fiber (8 g)). The amount of protein and fiber consumed at breakfast did not influence postprandial appetite or ad libitum energy intake at lunch. In the fasting-state, visual food stimuli elicited significant responses in the bilateral insula and amygdala and left orbitofrontal cortex. Contrary to our hypotheses, postprandial right insula responses were lower after consuming normal protein vs. high protein breakfasts. Postprandial responses in other a priori brain regions were not significantly influenced by protein or fiber intake at breakfast. In conclusion, these data do not support increasing dietary protein and fiber at breakfast as effective strategies for modulating neural reward processing and acute ingestive behavior in overweight adults. PMID:26742068
Sud, Shama; Tamayo, Nina Carmela; Faith, Myles S.; Keller, Kathleen L.
2016-01-01
Increased reports of restrictive feeding have shown positive relationships to child obesity, however, the mechanism between the two has not been elucidated. This study examined the relationship between reported use of restrictive feeding practices and 4–6-year-old children’s self-selected energy density (ED) and total energy intake from an ad libitum, laboratory dinner including macaroni and cheese, string beans, grapes, baby carrots, cheese sticks, pudding, milks, and a variety of sweetened beverages. A second objective explored the relationship between ED and child body mass index (BMI) z-score. Seventy (n = 70) healthy children from primarily non-Caucasian and lower socioeconomic status families participated. Mothers completed the Child Feeding Questionnaire (CFQ) to assess restrictive feeding practices. Energy density (kcal/g) values for both foods and drinks (EDfood+drink) and ED for foods only (EDfoods) were calculated by dividing the average number of calories consumed by the average weight eaten across 4 meals. Higher maternal restriction was associated with lower EDfood+drink. In overweight and obese children only, higher maternal restriction was associated with lower EDfood. There was a non-significant trend for both ED measures to be negatively associated with child BMI z-score. Overall, restrictive feeding practices were not associated with child BMI z-score. However, when analyzing separate aspects of restriction, parents reported higher use of restricting access to palatable foods but lower use of using palatable foods as rewards with heavier children. Previous reports of positive associations between child obesity and restrictive feeding practices may not apply in predominantly non-Caucasian, lower socioeconomic status cohorts of children. PMID:20594990
Motubatse, M R; Ng'ambi, J W; Norris, D; Malatje, M M
2008-04-01
In a first of two experiments, twenty yearling male Pedi goats weighing 21.3 +/- 0.5 kg live weight were used in a 37-day study in a 2 (levels of PEG 4000) x 2 (levels ofAcacia) Factorial arrangement in a Completely Randomised Design to determine the effect of the level of Acacia nilotica leaf meal supplementation plus 23 g polyethylene glycol 4000 on diet intake and digestibility, and growth rate of Pedi goats fed ad libitum Buffalo grass hay. Acacia nilotica leaf meal contained high amounts of total phenolics (2.04% DM) and low amounts of condensed tannins; both extracted (0.37% DM) and unextracted (1.83% DM). Supplementation with PEG 4000 increased (P < 0.05) crude protein intake as the level of Acacia nilotica leaf meal increased from 80 to 120 g. Similarly, treatment with PEG 4000 improved (P < 0.05) DM, OM and CP digestibilities when compared to 80 g Acacia nilotica leaf meal. Supplementation with PEG 4000 resulted in an increase (P < 0.05) in blood urea concentrations. Polyethylene glycol 4000 has the potential to improve the feeding value of A. nilotica leaf meal and can, therefore, be used in the feeding systems for ruminant animals. The second experiment determined the effect of A. nilotica leaf meal supplementation on in vitro digestibility of the diets similar to the actual ratios of the first experiment. Level of A. nilotica leaf meal supplementation plus 23 g PEG 4000 supplementation improved (P < 0.05) in vitro DM, OM and CP digestibilities where 120 g A. nilotica leaf meal was supplemented. Similarly, 23 g PEG 4000 supplementation also improved (P < 0.05) in vitro CP digestibility where 80 g A. nilotica leaf meal was supplemented. In vivo DM and OM digestibilities were best predicted from in vitro DM and OM digestibilities while in vivo CP was explained by in vitro OM and CP digestibilities. It is, therefore, concluded that in vitro DM and OM digestibilities have good capacity to predict in vivo DM and OM digestibilities while OM and CP
Donnelly, Joseph E.; Herrmann, Stephen D.; Lambourne, Kate; Szabo, Amanda N.; Honas, Jeffery J.; Washburn, Richard A.
2014-01-01
Background The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. Objective To address the question: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? Data Sources PubMed and Embase were searched (January 1990–January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Study Eligibility Criteria Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18–64 years). Study Appraisal and Synthesis Methods Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. Results No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. Limitations The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure
Alcaraz-Iborra, Manuel; Carvajal, Francisca; Lerma-Cabrera, José Manuel; Valor, Luis Miguel; Cubero, Inmaculada
2014-10-01
The orexin (OX) system has been implicated in food-reinforced behavior, food-seeking and food overconsumption. Recent evidence suggests that OX signaling might influence consumption of palatable foods with high reinforcing value depending upon the caloric status of the animal. The present study evaluates from a pharmacological and a molecular approach the contribution of OX to excessive binge-like consumption of highly preferred palatable substances (sucrose and saccharin) in ad libitum-fed C57BL/6J mice. The main findings of this study are: (1) intraperitoneal (ip) injection of SB-334867 (10, 20 or 30mg/kg), a selective OXR1 antagonist, significantly decreased binge-like consumption of sucrose (10%, w/v) and saccharin (0.15%, w/v) during the test day in a Drinking in the Dark procedure in ad libitum-fed animals, without evidence of any significant alteration of locomotor activity. (2) Four repetitive, 2-h daily episodes of sucrose and saccharin (but not water) binge-like drinking significantly dampened OX mRNA expression in the LH. Present findings show for the first time a role for OXR1 signaling in binge-like consumption of palatable substances in animals under no caloric needs. Targeting OXR1 could represent a novel pharmacological approach to treat binge-eating episodes. PMID:24983661
Dorich, C D; Varner, R K; Pereira, A B D; Martineau, R; Soder, K J; Brito, A F
2015-04-01
The objective of this study was to measure enteric CH4 emissions using a new portable automated open-circuit gas quantification system (GQS) and the sulfur hexafluoride tracer technique (SF6) in midlactation Holstein cows housed in a tiestall barn. Sixteen cows averaging 176 ± 34 d in milk, 40.7 ± 6.1 kg of milk yield, and 685 ± 49 kg of body weight were randomly assigned to 1 out of 2 treatments according to a crossover design. Treatments were (1) ad libitum (adjusted daily to yield 10% orts) and (2) restricted feed intake [set to restrict feed by 10% of baseline dry matter intake (DMI)]. Each experimental period lasted 22d, with 14 d for treatment adaptation and 8d for data and sample collection. A common diet was fed to the cows as a total mixed ration and contained 40.4% corn silage, 11.2% grass-legume haylage, and 48.4% concentrate on a dry matter basis. Spot 5-min measurements using the GQS were taken twice daily with a 12-h interval between sampling and sampling times advanced 2h daily to account for diurnal variation in CH4 emissions. Canisters for the SF6 method were sampled twice daily before milking with 4 local background gas canisters inside the barn analyzed for background gas concentrations. Enteric CH4 emissions were not affected by treatments and averaged 472 and 458 g/d (standard error of the mean = 18 g/d) for ad libitum and restricted intake treatments, respectively (data not shown). The GQS appears to be a reliable method because of the relatively low coefficients of variation (ranging from 14.1 to 22.4%) for CH4 emissions and a moderate relationship (coefficient of determination = 0.42) between CH4 emissions and DMI. The SF6 resulted in large coefficients of variation (ranging from 16.0 to 111%) for CH4 emissions and a poor relationship (coefficient of determination = 0.17) between CH4 emissions and DMI, likely because of limited barn ventilation and high background gas concentration. Research with improved barn ventilation systems or
Coradini, M; Rand, J S; Morton, J M; Rawlings, J M
2014-10-01
Overweight and obese conditions are common in cats and are associated with the development of a number of diseases. Knowledge of metabolic determinants and predictors of weight gain may enable better preventative strategies for obesity in cats. Lean, healthy cats were fed either a low-carbohydrate high-protein diet (n 16) or a high-carbohydrate low-protein (n 16) diet ad libitum for 8 wk. Potential determinants and predictors of final body weight assessed were body fat and lean masses, energy required for maintenance, energy requirements above maintenance for each kilogram of weight gain, insulin sensitivity index, fasting, mean 24-h and peak plasma glucose, insulin, and leptin concentrations, and fasting and mean 24-h serum adiponectin concentrations. In cats fed the low-carbohydrate high-protein diet, after adjusting for initial body weight, those with higher energy requirements for weight gain and higher fasting glucose concentration had higher final body weights (P ≤ 0.01). Predicted final body weights using initial body weight, fasting glucose and mean 24-h insulin concentrations (partial R(2) 37.3%) were imprecise. An equation using just initial body weight and fasting glucose concentration would be of more practical value, but was marginally less precise. In cats fed the high-carbohydrate low-protein diet, those with lower fasting leptin concentration initially had higher final body weights (P = 0.01). Predicted final body weights using initial body weight, energy requirements for maintenance, total body fat percentage and fasting leptin concentration (partial R(2) 39.2%) were reasonably precise. Further studies are warranted to confirm these findings and to improve the precision of predicted final body weights. PMID:25084314
Ibn al-Quff (1233-1286 AD), a medieval Arab surgeon and physician.
Dalfardi, Behnam; Yarmohammadi, Hassan
2016-02-01
Abū'l-Faraj ibn Ya'qūb ibn Isḥāq Ibn al-Quff al-Karakī (1233-1286 AD), best known as Ibn al-Quff in the West, was a 13(th) century Arab physician-surgeon. During his lifetime, Ibn al-Quff made some important contributions to the art of healing. He authored several books and commentaries in the field of medicine, in particular surgery. This paper aims to review Ibn al-Quff's life, career, and contributions to medical science. PMID:24585631
Twin Roll Casting of Al-Mg Alloy with High Added Impurity Content
NASA Astrophysics Data System (ADS)
Kumar, S.; Hari Babu, N.; Scamans, G. M.; Fan, Z.; O'Reilly, K. A. Q.
2014-06-01
The microstructural evolution during twin roll casting (TRC) and downstream processing of AA5754 Al alloy with high added impurity content have been investigated. Strip casts with a high impurity content resulted in coarse α-Al grains and complex secondary phases. The grain size and centerline segregation reduced significantly on the addition of Al-Ti-B grain refiner (GR). Coarse-dendrite arm spacing (DAS) "floating" grains are observed in the impure alloy (IA) with higher volume in the GR strips. Two-dimensional (2D) metallographic analysis of the as-cast strip suggests that secondary phases (Fe-bearing intermetallics and Mg2Si) are discrete and located at the α-Al cell/grain boundaries, while three-dimensional (3D) analysis of extracted particles revealed that they were intact, well interconnected, and located in interdendritic regions. Homogenizing heat treatment of the cast strip breaks the interconnective networks and modifies the secondary phases to a more equiaxed morphology. During rolling, the equiaxed secondary phases align along the rolling direction. X-ray diffraction (XRD) analysis suggests that α-Al(FeMn)Si and Mg2Si are the predominant secondary phases that are formed during casting and remain throughout the downstream processing of the GR-IA. The high-impurity sheet processed from TRC resulted in superior strength and ductility over the sheet processed from small book mold ingot casting. The current study has shown that the TRC process can tolerate higher impurity levels and produce formable sheets from the recycled aluminum for structural applications.
Krishnaraj, R Navanietha; Kumari, S S Sreeja; Mukhopadhyay, Sudit Sekhar
2016-01-01
Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS) are progressive neurodegenerative diseases that affect the neurons in the brain and the spinal cord. Neuroinflamation and apoptosis are key players in the progressive damage of the neurons in AD and ALS. Currently, there is no drug to offer complete cure for both these diseases. Riluzole is the only available drug that can prolong the life time of the ALS patients for nearly 3 months. Molecules that offer good HIT to the molecular targets of ALS will help to treat AD and ALS patients. P53 kinase receptor (4AT3), EphA4 (3CKH) and histone deacetylase (3SFF) are the promising disease targets of AD and ALS. This paper discusses on a new approach to combat neurodegenerative diseases using photosynthetic pigments. The docking studies were performed with the Autodock Vina algorithm to predict the binding of the natural pigments such as β carotene, chlorophyll a, chlorophyll b, phycoerythrin and phycocyanin on these targets. The β carotene, phycoerythrin and phycocyanin had higher binding energies indicating the antagonistic activity to the disease targets. These pigments serve as a potential therapeutic molecule to treat neuroinflammation and apoptosis in the AD and ALS patients. PMID:26053508
Surgery for Gynecomastia in the Islamic Golden Age: Al-Tasrif of Al-Zahrawi (936–1013 AD)
Chavoushi, Seyed Hadi; Ghabili, Kamyar; Kazemi, Abdolhassan; Aslanabadi, Arash; Babapour, Sarah; Ahmedli, Rafail; Golzari, Samad E. J.
2012-01-01
The rise of European science during the Renaissance is greatly indebted to the flourishing of the sciences during the Islamic Golden Age. However, some believe that medieval Islamic physicians and in particular surgeons had been merely a medium for Greco-Roman ideas. Contrarily, in some medieval Islamic medical books, such as Al-Tasrif of Al-Zahrawi (936–1013), the surgical instructions represent a change in the usual techniques or are accompanied by a case history, implying that the procedure was actually undertaken. Along with the hundreds of chapters on different diseases and related medical and surgical treatments, Al-Tasrif includes a chapter on surgical techniques for gynecomastia. The present paper is a review of the description of the surgical management of gynecomastia by Al-Zahrawi as well as that of the ancient Greek, medieval, and modern medicine. Although Al-Zahrawi seemed to base his descriptions of surgery for gynecomastia upon those of Paulus of Aegina, his modification of the procedure and application of the medicinal substances might be indicative of Al-Zahrawi's own practice of the procedure. Al-Zahrawi's surgical procedures remained unchanged for many centuries thenceforward until the technological evolution in the recent centuries. PMID:23050167
YAG laser surface densification of a zircon refractory by adding AlN nanoparticles
Wang, W.Y.; Wang, A.H. . E-mail: pmahwang@public.wh.hb.cn; Zeng, D.W.; Bai, Z.K.; Xie, C.S.; Song, W.L.; Zhu, X.C.
2006-04-15
A zircon refractory zirconium silicate was surface melted with a pulsed YAG laser to introduce AlN nanoparticles, with the aim of improving its surface density and modifying the corresponding microstructure. The microstructure and phase structure features of the refractory induced by the laser beam were studied by scanning transmission microscopy, incorporating energy dispersive X-ray and X-ray diffraction analysis. Results show that the addition of AlN nanoparticles into the refractory surface significantly reduced the laser beam energy required to melt the surface of the refractory. The laser-melted depth was increased with an increase of laser power from 133 to 200 W. The microstructure of the laser-treated zone with the addition of AlN nanoparticles has a much finer dendritic structure with undeveloped primary dendrite arms while without the addition of AlN nanoparticles, a coarser dendrite with much long primary dendrite arms was observed. The phase structure of the laser-treated layer with the addition of AlN nanoparticles was found to be composed of m-ZrO{sub 2}, c-ZrO{sub 2}, ZrSiO{sub 4} and H-AlN.
Microstructure and Creep Behavior of Fe-27Al-1Nb Alloys with Added Carbon
NASA Astrophysics Data System (ADS)
Dobeš, Ferdinand; Kratochvíl, Petr; Pešička, Josef; Vodičková, Věra
2015-04-01
The effect of Nb and C additions on the phase composition, microstructure, and creep resistance of Fe3Al-type alloys is investigated. Two alloys, which contained (at. pct) (i) 27.6 Al, 1.15 Nb and 0.19 C (Fe balance) and (ii) 27.1 Al, 1.11 Nb, and 0.76 C (Fe balance), were studied in a temperature range from 873 K to 1073 K (600 °C to 800 °C). The carbide in both alloys was identified as Nb6C5. The creep data can be rationalized by introducing a threshold stress, below which, the creep rate is negligible. The threshold stress and an effective stress exponent were found simultaneously by a numerical method. Using the obtained values of the threshold stress, the activation energy of creep was determined to be 328 kJ/mol. The effective stress exponent varied from 2.0 to 3.1. A breakdown of power-law behavior was observed at higher stresses. The transition occurred at the normalized creep rate of , which agrees with the rule suggested by Sherby and Burke and the diffusion coefficient D corresponding to the diffusion of Al in Fe-Al.
Sintering and microstructure of silicon carbide ceramic with Y3Al5O12 added by sol-gel method.
Guo, Xing-Zhong; Yang, Hui
2005-03-01
Silicon carbide (SiC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 1860 degrees C with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal 'bridging'. PMID:15682507
Sintering and microstructure of silicon carbide ceramic with Y3Al5O12 added by sol-gel method*
Guo, Xing-zhong; Yang, Hui
2005-01-01
Silicon carbide (SiC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 1860 °C with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal ‘bridging’. PMID:15682507
Zi, Guoli; Yan, Zhiying; Wang, Yangxia; Chen, Yongjuan; Guo, Yunlong; Yuan, Fagui; Gao, Wenyu; Wang, Yanmei; Wang, Jiaqiang
2015-01-22
Catalytic hydrolysis of biomass over solid catalysts can be one of the most efficient pathways for a future sustainable society dependent on cellulose biomass. In this work metal-organic framework MIL-53(Al) without any functionalization was directly employed as an efficient heterogeneous catalyst for the hydrolysis of carboxymethyl cellulose (CMC) to 5-hydroxymethyl-furaldehyde (5-HMF) in aqueous phase. A 5-HMF molar yield of 40.3% and total reducing sugar (TRS) molar yield of 54.2% were obtained with water as single solvent at 473 K for 4 h. The catalyst could be reused three times without losing activity to a greater extent. With the remarkable advantages such as the use of water as single solvent and MIL-53(Al) as a novel heterogeneous green catalyst, the work provides a new platform for the production of value added chemicals and liquid fuels from biomass. PMID:25439879
NASA Astrophysics Data System (ADS)
Puy, Arnald
2013-04-01
Traditional irrigated terraces of Spain (known as 'huertas') are among the most emblematic and productive agricultural fields of the Mediterranean. Several of these huertas were first built by Arab and Berber tribes and clans that entered the Iberian Peninsula (al-Andalus) after 711 AD, coinciding with the spread of Islam during Middle Ages (>632 AD). One thousand and three hundred years after their construction they are still operative, presenting a topic case of sustainable and resilient agricultural areas. However, up until recently no data was available regarding the pre-existing features of the terrains where they were built, the timing of their construction nor their construction process. In this communication I will present the results of the study of a palaeosoil buried under an Andalusi irrigated terrace in the huerta of Ricote (Murcia, Spain). Soil micromorphology, physico-chemical analysis (Loss On Ignition, Magnetic Susceptibility, Particle Size Distribution, pH/Electrical Conductivity) and AMS dating allowed to determine that 1) Andalusi peasants selected a highly saline Hypercalcic Calcisol to build up the first irrigated terraces; 2) They clear the slope of bushes by fire; 3) They used the slope soil to build the terrace fill, possibly by inverting the original soil horizonation, and 4) According to the date obtained from the organic matter embedded in the topmost horizon of the palaeosoil (647-778 AD), the original Andalusi irrigated fields of Ricote were possibly built shortly after 711 AD. The communication, in sum, will show through a case study how past peasant societies transformed semi-arid environments to create highly productive agrarian areas.
Improved single pellet grasping using automated ad libitum full-time training robot.
Fenrich, Keith K; May, Zacnicte; Hurd, Caitlin; Boychuk, Carolyn E; Kowalczewski, Jan; Bennett, David J; Whishaw, Ian Q; Fouad, Karim
2015-03-15
The single pellet grasping (SPG) task is a skilled forelimb motor task commonly used to evaluate reaching and grasp kinematics and recovery of forelimb function in rodent models of CNS injuries and diseases. To train rats in the SPG task, the animals are usually food restricted then placed in an SPG task enclosure and presented food pellets on a platform located beyond a slit located at the front of the task enclosure for 10-30 min, normally every weekday for several weeks. When the SPG task is applied in studies involving various experimental groups, training quickly becomes labor intensive, and can yield results with significant day-to-day variability. Furthermore, training is frequently done during the animals' light-cycle, which for nocturnal rodents such as mice and rats could affect performance. Here we describe an automated pellet presentation (APP) robotic system to train and test rats in the SPG task that reduces some of the procedural weaknesses of manual training. We found that APP trained rats performed significantly more trials per 24 h period, and had higher success rates with less daily and weekly variability than manually trained rats. Moreover, the results show that success rates are positively correlated with the number of dark-cycle trials, suggesting that dark-cycle training has a positive effect on success rates. These results demonstrate that automated training is an effective method for evaluating and training skilled reaching performance of rats, opening up the possibility for new approaches to investigating the role of motor systems in enabling skilled forelimb use and new approaches to investigating rehabilitation following CNS injury. PMID:25523027
A transient event in AD 775 reported by al-Tabarı: A bolide - not a nova, supernova, or kilonova
NASA Astrophysics Data System (ADS)
Neuhäuser, R.; Kunitzsch, P.
2014-11-01
Given that the cause for the strong increase in 14C in AD 774/5 in Japanese and German trees is still a matter of debate (e.g. short gamma-ray burst or solar super-flare), we have searched in Arabic chronicles for reports about unusual transient celestial events. In the History of al-Tabarı we found two (almost identical) reports about such an event. The group around caliph al-Mansūr observed a transient event while on the way from Baghdad to Mecca on AD 775 Augusst 29 - September 1 (Julian calendar). A celestial object (kawkab) was seen to fall or set (inqadda), and its trace (atharuhu) was seen for at least tens of minutes (up to 70-90 min) during morning twilight. The reports use the Arabic words kawkab and athar(uhu), which were also used in the known Arabic reports about supernovae SN 1006 and 1054, so that one might consider an interpretation as a nova-like event. The kawkab (celestial object) was observed only during the morning twilight at a brightness of probably between about -3 and 0 mag. Such a brightness and time-scale would be expected for optical kilonovae (at {˜ 3} to 9 kpc) in the context of short gamma-ray bursts. There are no similar reports from eastern Asia for this time. However, the short reports are fully consistent with a bolide: The word kawkab can be used for meteor, the verb inqadda normally means falling down, the word atharuhu can mean its trace. We therefore prefer the interpretation as bolide. We discuss in detail how to convert the Muslim calendar date to a date in the Julian calendar using first the calculated Islamic calendar and then considering the time when the crescent new moon could be visible at the given location.
Geosite of a steep lava spatter cone of the 1256 AD, Al Madinah eruption, Kingdom of Saudi Arabia
NASA Astrophysics Data System (ADS)
Moufti, M.; Németh, K.; Murcia, H.; Lindsay, J.; El-Masry, N.
2013-06-01
UNESCO promotes geoconservation through various programs intended to establish an inventory of geologically and geomorphologically significant features worldwide that can serve as an important database to understand the Earth's global geoheritage. An ultimate goal of such projects globally is to establish geoparks that represent an integrated network of knowledge transfer opportunities, based on a specific array of geological and geomorphological sites able to graphically demonstrate how the Earth works to the general public. In these complex geoconservation and geoeducational programs, the identification of significant geological and geomorphological features is very important. These are commonly referred to as `geosites' or `geomorphosites', depending on whether the feature or processes the site demonstrates is more geological or geomorphological, respectively. The Kingdom of Saudi Arabia is an extraordinary place due to its arid climate and therefore perfect exposures of rock formations. The Kingdom is also home to extensive volcanic fields, named "harrats" in Arabic, referring particularly to the black, basaltic lava fields that dominate the desert landscape. Current efforts to increase awareness of the importance of these volcanic fields in the geological landscape of Arabia culminated in the first proposal to incorporate the superbly exposed volcanic features into an integrated geoconservation and geoeducation program that will hopefully lead to the development of a geopark named, "The Harrat Al Madinah Volcanic Geopark" [1]. Here we describe one of the extraordinary features of the proposed Harrat Al Madinah Volcanic Geopark, namely a steep lava spatter cone formed during a historical eruption in 1256 AD.
Solid Particle Erosion Wear of GF/EP Composites with Added Al{sub 2}O{sub 3}
Bagci, Mehmet; Imrek, Huseyin
2011-01-17
This study has targeted to investigate wear behavior of a sort of new composite material where Al{sub 2}O{sub 3}({approx_equal}150 {mu}m) particles were added to glass fiber and epoxy resin (GF/EP) at an amount of 15% and 30%. The method used in the tests, was the one that use dry and compressed air to accelerate abrasive particles onto a specimen and from there the wear formed was investigated. Striking speed was determined with the help of a double disc method by making use of pressure difference, whereas impinging angles were set by turning the specimen holder around its axis. As a result, in this experimental study, solid particle erosion behavior of a new formed composite material was investigated and erosion rates computed where three different impinging angles (30 deg., 60 deg. and 90 deg.), three different striking speeds (23, 34 and 53 m/s) and two different fiber directions (0 deg. and 45 deg.) were used to enable angular aluminum abrasives with average diameter of 400 {mu}m to bombard target specimens to undertake the tests. In addition, the study presents microscopic views of the specimens after undergoing the tests.
NASA Astrophysics Data System (ADS)
Liakos, A.; Niarchos, P.; Budding, E.
2012-03-01
Aims: We aim to derive the absolute parameters of the components of AD And, AL Cam, and V338 Her, interpret their orbital period changes and discuss their evolutionary status. Methods: New and complete multi-filter light curves of the eclipsing binaries AD And, AL Cam, and V338 Her were obtained and analysed with modern methods. Using all reliably observed times of minimum light, we examined orbital period irregularities using the least squares method. In addition, we acquired new spectroscopic observations during the secondary eclipses for AL Cam and V338 Her. Results: For AL Cam and V338 Her, we derive reliable spectral types for their primary stars. Statistical checks of orbital period analysis for all systems are very reassuring in the cases of V338 Her and AD And, although less so for AL Cam. The LIght-Time Effect (LITE) results are checked by inclusion of a third light option in the photometric analyses. Light curve solutions provide the means to calculate the absolute parameters of the components of the systems and reliably estimate their present evolutionary status. Conclusions: AL Cam and V338 Her are confirmed as classical Algols of relatively low mass in similar configurations. Unlike AL Cam, however, V338 Her is still transferring matter between its components, raising interest in the determinability of the evolutionary histories of Algols. AD And is found to be a detached system in which both close stars are of age ~109 yr and is probably a "non-classical" young triple, at an interesting stage of its dynamical evolution. The spectra and reduced photometric data are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/539/A129
Ibn al-Haytham (965-1039 AD), the original portrayal of the modern theory of vision.
Daneshfard, Babak; Dalfardi, Behnam; Nezhad, Golnoush Sadat Mahmoudi
2016-05-01
Abū ՙAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham, known in the West as Alhazen, was an Arab-Islamic scholar who helped develop the science of ophthalmology during the medieval era. He was the first to reject firmly the extramission theory of vision, which was prevalent during his time, and suggested that the eyes are the source of the light rays responsible for vision. Ibn al-Haytham in his book entitled Kitab al-Manazir (Book of Optics) explained vision based on light emanating from objects. In this study we review Ibn al-Haytham's life and introduce his major contribution to the field of ophthalmology, his theory of vision. PMID:24737194
NASA Astrophysics Data System (ADS)
Afshar, M.; Hoseini, S. S.; Sargolzaei, M.
2016-07-01
In this paper, the magnetic and electronic properties of single aluminum and silicon atom added to small carbon clusters (C n X; X = Al, Si; n = 2-10) are studied in the framework of generalized-gradient approximation using density functional theory. The calculations were performed for linear, two dimensional and three dimensional clusters based on full-potential local-orbital (FPLO) method. The total energies, HOMO-LUMO energy gap and total magnetic moments of the most stable structures are presented in this work. The calculations show that C n Si clusters have more stability compared to C n Al clusters. In addition, our magnetic calculations were shown that the C n Al isomers are magnetic objects whereas C n Si clusters are nonmagnetic objects.
Observation of the TWIP + TRIP Plasticity-Enhancement Mechanism in Al-Added 6 Wt Pct Medium Mn Steel
NASA Astrophysics Data System (ADS)
Lee, Seawoong; Lee, Kyooyoung; De Cooman, Bruno C.
2015-06-01
The intercritically annealed Fe-0.15 pctC-6.0 pctMn-1.5 pctSi-3.0 pctAl and Fe-0.30 pctC-6.0 pctMn-1.5 pctSi-3.0 pctAl medium Mn steels were found to have improved mechanical properties due to the TWIP and TRIP plasticity-enhancing mechanisms being activated in succession during tensile deformation. The increase of the C content from 0.15 to 0.30 pct resulted in ultra-high strength properties and a strength-ductility balance of approximately 65,000 MPa-pct, i.e., equivalent to the strength-ductility balance of high Mn TWIP steel with a fully austenitic microstructure.
Technology Transfer Automated Retrieval System (TEKTRAN)
Reproductive performance was evaluated in heifers born in 4 years that were randomly assigned to either control (fed to appetite; n = 268) or restricted (fed at 80 % of that consumed by controls adjusted to a common BW basis; n = 263) feeding during a 140-d postweaning trial, beginning about 2 mo af...
Technology Transfer Automated Retrieval System (TEKTRAN)
Reproductive performance was evaluated in heifers born in 4 years that were randomly assigned to either control (fed to appetite; n = 268) or restricted (fed at 80 % of that consumed by controls adjusted to a common BW basis; n = 263) feeding during a 140-d postweaning trial, beginning about 2 mo af...
Technology Transfer Automated Retrieval System (TEKTRAN)
Reproductive performance was evaluated in composite heifers born over a 4-yr period that were randomly assigned to control (fed to appetite; n = 268) or restricted fed at 80 % of that consumed by controls adjusted to a common BW basis; n = 263) feeding for a 140-d period beginning about 2 mo after w...
El Khoury, Dalia; Panahi, Shirin; Luhovyy, Bohdan L; Douglas Goff, H; Harvey Anderson, G
2015-05-01
The objective of this study was to describe the interaction of beverage and food intake with meal advancement in healthy adults. In a randomized controlled study, 29 men and women consumed to satiation, over 20 min, a pizza meal with one of the five beverages including water, 1% milk, orange juice, regular cola and diet cola. Mealtime food and fluid intake were measured, within each of three 7-min phases of the meal. A progressive decline occurred from phase 1 to 3 in fluid intake and food intake, averaging 59 mL and 268 kcal (P < 0.0001) respectively; however, the relative intake of fluid to food (mL/kcal) increased (P < 0.0001). Beverage type was not a factor. All beverages resulted in similar fluid volume intake compared to water. However, caloric beverages led to higher mealtime total energy intake compared to water (P < 0.001) and diet cola (P < 0.0001). Baseline thirst correlated positively with both fluid (r = 0.28; P < 0.001) and food (r = 0.16; P < 0.05) intakes at the meal, whereas baseline appetite associated positively only with mealtime food intake (r = 0.23; P<0.01). In conclusion, mealtime fluid and food intakes interact, unaffected by beverage characteristics, to increase the ratio of fluid to food intake with meal progression. PMID:25700893
Hillman, Angela R; Turner, Mark C; Peart, Daniel J; Bray, James W; Taylor, Lee; McNaughton, Lars R; Siegler, Jason C
2013-01-01
Dehydration has been shown to augment cellular stress. Glycerol hyperhydration can delay dehydration, which may decrease the level of pre- and post-exercise oxidative stress. This study aimed to compare the effects of glycerol (G) or water (W) hyperhydration with no hyperhydration (C) on oxidative stress, thermoregulation, and cycle performance. Seven trained males consumed 1.2 g of glycerol·kg⁻¹ body mass (BM) in 26 ml·kg⁻¹ BM water or equal volume water to achieve hyperhydration followed by a 90 min time trial. Total glutathione increased post exercise (PE) in all trials (p < 0.01), while oxidized glutathione (p < 0.05) and protein carbonyl concentrations (p < 0.001) were increased PE for the C trial only. Mean body temperature and heart rate increased with exercise but were not different between interventions. Total distance covered and power outputs were not different between interventions. Fluid intake attenuated oxidative stress but did not enhance thermoregulation or performance. PMID:24067117
Meule, Adrian; Hormes, Julia M
2015-08-01
The Food Cravings Questionnaires are the most commonly used instruments for the assessment of trait and state food craving. Chocolate is the most frequently craved food in Western societies. In the current studies, the Food Cravings Questionnaire-Trait-reduced (FCQ-T-r) and the Food Cravings Questionnaire-State (FCQ-S) were adapted to capture strong urges for chocolate. In study 1, students (n = 492; 81.3% female) completed chocolate versions of the FCQ-T-r and FCQ-S among other measures online. The FCQ-T-r (α = .94) comprised two subscales representing lack of control (α = .91) and thoughts about chocolate (α = .91). The FCQ-S (α = .87) comprised two subscales representing chocolate craving (α = .90) and hunger (α = .85). FCQ-T-r scores were significantly and positively correlated with self-reported frequency of consuming chocolate and with scores on the Attitudes to Chocolate Questionnaire, indicating good convergent validity. In study 2, students (n = 76; 73.7% female) underwent a chocolate exposure in the laboratory. FCQ-S scores increased during chocolate exposure and increases in momentary chocolate craving were significantly positively correlated with increases in salivary flow. Higher momentary chocolate craving was positively correlated with higher laboratory chocolate consumption. Exploratory analyses revealed that increases in salivary flow were only associated with increased chocolate consumption in participants scoring high, but not low on trait chocolate craving. The chocolate versions of the FCQ-T-r and FCQ-S represent reliable and valid self-report measures for the assessment of trait and state chocolate craving. PMID:25913686
NASA Technical Reports Server (NTRS)
Ueno, Akiko; Vannais, Diane; Lenarczyk, Marek; Waldren, Charles A.; Chatterjee, A. (Principal Investigator)
2002-01-01
It has been reported that X-ray induced HPRT- mutation in cultured human cells is prevented by ascorbate added after irradiation. Mutation extinction is attributed to neutralization by ascorbate, of radiation-induced long-lived radicals (LLR) with half-lives of several hours. We here show that post-irradiation treatment with ascorbate (5 mM added 30 min after radiation) reduces, but does not eliminate, the induction of CD59- mutants in human-hamster hybrid A(L) cells exposed to high-LET carbon ions (LET of 100 KeV/microm). RibCys, [2(R,S)-D-ribo-1',2',3',4'-Tetrahydroxybutyl]-thiazolidene-4(R)-ca riboxylic acid] (4 mM) gave a similar but lesser effect. The lethality of the carbon ions was not altered by these chemicals. Preliminary data are presented that ascorbate also alters the spectrum of CD59- mutations induced by the carbon beam, mainly by reducing the incidence of small mutations and mutants displaying transmissible genomic instability (TGI), while large mutations are unaffected. Our results suggest that LLR are important in initiating TGI.
NASA Astrophysics Data System (ADS)
Cheng, Xu; Chai, Lianjing; Wu, Guoqing; Wang, Hong; Nan, Hai
2016-05-01
In this article, the chemical inertness of shell using Ti-added mullite backup coat against molten Ti-6Al-4V (Ti64) alloy was investigated. The metal/shell interfacial microstructures and compositions were characterized using an optical microscope, scanning electron microscope, roughness tester, and X-ray diffractometer; the hardened layer thickness was evaluated using a microhardness tester. By adding titanium powder into the mullite backup coat, the alpha case and hardened layer thickness of the Ti64 castings were largely reduced with good surface finishing. Silicon ions, from the backup coat, penetrated into the alloy and coarsened the β lath at the metal/shell interfacial area. The Ti powder in the mullite backup coat oxidized and interacted with silica during mold firing and casting, which reduced the silicon and oxygen concentrations at the metal/shell interfacial area. The oxygen penetration depth is thicker than the alpha case layer thickness, and around 0.26 wt pct, oxygen can obviously coarsen the alpha lath at the metal/shell interfacial area during investment casting.
NASA Astrophysics Data System (ADS)
Kumar, S.; Hari Babu, N.; Scamans, G. M.; Fan, Z.
2011-10-01
We have investigated the influence of melt conditioning by intensive shearing on the mechanical behavior and microstructure of Al-Mg-Mn-Fe-Cu-Si alloy sheet produced from a small book mold ingot with high added impurity content. The melt conditioned ingot has fine grains throughout its cross section, whereas a conventionally cast ingot, without melt shearing, has coarser grains and shows a wider variation of grain size. Both needle-shaped and coarse Chinese script iron bearing intermetallic particles are found in the microstructure at the center of the conventionally processed ingot, but for the melt conditioned ingot, only fine Chinese script intermetallic particles are observed. In addition to the iron bearing intermetallics, Mg2Si particles are also observed. The ingots were rolled to thin sheet and solution heat treated (SHT). During rolling, the iron-based intermetallics and Mg2Si particles are broken and aligned along the rolling direction. Yield strength (YS), ultimate tensile strength (UTS), and elongation of the intensively melt sheared and processed sheet are all improved compared to the conventionally cast and processed sheet. Fractographic analysis of the tensile fracture surfaces shows that the clustered and coarse iron bearing intermetallic particles are responsible for the observed reduction in mechanical properties of the conventionally cast sheet. We have shown that by refining the initial microstructure of the ingot by intensive shear melt conditioning, it is possible to achieve improved mechanical properties at the final sheet gage of an AlMgMn alloy with a high content of impurities.
NASA Astrophysics Data System (ADS)
Kereszturi, Gábor; Németh, Károly; Moufti, Mohammed R.; Cappello, Annalisa; Murcia, Hugo; Ganci, Gaetana; Del Negro, Ciro; Procter, Jonathan; Zahran, Hani Mahmoud Ali
2016-01-01
Lava flow hazard modelling requires detailed geological mapping, and a good understanding of emplacement settings and the processes involved in the formation of lava flows. Harrat Rahat, Kingdom of Saudi Arabia, is a large volcanic field, comprising about 1000 predominantly small-volume volcanoes most of which have emitted lava flows of various lengths. A few eruptions took place in this area during the Holocene, and they were located in the northern extreme of the Harrat Rahat, a close proximity to critical infrastructure and population living in Al-Madinah City. In the present study, we combined field work, high resolution digital topography and morphometric analysis to infer the emplacement history of the last historical event in the region represented by the 1256 AD Al-Madinah lava flow field. These data were also used to simulate 1256 AD-type lava flows in the Harrat Rahat by the MAGFLOW lava flow emplacement model, which is able to relate the flow evolution to eruption conditions. The 1256 AD lava flow field extent was mapped at a scale of 1:1000 from a high resolution (0.5 m) Light Detection And Ranging (LiDAR) Digital Terrain Model (DTM), aerial photos with field support. The bulk volume of the lava flow field was estimated at 0.4 km3, while the source volume represented by seven scoria cone was estimated at 0.023 km3. The lava flow covered an area of 60 km2 and reached a maximum length of 23.4 km. The lava flow field comprises about 20.9% of pāhoehoe, 73.8% of 'a'ā, and 5.3% of late-stage outbreaks. Our field observation, also suggests that the lava flows of the Harrat Rahat region are mainly core-dominated and that they formed large lava flow fields by amalgamation of many single channels. These channels mitigated downslope by topography-lava flow and channel-channel interactions, highlighting this typical process that needs to be considered in the volcanic hazard assessment in the region. A series of numerical lava flow simulations was carried out
Abdel-Halim, Rabie E
2008-01-01
This primary-source study of 4 medical works of the 13th century Muslim scholar Ibn Al-Nafis confirmed that his Kitab Al-Mujaz Fi Al-Tibb was authored as an independent book meant to be a handbook for medical students and practitioners not as an epitome of Kitab Al-Qanun of Ibn Sina as thought by recent historians. His huge medical encyclopedia, Al-Shamil, represents a wave of intense scientific activity that spread among the scholars of Cairo and Damascus following the massive destruction of books by Hulako's Army during the devastation of Baghdad in 1258. Like his predecessors in the Islamic Era, Ibn Al-Nafis critically appraised the views of scholars before him in the light of his own experimentation and direct observations. Accordingly, in his books Sharh Tashreeh Al-Qanun, Risalat al-Aadaa and Al-Risalah Al-Kameleyyah, we find the first description of the coronary vessels and the true concept of the blood supply of the heart as well as the correct description of the pulmonary circulation and the beginnings of the proper understanding of the systemic circulation. Those discoveries of Ibn Al-Nafis, translated to Latin by Andreas Alpagus printed in Venice in 1547, appeared, 6 years later, in the Christianismi Restituto of Servetus and, in 1555, in the De Fabrica Humani Corporis of Vesalius 2nd edition then in the works of Valvarde 1554, Columbus 1559, Cesalpino 1571, and finally Harvey in 1628. Furthermore, this study documented several other contributions of Ibn Al-Nafis to the progress of human functional anatomy and to advances in medical and surgical practice. PMID:18176669
ERIC Educational Resources Information Center
UCLA IDEA, 2012
2012-01-01
Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…
NASA Astrophysics Data System (ADS)
Xia, Yu; Ma, Liang; Lu, Hui; Wang, Xian-Ping; Gao, Yun-Xia; Liu, Wang; Zhuang, Zong; Guo, Li-Jun; Fang, Qian-Feng
2015-12-01
Garnet-like Li6.8La3Zr1.8Bi0.2O12 (LLZBO) + x mol.% Al2O3 ( x = 0, 1.25, 2.50) lithium ionic electrolytes were prepared by conventional solid state reaction method under two different sintering temperatures of 1000°C and 1100°C. XPS, induced coupled plasma optical emission spectrometer (ICP-OES), XRD and AC impedance spectroscopy were applied to investigate the bismuth valance, lithium concentration, phase structure and lithium ionic conductivity, respectively. Electrical measurement demonstrated that ionic conductivity of Al-added LLZBO compounds could be obviously improved when the sample sintering temperature increased from 1000°C to 1100°C. The highest ionic conductivity 6.3×10-5 S/cm was obtained in the LLZBO-1.25%Al sample sintered at 1100°C, in consistent with the lowest activation energy 0.45 eV for the lithium ion migration. The mechanism related with good ionic conductivity in the Al-added LLZBO sample was attributed to the lattice distortion induced by the partial Al substitution at Zr sites, which is helpful to improve the migration ability of Li ions in lattice.
ERIC Educational Resources Information Center
Orsini, Larry L.; Hudack, Lawrence R.; Zekan, Donald L.
1999-01-01
The value-added statement (VAS), relatively unknown in the United States, is used in financial reports by many European companies. Saint Bonaventure University (New York) has adapted a VAS to make it appropriate for not-for-profit universities by identifying stakeholder groups (students, faculty, administrators/support personnel, creditors, the…
NASA Astrophysics Data System (ADS)
Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios
2009-03-01
We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS5. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS5 shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Qs is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Qs˜A1/3. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of αP = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of αP = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be αP = 1.5.
Effect of adding Co to MoS{sub 2}/Al{sub 2}O{sub 3} upon the kinetics of the water-gas shift
Lund, C.R.F.
1996-09-01
A microkinetic model for the kinetics of the water-gas shift over sulfided CoMo/Al{sub 2}O{sub 3} catalysts was developed starting from a similar model for unpromoted sulfided Mo/Al{sub 2}O{sub 3} catalysts. Co was found to promote the catalyst`s activity only at low CO/H{sub 2}O ratios; at high ratios the Mo catalyst was marginally more active than the CoMo catalyst. The most important different between the two models was the strength of interactions between the surface and hydroxyl groups. The addition of Co increased the stability of hydroxyl groups relative to sulfhydryl groups, and at higher H{sub 2}O concentrations this allowed oxidized surface sites to more readily participate in both steam adsorption and hydrogen desorption steps. The results are most easily reconciled in terms of a promotional model where the Co and Mo are in close proximity and the active sites are similar to sites on unpromoted Mo catalysts.
Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios
2009-03-23
We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.
NASA Astrophysics Data System (ADS)
Martelli, Dario; Morales, Jose F.
2005-02-01
In the light of the recent Lin, Lunin, Maldacena (LLM) results, we investigate 1/2-BPS geometries in minimal (and next to minimal) supergravity in D = 6 dimensions. In the case of minimal supergravity, solutions are given by fibrations of a two-torus T2 specified by two harmonic functions. For a rectangular torus the two functions are related by a non-linear equation with rare solutions: AdS3 × S3, the pp-wave and the multi-center string. ``Bubbling'', i.e. superpositions of droplets, is accommodated by allowing the complex structure of the T2 to vary over the base. The analysis is repeated in the presence of a tensor multiplet and similar conclusions are reached, with generic solutions describing D1D5 (or their dual fundamental string-momentum) systems. In this framework, the profile of the dual fundamental string-momentum system is identified with the boundaries of the droplets in a two-dimensional plane.
Evaluación de la utilidad diagnóstica de la versión española del cuestionario al informador «AD8»☆
Pardo, C. Carnero; de la Vega Cotarelo, R.; Alcalde, S. López; Aparicio, C. Martos; Carrillo, R. Vílchez; Gavilán, E. Mora; Galvin, J.E.
2012-01-01
Introducción El AD8 es un cuestionario al informador breve que puede ser autoaplicado y facilita la identificación de deterioro cognitivo (DC); nuestro objetivo es evaluar la utilidad diagnóstica (UD) de una versión española. Material y métodos Estudio transversal en una muestra clínica de díadas paciente/ informador, 330 sujetos con sospecha de DC o demencia (DEM) y 71 controles. Se ha evaluado la consistencia interna (α de Cronbach) y la validez (correlaciones parciales con estadio GDS, Fototest e índice funcional [IF]). La UD se ha evaluado para no DC vs DC (GDS 3–4) por medio del área bajo la curva ROC (aROC) y se ha considerado mejor punto de corte aquel que hacía máximo el índice de Youden. Resultados En la muestra, 105 no tenían DC, 99 tenían DC sin DEM y 203 DEM. La consistencia interna es alta (α 0,90, IC del 95%, 0,89–0,92), al igual que las correlaciones con GDS (r = 0,72, p < 0,001), Fototest (r = −0,61, p < 0,001) e IF (r = 0,59, p < 0,001). El aROC del AD8 es 0,90 (IC del 95%, 0,86–0,93), sin diferencia significativa con la del Fototest (aROC 0,93, IC del 95%, 0,89–0,96); el mejor punto de corte es 3/4 con sensibilidad de 0,93 (IC del 95%, 0,88–0,96), especificidad de 0,81 (IC del 95%, 0,72–0,88) y el 88,8% de las clasificaciones correctas. El uso conjunto de AD8 y Fototest mejora de forma significativa la UD de ambos (aROC 0,96, IC del 95%, 0,93–0,98, p < 0,05). Conclusiones La versión española del AD8 conserva las cualidades psicométricas y la UD de la versión original; su uso combinado con el Fototest mejora de forma significativa la UD de ambos. PMID:22652137
Klein, Jonathon D.; Sherrill, Jeremy B.; Morello, Gabriella M.; San Miguel, Phillip J.; Ding, Zhenming; Liangpunsakul, Suthat; Liang, Tiebing; Muir, William M.; Lumeng, Lawrence; Lossie, Amy C.
2014-01-01
Research is uncovering the genetic and biochemical effects of consuming large quantities of alcohol. One prime example is the J- or U-shaped relationship between the levels of alcohol consumption and the risk of atherosclerotic cardiovascular disease. Moderate alcohol consumption in humans (about 30 g ethanol/d) is associated with reduced risk of coronary heart disease, while abstinence and heavier alcohol intake is linked to increased risk. However, the hepatic consequences of moderate alcohol drinking are largely unknown. Previous data from alcohol-preferring (P) rats showed that chronic consumption does not produce significant hepatic steatosis in this well-established model. Therefore, free-choice alcohol drinking in P rats may mimic low risk or nonhazardous drinking in humans, and chronic exposure in P animals can illuminate the molecular underpinnings of free-choice drinking in the liver. To address this gap, we captured the global, steady-state liver transcriptome following a 23 week free-choice, moderate alcohol consumption regimen (∼7.43 g ethanol/kg/day) in inbred alcohol-preferring (iP10a) rats. Chronic consumption led to down-regulation of nine genes in the cholesterol biosynthesis pathway, including HMG-CoA reductase, the rate-limiting step for cholesterol synthesis. These findings corroborate our phenotypic analyses, which indicate that this paradigm produced animals whose hepatic triglyceride levels, cholesterol levels and liver histology were indistinguishable from controls. These findings explain, at least in part, the J- or U-shaped relationship between cardiovascular risk and alcohol intake, and provide outstanding candidates for future studies aimed at understanding the mechanisms that underlie the salutary cardiovascular benefits of chronic low risk and nonhazardous alcohol intake. PMID:25542004
Genoni, Angela; Lyons-Wall, Philippa; Lo, Johnny; Devine, Amanda
2016-01-01
(1) BACKGROUND: The Paleolithic diet is popular in Australia, however, limited literature surrounds the dietary pattern. Our primary aim was to compare the Paleolithic diet with the Australian Guide to Healthy Eating (AGHE) in terms of anthropometric, metabolic and cardiovascular risk factors, with a secondary aim to examine the macro and micronutrient composition of both dietary patterns; (2) METHODS: 39 healthy women (mean ± SD age 47 ± 13 years, BMI 27 ± 4 kg/m²) were randomised to either the Paleolithic (n = 22) or AGHE diet (n = 17) for four weeks. Three-day weighed food records, body composition and biochemistry data were collected pre and post intervention; (3) RESULTS: Significantly greater weight loss occurred in the Paleolithic group (-1.99 kg, 95% CI -2.9, -1.0), p < 0.001). There were no differences in cardiovascular and metabolic markers between groups. The Paleolithic group had lower intakes of carbohydrate (-14.63% of energy (E), 95% CI -19.5, -9.7), sodium (-1055 mg/day, 95% CI -1593, -518), calcium (-292 mg/day 95% CI -486.0, -99.0) and iodine (-47.9 μg/day, 95% CI -79.2, -16.5) and higher intakes of fat (9.39% of E, 95% CI 3.7, 15.1) and β-carotene (6777 μg/day 95% CI 2144, 11410) (all p < 0.01); (4) CONCLUSIONS: The Paleolithic diet induced greater changes in body composition over the short-term intervention, however, larger studies are recommended to assess the impact of the Paleolithic vs. AGHE diets on metabolic and cardiovascular risk factors in healthy populations. PMID:27223304
Technology Transfer Automated Retrieval System (TEKTRAN)
Tumor necrosis factor-alpha (TNF-') is a pro-inflammatory cytokine that upregulates mRNA expression of suppressors of cytokine signaling (SOCS) and induces nitric oxide (NO) production. Both SOCS and NO inhibit intracellular growth hormone (GH) signaling and uncouple the somatotropic axis. Expressio...
NASA Astrophysics Data System (ADS)
Shi, Ce; Liu, Ying; Yi, Mengmeng; Zheng, Jimeng; Tian, Huiqin; Du, Yishuai; Li, Xian; Sun, Guoxiang
2016-07-01
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and, hence, better growth performance, the assumption has rarely been tested. This study compares the Effects of time-restricted versus free access self-feeding on the growth, feeding behavior and daily digestive enzyme rhythms of Atlantic salmon (Salmo salar). In an experiment that lasted 6 weeks, fish (109.9 g) were divided into two groups: group 1 had free access to a self-feeder (FA); group 2 received three meals per day (2 h per meal) at dawn, midday and dusk via a time-restricted self-feeder (TR). At the end of the experiment, the fish were sampled every 3 h over a 24-h period. The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase, while FA fish displayed no statistically significant rhythms (P<0.05). Pepsin activity of TR fish also showed a significant daily rhythm (P<0.05) with the acrophase at the second feed and a decrease over the next 12 h. Average daily trypsin, lipase and amylase levels of FA fish were significantly lower than those of TR fish (P<0.01); however, the growth performance of both groups was similar (P>0.05). In conclusion, the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance, with the TR group showing comparatively poor blood glucose regulation.
Technology Transfer Automated Retrieval System (TEKTRAN)
High protein diets may attenuate bone loss during energy restriction (ER). The objective of the current study was to determine whether high protein diets suppress bone turnover and improve bone quality in rats during ER and whether dietary protein source affects this relationship. Eighty 12-week o...
Genoni, Angela; Lyons-Wall, Philippa; Lo, Johnny; Devine, Amanda
2016-01-01
(1) Background: The Paleolithic diet is popular in Australia, however, limited literature surrounds the dietary pattern. Our primary aim was to compare the Paleolithic diet with the Australian Guide to Healthy Eating (AGHE) in terms of anthropometric, metabolic and cardiovascular risk factors, with a secondary aim to examine the macro and micronutrient composition of both dietary patterns; (2) Methods: 39 healthy women (mean ± SD age 47 ± 13 years, BMI 27 ± 4 kg/m2) were randomised to either the Paleolithic (n = 22) or AGHE diet (n = 17) for four weeks. Three-day weighed food records, body composition and biochemistry data were collected pre and post intervention; (3) Results: Significantly greater weight loss occurred in the Paleolithic group (−1.99 kg, 95% CI −2.9, −1.0), p < 0.001). There were no differences in cardiovascular and metabolic markers between groups. The Paleolithic group had lower intakes of carbohydrate (−14.63% of energy (E), 95% CI −19.5, −9.7), sodium (−1055 mg/day, 95% CI −1593, −518), calcium (−292 mg/day 95% CI −486.0, −99.0) and iodine (−47.9 μg/day, 95% CI −79.2, −16.5) and higher intakes of fat (9.39% of E, 95% CI 3.7, 15.1) and β-carotene (6777 μg/day 95% CI 2144, 11410) (all p < 0.01); (4) Conclusions: The Paleolithic diet induced greater changes in body composition over the short-term intervention, however, larger studies are recommended to assess the impact of the Paleolithic vs. AGHE diets on metabolic and cardiovascular risk factors in healthy populations. PMID:27223304
Microwave Dielectric Properties of TiO2-Added Li2ZnTi3O8 Ceramics Doped with Li2O-Al2O3-B2O3 Glass
NASA Astrophysics Data System (ADS)
Li, Ying-xiang; Qin, Zhen-jun; Tang, Bin; Zhang, Shu-ren; Chang, Geng; Li, Hao; Chen, He-tuo; Yang, Han; Li, Jun-shan
2015-01-01
The effect of Li2O-Al2O3-B2O3 (LAB) glass addition on phase composition, microstructure and the microwave dielectric properties of Li2ZnTi3O8 ceramics with TiO2 were investigated using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and a vector network analyzer. With the addition of 17 mol% TiO2 on Li2ZnTi3O8 ceramics, the temperature coefficient of the resonant frequency ( τ ƒ) value could be adjusted to +3.3 ppm/°C. When a small amount of LAB glass was added to the Li2ZnTi3O8 + 17 mol% TiO2 materials, the sintering temperature could be significantly lowered from 1160°C to 900°C. With increasing the LAB glass, the Q × f value first increased and then decreased. Typically, the 1 wt.% LAB glass-added Li2ZnTi3O8 + 17 mol% TiO2 ceramics sintered at 900°C for 4 h had good microwave dielectric properties with ɛr = 26.8, Q × f = 28,000 GHz and τ ƒ = + 2.5 ppm/°C, which made it a promising ceramic for LTCC technology application.
Mix, Christian; Finizio, Simone; Kläui, Mathias; Jakob, Gerhard
2014-06-30
Multilayered BiFeO{sub 3} (BFO)/LaAlO{sub 3} (LAO) thin film samples were fabricated on SrTiO{sub 3} (STO) substrates by pulsed laser deposition. In this work, the ferroelectric polarization of a multiferroic BFO ad-layer on top of the quasi-two-dimensional electron gas (2DEG) at the LAO/STO interface is used to manipulate the conductivity of the quasi-2DEG. By microstructuring the conductive area of the LAO/STO-interface, a four-point geometry for the measurement of the resistivity was achieved. Piezo force microscopy allows for imaging and poling the spontaneous ferroelectric polarization of the multiferroic layer. The resistance changes showed a linear dependence on the area scanned and a hysteretic behavior with respect to the voltages applied in the scanning process. This is evidence for the ferroelectric polarization of the multiferroic causing the resistance changes. Coupling the antiferromagnetic BFO layer to another ferromagnetic layer could enable a magnetic field control of the conductance of the quasi-2DEG at the LAO/STO interface.
NASA Astrophysics Data System (ADS)
Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.
2016-06-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.
Smeared antibranes polarise in AdS
NASA Astrophysics Data System (ADS)
Gautason, Fridrik Freyr; Truijen, Brecht; Van Riet, Thomas
2015-07-01
In the recent literature it has been questioned whether the local backreaction of antibranes in flux throats can induce a perturbative brane-flux decay. Most evidence for this can be gathered for D6 branes and D p branes smeared over 6 - p compact directions, in line with the absence of finite temperature solutions for these cases. The solutions in the literature have flat worldvolume geometries and non-compact transversal spaces. In this paper we consider what happens when the worldvolume is AdS and the transversal space is compact. We show that in these circumstances brane polarisation smoothens out the flux singularity, which is an indication that brane-flux decay is prevented. This is consistent with the fact that the cosmological constant would be less negative after brane-flux decay. Our results extend recent results on AdS7 solutions from D6 branes to AdS p+1 solutions from D p branes. We show that supersymmetry of the AdS solutions depend on p non-trivially.
AdS orbifolds and Penrose limits
Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu
2002-12-09
In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.
The AdS particle [rapid communication
NASA Astrophysics Data System (ADS)
Ghosh, Subir
2005-09-01
In this Letter we have considered a relativistic Nambu-Goto model for a particle in AdS metric. With appropriate gauge choice to fix the reparameterization invariance, we recover the previously discussed [S. Ghosh, P. Pal, Phys. Lett. B 618 (2005) 243, arxiv:hep-th/0502192] "exotic oscillator". The Snyder algebra and subsequently the κ-Minkowski spacetime are also derived. Lastly we comment on the impossibility of constructing a non-commutative spacetime in the context of open string where only a curved target space is introduced.
Probing crunching AdS cosmologies
NASA Astrophysics Data System (ADS)
Kumar, S. Prem; Vaganov, Vladislav
2016-02-01
Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of {N}=8 supergravity on AdS4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã max. Radial geodesics connecting antipodal points necessarily have de Sitter energy Ɛ ≲ ã max, while geodesics with Ɛ > ã max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outward" in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by ã max which corresponds to the lowest quasinormal frequency.
NASA Astrophysics Data System (ADS)
Turco, M.; Milelli, M.
2009-09-01
To the authors' knowledge there are relatively few studies that try to answer this topic: "Are humans able to add value to computer-generated forecasts and warnings ?". Moreover, the answers are not always positive. In particular some postprocessing method is competitive or superior to human forecast (see for instance Baars et al., 2005, Charba et al., 2002, Doswell C., 2003, Roebber et al., 1996, Sanders F., 1986). Within the alert system of ARPA Piemonte it is possible to study in an objective manner if the human forecaster is able to add value with respect to computer-generated forecasts. Every day the meteorology group of the Centro Funzionale of Regione Piemonte produces the HQPF (Human QPF) in terms of an areal average for each of the 13 regional warning areas, which have been created according to meteo-hydrological criteria. This allows the decision makers to produce an evaluation of the expected effects by comparing these HQPFs with predefined rainfall thresholds. Another important ingredient in this study is the very dense non-GTS network of rain gauges available that makes possible a high resolution verification. In this context the most useful verification approach is the measure of the QPF and HQPF skills by first converting precipitation expressed as continuous amounts into ‘‘exceedance'' categories (yes-no statements indicating whether precipitation equals or exceeds selected thresholds) and then computing the performances for each threshold. In particular in this work we compare the performances of the latest three years of QPF derived from two meteorological models COSMO-I7 (the Italian version of the COSMO Model, a mesoscale model developed in the framework of the COSMO Consortium) and IFS (the ECMWF global model) with the HQPF. In this analysis it is possible to introduce the hypothesis test developed by Hamill (1999), in which a confidence interval is calculated with the bootstrap method in order to establish the real difference between the
NASA Astrophysics Data System (ADS)
Bena, Iosif; Heurtier, Lucien; Puhm, Andrea
2016-05-01
It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.
Shadows, currents, and AdS fields
Metsaev, R. R.
2008-11-15
Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.
Mapping AdS to dS spaces and back
NASA Astrophysics Data System (ADS)
Di Dato, Adriana; Fröb, Markus B.
2015-03-01
We derive a map between Einstein spaces of positive and negative curvature, including scalar matter. Starting from a space of positive curvature with some dimensions compactified on a sphere and analytically continuing the number of compact dimensions, we obtain a space of negative curvature with a compact hyperbolic subspace, and vice versa. Prime examples of such spaces are de Sitter (dS) and anti-de Sitter (AdS) space, as well as black hole spacetimes with (A)dS asymptotics and perturbed versions thereof, which play an important role in holography. This map extends work done by Caldarelli et al., who map asymptotically AdS spaces to Ricci-flat ones. A remarkable result is that the boundary of asymptotically AdS spaces is mapped to a brane in the bulk of de Sitter, and perturbations near the AdS boundary are sourced by a stress tensor confined to this brane. We also calculate the Brown-York stress tensor for the perturbed AdS metric, which turns out to be the negative of the stress tensor on the de Sitter brane. The map can also be used as a solution generator, and we obtain a Kerr/AdS solution with hyperbolic horizon from a known Kerr/dS one.
NASA Technical Reports Server (NTRS)
Clauson, J.; Heuser, J.
1981-01-01
The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.
Two Visual-Spectroscopic Binary Orbits - ADS7780 and ADS11060
NASA Astrophysics Data System (ADS)
Heintz, W. D.
1982-08-01
The combination of micrometer and radial-velocity observations is applied to two orbits of high eccentricities and inclinations. All results on the G1 V triple star ADS 11060 (including the subsystem studied by Batten et al.) show good consistency and precision. Substantial uncertainty remains in the component masses of ADS 7780 = β LMi (G9 III) which could be also a triple star.
Innovations Without Added Costs
ERIC Educational Resources Information Center
Cereghino, Edward
1974-01-01
There is no question that we are in a tight money market, and schools are among the first institutions to feel the squeeze. Therefore, when a plan is offered that provides for innovations without added costs, its something worth noting. (Editor)
ERIC Educational Resources Information Center
Richards, Andrew
2015-01-01
Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…
NASA Astrophysics Data System (ADS)
Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.
2011-05-01
ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org
Two Virasoro symmetries in stringy warped AdS3
NASA Astrophysics Data System (ADS)
Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.
2014-12-01
We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.
Inactivated phosphorus by added aluminum in Baltic Sea sediment
NASA Astrophysics Data System (ADS)
Rydin, Emil
2014-12-01
Decreased phosphorus (P) retention in aquatic sediments during hypoxic periods results in increased P recycling to the water column. To revert to less productive conditions in the enclosed bays of the Baltic Sea archipelago, increased sediment P burial capacity is needed. Aluminum (Al) addition is considered to be a cost-effective lake restoration method, as it improves sediment P burial capacity. However, little is known about its ability to permanently bind P in brackish systems. In summer 2000, Al sulfate granules were added to a hypoxic bottom area in the Östhammar bay, Sweden. Sediment core samples from the area were collected 10 years later. A peak in Al and P was detected at 20 cm sediment depth, reflecting the added Al and P trapped to it. Only part of the added Al was recovered, but the recovered Al (8 g Al/m2) trapped P at a ratio of 5:1 (molar). Chemical fractionation showed that P extracted as 'Al-P' constituted 55% of the trapped P, indicating that Al added also trapped P extracted as other P forms.
Evans, Nick
2016-09-12
Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573
Technology Transfer Automated Retrieval System (TEKTRAN)
The sulfur hexafluoride tracer technique (SF**6) is a commonly used method for measuring CH**4 enteric emissions in ruminants. Studies using SF**6 have shown large variation in CH**4 emissions data, inconsistencies in CH**4 emissions across studies, and potential methodological errors. Therefore, th...
Kalmar, I D; Veys, A C; Geeroms, B; Reinschmidt, M; Waugh, D; Werquin, G; Janssens, G P J
2010-12-01
Parrots are commonly fed multi-component seed diets; however, both segregation and feeding behaviour might alter ingredient and nutrient composition of the offered diet. First, the nutritional impact of segregation was assessed as it occurs when multi-component diets are temporarily stored in food containers that are replenished before completely emptied and birds being fed from the upper layer. The most detrimental effect hereof was a vast decrease in mineral supplements, leading to a decrease in Ca:P ratio in the offered food in relation to the formulated diet. Next, caloric distribution shifted towards more EE energy at the expense of NFE energy, as proportion of oilseeds increased and NFE-rich seeds decreased. Next, a feeding trial was performed on six yellow-shouldered amazons (Amazona Barbadensis) in which nutritional impact of parrot-specific feeding behaviour was assessed as well as the influence of additional provision of fruit next to the seed mixture. Profound selective feeding behaviour and dehusking of seeds resulted in a vast increase in energetic density by up to 64% in the ingested fraction in relation to the offered mixture in toto. Furthermore, the already suboptimal Ca:P ratio further deteriorated and caloric distribution shifted by over twofold towards EE energy accompanied with a vast decline in NFE energy, CP energy remaining similar. Finally, provision of fruit next to the seed diet significantly lowered voluntary energy intake from 936 ± 71 to 809 ± 109 kJ ME/kg(0.75)/day, without compromising adequate protein intake. In conclusion, notwithstanding efforts of nutritionists to formulate diets to approximate estimated, species-specific requirements, nutritional composition of the actually consumed fraction of multi-component seed diets can be vastly deteriorated by both animal and management factors. Furthermore, offering of fruit next to a seed-based diet effectively reduces voluntary energy intake and can hence be applied to abate obesity. PMID:20662963
NASA Astrophysics Data System (ADS)
Fakhri, Hossein; Imaanpur, Ali
2003-03-01
In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.
NASA Astrophysics Data System (ADS)
Molina-Vilaplana, Javier; Sierra, Germán
2013-12-01
In this paper we formulate the xp model on the AdS2 spacetime. We find that the spectrum of the Hamiltonian has positive and negative eigenvalues, whose absolute values are given by a harmonic oscillator spectrum, which in turn coincides with that of a massive Dirac fermion in AdS2. We extend this result to generic xp models which are shown to be equivalent to a massive Dirac fermion on spacetimes whose metric depend of the xp Hamiltonian. Finally, we construct the generators of the isometry group SO(2,1) of the AdS2 spacetime, and discuss the relation with conformal quantum mechanics.
NASA Astrophysics Data System (ADS)
Kikuchi, Kenji
2010-06-01
Accelerator driven nuclear transmutation system has been pursued to have a clue to the solution of high-level radioactive waste management. The concept consists of super conducting linac, sub-critical reactor and the beam window. Reference model is set up to 800MW thermal power by using 1.5GeV proton beams with considerations multi-factors such as core criticality. Materials damage is simulated by high-energy particle transport codes and so on. Recent achievement on irradiation materials experiment is stated and the differences are pointed out if core burn-up is considered or not. Heat balance in tank-type ADS indicates the temperature conditions of steam generator, the beam widow and cladding materials. Lead-bismuth eutectics demonstration has been conducted. Corrosion depth rate was shown by experiments.
Supersymmetric warped AdS in extended topologically massive supergravity
NASA Astrophysics Data System (ADS)
Deger, N. S.; Kaya, A.; Samtleben, H.; Sezgin, E.
2014-07-01
We determine the most general form of off-shell N=(1,1) supergravity field configurations in three dimensions by requiring that at least one off-shell Killing spinor exists. We then impose the field equations of the topologically massive off-shell supergravity and find a class of solutions whose properties crucially depend on the norm of the auxiliary vector field. These are spacelike-squashed and timelike-stretched AdS3 for the spacelike and timelike norms, respectively. At the transition point where the norm vanishes, the solution is null warped AdS3. This occurs when the coefficient of the Lorentz-Chern-Simons term is related to the AdS radius by μℓ=2. We find that the spacelike-squashed AdS3 can be modded out by a suitable discrete subgroup of the isometry group, yielding an extremal black hole solution which avoids closed timelike curves.
Value Added in English Schools
ERIC Educational Resources Information Center
Ray, Andrew; McCormack, Tanya; Evans, Helen
2009-01-01
Value-added indicators are now a central part of school accountability in England, and value-added information is routinely used in school improvement at both the national and the local levels. This article describes the value-added models that are being used in the academic year 2007-8 by schools, parents, school inspectors, and other…
Hartung, Thomas
2009-12-01
Taking the 110th anniversary of marketing of aspirin as starting point, the almost scary toxicological profile of aspirin is contrasted with its actual use experience. The author concludes that we are lucky that, in 1899, there was no regulatory toxicology. Adding, for the purpose of this article, a fourth R to the Three Rs, i.e. Realism, three reality-checks are carried out. The first one comes to the conclusion that the tools of toxicology are hardly adequate for the challenges ahead. The second one concludes that, specifically, the implementation of the EU REACH system is not feasible with these tools, mainly with regard to throughput. The third one challenges the belief that classical alternative methods, i.e. replacing animal test-based tools one by one, is actually leading to a new toxicology - it appears to change only patches of the patchwork, but not to overcome any inherent limitations other than ethical ones. The perspective lies in the Toxicology for the 21st Century initiatives, which aim to create a new approach from the scratch, by an evidence-based toxicology and a global "Human Toxicology Programme". PMID:20105011
NASA Astrophysics Data System (ADS)
Roy, Shibaji
2015-10-01
It is known from the work in [1] of Lu et al. that the non-supersymmetric charged D3-brane (with anisotropies in time as well as one of the spatial directions of D3-brane) of type IIB string theory is characterized by five independent parameters. By fixing one of the parameters and zooming into a particular region of space-time we construct a four parameter family of solution in AdS5, which interpolates between AdS5 black hole and AdS5 soliton (when one of the spatial directions in the Poincare coordinates is compact) by continuously changing the parameters (there is no need to take a double Wick rotation as is usual to go from one solution to the other) from one set of values to another. We consider two cases. In the first case the dilaton is constant for this transition and there are only three independent parameters, whereas in the second case the dilaton varies and there are four independent parameters. In the latter case, the solution interpolates between AdS5 black hole, AdS5 soliton as well as the so-called `soft-wall' gravity solution of AdS/QCD model. We also compare our solution to the previously obtained Constable-Myers solution which is helpful in generalizing the solution for other D p (for p ≠ 3) branes.
Supergravity at the boundary of AdS supergravity
NASA Astrophysics Data System (ADS)
Amsel, Aaron J.; Compère, Geoffrey
2009-04-01
We give a general analysis of AdS boundary conditions for spin-3/2 Rarita-Schwinger fields and investigate boundary conditions preserving supersymmetry for a graviton multiplet in AdS4. Linear Rarita-Schwinger fields in AdSd are shown to admit mixed Dirichlet-Neumann boundary conditions when their mass is in the range 0≤|m|<1/2lAdS. We also demonstrate that mixed boundary conditions are allowed for larger masses when the inner product is “renormalized” accordingly with the action. We then use the results obtained for |m|=1/lAdS to explore supersymmetric boundary conditions for N=1 AdS4 supergravity in which the metric and Rarita-Schwinger fields are fluctuating at the boundary. We classify boundary conditions that preserve boundary supersymmetry or superconformal symmetry. Under the AdS/CFT dictionary, Neumann boundary conditions in d=4 supergravity correspond to gauging the superconformal group of the three-dimensional CFT describing M2-branes, while N=1 supersymmetric mixed boundary conditions couple the CFT to N=1 superconformal topologically massive gravity.
Asymptotically AdS spacetimes with a timelike Kasner singularity
NASA Astrophysics Data System (ADS)
Ren, Jie
2016-07-01
Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.
All AdS7 solutions of type II supergravity
NASA Astrophysics Data System (ADS)
Apruzzi, Fabio; Fazzi, Marco; Rosa, Dario; Tomasiello, Alessandro
2014-04-01
In M-theory, the only AdS7 supersymmetric solutions are AdS7 × S 4 and its orbifolds. In this paper, we find and classify new supersymmetric solutions of the type AdS7 × M 3 in type II supergravity. While in IIB none exist, in IIA with Romans mass (which does not lift to M-theory) there are many new ones. We use a pure spinor approach reminiscent of generalized complex geometry. Without the need for any Ansatz, the system determines uniquely the form of the metric and fluxes, up to solving a system of ODEs. Namely, the metric on M 3 is that of an S 2 fibered over an interval; this is consistent with the Sp(1) R-symmetry of the holographically dual (1,0) theory. By including D8 brane sources, one can numerically obtain regular solutions, where topologically M 3 ≅ S 3.
Worldsheet scattering in AdS3/CFT2
NASA Astrophysics Data System (ADS)
Sundin, Per; Wulff, Linus
2013-07-01
We confront the recently proposed exact S-matrices for AdS 3/ CFT 2 with direct worldsheet calculations. Utilizing the BMN and Near Flat Space (NFS) expansions for strings on AdS 3 × S 3 × S 3 × S 1 and AdS 3 × S 3 × T 4 we compute both tree-level and one-loop scattering amplitudes. Up to some minor issues we find nice agreement in the tree-level sector. At the one-loop level however we find that certain non-zero tree-level processes, which are not visible in the exact solution, contribute, via the optical theorem, and give an apparent mismatch for certain amplitudes. Furthermore we find that a proposed one-loop modification of the dressing phase correctly reproduces the worldsheet calculation while the standard Hernandez-Lopez phase does not. We also compute several massless to massless processes.
Detailed ultraviolet asymptotics for AdS scalar field perturbations
NASA Astrophysics Data System (ADS)
Evnin, Oleg; Jai-akson, Puttarak
2016-04-01
We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.
New massive gravity and AdS(4) counterterms.
Jatkar, Dileep P; Sinha, Aninda
2011-04-29
We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026
Phases of global AdS black holes
NASA Astrophysics Data System (ADS)
Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala
2016-06-01
We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.
NASA Technical Reports Server (NTRS)
Stothers, R. B.
1984-01-01
The possible cause of the densest and most persistent dry fog on record, which was observed in Europe and the Middle East during AD 536 and 537, is discussed. The fog's long duration toward the south and the high sulfuric acid signal detected in Greenland in ice cores dated around AD 540 support the theory that the fog was due to the explosion of the Rabaul volcano, the occurrence of which has been dated at about AD 540 by the radiocarbon method.
AdS Branes from Partial Breaking of Superconformal Symmetries
Ivanov, E.A.
2005-10-01
It is shown how the static-gauge world-volume superfield actions of diverse superbranes on the AdS{sub d+1} superbackgrounds can be systematically derived from nonlinear realizations of the appropriate AdS supersymmetries. The latter are treated as superconformal symmetries of flat Minkowski superspaces of the bosonic dimension d. Examples include the N = 1 AdS{sub 4} supermembrane, which is associated with the 1/2 partial breaking of the OSp(1|4) supersymmetry down to the N = 1, d = 3 Poincare supersymmetry, and the T-duality related L3-brane on AdS{sub 5} and scalar 3-brane on AdS{sub 5} x S{sup 1}, which are associated with two different patterns of 1/2 breaking of the SU(2, 2|1) supersymmetry. Another (closely related) topic is the AdS/CFT equivalence transformation. It maps the world-volume actions of the codimension-one AdS{sub d+1} (super)branes onto the actions of the appropriate Minkowski (super)conformal field theories in the dimension d.
AdS5 backgrounds with 24 supersymmetries
NASA Astrophysics Data System (ADS)
Beck, S.; Gutowski, J.; Papadopoulos, G.
2016-06-01
We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.
Entanglement temperature and perturbed AdS3 geometry
NASA Astrophysics Data System (ADS)
Levine, G. C.; Caravan, B.
2016-06-01
Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .
Lorentzian AdS geometries, wormholes, and holography
Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo
2011-03-15
We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.
Self-dual warped AdS3 black holes
NASA Astrophysics Data System (ADS)
Chen, Bin; Ning, Bo
2010-12-01
We study a new class of solutions of three-dimensional topological massive gravity. These solutions can be taken as nonextremal black holes, with their extremal counterparts being discrete quotients of spacelike warped AdS3 along the U(1)L isometry. We study the thermodynamics of these black holes and show that the first law is satisfied. We also show that for consistent boundary conditions, the asymptotic symmetry generators form only one copy of the Virasoro algebra with central charge cL=(4νℓ)/(G(ν2+3)), with which the Cardy formula reproduces the black hole entropy. We compute the real-time correlators of scalar perturbations and find a perfect match with the dual conformal field theory (CFT) predictions. Our study provides a novel example of warped AdS/CFT correspondence: the self-dual warped AdS3 black hole is dual to a CFT with nonvanishing left central charge. Moreover, our investigation suggests that the quantum topological massive gravity asymptotic to the same spacelike warped AdS3 in different consistent ways may be dual to different two-dimensional CFTs.
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Warped AdS3/dipole-CFT duality
NASA Astrophysics Data System (ADS)
Song, Wei; Strominger, Andrew
2012-05-01
String theory contains solutions with {{SL}}( {{2},{R}} ){{R}} × {{U}}{( {1} )_L} -invariant warped AdS3 (WAdS3) factors arising as continuous deformations of ordinary AdS3 factors. We propose that some of these are holographically dual to the IR limits of nonlocal dipole-deformed 2D D-brane gauge theories, referred to as "dipole CFTs". Neither the bulk nor boundary theories are currently well-understood, and consequences of the proposed duality for both sides is investigated. The bulk entropy-area law suggests that dipole CFTs have (at large N) a high-energy density of states which does not depend on the deformation parameter. Putting the boundary theory on a spatial circle leads to closed timelike curves in the bulk, suggesting a relation of the latter to dipole-type nonlocality.
New boundary conditions for AdS3
NASA Astrophysics Data System (ADS)
Compère, Geoffrey; Song, Wei; Strominger, Andrew
2013-05-01
New chiral boundary conditions are found for quantum gravity with matter on AdS3. The associated asymptotic symmetry group is generated by a single right-moving U(1) Kac-Moody-Virasoro algebra with {c_R}={3ℓ}/2G . The Kac-Moody zero mode generates global left-moving translations and equals, for a BTZ black hole, the sum of the total mass and spin. The level is positive about the global vacuum and negative in the black hole sector, corresponding to ergosphere formation. Realizations arising in Chern-Simons gravity and string theory are analyzed. The new boundary conditions are shown to naturally arise for warped AdS3 in the limit that the warp parameter is taken to zero.
Observing quantum gravity in asymptotically AdS space
NASA Astrophysics Data System (ADS)
Emelyanov, Slava
2015-12-01
The question is studied of whether an observer can discover quantum gravity in the semiclassical regime. It is shown that it is indeed possible to probe a certain quantum gravity effect by employing an appropriately designed detector. The effect is related to the possibility of having topologically inequivalent geometries in the path-integral approach at the same time. A conformal field theory (CFT) state which is expected to describe the eternal anti-de Sitter (AdS) black hole in the large-N limit is discussed. It is argued under certain assumptions that the black hole boundary should be merely a patch of the entire AdS boundary. This leads then to a conclusion that that CFT state is the ordinary CFT vacuum restricted to that patch. If existent, the bulk CFT operators can behave as the ordinary semiclassical quantum field theory in the large-N limit in the weak sense.
Semiclassical Virasoro blocks from AdS3 gravity
NASA Astrophysics Data System (ADS)
Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River
2015-12-01
We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in [1], evaluated in locally AdS3 geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block — in which two external operators become parametrically heavy — as a certain scattering process involving higher spin gauge fields in AdS3; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.
Entangled photon-added coherent states
NASA Astrophysics Data System (ADS)
Domínguez-Serna, Francisco A.; Mendieta-Jimenez, Francisco J.; Rojas, Fernando
2016-08-01
We study the degree of entanglement of arbitrary superpositions of m, n photon-added coherent states (PACS) {|{ψ }rangle } ∝ u {|{{α },m}rangle }{|{{β },n }rangle }+ v {|{{β },n}rangle }{|{{α },m}rangle } using the concurrence and obtain the general conditions for maximal entanglement. We show that photon addition process can be identified as an entanglement enhancer operation for superpositions of coherent states (SCS). Specifically for the known bipartite positive SCS: {|{ψ }rangle } ∝ {|{α }rangle }_a{|{-α }rangle }_b + {|{-α }rangle }_a{|{α }rangle }_b whose entanglement tends to zero for α → 0, can be maximal if al least one photon is added in a subsystem. A full family of maximally entangled PACS is also presented. We also analyzed the decoherence effects in the entangled PACS induced by a simple depolarizing channel . We find that robustness against depolarization is increased by adding photons to the coherent states of the superposition. We obtain the dependence of the critical depolarization p_{ {crit}} for null entanglement as a function of m,n, α and β.
Entangled photon-added coherent states
NASA Astrophysics Data System (ADS)
Domínguez-Serna, Francisco A.; Mendieta-Jimenez, Francisco J.; Rojas, Fernando
2016-05-01
We study the degree of entanglement of arbitrary superpositions of m, n photon-added coherent states (PACS) {|{ψ }rangle } ∝ u {|{{α },m}rangle }{|{{β },n }rangle }+ v {|{{β },n}rangle }{|{{α },m}rangle } using the concurrence and obtain the general conditions for maximal entanglement. We show that photon addition process can be identified as an entanglement enhancer operation for superpositions of coherent states (SCS). Specifically for the known bipartite positive SCS: {|{ψ }rangle } ∝ {|{α }rangle }_a{|{-α }rangle }_b + {|{-α }rangle }_a{|{α }rangle }_b whose entanglement tends to zero for α → 0 , can be maximal if al least one photon is added in a subsystem. A full family of maximally entangled PACS is also presented. We also analyzed the decoherence effects in the entangled PACS induced by a simple depolarizing channel . We find that robustness against depolarization is increased by adding photons to the coherent states of the superposition. We obtain the dependence of the critical depolarization p_{crit} for null entanglement as a function of m,n, α and β.
Alday-Maldacena Duality and AdS Plateau Problem
NASA Astrophysics Data System (ADS)
Morozov, A.
A short summary of approximate approach to the study of minimal surfaces in AdS, based on solving Nambu-Goto equations iteratively. Today, after partial denunciation of the BDS conjecture, this looks like the only constructive approach to understanding the ways of its possible modification and thus to saving the Alday-Maldacena duality. Numerous open technical problems are explicitly formulated throughout the text.
On information loss in AdS3/CFT2
NASA Astrophysics Data System (ADS)
Fitzpatrick, A. Liam; Kaplan, Jared; Li, Daliang; Wang, Junpu
2016-05-01
We discuss information loss from black hole physics in AdS3, focusing on two sharp signatures infecting CFT2 correlators at large central charge c: `forbidden singularities' arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite c, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior of correlators at times t ˜ S BH , the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the 1 /c expansion of exact examples, we explicitly identify `information-restoring' effects from heavy states that should correspond to classical solutions in AdS3. Our results suggest a line of inquiry towards a more precise formulation of the gravitational path integral in AdS3.
Supersymmetric giant graviton solutions in AdS3
NASA Astrophysics Data System (ADS)
Mandal, Gautam; Raju, Suvrat; Smedbäck, Mikael
2008-02-01
We parametrize all classical probe brane configurations that preserve four supersymmetries in (a) the extremal D1-D5 geometry, (b) the extremal D1-D5-P geometry, (c) the smooth D1-D5 solutions proposed by Lunin and Mathur, and (d) global AdS3×S3×T4/K3. These configurations consist of D1 branes, D5 branes, and bound states of D5 and D1 branes with the property that a particular Killing vector is tangent to the brane world volume at each point. We show that the supersymmetric sector of the D5-brane world volume theory may be analyzed in an effective 1+1 dimensional framework that places it on the same footing as D1 branes. In global AdS and the corresponding Lunin-Mathur solution, the solutions we describe are “bound” to the center of AdS for generic parameters and cannot escape to infinity. We show that these probes only exist on the submanifold of moduli space where the background BNS field and theta angle vanish. We quantize these probes in the near-horizon region of the extremal D1-D5 geometry and obtain the theory of long strings discussed by Seiberg and Witten.
Bending AdS waves with new massive gravity
NASA Astrophysics Data System (ADS)
Ayón-Beato, Eloy; Giribet, Gaston; Hassaïne, Mokhtar
2009-05-01
We study AdS-waves in the three-dimensional new theory of massive gravity recently proposed by Bergshoeff, Hohm, and Townsend. The general configuration of this type is derived and shown to exhibit different branches, with different asymptotic behaviors. In particular, for the special fine tuning m2 = ±1/(2l2), solutions with logarithmic fall-off arise, while in the range m2 > -1/(2l2), spacetimes with Schrödinger isometry group are admitted as solutions. Spacetimes that are asymptotically AdS3, both for the Brown-Henneaux and for the weakened boundary conditions, are also identified. The metric function that characterizes the profile of the AdS-wave behaves as a massive excitation on the spacetime, with an effective mass given by meff2 = m2-1/(2l2). For the critical value m2 = -1/(2l2), the value of the effective mass precisely saturates the Breitenlohner-Freedman bound for the AdS3 space where the wave is propagating on. The analogies with the AdS-wave solutions of topologically massive gravity are also discussed. Besides, we consider the coupling of both massive deformations to Einstein gravity and find the exact configurations for the complete theory, discussing all the different branches exhaustively. One of the effects of introducing the Chern-Simons gravitational term is that of breaking the degeneracy in the effective mass of the generic modes of pure New Massive Gravity, producing a fine structure due to parity violation. Another effect is that the zoo of exact logarithmic specimens becomes considerably enlarged.
Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U. /SLAC
2007-02-21
The AdS/CFT correspondence between string theory in AdS space and conformal .eld theories in physical spacetime leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. Although QCD is not conformally invariant, one can nevertheless use the mathematical representation of the conformal group in five-dimensional anti-de Sitter space to construct a first approximation to the theory. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD, such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties and allow the computation of decay constants, form factors, and other exclusive scattering amplitudes. New relativistic lightfront equations in ordinary space-time are found which reproduce the results obtained using the 5-dimensional theory. The effective light-front equations possess remarkable algebraic structures and integrability properties. Since they are complete and orthonormal, the AdS/CFT model wavefunctions can also be used as a basis for the diagonalization of the full light-front QCD Hamiltonian, thus systematically improving the AdS/CFT approximation.
Ultraviolet asymptotics and singular dynamics of AdS perturbations
NASA Astrophysics Data System (ADS)
Craps, Ben; Evnin, Oleg; Vanhoof, Joris
2015-10-01
Important insights into the dynamics of spherically symmetric AdS-scalar field perturbations can be obtained by considering a simplified time-averaged theory accurately describing perturbations of amplitude ɛ on time-scales of order 1/ ɛ 2. The coefficients of the time-averaged equations are complicated expressions in terms of the AdS scalar field mode functions, which are in turn related to the Jacobi polynomials. We analyze the behavior of these coefficients for high frequency modes. The resulting asymptotics can be useful for understanding the properties of the finite-time singularity in solutions of the time-averaged theory recently reported in the literature. We highlight, in particular, the gauge dependence of this asymptotics, with respect to the two most commonly used gauges. The harsher growth of the coefficients at large frequencies in higher-dimensional AdS suggests strengthening of turbulent instabilities in higher dimensions. In the course of our derivations, we arrive at recursive relations for the coefficients of the time-averaged theory that are likely to be useful for evaluating them more efficiently in numerical simulations.
NASA Astrophysics Data System (ADS)
Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Di Milia, G.; Luker, J.; Murray, S. S.
2013-01-01
The NASA Astrophysics Data System (ADS) has been working hard on updating its services and interfaces to better support our community's research needs. ADS Labs is a new interface built on the old tried-and-true ADS Abstract Databases, so all of ADS's content is available through it. In this presentation we highlight the new features that have been developed in ADS Labs over the last year: new recommendations, metrics, a citation tool and enhanced fulltext search. ADS Labs has long been providing article-level recommendations based on keyword similarity, co-readership and co-citation analysis of its corpus. We have now introduced personal recommendations, which provide a list of articles to be considered based on a individual user's readership history. A new metrics interface provides a summary of the basic impact indicators for a list of records. These include the total and normalized number of papers, citations, reads, and downloads. Also included are some of the popular indices such as the h, g and i10 index. The citation helper tool allows one to submit a set of records and obtain a list of top 10 papers which cite and/or are cited by papers in the original list (but which are not in it). The process closely resembles the network approach of establishing "friends of friends" via an analysis of the citation network. The full-text search service now covers more than 2.5 million documents, including all the major astronomy journals, as well as physics journals published by Springer, Elsevier, the American Physical Society, the American Geophysical Union, and all of the arXiv eprints. The full-text search interface interface allows users and librarians to dig deep and find words or phrases in the body of the indexed articles. ADS Labs is available at http://adslabs.org
The AdS central charge in string theory
NASA Astrophysics Data System (ADS)
Troost, Jan
2011-11-01
We evaluate the vacuum expectation value of the central charge operator in string theory in an AdS3 vacuum. Our calculation provides a rare non-zero one-point function on a spherical worldsheet. The evaluation involves the regularization both of a worldsheet ultraviolet divergence (associated to the infinite volume of the conformal Killing group), and a space-time infrared divergence (corresponding to the infinite volume of space-time). The two divergences conspire to give a finite result, which is the classical general relativity value for the central charge, corrected in bosonic string theory by an infinite series of tree level higher derivative terms.
Small black holes in global AdS spacetime
NASA Astrophysics Data System (ADS)
Jokela, Niko; Pönni, Arttu; Vuorinen, Aleksi
2016-04-01
We study the properties of two-point functions and quasinormal modes in a strongly coupled field theory holographically dual to a small black hole in global anti-de Sitter spacetime. Our results are seen to smoothly interpolate between known limits corresponding to large black holes and thermal AdS space, demonstrating that the Son-Starinets prescription works even when there is no black hole in the spacetime. Omitting issues related to the internal space, the results can be given a field theory interpretation in terms of the microcanonical ensemble, which provides access to energy densities forbidden in the canonical description.
Entanglement entropy and duality in AdS4
NASA Astrophysics Data System (ADS)
Bakas, Ioannis; Pastras, Georgios
2015-07-01
Small variations of the entanglement entropy δS and the expectation value of the modular Hamiltonian δE are computed holographically for circular entangling curves in the boundary of AdS4, using gravitational perturbations with general boundary conditions in spherical coordinates. Agreement with the first law of thermodynamics, δS = δE, requires that the line element of the entangling curve remains constant. In this context, we also find a manifestation of electric-magnetic duality for the entanglement entropy and the corresponding modular Hamiltonian, following from the holographic energy-momentum/Cotton tensor duality.
NASA Astrophysics Data System (ADS)
Belin, Alexandre; Castro, Alejandra; Hung, Ling-Yan
2015-11-01
We discuss properties of interpolating geometries in three dimensional gravity in the presence of a chiral anomaly. This anomaly, which introduces an unbalance between left and right central charges, is protected under RG flows. For this simple reason it is impossible to gap a system with such an anomaly. Our goal is to discuss how holography captures this basic and robust feature. We demonstrate the absence of a mass gap by analysing the linearized spectrum and holographic entanglement entropy of these backgrounds in the context of AdS3/CFT2.
Pure Spinors in AdS and Lie Algebra Cohomology
NASA Astrophysics Data System (ADS)
Mikhailov, Andrei
2014-10-01
We show that the BRST cohomology of the massless sector of the Type IIB superstring on AdS5 × S 5 can be described as the relative cohomology of an infinite-dimensional Lie superalgebra. We explain how the vertex operators of ghost number 1, which correspond to conserved currents, are described in this language. We also give some algebraic description of the ghost number 2 vertices, which appears to be new. We use this algebraic description to clarify the structure of the zero mode sector of the ghost number two states in flat space, and initiate the study of the vertices of the higher ghost number.
Internal structure of charged AdS black holes
NASA Astrophysics Data System (ADS)
Bhattacharjee, Srijit; Sarkar, Sudipta; Virmani, Amitabh
2016-06-01
When an electrically charged black hole is perturbed, its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: Although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.
The Chinese comet observation in AD 773 January
NASA Astrophysics Data System (ADS)
Chapman, J.; Csikszentmihalyi, M.; Neuhäuser, R.
2014-11-01
The strong 14C increase in the year AD 774/5 detected in one German and two Japanese trees was recently suggested to have been caused by an impact of a comet onto Earth and a deposition of large amounts of 14C into the atmosphere (Liu et al. 2014). The authors supported their claim using a report of a historic Chinese observation of a comet ostensibly colliding with Earth's atmosphere in AD 773 January. We show here that the Chinese text presented by those authors is not an original historic text, but that it is comprised of several different sources. Moreover, the translation presented in Liu et al. is misleading and inaccurate. We give the exact Chinese wordings and our English translations. According to the original sources, the Chinese observed a comet in mid January 773, but they report neither a collision nor a large coma, just a long tail. Also, there is no report in any of the source texts about "dust rain in the daytime" as claimed by Liu et al. (2014), but simply a normal dust storm. Ho (1962) reports sightings of this comet in China on AD 773 Jan 15 and/or 17 and in Japan on AD 773 Jan 20 (Ho 1962). At the relevant historic time, the Chinese held that comets were produced within the Earth's atmosphere, so that it would have been impossible for them to report a "collision" of a comet with Earth's atmosphere. The translation and conclusions made by Liu et al. (2014) are not supported by the historical record. Therefore, postulating a sudden increase in 14C in corals off the Chinese coast precisely in mid January 773 (Liu et al. 2014) is not justified given just the 230Th dating for AD 783 ± 14.
NASA Astrophysics Data System (ADS)
Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.
2014-01-01
In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.
Critical gravity on AdS2 spacetimes
NASA Astrophysics Data System (ADS)
Myung, Yun Soo; Kim, Yong-Wan; Park, Young-Jai
2011-09-01
We study the critical gravity in two-dimensional anti-de Sitter (AdS2) spacetimes, which was obtained from the cosmological topologically massive gravity (TMGΛ) in three dimensions by using the Kaluza-Klein dimensional reduction. We perform the perturbation analysis around AdS2, which may correspond to the near-horizon geometry of the extremal Banados, Teitelboim, and Zanelli (BTZ) black hole obtained from the TMGΛ with identification upon uplifting three dimensions. A massive propagating scalar mode δF satisfies the second-order differential equation away from the critical point of K=l, whose solution is given by the Bessel functions. On the other hand, δF satisfies the fourth-order equation at the critical point. We exactly solve the fourth-order equation, and compare it with the log gravity in two dimensions. Consequently, the critical gravity in two dimensions could not be described by a massless scalar δFml and its logarithmic partner δFlog4th.
Conserved charges in timelike warped AdS3 spaces
NASA Astrophysics Data System (ADS)
Donnay, L.; Fernández-Melgarejo, J. J.; Giribet, G.; Goya, A.; Lavia, E.
2015-06-01
We consider the timelike version of warped anti-de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike WAdS3 space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the WAdS3 solutions coincide with locally AdS3 and locally AdS2×R spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically WAdS3 spaces in NMG.
Primordial fluctuations from complex AdS saddle points
NASA Astrophysics Data System (ADS)
Hertog, Thomas; van der Woerd, Ellen
2016-02-01
One proposal for dS/CFT is that the Hartle-Hawking (HH) wave function in the large volume limit is equal to the partition function of a Euclidean CFT deformed by various operators. All saddle points defining the semiclassical HH wave function in cosmology have a representation in which their interior geometry is part of a Euclidean AdS domain wall with complex matter fields. We compute the wave functions of scalar and tensor perturbations around homogeneous isotropic complex saddle points, turning on single scalar field matter only. We compare their predictions for the spectra of CMB perturbations with those of a different dS/CFT proposal based on the analytic continuation of inflationary universes to real asymptotically AdS domain walls. We find the predictions of both bulk calculations agree to first order in the slow roll parameters, but there is a difference at higher order which, we argue, is a signature of the HH state of the fluctuations.
Greig, Jenny A; Buckley, Suzanne Mk; Waddington, Simon N; Parker, Alan L; Bhella, David; Pink, Rebecca; Rahim, Ahad A; Morita, Takashi; Nicklin, Stuart A; McVey, John H; Baker, Andrew H
2009-10-01
The binding of coagulation factor X (FX) to the hexon of adenovirus (Ad) 5 is pivotal for hepatocyte transduction. However, vectors based on Ad35, a subspecies B Ad, are in development for cancer gene therapy, as Ad35 utilizes CD46 (which is upregulated in many cancers) for transduction. We investigated whether interaction of Ad35 with FX influenced vector tropism using Ad5, Ad35, and Ad5/Ad35 chimeras: Ad5/fiber(f)35, Ad5/penton(p)35/f35, and Ad35/f5. Surface plasmon resonance (SPR) revealed that Ad35 and Ad35/f5 bound FX with approximately tenfold lower affinities than Ad5 hexon-containing viruses, and electron cryomicroscopy (cryo-EM) demonstrated a direct Ad35 hexon:FX interaction. The presence of physiological levels of FX significantly inhibited transduction of vectors containing Ad35 fibers (Ad5/f35, Ad5/p35/f35, and Ad35) in CD46-positive cells. Vectors were intravenously administered to CD46 transgenic mice in the presence and absence of FX-binding protein (X-bp), resulting in reduced liver accumulation for all vectors. Moreover, Ad5/f35 and Ad5/p35/f35 efficiently accumulated in the lung, whereas Ad5 demonstrated poor lung targeting. Additionally, X-bp significantly reduced lung genome accumulation for Ad5/f35 and Ad5/p35/f35, whereas Ad35 was significantly enhanced. In summary, vectors based on the full Ad35 serotype will be useful vectors for selective gene transfer via CD46 due to a weaker FX interaction compared to Ad5. PMID:19603000
Chambers, D W
1998-01-01
Dentists and many staff enjoy characteristics of work associated with high levels of satisfaction and performance. Although value can be added to oral health care professionals' jobs through enlargement, enrichment, rotations, and autonomous work groups, there are limits to these techniques. Controlling work performance by means of rewards is risky. Probably the most effective means of adding value to jobs is through the Quality of Work Life approach, concentrating on job design and placement to make work meaningful and autonomous and to provide feedback. PMID:9697373
Higher-derivative superparticle in AdS3 space
NASA Astrophysics Data System (ADS)
Kozyrev, Nikolay; Krivonos, Sergey; Lechtenfeld, Olaf
2016-03-01
Employing the coset approach we construct component actions for a superparticle moving in AdS3 with N =(2 ,0 ), D =3 supersymmetry partially broken to N =2 , d =1 . These actions may contain higher time-derivative terms, which are chosen to possess the same (super)symmetries as the free superparticle. In terms of the nonlinear-realization superfields, the component actions always take a simpler form when written in terms of covariant Cartan forms. We also consider in detail the reduction to the nonrelativistic case and construct the corresponding action of a Newton-Hooke superparticle and its higher-derivative generalizations. The structure of these higher time-derivative generalizations is completely fixed by invariance under the supersymmetric Newton-Hooke algebra extended by two central charges.
Aspects of warped AdS3/CFT2 correspondence
NASA Astrophysics Data System (ADS)
Chen, Bin; Zhang, Jia-Ju; Zhang, Jian-Dong; Zhong, De-Liang
2013-04-01
In this paper we apply the thermodynamics method to investigate the holographic pictures for the BTZ black hole, the spacelike and the null warped black holes in three-dimensional topologically massive gravity (TMG) and new massive gravity (NMG). Even though there are higher derivative terms in these theories, the thermodynamics method is still effective. It gives consistent results with the ones obtained by using asymptotical symmetry group (ASG) analysis. In doing the ASG analysis we develop a brute-force realization of the Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to calculate the masses and the angular momenta of the black holes. In particular, we propose the warped AdS3/CFT2 correspondence in the new massive gravity, which states that quantum gravity in the warped spacetime could holographically dual to a two-dimensional CFT with {c_R}={c_L}=24 /{Gm{β^2√{{2( {21-4{β^2}} )}}}}.
Thermodynamics of charged Lovelock: AdS black holes
NASA Astrophysics Data System (ADS)
Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.
2016-04-01
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.
Vortex hair on AdS black holes
NASA Astrophysics Data System (ADS)
Gregory, Ruth; Gustainis, Peter C.; Kubizňák, David; Mann, Robert B.; Wills, Danielle
2014-11-01
We analyse vortex hair for charged rotating asymptotically AdS black holes in the abelian Higgs model. We give analytical and numerical arguments to show how the vortex interacts with the horizon of the black hole, and how the solution extends to the boundary. The solution is very close to the corresponding asymptotically flat vortex, once one transforms to a frame that is non-rotating at the boundary. We show that there is a Meissner effect for extremal black holes, with the vortex flux being expelled from sufficiently small black holes. The phase transition is shown to be first order in the presence of rotation, but second order without rotation. We comment on applications to holography.
An investigation of AdS2 backreaction and holography
NASA Astrophysics Data System (ADS)
Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman
2016-07-01
We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.
Systematics of Coupling Flows in AdS Backgrounds
Goldberger, Walter D.; Rothstein, Ira Z.
2003-03-18
We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge
On thermodynamics of charged AdS black holes in extended phases space via M2-branes background
NASA Astrophysics Data System (ADS)
Chabab, M.; El Moumni, H.; Masmar, K.
2016-06-01
Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate both thermodynamics and the thermodynamical geometry of Reissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in AdS4× S7, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner, and Quevedo metrics for M2-branes geometry to study the stability of such a black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results to those obtained by the phase transition diagram via the heat capacities in different ensembles either when the number of the M2 branes or the charge is held fixed. Also, we note that all results derived in Belhaj et al. (Eur Phys J C 76(2):73, 2016) are recovered in the limit of the vanishing charge.
Holography beyond conformal invariance and AdS isometry?
Barvinsky, A. O.
2015-03-15
We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O(N{sup 0}) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the “double-trace” deformation of the boundary theory, which is responsible in the case of large-N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.
Holography beyond conformal invariance and AdS isometry?
NASA Astrophysics Data System (ADS)
Barvinsky, A. O.
2015-03-01
We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O( N 0) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the "double-trace" deformation of the boundary theory, which is responsible in the case of large- N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.
Islands of stability and recurrence times in AdS
NASA Astrophysics Data System (ADS)
Green, Stephen R.; Maillard, Antoine; Lehner, Luis; Liebling, Steven L.
2015-10-01
We study the stability of anti-de Sitter (AdS) spacetime to spherically symmetric perturbations of a real scalar field in general relativity. Further, we work within the context of the "two time framework" (TTF) approximation, which describes the leading nonlinear effects for small amplitude perturbations, and is therefore suitable for studying the weakly turbulent instability of AdS—including both collapsing and noncollapsing solutions. We have previously identified a class of quasiperiodic (QP) solutions to the TTF equations, and in this paper we analyze their stability. We show that there exist several families of QP solutions that are stable to linear order, and we argue that these solutions represent islands of stability in TTF. We extract the eigenmodes of small oscillations about QP solutions, and we use them to predict approximate recurrence times for generic noncollapsing initial data in the full (non-TTF) system. Alternatively, when sufficient energy is driven to high-frequency modes, as occurs for initial data far from a QP solution, the TTF description breaks down as an approximation to the full system. Depending on the higher order dynamics of the full system, this often signals an imminent collapse to a black hole.
Droplet Number Concentration Value Added Product
2015-08-06
Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration (Nd) will increase and droplet size will decrease, for a given liquid water path. This will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation; however, the magnitude and variability of these processes under different environmental conditions is still uncertain.McComiskey et al. (2009) have implemented a method, based onBoers andmore » Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloud interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions. In order to provide data sets for studying aerosol-cloud interactions, the McComiskey et al. (2009) method was implemented as the Droplet Number Concentration (NDROP) value-added product (VAP).« less
Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC
2012-02-14
We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.
ADS's Dexter Data Extraction Applet
NASA Astrophysics Data System (ADS)
Demleitner, M.; Accomazzi, A.; Eichhorn, G.; Grant, C. S.; Kurtz, M. J.; Murray, S. S.
The NASA Astrophysics Data System (ADS) now holds 1.3 million scanned pages, containing numerous plots and figures for which the original data sets are lost or inaccessible. The availability of scans of the figures can significantly ease the regeneration of the data sets. For this purpose, the ADS has developed Dexter, a Java applet that supports the user in this process. Dexter's basic functionality is to let the user manually digitize a plot by marking points and defining the coordinate transformation from the logical to the physical coordinate system. Advanced features include automatic identification of axes, tracing lines and finding points matching a template. This contribution both describes the operation of Dexter from a user's point of view and discusses some of the architectural issues we faced during implementation.
Realizing "value-added" metrology
NASA Astrophysics Data System (ADS)
Bunday, Benjamin; Lipscomb, Pete; Allgair, John; Patel, Dilip; Caldwell, Mark; Solecky, Eric; Archie, Chas; Morningstar, Jennifer; Rice, Bryan J.; Singh, Bhanwar; Cain, Jason; Emami, Iraj; Banke, Bill, Jr.; Herrera, Alfredo; Ukraintsev, Vladamir; Schlessinger, Jerry; Ritchison, Jeff
2007-03-01
The conventional premise that metrology is a "non-value-added necessary evil" is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes. Various key trends in modern, state-of-the-art processing such as optical proximity correction (OPC), design for manufacturability (DFM), and advanced process control (APC) are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Examples used will be from critical dimension (CD
Missing top of the AdS resonance structure
NASA Astrophysics Data System (ADS)
Yang, I.-Sheng
2015-03-01
We study a massless scalar field in AdSd +1 with a nonlinear coupling ϕN and not limited to spherical symmetry. The free-field-eigenstate spectrum is strongly resonant, and it is commonly believed that the nonlinear coupling leads to energy transfer between eigenstates. We prove that when N d is even, the most efficient resonant channels to transfer energy are always absent. In particular, for N =3 this means no energy transfer at all. For N =4 , this effectively kills half of the channels, leading to the same set of extra conservation laws recently derived for gravitational interactions within spherical symmetry.
Magnetic mass in 4D AdS gravity
NASA Astrophysics Data System (ADS)
Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, Rodrigo
2016-04-01
We provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.
Canonical energy and hairy AdS black holes
NASA Astrophysics Data System (ADS)
Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon
2016-08-01
We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.
NASA Astrophysics Data System (ADS)
Goodman, Alyssa
We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where
Thermodynamics of dual conformal field theories for Kerr-AdS black holes
Cai Ronggen; Cao Liming; Pang Dawei
2005-08-15
Recently Gibbons et al. in [G. W. Gibbons et al. Class. Quant. Grav. 22, 1503 (2005)] defined a set of conserved quantities for Kerr-AdS black holes with the maximal number of rotation parameters in arbitrary dimension. This set of conserved quantities is defined with respect to a frame which is nonrotating at infinity. On the other hand, there is another set of conserved quantities for Kerr-AdS black holes, defined by Hawking et al. in [Hawking et al. Phys. Rev. D 59, 064005 (1999)], which is measured relative to a frame rotating at infinity. Gibbons et al. explicitly showed that the quantities defined by them satisfy the first law of black hole thermodynamics, while those quantities defined by Hawking et al. do not obey the first law. In this paper we discuss thermodynamics of dual CFTs to the Kerr-AdS black holes by mapping the bulk thermodynamic quantities to the boundary of the AdS space. We find that thermodynamic quantities of dual CFTs satisfy the first law of thermodynamics and Cardy-Verlinde formula only when these thermodynamic quantities result from the set of bulk quantities given by Hawking et al.. We discuss the implication of our results.
The inside outs of AdS3/CFT2: exact AdS wormholes with entangled CFT duals
NASA Astrophysics Data System (ADS)
Mandal, Gautam; Sinha, Ritam; Sorokhaibam, Nilakash
2015-01-01
We present the complete family of solutions of 3D gravity (Λ < 0) with two asymptotically AdS exterior regions. The solutions are constructed from data at the two boundaries, which correspond to two independent and arbitrary stress tensors T R , , and T L , . The two exteriors are smoothly joined on to an interior region through a regular horizon. We find CFT duals of these geometries which are entangled states of two CFT's. We compute correlators between general operators at the two boundaries and find perfect agreement between CFT and bulk calculations. We calculate and match the CFT entanglement entropy (EE) with the holographic EE which involves geodesics passing through the wormhole. We also compute a holographic, non-equilibrium entropy for the CFT using properties of the regular horizon. The construction of the bulk solutions here uses an exact version of Brown-Henneaux type diffeomorphisms which are asymptotically nontrivial and transform the CFT states by two independent unitary operators on the two sides. Our solutions provide an infinite family of explicit examples of the ER=EPR relation of Maldacena and Susskind [1].
NASA Astrophysics Data System (ADS)
Chandanayaka, Tharaka; Azarmi, Fardad
2014-05-01
In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.
Conditionally extended validity of perturbation theory: Persistence of AdS stability islands
NASA Astrophysics Data System (ADS)
Dimitrakopoulos, Fotios; Yang, I.-Sheng
2015-10-01
Approximating nonlinear dynamics with a truncated perturbative expansion may be accurate for a while, but it, in general, breaks down at a long time scale that is one over the small expansion parameter. There are interesting cases in which such breakdown does not happen. We provide a mathematically general and precise definition of those cases, in which we prove that the validity of truncated theory trivially extends to the long time scale. This enables us to utilize numerical results, which are only obtainable within finite times, to legitimately predict the dynamics when the expansion parameter goes to zero, and thus the long time scale goes to infinity. In particular, this shows that existing noncollapsing solutions in the AdS (in)stability problem persist to the zero-amplitude limit, opposing the conjecture by Dias, Horowitz, Marolf, and Santos that predicts a shrinkage to measure zero [O. J. Dias et al., Classical Quantum Gravity 29, 235019 (2012)]. We also point out why the persistence of collapsing solutions is harder to prove, and how the recent interesting progress by Bizon, Maliborski, and Rostoworowski has not yet proven this [P. Bizon, M. Maliborski, and A. Rostworowski, arXiv:1506.03519].
2012-01-01
Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig) light chains (LC) (most commonly of lambda isotype) usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in β leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and/or immunofluorescence. Due to the
Wang, Hongjie; Ducournau, Corinne; Saydaminova, Kamola; Richter, Maximilian; Yumul, Roma; Ho, Martin; Carter, Darrick; Zubieta, Chloé
2015-01-01
ABSTRACT We recently discovered that desmoglein 2 (DSG2) is a receptor for human adenovirus species B serotypes Ad3, Ad7, Ad11, and Ad14. Ad3 is considered to be a widely distributed human pathogen. Ad3 binding to DSG2 triggers the transient opening of epithelial junctions. Here, we further delineate the mechanism that leads to DSG2-mediated epithelial junction opening in cells exposed to Ad3 and recombinant Ad3 fiber proteins. We identified an Ad3 fiber knob-dependent pathway that involves the phosphorylation of mitogen-activated protein (MAP) kinases triggering the activation of the matrix-metalloproteinase ADAM17. ADAM17, in turn, cleaves the extracellular domain of DSG2 that links epithelial cells together. The shed DSG2 domain can be detected in cell culture supernatant and also in serum of mice with established human xenograft tumors. We then extended our studies to Ad14 and Ad14P1. Ad14 is an important research and clinical object because of the recent appearance of a new, more pathogenic strain (Ad14P1). In a human epithelial cancer xenograft model, Ad14P1 showed more efficient viral spread and oncolysis than Ad14. Here, we tested the hypothesis that a mutation in the Ad14P1 fiber knob could account for the differences between the two strains. While our X-ray crystallography studies suggested an altered three-dimensional (3D) structure of the Ad14P1 fiber knob in the F-G loop region, this did not significantly change the fiber knob affinity to DSG2 or the intracellular signaling and DSG2 shedding in epithelial cancer cells. IMPORTANCE A number of widely distributed adenoviruses use the epithelial junction protein DSG2 as a receptor for infection and lateral spread. Interaction with DSG2 allows the virus not only to enter cells but also to open epithelial junctions which form a physical barrier to virus spread. Our study elucidates the mechanism beyond virus-triggered junction opening with a focus on adenovirus serotype 3. Ad3 binds to DSG2 with its fiber
16 CFR 460.18 - Insulation ads.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Insulation ads. 460.18 Section 460.18... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness,...
16 CFR 460.18 - Insulation ads.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Insulation ads. 460.18 Section 460.18... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness,...
16 CFR 460.18 - Insulation ads.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Insulation ads. 460.18 Section 460.18... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness,...
16 CFR 460.18 - Insulation ads.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Insulation ads. 460.18 Section 460.18... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness,...
16 CFR 460.18 - Insulation ads.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Insulation ads. 460.18 Section 460.18... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness,...
Myths & Facts about Value-Added Analysis
ERIC Educational Resources Information Center
TNTP, 2011
2011-01-01
This paper presents myths as well as facts about value-added analysis. These myths include: (1) "Value-added isn't fair to teachers who work in high-need schools, where students tend to lag far behind academically"; (2) "Value-added scores are too volatile from year-to-year to be trusted"; (3) "There's no research behind value-added"; (4) "Using…
What's the Value in Value-Added?
ERIC Educational Resources Information Center
Duffrin, Elizabeth
2011-01-01
A growing number of school districts are adopting "value-added" measures of teaching quality to award bonuses or even tenure. And two competitive federal grants are spurring them on. Districts using value-added data are encouraged by the results. But researchers who support value-added measures advise caution. The ratings, which use a statistical…
Value Added and Other Related Matters.
ERIC Educational Resources Information Center
Whitla, Dean K.
The term "value added" refers to the assessment of the amount of learning that takes place during the college years. Two experiments, Value Added I and Value Added II, attempted to measure college students' attainment of eight liberal education objectives: (1) writing ability; (2) analytical ability; (3) sensitivity to ethics, morals, and values;…
New Features in the ADS Abstract Service
NASA Technical Reports Server (NTRS)
Eichhorn, Guenther; Accomazzi, Alberto; Grant, Carolyn S.; Kurtz, Michael J.; Henneken, Edwin A.; Thompson, Donna M.; Murray, Stephen S.
2005-01-01
The NASA-ADS Abstract Service provides a sophisticated search capability for the literature in Astronomy, Planetary Sciences, Physics/Geophysics, and Space Instrumentation. The ADS is funded by NASA and access to the ADS services is free to anybody world-wide without restrictions. It allows the user to search the literature by author, title, and abstract text.
27 CFR 19.456 - Adding denaturants.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Adding denaturants. 19.456... Denaturation § 19.456 Adding denaturants. Denaturants and spirits shall be mixed in packages, tanks, or bulk... proprietor shall submit a flow diagram of the intended process or method of adding denaturants. (Sec....
ERIC Educational Resources Information Center
Lovecky, Deirdre V.
This brief paper on gifted children with attention deficit hyperactivity disorder (AD/HD) focuses on the special educational needs of this population. Emphasis is on four major conclusions: (1) gifted children with AD/HD differ from average children with AD/HD in cognitive, social, and emotional variables (e.g., the gifted child is likely to show…
Condom ads promote illicit sex.
Kippley, J F
1994-01-01
Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads. PMID:12345946
Appetite and food intake after consumption of sausages with 10% fat and added wheat or rye bran.
Vuholm, Stine; Arildsen Jakobsen, Louise Margrethe; Vejrum Sørensen, Karina; Kehlet, Ursula; Raben, Anne; Kristensen, Mette
2014-02-01
The use of dietary fibers as fat-replacers in sausages gives less energy-dense and thereby healthier foods. Also, dietary fibers have been shown to induce satiety. The objectives of this study were to investigate if appetite sensations and energy intake was affected by (1) addition of dietary fibers to sausages, (2) type of dietary fibers and (3) the food matrix of the dietary fibers. In this randomized cross-over study 25 young men were served four test meals; wheat bran sausages, rye bran sausages, rye bran bread and wheat flour sausages. The test meals were served as breakfast after an overnight fast. Appetite sensations were evaluated by visual analogue scales (VAS) assessed every 30 min for 240 min followed by an ad libitum lunch meal where energy intake was calculated. Both rye bran and wheat bran sausages increased satiety (P < 0.01) and fullness (P < 0.02) and decreased hunger (P < 0.001) and prospective consumption (P < 0.001) compared to wheat flour sausages. Furthermore, rye bran sausages increased satiety (P < 0.05) and fullness (P < 0.02) and decreased prospective consumption (P < 0.01) compared to rye bran bread. No differences in subsequent energy intake were observed. In conclusion, wheat and rye bran added to sausages decreased appetite sensations and thereby has a potential added health benefit beyond the role as fat-replacer. The satisfying effect of dietary fibers appears to be more pronounced when added to sausages than when added to bread, stressing the importance of food matrix and food processing. PMID:24511620
Appetite and food intake after consumption of sausages with 10% fat and added wheat or rye bran.
Vuholm, Stine; Jakobsen, Louise Margrethe; Sørensen, Karina Vejrum; Kehlet, Ursula; Raben, Anne; Kristensen, Mette
2013-10-25
The use of dietary fibers as fat-replacers in sausages gives less energy-dense and thereby healthier foods. Also, dietary fibers have been shown to induce satiety. The objectives of this study were to investigate if appetite sensations and energy intake was affected by (1) addition of dietary fibers to sausages, (2) type of dietary fibers and (3) the food matrix of the dietary fibers. In this randomized cross-over study 25 young men were served four test meals; wheat bran sausages, rye bran sausages, rye bran bread and wheat flour sausages. The test meals were served as breakfast after an overnight fast. Appetite sensations were evaluated by visual analogue scales (VAS) assessed every 30 minutes for 240 minutes followed by an ad libitum lunch meal where energy intake was calculated. Both rye bran and wheat bran sausages increased satiety (P < 0.01) and fullness (P < 0.02) and decreased hunger (P < 0.001) and prospective consumption (P < 0.001) compared to wheat flour sausages. Furthermore, rye bran sausages increased satiety (P < 0.05) and fullness (P < 0.02) and decreased prospective consumption (P < 0.01) compared to rye bran bread. No differences in subsequent energy intake were observed. In conclusion, wheat and rye bran added to sausages decreased appetite sensations and thereby has a potential added health benefit beyond the role as fat-replacer. The satisfying effect of dietary fibers appears to be more pronounced when added to sausages than when added to bread, stressing the importance of food matrix and food processing. PMID:24512899
Historical Literature in the ADS
NASA Astrophysics Data System (ADS)
Eichhorn, G.; Kurtz, M. J.; Accomazzi, A.; Grant, C. S.
1997-12-01
The Astrophysics Data System at http://adswww.harvard.edu is in the process of scanning the historical astronomical literature and making it available through the World Wide Web. We have scanned several volumes from the early 1800's of the "Astronomische Nachrichten", and the "Monthly Notices of the Royal Astronomical Society", the two oldest astronomical journals. We also have several of the early volumes of the "Astrophysical Journal" and the "Astronomical Journal" available. For all the journals that we cover, we have scanned volume 1. These early volumes can be accessed on a page-by-page basis. We plan to continue to scan this historical literature and complete these journals within the next year. We are also collaborating with a preservation project at Harvard University. This project will microfilm selected parts of astronomical Observatory reports. We plan to scan these microfilms to produce electronic images of these reports and put them on-line in the ADS. We hope to eventually cover most of the astronomical literature. In order to organize the scanned pages into articles, we need tables of contents (ToC). The early issues of the journals did not have printed ToC pages, so this needs to be done by hand. We do not have the financial resources to build these ToCs. We are looking for collaborators who would be willing to work with us in building these ToCs for the older journals and observatory reports. If you are interested in such a project, please contact the first author at gei@cfa.harvard.edu.
Different phases of hairy black holes in AdS5 space
NASA Astrophysics Data System (ADS)
Giribet, Gaston; Goya, Andrés; Oliva, Julio
2015-02-01
We investigate the thermodynamics of hairy black holes in asymptotically anti-de Sitter (AdS) space, including backreaction. Resorting to the Euclidean path integral approach, we show that matter conformally coupled to Einstein gravity in five dimensions may exhibit a phase transition whose endpoint turns out to be a hairy black hole in AdS5 space. The scalar field configuration happens to be regular everywhere outside and on the horizon and behaves asymptotically in such a way that respects the AdS boundary conditions that are relevant for AdS/CFT. The theory presents other peculiar features in the ultraviolet, like the existence of black holes with arbitrarily low temperature in AdS5 . This provides a simple setup in which the fully backreacting problem of a hair forming in AdS at a certain critical temperature can be solved analytically.
Scaling symmetry and scalar hairy rotating AdS3 black holes
NASA Astrophysics Data System (ADS)
Ahn, Byoungjoon; Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon
2016-01-01
By using the scaling symmetry in the reduced action formalism, we derive the novel Smarr relation which holds even for the hairy rotating AdS3 black holes. Then, by using the Smarr relation we argue that the hairy rotating AdS3 black holes are stable thermodynamically, compared to the nonhairy ones.
Effects of ad placement and type on consumer responses to podcast ads.
Ritter, Eric A; Cho, Chang-Hoan
2009-10-01
The purpose of this study was to understand the effects of podcast ad placement and podcast ad type on consumers' perceived intrusiveness, perceived irritation, attitude toward the ad, and ad avoidance. Our 2 x 2 (traditional ad vs. sponsorship by beginning vs. middle) experimental study found that sponsorships generated better consumer responses than did traditional ads and that podcast ads placed at the beginning of audio podcasts yielded better consumer responses than those placed in the middle. Implications for marketers and advertisers are discussed. PMID:19817565
LWR (Light Water Reactor) power plant simulations using the AD10 and AD100 systems
Wulff, W.; Cheng, H.S.; Chien, C.J.; Jang, J.Y.; Lin, H.C.; Mallen, A.N.; Wang, S.J.; Institute of Nuclear Energy Research, Lung-Tan; Tawian Power Co., Taipei; Brookhaven National Lab., Upton, NY; Institute of Nuclear Energy Research, Lung-Tan )
1989-01-01
Boiling (BWR) and Pressurized (PWR) Water Reactor Power Plants are being simulated at BNL with the AD10 and AD100 Peripheral Processor Systems. The AD10 system has been used for BWR simulations since 1984 for safety analyses, emergency training and optimization studies. BWR simulation capabilities have been implemented recently on the AD100 system and PWR simulation capabilities are currently being developed under the auspices of international cooperation. Modeling and simulation methods are presented with emphasis on the simulation of the Nuclear Steam Supply System. Results are presented for BWR simulation and performance characteristics are compared of the AD10 and AD100 systems. It will be shown that the AD100 simulates two times faster than two AD10 processors operating in parallel and that the computing capacity of one AD100 (with FMU processor) is twice as large as that of two AD10 processors. 9 refs., 5 figs., 1 tab.
AdS perturbations, isometries, selection rules and the Higgs oscillator
NASA Astrophysics Data System (ADS)
Evnin, Oleg; Nivesvivat, Rongvoram
2016-01-01
Dynamics of small-amplitude perturbations in the global anti-de Sitter (AdS) spacetime is restricted by selection rules that forbid effective energy transfer between certain sets of normal modes. The selection rules arise algebraically because some integrals of products of AdS mode functions vanish. Here, we reveal the relation of these selection rules to AdS isometries. The formulation we discover through this systematic approach is both simpler and stronger than what has been reported previously. In addition to the selection rule considerations, we develop a number of useful representations for the global AdS mode functions, with connections to algebraic structures of the Higgs oscillator, a superintegrable system describing a particle on a sphere in an inverse cosine-squared potential, where the AdS isometries play the role of a spectrum-generating algebra.
Inseparability of photon-added Gaussian states
Li Hongrong; Li Fuli; Zhu Shiyao
2007-06-15
The inseparability of photon-added Gaussian states which are generated from two-mode Gaussian states by adding photons is investigated. According to the established inseparability conditions [New J. Phys. 7, 211 (2005); Phys. Rev. Lett. 96, 050503 (2006)], we find that even if a two-mode Gaussian state is separable, the photon-added Gaussian state becomes entangled when the purity of the Gaussian state is larger than a certain value. The lower bound of entanglement of symmetric photon-added Gaussian states is derived. The result shows that entanglement of the photon-added Gaussian states is involved with high-order moment correlations. We find that fidelity of teleporting coherent states cannot be raised by employing the photon-added Gaussian states as a quantum channel of teleportation.
The forecaster's added value in QPF
NASA Astrophysics Data System (ADS)
Turco, M.; Milelli, M.
2009-04-01
To the authors' knowledge there are relatively few studies that try to answer this topic: "Are humans able to add value to computer-generated forecasts and warnings ?". Moreover, the answers are not always positive. In particular some postprocessing method is competitive or superior to human forecast (see for instance Baars et al., 2005, Charba et al., 2002, Doswell C., 2003, Roebber et al., 1996, Sanders F., 1986). Within the alert system of ARPA Piemonte it is possible to study in an objective manner if the human forecaster is able to add value with respect to computer-generated forecasts. Every day the meteorology group of the Centro Funzionale of Regione Piemonte produces the HQPF (Human QPF) in terms of an areal average for each of the 13 regional warning areas, which have been created according to meteo-hydrological criteria. This allows the decision makers to produce an evaluation of the expected effects by comparing these HQPFs with predefined rainfall thresholds. Another important ingredient in this study is the very dense non-GTS network of rain gauges available that makes possible a high resolution verification. In this context the most useful verification approach is the measure of the QPF and HQPF skills by first converting precipitation expressed as continuous amounts into ‘‘exceedance'' categories (yes-no statements indicating whether precipitation equals or exceeds selected thresholds) and then computing the performances for each threshold. In particular in this work we compare the performances of the latest three years of QPF derived from two meteorological models COSMO-I7 (the Italian version of the COSMO Model, a mesoscale model developed in the framework of the COSMO Consortium) and IFS (the ECMWF global model) with the HQPF. In this analysis it is possible to introduce the hypothesis test developed by Hamill (1999), in which a confidence interval is calculated with the bootstrap method in order to establish the real difference between the
Patrick Moore's millennium yearbook : the view from AD 1001
NASA Astrophysics Data System (ADS)
Moore, Patrick, Chapman, Allan
In a year that will probably be remembered almost as much for books about the millennium as for the turn of 2000 A.D itself, Patrick Moore's Millennium Yearbook celebrates.....well, the wrong millennium! This thoroughly entertaining book - which is for everyone, not just astronomers - contains articles on King Alfred's chronological work, reviews of the new Star Catalogue by the Arab Al-Sufi and the latest edition of Ptolemy's Almagast. And foreshadowing the change to metric units by 1000 years, the book uses arabic numbers instead of Roman - but there is a conversion table if you have trouble with the idea of "zero" and prefer the older system.
Solar activity around AD 775 from aurorae and radiocarbon
NASA Astrophysics Data System (ADS)
Neuhäuser, R.; Neuhäuser, D. L.
2015-04-01
discuss two more Schwabe cycles until AD {˜ 844}. The 14C record (from both Intcal and Miyake et al. 2013a) is anti-correlated to auroral and sunspot activity, as expected from solar wind modulation of cosmic rays which produce the radiocarbon.
Micropulse Lidar Cloud Mask Value-Added Product Technical Report
Sivaraman, C; Comstock, J
2011-07-25
Lidar backscattered signal is a useful tool for identifying vertical cloud structure in the atmosphere in optically thin clouds. Cloud boundaries derived from lidar signals are a necessary input for popular ARM data products, such as the Active Remote Sensing of Clouds (ARSCL) product. An operational cloud boundary algorithm (Wang and Sassen 2001) has been implemented for use with the ARM Micropulse Lidar (MPL) systems. In addition to retrieving cloud boundaries above 500 m, the value-added product (VAP) named Micropulse Lidar Cloud Mask (MPLCMASK) applies lidar-specific corrections (i.e., range-square, background, deadtime, and overlap) as described in Campbell et al. (2002) to the measured backscattered lidar. Depolarization ratio is computed using the methodology developed by Flynn et al. (2007) for polarization-capable MPL systems. The cloud boundaries output from MPLCMASK will be the primary lidar cloud mask for input to the ARSCL product and will be applied to all MPL systems, including historical data sets.
On deformations of AdS n × S n supercosets
NASA Astrophysics Data System (ADS)
Hoare, B.; Roiban, R.; Tseytlin, A. A.
2014-06-01
We study the deformed AdS 5 × S 5 supercoset model of arXiv:1309.5850 which depends on one parameter κ and has classical quantum group symmetry. We confirm the conjecture that in the "maximal" deformation limit, κ → ∞, this model is T-dual to "flipped" double Wick rotation of the target space AdS 5 × S 5, i.e. dS 5 × H 5 space supported by an imaginary 5-form flux. In the imaginary deformation limit, κ → i, the corresponding target space metric is of a pp-wave type and thus the resulting light-cone gauge S-matrix becomes relativistically invariant. Omitting non-unitary contributions of imaginary WZ terms, we find that this tree-level S-matrix is equivalent to that of the generalized sine-Gordon model representing the Pohlmeyer reduction of the undeformed AdS 5 × S 5 superstring model. We also study in some detail similar deformations of the AdS 3 × S 3 and AdS 2 × S 2 supercosets. The bosonic part of the deformed AdS 3 × S 3 model happens to be equivalent to the symmetric case of the sum of the Fateev integrable deformation of the SL(2) and SU(2) principal chiral models, while in the AdS 2 × S 2 case the role of the Fateev model is played by the 2d "sausage" model. The κ = i limits are again directly related to the Pohlmeyer reductions of the corresponding AdS n × S n supercosets: (2,2) super sine-Gordon model and its complex sine-Gordon analog. We also discuss possible deformations of AdS 3 × S 3 with more than one parameter.
Akhawayni (?-983 AD): A Persian neuropsychiatrist in the early medieval era (9th-12th Century AD).
Zargaran, Arman; Kordafshari, Gholamreza; Hosseini, Seyyed Rouhollah; Mehdizadeh, Alireza
2016-05-01
The early medieval era is also called the Islamic Golden Age because of the significant rise in sciences, including medicine. Abū Bakr Rabi' ibn Ahmad Akhawayni Bukhāri (better known as Akhawayni) was one of the notable medical practitioners in his lifetime. His fame was in neuroscience and he became known as Pezeshk-e-Divanegan (Physician to the Insane). His only surviving book, Hidāyat al-Muta'allimin fi al-Tibb (The Students' Handbook of Medicine), is the first medical textbook in Persian, after Islam. Akhawayni gathered and categorized available knowledge on neuropsychiatry and added his own. He was the first to describe sleep paralysis and to suggest pragmatic rather than supernatural treatment. He was also the first to present fever cure and his descriptions of meningitis (Lisarghos in Hidāyat), mania, psychosis (Malikhulia), dementia (Ghotrab), etc., are close to current concepts. PMID:24658213
Geometric finiteness, holography and quasinormal modes for the warped AdS3 black hole
NASA Astrophysics Data System (ADS)
Gupta, Kumar S.; Harikumar, E.; Sen, Siddhartha; Sivakumar, M.
2010-08-01
We show that there exists a precise kinematical notion of holography for the Euclidean warped AdS3 black hole. This follows from the fact that the Euclidean warped AdS3 black hole spacetime is a geometrically finite hyperbolic manifold. For such manifolds a theorem of Sullivan provides a one-to-one correspondence between the hyperbolic structure in the bulk and the conformal structure of its boundary. Using this theorem we obtain the holographic quasinormal modes for the warped AdS3 black hole.
Next-Generation A/D Sampler ADS3000+ for VLBI2010
NASA Technical Reports Server (NTRS)
Takefuji, Kazuhiro; Takeuchi, Hiroshi; Tsutsumi, Masanori; Koyama, Yasuhiro
2010-01-01
A high-speed A/D sampler, called ADS3000+, has been developed in 2008, which can sample one analog signal up to 4 Gbps to versatile Linux PC. After A/D conversion, the ADS3000+ can perform digital signal processing such as real-time DBBC (Digital Base Band Conversion) and FIR filtering such as simple CW RFI filtering using the installed FPGAs. A 4 Gsps fringe test with the ADS3000+ has been successfully performed. The ADS3000+ will not exclusively be used for VLBI but will also be employed in other applications.
ERIC Educational Resources Information Center
Walsh, John; Johnson, Miriam
1974-01-01
The Olympus Research Corporation (ORC) made an in-depth study of want ads. It was found the ads did not offer adequate, accurate, or easily obtained information that would make it possible for job seekers to decide whether they are suited to a job, or want it. (Author/BP)
Schvellinger, Martin
2008-07-28
We briefly review one of the current applications of the AdS/CFT correspondence known as AdS/QCD and discuss about the calculation of four-point quark-flavour current correlation functions and their applications to the calculation of observables related to neutral kaon decays and neutral kaon mixing processes.
The eleven observations of comets between 687 AD and 1114 AD recorded in the Anglo Saxon Chronicle
NASA Technical Reports Server (NTRS)
Mardon, E. G.; Williams, J.; Mardon, A. A.
1992-01-01
This research paper is an examination of the eleven cometary references (679AD, 729AD, 892AD, 950AD, 975AD, 995AD, 1066AD, 1097AD, 1106AD, 1110AD and 1114AD) found in the various manuscripts of The Anglo Saxon Chronicle between 678 AD and 1114 AD. The manuscripts contain more than 35 celestial observations. This is an examination of astronomical phenomena and other climatic or natural events, that are described in The Anglo Saxon Chronicle, which is also referred to as The Old English Annals.
Freivogel, Ben; Hubeny, Veronika E.; Maloney, Alexander; Myers, Rob; Rangamani, Mukund; Shenker, Stephen; /Stanford U., Phys. Dept.
2005-10-07
We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.
Supergravity background of the λ-deformed AdS3 × S3 supercoset
NASA Astrophysics Data System (ADS)
Chervonyi, Yuri; Lunin, Oleg
2016-09-01
We construct the solution of type IIB supergravity describing the integrable λ-deformation of the AdS3 ×S3 supercoset. While the geometry corresponding to the deformation of the bosonic coset has been found in the past, our background is more natural for studying superstrings, and several interesting features distinguish our solution from its bosonic counterpart. We also report progress towards constructing the λ-deformation of the AdS5 ×S5 supercoset.
Al-Akhawayni's description of pulmonary circulation.
Yarmohammadi, Hassan; Dalfardi, Behnam; Rezaian, Jafar; Ghanizadeh, Ahmad
2013-10-01
Since antiquity, heart function and the mechanism of blood circulation within the human body have been the focus of attention of scientists from different parts of the world. Over the passage of time, the theories and works of these scientists have resulted in the achievement of today's knowledge of circulation. The medieval Persian scholar, Al-Akhawayni Bukhari (?-983AD), is among the physicians who investigated both the anatomy and the physiology of the human body. Al-Akhawayni describes the mechanism of pulmonary circulation in his only extant book, "Hidayat al-Muta`llemin fi al-Tibb" (A Scholar's Guide to Medicine) with which he made a contribution to the development of knowledge regarding this mechanism in the medicine of the Islamic world. In this paper, Al-Akhawayni's viewpoints on anatomy and the function of the heart, its related vessels, and also pulmonary circulation will be briefly discussed. PMID:23890868
Arshad, Muhammad Umair; Ishtiaq, Saima; Anjum, Faqir Muhammad; Saeed, Farhan; Chatha, Shahzad Ali Shahid; Imran, Ali
2016-09-01
In the present study we compared the postprandial glycemic and satiety responses of different dietary polysaccharides when added in milk (2% M.F.). The objective of this study was to evaluate different polysaccharides against postprandial glucose, appetite responses and food intake at subsequent meal. In a repeated measures design, 30 females (18-30 years) consumed 250 ml milk 2% M.F. (control), or milk with carrageenan (2.5 g), guar gum (2.5 g) and alginate (2.5 g), followed by an ad libitum pizza meal after 120 min. Alginate and guar gum addition resulted in lower caloric intake at subsequent pizza meal. The post-treatment (0-120 min) glucose and average appetite were suppressed by alginate and guar gum (p < 0.0001), with more pronounced effect of guar gum. However, alginate resulted in lower blood glucose (p < 0.0001) compared with control and carrageenan during post-treatment. Alginate and guar gum added beverages would be beneficial in short-term regulation of postprandial glycemia and satiety. PMID:27352777
Middle Schoolers Exposed to Alcohol Ads Every Day
... html Middle Schoolers Exposed to Alcohol Ads Every Day: Study Researchers say billboards, signs and TV ads ... kids typically saw two to four ads a day. Hispanic and black kids saw more ads, an ...
Classical worldsheets for string scattering on flat and AdS spacetime
Sommerfield, Charles M.; Thorn, Charles B.
2008-08-15
We present a study of the worldsheets that describe the classical limit of various string scattering processes. Our main focus is on string scattering in AdS spacetime because of its relation via the AdS/CFT (anti-de Sitter/conformal field theory) correspondence to gluon scattering in N=4 supersymmetric Yang-Mills theory. But we also consider analogous processes in flat Minkowski spacetime which we compare to the AdS case. In addition to scattering of string by string we also find and study worldsheets describing the scattering of a string by external sources.
Testing the AdS/CFT Correspondence
Klebanov, Igor R.
2008-07-28
This lecture begins with some history and basic facts about string theory and its connections with strong interactions. Comparisons of stacks of Dirichlet branes with curved backgrounds produced by them are used to motivate the AdS/CFT correspondence between superconformal gauge theory and string theory on a product of Anti-de Sitter space and a compact manifold. The ensuing duality between semi-classical spinning strings and long gauge theory operators is briefly reviewed. We go on to describe a recent test of the AdS/CFT correspondence using the Wilson loop cusp anomaly as a function of the coupling, which also enters dimensions of high-spin operators. Finally, strongly coupled thermal SYM theory is explored via a black hole in 5-dimensional AdS space, which leads to explicit results for its entropy and shear viscosity.
Heat kernels on cone of AdS2 and k-wound circular Wilson loop in AdS5 × S5 superstring
NASA Astrophysics Data System (ADS)
Bergamin, R.; Tseytlin, A. A.
2016-04-01
We compute the one-loop world-sheet correction to partition function of {{AdS}}5× {{{S}}}5 superstring that should be representing k-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on k-wound circle at the boundary is that of a cone of AdS2 with deficit 2π (1-k). We compute the determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.
Research of Ad Hoc Networks Access Algorithm
NASA Astrophysics Data System (ADS)
Xiang, Ma
With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. When the ad hoc network is the access network of the internet, the gateway discovery protocol is very important to choose the most appropriate gateway to guarantee the connectivity between ad hoc network and IP based fixed networks. The paper proposes a QoS gateway discovery protocol which uses the time delay and stable route to the gateway selection conditions. And according to the gateway discovery protocol, it also proposes a fast handover scheme which can decrease the handover time and improve the handover efficiency.
Microbial production of value-added nutraceuticals.
Wang, Jian; Guleria, Sanjay; Koffas, Mattheos A G; Yan, Yajun
2016-02-01
Nutraceuticals are important natural bioactive compounds that confer health-promoting and medical benefits to humans. Globally growing demands for value-added nutraceuticals for prevention and treatment of human diseases have rendered nutraceuticals a multi-billion dollar market. However, supply limitations and extraction difficulties from natural sources such as plants, animals or fungi, restrict the large-scale use of nutraceuticals. Metabolic engineering via microbial production platforms has been advanced as an eco-friendly alternative approach for production of value-added nutraceuticals from simple carbon sources. Microbial platforms like the most widely used Escherichia coli and Saccharomyces cerevisiae have been engineered as versatile cell factories for production of diverse and complex value-added chemicals such as phytochemicals, prebiotics, polysaccaharides and poly amino acids. This review highlights the recent progresses in biological production of value-added nutraceuticals via metabolic engineering approaches. PMID:26716360
Genes Might Explain Hispanics' Added Longevity
... University of California, Los Angeles. For example, the biological clock measured Hispanic women's "genetic" age as 2. ... and how long they live," he added. The biological clock used in the new study evaluates the ...
FDA Launches Ad Campaign Against Chewing Tobacco
... 158385.html FDA Launches Ad Campaign Against Chewing Tobacco Health officials targeting rural teens with messages about health risks of smokeless tobacco products To use the sharing features on this ...
Junk Food Ads Sway Kids' Preferences
... Kids' Preferences Children under 8 most vulnerable to marketing's effects, study says To use the sharing features ... studies. The researchers found that ads and other marketing for products high in sugar or salt have ...
A guide to gauging ad effectiveness.
Cashill, J
1987-09-01
Techniques that have proven successful in private industry can help hospital executives increase their accountability for advertising expenditures. Among these techniques are: The random telephone survey, which can be used to measure whether the hospital's awareness level among the public has increased as the result of a particular ad; The focus group, which assists the hospital in evaluating how it is perceived in relation to other hospitals in its market; The pretest, to determine which ads to eliminate from a campaign and which ones to refine; Educational seminars and direct-response ads; Reliable baseline data on patients and services for use in comparing figures before and after an ad has been used. Above all, careful planning is required to enable the marketing staff to determine what it wishes to accomplish through advertising and to set measurable goals that reflect its expectations for each component of a campaign. PMID:10283482
ERIC Educational Resources Information Center
Johnston, Anne; Kaid, Lynda Lee
2002-01-01
Explores the differences in techniques, strategies, narratives, and symbols used in 1,213 television issue ads and image ads from 13 U.S. presidential campaigns. Concludes that although the majority of both types of ads were positive, negative appeals dominated a higher percentage of issue ads as compared with image ads. (SG)
Hadrons in AdS/QCD correspondence
Vega, Alfredo; Schmidt, Ivan
2009-03-01
We present a holographical soft wall model that is able to reproduce not only Regge spectra for hadrons with arbitrary integer spin, but also with spin 1/2 and 3/2, and with an arbitrary number of constituents. The model includes the anomalous dimension of operators that create hadrons, together with a dilaton, whose form is suggested by Einstein equations and the AdS metric used.
Adding stress plot function to NASTRAN
NASA Technical Reports Server (NTRS)
Katoh, S.
1978-01-01
Stress plot function was developed and added to the NASTRAN level 15.5. Computed stress distribution can be displayed by this function, with vectors showing the principal stresses of the finite elements over the specified portions of the structure. NASTRAN is reviewed in the aspect of plotting capabilities. Stress tensor field is examined in preparation of stress display. Then the stress plot function as added to the NASTRAN is described. A sample plotout by this function is shown.
CFT adapted gauge invariant formulation of massive arbitrary spin fields in AdS
NASA Astrophysics Data System (ADS)
Metsaev, R. R.
2010-01-01
Using Poincaré parametrization of AdS space, we study massive totally symmetric arbitrary spin fields in AdS space of dimension greater than or equal to four. CFT adapted gauge invariant formulation for such fields is developed. Gauge symmetries are realized by using Stueckelberg formulation of massive fields. We demonstrate that the mass parameter, curvature and radial coordinate contributions to the gauge transformation and Lagrangian of the AdS massive fields can be expressed in terms of ladder operators. Three representations for the Lagrangian are discussed. Realization of the global AdS symmetries in the conformal algebra basis is obtained. Modified de Donder gauge leading to simple gauge fixed Lagrangian is found. The modified de Donder gauge leads to decoupled equations of motion which can easily be solved in terms of the Bessel function. New simple representation for gauge invariant Lagrangian of massive (A)dS field in arbitrary coordinates is obtained. Light-cone gauge Lagrangian of massive AdS field is also presented.
AdS5×S(5) mirror model as a string sigma model.
Arutyunov, Gleb; van Tongeren, Stijn J
2014-12-31
Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally. PMID:25615306
NASA Astrophysics Data System (ADS)
Kay, Bernard S.; Ortíz, L.
2014-05-01
We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other `fixed-background', QFT-based, approaches to holography) and in mainstream string-theoretic `Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the point of view of QFT in curved spacetime—in the framework of 't Hooft's `brick wall' model—with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein-Gordon field in the Hartle-Hawking-Israel state on dimensional Schwarzschild AdS has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the `complementarity principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to black hole entropy. Working on the assumption that similar results will hold for bulk QFT other than the Klein-Gordon field and for Schwarzschild AdS in other dimensions, and recalling the first author's proposed resolution to the Mukohyama-Israel puzzle based on his `matter-gravity entanglement hypothesis', we argue that, in Maldacena AdS/CFT, the algebra of the boundary CFT is isomorphic only to a proper subalgebra of the bulk algebra, albeit (at non-zero temperature) the (GNS) Hilbert spaces of bulk and boundary theories are still the `same'—the total bulk state being pure, while the boundary state is mixed (thermal). We also argue from the finiteness of its boundary (and hence, on our assumptions, also bulk) entropy at finite temperature, that the Rehren dual of the Maldacena boundary CFT cannot itself be a QFT and must, instead, presumably be something like a string theory.
Ad Hoc Access Gateway Selection Algorithm
NASA Astrophysics Data System (ADS)
Jie, Liu
With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. For mobile nodes in Ad Hoc network to internet, internet communications in the peer nodes must be achieved through the gateway. Therefore, the key Ad Hoc Access Networks will focus on the discovery gateway, as well as gateway selection in the case of multi-gateway and handover problems between different gateways. This paper considers the mobile node and the gateway, based on the average number of hops from an average access time and the stability of routes, improved gateway selection algorithm were proposed. An improved gateway selection algorithm, which mainly considers the algorithm can improve the access time of Ad Hoc nodes and the continuity of communication between the gateways, were proposed. This can improve the quality of communication across the network.
Black hole microstates in AdS4 from supersymmetric localization
NASA Astrophysics Data System (ADS)
Benini, Francesco; Hristov, Kiril; Zaffaroni, Alberto
2016-05-01
This paper addresses a long standing problem, the counting of the microstates of supersymmetric asymptotically AdS black holes in terms of a holographically dual field theory. We focus on a class of asymptotically AdS4 static black holes preserving two real supercharges which are dual to a topologically twisted deformation of the ABJM theory. We evaluate in the large N limit the topologically twisted index of the ABJM theory and we show that it correctly reproduces the entropy of the AdS4 black holes. An extremization of the index with respect to a set of chemical potentials is required. We interpret it as the selection of the exact R-symmetry of the superconformal quantum mechanics describing the horizon of the black hole.
QCD Condensates and Holographic Wilson Loops for Asymptotically AdS Spaces
Quevedo, R. Carcasses; Goity, Jose L.; Trinchero, Roberto C.
2014-02-01
The minimization of the Nambu-Goto (NG) action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the border is considered. This is done for asymptotically AdS spaces. The condensates of dimension n = 2, 4, 6, 8, and 10 are calculated in terms of the coefficients in the expansion in powers of the radius a of the on-shell subtracted NG action for small a->0. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the gluon condensates is universal in the sense that it only depends on the first coefficients of the difference with the AdS case.
Solutions in bosonic string field theory and higher spin algebras in AdS
NASA Astrophysics Data System (ADS)
Polyakov, Dimitri
2015-11-01
We find a class of analytic solutions in open bosonic string field theory, parametrized by the chiral copy of higher spin algebra in AdS3. The solutions are expressed in terms of the generating function for the products of Bell polynomials in derivatives of bosonic space-time coordinates Xm(z ) of the open string, the form of which is determined in this work. The products of these polynomials form a natural operator algebra realizations of w∞ (area-preserving diffeomorphisms), enveloping algebra of SU(2) and higher spin algebra in AdS3. The class of string field theory solutions found can, in turn, be interpreted as the "enveloping of enveloping," or the enveloping of AdS3 higher spin algebra. We also discuss the extensions of this class of solutions to superstring theory and their relations to higher spin algebras in higher space-time dimensions.
Photon gas thermodynamics in dS and AdS momentum spaces
NASA Astrophysics Data System (ADS)
Gorji, M. A.; Hosseinzadeh, V.; Nozari, K.; Vakili, B.
2016-07-01
In this paper, we study thermostatistical properties of a photon gas in the framework of two deformed special relativity models defined by the cosmological coordinatizations of the de Sitter (dS) and anti-de Sitter (AdS) momentum spaces. The dS model is a doubly special relativity theory in which an ultraviolet length scale is invariant under the deformed Lorentz transformations. For the case of the AdS model, however, the Lorentz symmetry breaks at the high energy regime. We show that the existence of a maximal momentum in dS momentum space leads to maximal pressure and temperature at the thermodynamical level, while maximal internal energy and entropy arise for the case of the AdS momentum space due to the existence of a maximal kinematical energy. These results show that the thermodynamical duality of these models is very similar to their well-known kinematical duality.
Analytical study on holographic superfluid in AdS soliton background
NASA Astrophysics Data System (ADS)
Lai, Chuyu; Pan, Qiyuan; Jing, Jiliang; Wang, Yongjiu
2016-06-01
We analytically study the holographic superfluid phase transition in the AdS soliton background by using the variational method for the Sturm-Liouville eigenvalue problem. By investigating the holographic s-wave and p-wave superfluid models in the probe limit, we observe that the spatial component of the gauge field will hinder the phase transition. Moreover, we note that, different from the AdS black hole spacetime, in the AdS soliton background the holographic superfluid phase transition always belongs to the second order and the critical exponent of the system takes the mean-field value in both s-wave and p-wave models. Our analytical results are found to be in good agreement with the numerical findings.
Ad-hoc percutaneous coronary intervention and staged percutaneous coronary intervention.
Rahman, Z; Paul, G K; Choudhury, A K
2011-10-01
Percutaneous coronary intervention (PCI) is a catheter based procedure where a catheter system is introduced through a systemic artery under local anesthesia in a stenotic coronary artery by controlled inflation of a distensible balloon. At early period, PCI was done in a separate session following coronary angiogram (Staged PCI) and it was more costly and hospital stay was long. As the expertization and laboratory facilities improved, the health care providers think about cost, hospital stay and patient convenience. So, to reduce the cost and patient preferred more PCI being done immediately following diagnostic catheterization (Ad-hoc PCI). Subsequently this Ad-hoc procedure becomes popular and now most of the PCI are Ad-hoc PCI worldwide. Rate of combined procedure (Ad-hoc) progressively increased from 54% in 1990 to 88% in 2000 with a significant decrease in rate of complications. In the initial study of Ad-hoc PCI suggested that Ad-hoc PCI should be done in selected group of patients as there was some potential risk factors (e.g. Multivessel diseases, unstable angina, aortic valve disease, and recent infarction or thrombolytic therapy) for Ad-hoc procedure and some (e.g. Older age, multivessel PTCA and complex lesion PTCA) for staged procedure. But recent studies showed that no significant difference in respect of safety and efficacy between Ad-hoc and staged PCI. Previous studies, in the era of balloon angioplasty from 1985 to 1995, Haraphonges et al. (1988), Rozenman et al. (1995) and Kimmel et al. (1997) suggested that an ad hoc approach is safe, with potentially more complications in patients with unstable angina pectoris or other high-risk factors. However, these reports have been limited to observational studies representing single institution experiences with small samples and inclusion of patients who underwent emergency PCI procedures. In Bangladesh a prospective observational study was done among 120 patients to compare the outcome of Ad-hoc and
Short-term memory binding is impaired in AD but not in non-AD dementias.
Della Sala, Sergio; Parra, Mario A; Fabi, Katia; Luzzi, Simona; Abrahams, Sharon
2012-04-01
Binding is a cognitive function responsible for integrating features within complex stimuli (e.g., shape-colour conjunctions) or events within complex memories (e.g., face-name associations). This function operates both in short-term memory (STM) and in long-term memory (LTM) and is severely affected by Alzheimer's disease (AD). However, forming conjunctions in STM is the only binding function which is not affected by healthy ageing or chronic depression. Whether this specificity holds true across other non-AD dementias is as yet unknown. The present study investigated STM conjunctive binding in a sample of AD patients and patients with other non-AD dementias using a task which has proved sensitive to the effects of AD. The STM task assesses the free recall of objects, colours, and the bindings of objects and colours. Patients with AD, frontotemporal dementia, vascular dementia, lewy body dementia and dementia associated with Parkinson's disease showed memory, visuo-spatial, executive and attentional deficits on standard neuropsychological assessment. However, only AD patients showed STM binding deficits. This deficit was observed even when memory for single features was at a similar level across patient groups. Regression and discriminant analyses confirmed that the STM binding task accounted for the largest proportion of variance between AD and non-AD groups and held the greatest classification power to identify patients with AD. STM conjunctive binding places little demands on executive functions and appears to be subserved by components of the memory network which are targeted by AD, but not by non-AD dementias. PMID:22289292
Computing and Using Metrics in the ADS
NASA Astrophysics Data System (ADS)
Henneken, E. A.; Accomazzi, A.; Kurtz, M. J.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Holachek, A.; Murray, S. S.
2015-04-01
Finding measures for research impact, be it for individuals, institutions, instruments, or projects, has gained a lot of popularity. There are more papers written than ever on new impact measures, and problems with existing measures are being pointed out on a regular basis. Funding agencies require impact statistics in their reports, job candidates incorporate them in their resumes, and publication metrics have even been used in at least one recent court case. To support this need for research impact indicators, the SAO/NASA Astrophysics Data System (ADS) has developed a service that provides a broad overview of various impact measures. In this paper we discuss how the ADS can be used to quench the thirst for impact measures. We will also discuss a couple of the lesser-known indicators in the metrics overview and the main issues to be aware of when compiling publication-based metrics in the ADS, namely author name ambiguity and citation incompleteness.
Warped AdS3 , dS3 , and flows from N =(0 ,2 ) SCFTs
NASA Astrophysics Data System (ADS)
O'Colgáin, Eoin
2015-05-01
We present the general form of all timelike supersymmetric solutions to three-dimensional U (1 )3 gauged supergravity, a known consistent truncation of string theory. We uncover a rich vacuum structure, including an infinite class of new timelike-warped AdS3 (Gödel) and timelike-warped dS3 critical points. We outline the construction of supersymmetric flows, driven by irrelevant scalar operators in the SCFT, which interpolate between critical points. For flows from AdS3 to Gödel, the natural candidate for the central charge decreases along the flow. Flows to timelike-warped dS3 exhibit topology change.
Value-Added Chemicals from Animal Manure
Chen, Shulin; Liao, Wei; Liu, Chuanbin; Wen, Zhiyou; Kincaid, R L.; Harrison, J H.; Elliott, Douglas C.; Brown, Michael D.; Solana, Amy E.; Stevens, Don J.
2003-12-19
The objective of the project proposed by Washington State University (WSU) and Pacific Northwest National Laboratory (PNNL) was to develop technology for the utilization of animal manures as feedstocks to produce value-added products. These included medium-volume commodity chemicals such as glycols or diols and protein-based products such as chemicals or feed supplements. The research focused on two aspects of this approach including the analysis and treatment of the feedstock to produce intermediate chemical precursors and the aqueous phase conversion of these intermediates to chemicals and other value-added products.
Issue ads and the health reform debate.
Bergan, Daniel; Risner, Genevieve
2012-06-01
The public debate over health care reform in 2009 was carried out partly through issue advertisements aired online and on television. Did these advertisements alter the course of the debate over health care reform? While millions of dollars are spent each year on issue ads, little is known about their effects. Results from a naturalistic online experiment on the effects of issue ads suggest that they can influence the perceived importance of an issue and perceptions of politicians associated with the featured policy while influencing policy support only among those low in political awareness. PMID:22323237
Yang, Jae-Kyo; Shim, Kwang-Bo; Kim, Hee-Taik; Choa, Yong-Ho
2006-11-01
Al2O3 nanoparticles added the YSZ for improving the mechanical property and the ionic conductivity. Al2O3/YSZ nanocomposites were prepared by ultrasonic spray pyrolysis and PECS process. The relative density of the Al2O3/YSZ nanocomposites was fully densified at a sintering temperature of 1100 degrees C. The grain size for 5 vol.% Al2O3/YSZ was less than 100 nm. The fracture toughness and total ionic conductivity of Al2O3/YSZ nanocomposites were improved compared with Al2O3/YSZ nanocomposites by conventional process, due to homogeneous dispersion and uniform particle size of added Al2O3. PMID:17252776
Gubser, Steven S.
2006-12-15
The AdS/CFT correspondence and a classical test string approximation are used to calculate the drag force on an external quark moving in a thermal plasma of N=4 super-Yang-Mills theory. This computation is motivated by the phenomenon of jet-quenching in relativistic heavy ion collisions.
The AD Nurse: Prepared to be Prepared
ERIC Educational Resources Information Center
Beverly, Lynne; Junker, Mary H.
1977-01-01
It is not enough for the new associate degree (AD) nursing graduate to know the theory and be willing to learn. She must also have some skill in providing basic nursing care. Examples of applicants, both ADNs and BSNs, are described to illustrate the nursing talent necessary to practice sensitively and effectively. (Editor/TA)
Value Added School Review Field Guide
ERIC Educational Resources Information Center
Alberta Education, 2009
2009-01-01
The "Value-Added School Review (VSR)" is an analytical model designed to assist schools in identifying and addressing opportunities for school improvement. The model works best when it is focused purposefully on students and the student learning outcomes as defined in the "Guide to Education". It complements the processes described in Alberta…
"Value Added" Proves Beneficial to Teacher Prep
ERIC Educational Resources Information Center
Sawchuk, Stephen
2012-01-01
The use of "value added" information appears poised to expand into the nation's teacher colleges, with more than a dozen states planning to use the technique to analyze how graduates of training programs fare in classrooms. Supporters say the data could help determine which teacher education pathways produce teachers who are at least as…
Gubser, Steven S.
2001-04-15
The radiation-dominated k=0 FRW cosmology emerges as the induced metric on a codimension one hypersurface of constant extrinsic curvature in the five-dimensional AdS-Schwarzschild solution. That we should get FRW cosmology in this way is an expected result from AdS/CFT in light of recent comments regarding the coupling of gravity to ''boundary'' conformal field theories. I remark on how this calculation bears on the understanding of the Randall-Sundrum ''alternative to compactification.'' A generalization of the AdS/CFT prescription for computing Green's functions is suggested, and it is shown how gravity emerges from it with a strength G{sub 4}=2G{sub 5}/L. Some upper bounds are set on the radius of curvature L of AdS{sub 5}. One of them comes from estimating the rate of leakage of visible sector energy into the CFT. That rate is connected via a unitarity relation to deviations from Newton's force law at short distances. The best bound on L obtained in this paper comes from a match to the parameters of string theory. It is L{approx}<1nm if the string scale is 1GeV. Higher string scales imply a tighter bound on L.
Fitting Value-Added Models in R
ERIC Educational Resources Information Center
Doran, Harold C.; Lockwood, J. R.
2006-01-01
Value-added models of student achievement have received widespread attention in light of the current test-based accountability movement. These models use longitudinal growth modeling techniques to identify effective schools or teachers based upon the results of changes in student achievement test scores. Given their increasing popularity, this…
Imago Mundi, Imago AD, Imago ADNI
2014-01-01
Since the launch in 2003 of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) in the USA, ever growing, similarly oriented consortia have been organized and assembled around the world. The various accomplishments of ADNI have contributed substantially to a better understanding of the underlying physiopathology of aging and Alzheimer’s disease (AD). These accomplishments are basically predicated in the trinity of multimodality, standardization and sharing. This multimodality approach can now better identify those subjects with AD-specific traits that are more likely to present cognitive decline in the near future and that might represent the best candidates for smaller but more efficient therapeutic trials – trials that, through gained and shared knowledge, can be more focused on a specific target or a specific stage of the disease process. In summary, data generated from ADNI have helped elucidate some of the pathophysiological mechanisms underpinning aging and AD pathology, while contributing to the international effort in setting the groundwork for biomarker discovery and establishing standards for early diagnosis of AD. PMID:25478022
Adding calcium improves lithium ferrite core
NASA Technical Reports Server (NTRS)
Lessoff, H.
1969-01-01
Adding calcium increases uniformity of grain growth over a wide range of sintering temperatures and reduces porosity within the grain. Ferrite cores containing calcium have square hysteresis loops and high curie temperatures, making them useful in coincident current memories of digital electronic computers.
Agency Presidents Rank Ad Courses, Job Opportunities.
ERIC Educational Resources Information Center
Marquez, F. T.
1980-01-01
Relates results of a survey of 118 advertising agency presidents: most think college training is useful in an ad agency, job opportunities in advertising are good, internship programs would be helpful to students, and courses in advertising principles and management are especially helpful. (TJ)
Adding Test Generation to the Teaching Machine
ERIC Educational Resources Information Center
Bruce-Lockhart, Michael; Norvell, Theodore; Crescenzi, Pierluigi
2009-01-01
We propose an extension of the Teaching Machine project, called Quiz Generator, that allows instructors to produce assessment quizzes in the field of algorithm and data structures quite easily. This extension makes use of visualization techniques and is based on new features of the Teaching Machine that allow third-party visualizers to be added as…
Anomaly Detection Techniques for Ad Hoc Networks
ERIC Educational Resources Information Center
Cai, Chaoli
2009-01-01
Anomaly detection is an important and indispensable aspect of any computer security mechanism. Ad hoc and mobile networks consist of a number of peer mobile nodes that are capable of communicating with each other absent a fixed infrastructure. Arbitrary node movements and lack of centralized control make them vulnerable to a wide variety of…
Y-system for form factors at strong coupling in AdS5 and with multi-operator insertions in AdS3
NASA Astrophysics Data System (ADS)
Gao, Zhiquan; Yang, Gang
2013-06-01
We study form factors in {N}=4 SYM at strong coupling in general kinematics and with multi-operator insertions by using gauge/string duality and integrability techniques. This generalizes the AdS3 results of Maldacena and Zhiboedov in two non-trivial aspects. The first generalization to AdS5 space was motivated by its potential connection to strong coupling Higgs-to-three-gluons amplitudes in QCD which was observed recently at weak coupling. The second generalization to multi-operator insertions was motivated as a step towards applying on-shell techniques to compute correlation functions at strong coupling. In this picture, each operator is associated to a monodromy condition on the cusp solutions. We construct Y-systems for both cases. The Y -functions are related to the spacetime (cross) ratios. Their WKB approximations based on a rational function P ( z) are also studied. We focus on the short operators, while the prescription is hopefully also applicable for more general operators.
What's the Value in Value-Added?
ERIC Educational Resources Information Center
Duffrin, Elizabeth
2011-01-01
As the profession of teaching continues to get more attention given recent events, a growing number of school districts from New York to California are adopting "value-added" measures of teaching quality to award bonuses or even tenure. And two competitive federal grants are spurring them on. The Teacher Incentive Fund has awarded 95 grants since…
NASA Astrophysics Data System (ADS)
Amiri-Sharifi, S.; Ali-Akbari, M.; Kishani-Farahani, A.; Shafie, N.
2016-08-01
We exploit the AdS/CFT correspondence to investigate thermalization in an N = 2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under influence of an external electric field which leads to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS5 ×S5 background. In the dual gravity theory an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory side. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions, where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe the formation of two separate apparent horizons on the brane. This means that the state of the gauge theory experiences two different temperature regimes during its time evolution.
Cutting Budget Corners While Adding Value.
ERIC Educational Resources Information Center
Veile, Craig N.; Carpenter, Mark J.
2000-01-01
Discusses how one school district saved money while adding long- term value to its capital improvement project. Planning issues involving square footage requirements, quality of material to be used, and heating and cooling system selection are discussed as are concepts to increase student learning capacity for the same construction dollars. (GR)
Adding Users to the Website Design Process
ERIC Educational Resources Information Center
Tomeo, Megan L.
2012-01-01
Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…
"Value Added" Proves Beneficial to Teacher Prep
ERIC Educational Resources Information Center
Sawchuk, Stephen
2012-01-01
The use of "value added" information appears poised to expand into the nation's teacher colleges, with more than a dozen states planning to use the technique to analyze how graduates of training programs fare in classrooms. Supporters say the data could help determine which teacher education pathways produce teachers who are at least as good…
"Value Added" Gauge of Teaching Probed
ERIC Educational Resources Information Center
Viadero, Debra
2009-01-01
A new study by a public and labor economist suggests that "value added" methods for determining the effectiveness of classroom teachers are built on some shaky assumptions and may be misleading. The study, due to be published in February in the "Quarterly Journal of Economics," is the first of a handful of papers now in the publishing pipeline…
Value Added to What? How a Ceiling in the Testing Instrument Influences Value-Added Estimation
ERIC Educational Resources Information Center
Koedel, Cory; Betts, Julian
2010-01-01
Value-added measures of teacher quality may be sensitive to the quantitative properties of the student tests upon which they are based. This article focuses on the sensitivity of value added to test score ceiling effects. Test score ceilings are increasingly common in testing instruments across the country as education policy continues to…
String in AdS black hole: A thermo field dynamic approach
NASA Astrophysics Data System (ADS)
Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dáfni F. Z.; Nedel, Daniel Luiz
2012-10-01
Based on Maldacena’s description of an eternal anti-de Sitter (AdS) black hole, we reassess the thermo field dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (noninteracting) copies of the conformal field theory (CFT) associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary state which is identified with the TFD thermal vacuum, globally defined in the Kruskal extension of the AdS black hole. We emphasize the connection of this picture with unitary SU(1,1) TFD formulation, and we show that information about the bulk and the conformal boundary is present in the SU(1,1) parameters. Using the unitary SU(1,1) TFD formulation, a canonical prescription for calculating the world sheet real time thermal Green’s function is made, and the entropy associated with the entanglement of the two CFT’s is calculated.
Avoiding Ad Avoidance: Factors Affecting the Perception of Online Banner Ads
ERIC Educational Resources Information Center
Portnoy, Felix
2012-01-01
This dissertation examined the effect of search type, ad saliency, and ad repetition on the perception of online banner advertisements. In the first study, 48 student participants conducted simulated search tasks using mixed factorial design where search type (known-item vs. exploratory) was manipulated within-subject and the banner saliency level…
Designing added functions in engineered cementitious composites
NASA Astrophysics Data System (ADS)
Yang, En-Hua
In this dissertation, a new and systematic material design approach is developed for ECC with added functions through material microstructures linkage to composite macroscopic behavior. The thesis research embodies theoretical development by building on previous ECC micromechanical models, and experimental investigations into three specific new versions of ECC with added functions aimed at addressing societal demands of our built infrastructure. Specifically, the theoretical study includes three important ECC modeling elements: Steady-state crack propagation analyses and simulation, predictive accuracy of the fiber bridging constitutive model, and development of the rate-dependent strain-hardening criteria. The first element establishes the steady-state cracking criterion as a fundamental requirement for multiple cracking behavior in brittle matrix composites. The second element improves the accuracy of crack-width prediction in ECC. The third element establishes the micromechanics basis for impact-resistant ECC design. Three new ECCs with added functions were developed and experimentally verified in this thesis research through the enhanced theoretical framework. A green ECC incorporating a large volume of industrial waste was demonstrated to possess reduced crack width and drying shrinkage. The self-healing ECC designed with tight crack width was demonstrated to recover transport and mechanical properties after microcrack damage when exposed to wet and dry cycles. The impact-resistant ECC was demonstrated to retain tensile ductility with increased strength under moderately high strain-rate loading. These new versions of ECC with added functions are expected to contribute greatly to enhancing the sustainability, durability, and safety of civil infrastructure built with ECC. This research establishes the effectiveness of micromechanics-based design and material ingredient tailoring for ECC with added new attributes but without losing its basic tensile ductile
Hairy black holes in AdS5 × S 5
NASA Astrophysics Data System (ADS)
Markeviciute, Julija; Santos, Jorge E.
2016-06-01
We use numerical methods to exhaustively study a novel family of hairy black hole solutions in AdS5. These solutions can be uplifted to solutions of type IIB supergravity with AdS5 × S 5 asymptotics and are thus expected to play an important role in our understanding of AdS/CFT. We find an intricate phase diagram, with the aforementioned family of hairy black hole solutions branching from the Reissner-Nordström black hole at the onset of the superradiance instability. We analyse black holes with spherical and planar horizon topology and explain how they connect in the phase diagram. Finally, we detail their global and local thermodynamic stability across several ensembles.
Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774-775
NASA Astrophysics Data System (ADS)
Rakowski, Andrzej Z.; Krąpiec, Marek; Huels, Mathias; Pawlyta, Jacek; Dreves, Alexander; Meadows, John
2015-10-01
Evidence of a rapid increase in atmospheric radiocarbon (14C) content in AD 774-775 was presented by Miyake et al. (2012), who observed an increase of about 12‰ in the 14C content in annual tree rings from Japanese cedar. Usoskin et al. (2013) report a similar 14C spike in German oak, and attribute it to exceptional solar activity. If this phenomenon is global in character, such rapid changes in 14C concentration may affect the accuracy of calibrated dates, as the existing calibration curve is composed mainly of decadal samples. Single-year samples of dendro-chronologically dated tree rings of deciduous oak (Quercus robur) from Kujawy, a village near Krakow (SE Poland), spanning the years AD 765-796, were collected and their 14C content was measured using the AMS system in the Leibniz Laboratory. The results clearly show a rapid increase of 9.2 ± 2.1‰ in the 14C concentration in tree rings between AD 774 and AD 775, with maximum Δ14C = 4.1 ± 2.3‰ noted in AD 776.
Iyer, Ramakrishnan; Mukhopadhyay, Ayan
2010-04-15
The AdS/CFT correspondence defines a sector with universal strongly coupled dynamics in the field theory as the dual of pure gravity in AdS described by Einstein's equation with a negative cosmological constant. We explain here, from the field-theoretic viewpoint how the dynamics in this sector gets determined by the expectation value of the energy-momentum tensor alone. We first show that the Boltzmann equation has very special solutions which could be functionally completely determined in terms of the energy-momentum tensor alone. We call these solutions conservative solutions. We indicate why conservative solutions should also exist when we refine this kinetic description to go closer to the exact microscopic theory or even move away from the regime of weak coupling so that no kinetic description could be employed. We argue that these conservative solutions form the universal sector dual to pure gravity at strong coupling and large N. Based on this observation, we propose a regularity condition on the energy-momentum tensor so that the dual solution in pure gravity has a smooth future horizon. We also study if irreversibility emerges only at long time scales of observation, unlike the case of the Boltzmann equation.
GENERAL: On particles tunneling from the Taub-NUT-AdS black hole
NASA Astrophysics Data System (ADS)
Zeng, Xiao-Xiong; Li, Qiang
2009-11-01
This paper discusses tunneling of scalar particles and Dirac particles from the Taub-NUT-AdS black hole by the Hamilton-Jacobi equation, initially used by Angheben et al, and the Dirac equation, recently proposed by Kerner and Mann. This is performed in the dragging coordinate frame so as to avoid the ergosphere dragging effect. A general form is obtained for the temperature of scalar and Dirac particles tunneling from the Taub-NUT-Ads black hole, which is commensurate with other methods as expected.
NASA Astrophysics Data System (ADS)
Chai, Ya-Ting; Zou, Yuan-Chuan
2015-09-01
According to analysis of the 14C content in two Japanese trees, that grew over a period of approximately 3000 years, with high time resolution, Miyake et al. found a rapid increase at AD 774-775 and another one at AD 993-994. These increases correspond to high-energy events that happened within those years and radiated γ-ray energy of about 7×1024 erg toward the Earth. The origin of these events is a mystery. Such strong events should have an unusual optical counterpart, and have been recorded in historical literatures. We searched Chinese historical materials around AD 744-775 and AD 993-994, but no remarkable event was found except for a violent thunderstorm in AD 775. However, the possibility of a thunderstorm containing so much energy is unlikely. We conclude that the events, which caused the 14C increase, are still unclear. These events most probably had no optical counterpart, and a short gamma-ray burst, giant flare of a soft gamma-ray repeater or a terrestrial γ-ray flash could all be candidates.
Holographic Rényi entropy in AdS3/LCFT2 correspondence
NASA Astrophysics Data System (ADS)
Chen, Bin; Song, Feng-yan; Zhang, Jia-ju
2014-03-01
The recent study in AdS3/CFT2 correspondence shows that the tree level contribution and 1-loop correction of holographic Rényi entanglement entropy (HRE) exactly match the direct CFT computation in the large central charge limit. This allows the Rényi entanglement entropy to be a new window to study the AdS/CFT correspondence. In this paper we generalize the study of Rényi entanglement entropy in pure AdS3 gravity to the massive gravity theories at the critical points. For the cosmological topological massive gravity (CTMG), the dual conformal field theory (CFT) could be a chiral conformal field theory or a logarithmic conformal field theory (LCFT), depending on the asymptotic boundary conditions imposed. In both cases, by studying the short interval expansion of the Rényi entanglement entropy of two disjoint intervals with small cross ratio x, we find that the classical and 1-loop HRE are in exact match with the CFT results, up to order x 6. To this order, the difference between the massless graviton and logarithmic mode can be seen clearly. Moreover, for the cosmological new massive gravity (CNMG) at critical point, which could be dual to a logarithmic CFT as well, we find the similar agreement in the CNMG/LCFT correspondence. Furthermore we read the 2-loop correction of graviton and logarithmic mode to HRE from CFT computation. It has distinct feature from the one in pure AdS3 gravity.
Euclidean Wilson loops and minimal area surfaces in lorentzian AdS 3
NASA Astrophysics Data System (ADS)
Irrgang, Andrew; Kruczenski, Martin
2015-12-01
The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS 5 × S 5 space. If the Wilson loop is Euclidean and confined to a plane ( t, x) then the dual surface is Euclidean and lives in Lorentzian AdS 3 ⊂ AdS 5. In this paper we study such minimal area surfaces generalizing previous results obtained in the Euclidean case. Since the surfaces we consider have the topology of a disk, the holonomy of the flat current vanishes which is equivalent to the condition that a certain boundary Schrödinger equation has all its solutions anti-periodic. If the potential for that Schrödinger equation is found then reconstructing the surface and finding the area become simpler. In particular we write a formula for the Area in terms of the Schwarzian derivative of the contour. Finally an infinite parameter family of analytical solutions using Riemann Theta functions is described. In this case, both the area and the shape of the surface are given analytically and used to check the previous results.
77 FR 6466 - Schedule for Rating Disabilities; AL Amyloidosis (Primary Amyloidosis)
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-08
... 22, 2010, VA published in the Federal Register (75 FR 65279) a proposed rule that would add AL... decision was published in the Federal Register at 74 FR 21258, which amended 38 CFR 3.309(e) by adding AL... hemic and lymphatic systems to include AL amyloidosis. This regulatory action is necessary to add...
Supporting Dynamic Ad hoc Collaboration Capabilities
Agarwal, Deborah A.; Berket, Karlo
2003-07-14
Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.
AdOpt@TNG control system software
NASA Astrophysics Data System (ADS)
Baruffolo, Andrea; Ragazzoni, Roberto; Farinato, Jacopo
1998-09-01
AdOptTNG is the Adaptive Optics Module for the Galileo National telescope (TNG). At first light this module will feature tip-tilt correction capabilities and a speckle interferometry facility. In this paper we describe the main characteristics of the AdOptTNG Control System Software. The system is composed by a real-time part and a graphical user interface. The real-time software computes the required corrections, drives the tip-tilt mirror and function. The user interface has been written in IDL, using the IDL Widget set, taking advantage of its powerful data manipulation and analysis capabilities for data presentation and diagnostics. The integration of all these components into the TNG Control System Software, in order to allow for remote control and data archiving, is also briefly described.
NASA Astrophysics Data System (ADS)
Fini, Luca; Puglisi, Alfio; Riccardi, Armando
2004-09-01
The LBT-AdOpt subsystem is a complex machine which includes several software controlled parts. It is essentially divided into two parts: a real-time loop which implements the actual adaptive optics control loop, from the wavefront sensor to the deformable secondary mirror, and a supervisor which performs a number of coordination and diagnostics tasks. The coordination and diagnostics task are essential for the proper operation of the system both as an aid for the preparation of observations and because only a continuous monitoring of dynamic system parameters can guarantee optimal performances and system safety during the operation. In the paper we describe the overall software architecture of the LBT-AdOpt supervisor and we discuss the functionalities required for a proper operation.
Adding coal dust to coal batch
V.S. Shved; A.V.Berezin
2009-05-15
The granulometric composition of coke dust from the dry-slaking machine is determined. The influence of additions of 3-7% coke dust on the quality of industrial coking batch and the coke obtained by box coking is estimated. Adding 1% coke dust to coking batch does not markedly change the coke quality. Industrial equipment for the supply of dry-slaking dust to the batch is described.
Hydrogen added after-burner system
Kanada, Youji; Hayasi, Masaharu; Akaki, Motonobu; Tsuchikawa, Shunzou; Isomura, Akihito
1996-09-01
The authors developed a hydrogen-added afterburner system for a new catalyst heating system, which realized large reduction of emissions during start-up at low temperatures when hydrocarbon (HC) emission was rather high. Key development items of this system are a water electrolysis type small size on-board hydrogen supply unit and an engine matching technique for the verification of emission reduction effects.
ARM KAZR-ARSCL Value Added Product
Jensen, Michael
2012-09-28
The Ka-band ARM Zenith Radars (KAZRs) have replaced the long-serving Millimeter Cloud Radars, or MMCRs. Accordingly, the primary MMCR Value Added Product (VAP), the Active Remote Sensing of CLouds (ARSCL) product, is being replaced by a KAZR-based version, the KAZR-ARSCL VAP. KAZR-ARSCL provides cloud boundaries and best-estimate time-height fields of radar moments.
Merged Sounding Value-Added Product
Troyan, D
2010-03-03
The Merged Sounding value-added product (VAP) uses a combination of observations from radiosonde soundings, the microwave radiometer (MWR), surface meteorological instruments, and European Centre for Medium-Range Weather Forecasts (ECMWF) model output with a sophisticated scaling/interpolation/smoothing scheme in order to define profiles of the atmospheric thermodynamic state at one-minute temporal intervals and a total of 266 altitude levels.
Routing Security in Ad Hoc Wireless Networks
NASA Astrophysics Data System (ADS)
Pervaiz, Mohammad O.; Cardei, Mihaela; Wu, Jie
Wireless networks provide rapid, untethered access to information and computing, eliminating the barriers of distance, time, and location for many applications ranging from collaborative, distributed mobile computing to disaster recovery (such as fire, flood, earthquake), law enforcement (crowd control, search, and rescue), and military communications (command, control, surveillance, and reconnaissance). An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration [11
Drag cancellation by added-mass pumping
NASA Astrophysics Data System (ADS)
Giorgio-Serchi, F.; Weymouth, G. D.
2016-07-01
A submerged body subject to a sudden shape-change experiences large forces due to the variation of added-mass energy. While this phenomenon has been studied for single actuation events, application to sustained propulsion requires studying \\textit{periodic} shape-change. We do so in this work by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. We develop an analytical model to investigate the relationship between added-mass variation and viscous damping and demonstrate its range of application with fully coupled fluid-solid Navier-Stokes simulations at large Stokes number. Our results demonstrate that the recovery of added-mass kinetic energy can be used to completely cancel the viscous damping of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius $r_0$. A quasi-linear relationship is found to link the terminal amplitude of the oscillations $X$, to the extent of size change $a$, with $X/a$ peaking at values from 4 to 4.75 depending on the details of the shape-change kinematics. In addition, it is found that pumping in the frequency range of $1-\\frac{a}{2r_0}<\\omega^2/\\omega_n^2<1+\\frac{a}{2r_0}$ is required for sustained oscillations. The results of this analysis shed light on the role of added-mass recovery in the context of shape-changing bodies and biologically-inspired underwater vehicles.
LINAC for ADS application - accelerator technologies
Garnett, Robert W; Sheffreld, Richard L
2009-01-01
Sifnificant high-current, high-intensity accelerator research and development have been done in the recent past in the US, centered primarily at Los Alamos National Laboratory. These efforts have included designs for the Accelerator Production of Tritium Project, Accelerator Transmutation of Waste, and Accelerator Driven Systems, as well as many others. This past work and some specific design principles that were developed to optimie linac designs for ADS and other high-intensity applications will be discussed briefly.
ADS: The Next Generation Search Platform
NASA Astrophysics Data System (ADS)
Accomazzi, A.; Kurtz, M. J.; Henneken, E. A.; Chyla, R.; Luker, J.; Grant, C. S.; Thompson, D. M.; Holachek, A.; Dave, R.; Murray, S. S.
2015-04-01
Four years after the last LISA meeting, the NASA Astrophysics Data System (ADS) finds itself in the middle of major changes to the infrastructure and contents of its database. In this paper we highlight a number of features of great importance to librarians and discuss the additional functionality that we are currently developing. Our citation coverage has doubled since 2010 and now consists of over 10 million citations. We are normalizing the affiliation information in our records and we have started collecting and linking funding sources with papers in our system. At the same time, we are undergoing major technology changes in the ADS platform. We have rolled out and are now enhancing a new high-performance search engine capable of performing full-text as well as metadata searches using an intuitive query language. We are currently able to index acknowledgments, affiliations, citations, and funding sources. While this effort is still ongoing, some of its benefits are already available through the ADS Labs user interface and API at http://adslabs.org/adsabs/.
Conformal mass in Einstein-Gauss-Bonnet AdS gravity
NASA Astrophysics Data System (ADS)
Jatkar, Dileep P.; Kofinas, Georgios; Miskovic, Olivera; Olea, Rodrigo
2015-05-01
In this paper, we show that the physical information given by conserved charges for asymptotically AdS spacetimes in Einstein-Gauss-Bonnet AdS gravity is encoded in the electric part of the Weyl tensor. This result generalizes the conformal mass definition by Ashtekar-Magnon-Das (AMD) to a gravity theory with a Gauss-Bonnet term. This proof makes use of the Noether charges obtained from an action renormalized by the addition of counterterms which depend on the extrinsic curvature (Kounterterms). If the asymptotic fall-off behavior of the Weyl tensor is same as the one considered in the AMD method, then the Kounterterm charges and the AMD charges agree in any dimension.
The spectrum of strings on warped AdS3 × S3
NASA Astrophysics Data System (ADS)
Azeyanagi, Tatsuo; Hofman, Diego M.; Song, Wei; Strominger, Andrew
2013-04-01
String theory on NS-NS AdS3 × S3 admits an exactly marginal deformation which breaks the {{overline{{SL( {2,{R}} )}}}_R} × SL(2, {R} ) L isometry of AdS3 down to {{overline{{SL( {2,{R}} )}}}_R} × U(1) L . The holographic dual is an exotic and only partially understood type of two-dimensional CFT with a reduced unbroken global conformal symmetry group. In this paper we study the deformed theory on the string worldsheet. It is found to be related by a spectral flow which is nonlocal in spacetime to the undeformed worldsheet theory. An exact formula for the spectrum of massive strings is presented.
Stability of warped AdS3 black holes in topologically massive gravity under scalar perturbations
NASA Astrophysics Data System (ADS)
Ferreira, Hugo R. C.
2013-06-01
We demonstrate that the warped AdS3 black hole solutions of topologically massive gravity are classically stable against massive scalar field perturbations by analyzing the quasinormal and bound state modes of the scalar field. In particular, it is found that although classical superradiance is present it does not give rise to superradiant instabilities. The stability is shown to persist even when the black hole is enclosed by a stationary mirror with Dirichlet boundary conditions. This is a surprising result in view of the similarity between the causal structure of the warped AdS3 black hole and the Kerr spacetime in 3+1 dimensions. This work provides the foundations for the study of quantum field theory in this spacetime.
Stability and thermodynamics of AdS black holes with scalar hair
Hertog, Thomas; Maeda, Kengo
2005-01-15
Recently a class of static spherical black hole solutions with scalar hair was found in four and five dimensional gauged supergravity with modified, but anti-de Sitter (AdS) invariant boundary conditions. These black holes are fully specified by a single conserved charge, namely, their mass, which acquires a contribution from the scalar field. Here we report on a more detailed study of some of the properties of these solutions. A thermodynamic analysis shows that in the canonical ensemble the standard Schwarzschild-AdS black hole is stable against decay into a hairy black hole. We also study the stability of the hairy black holes and find there always exists an unstable radial fluctuation, in both four and five dimensions. We argue, however, that Schwarzschild-AdS is probably not the end state of evolution under this instability.
Witten diagrams revisited: the AdS geometry of conformal blocks
NASA Astrophysics Data System (ADS)
Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River
2016-01-01
We develop a new method for decomposing Witten diagrams into conformal blocks. The steps involved are elementary, requiring no explicit integration, and operate directly in position space. Central to this construction is an appealingly simple answer to the question: what object in AdS computes a conformal block? The answer is a "geodesic Witten diagram", which is essentially an ordinary exchange Witten diagram, except that the cubic vertices are not integrated over all of AdS, but only over bulk geodesics connecting the boundary operators. In particular, we consider the case of four-point functions of scalar operators, and show how to easily reproduce existing results for the relevant conformal blocks in arbitrary dimension.
Localization in supergravity and quantum AdS 4 /CFT3 holography
NASA Astrophysics Data System (ADS)
Dabholkar, Atish; Drukker, Nadav; Gomes, João
2014-10-01
We compute the quantum gravity partition function of M-theory on AdS 4 × X 7 by using localization techniques in four-dimensional gauged supergravity obtained by a consistent truncation on the Sasaki-Einstein manifold X 7. The supergravity path integral reduces to a finite dimensional integral over two collective coordinates that parametrize the localizing instanton solutions. The renormalized action of the off-shell instanton solutions depends linearly and holomorphically on the "square root" prepotential evaluated at the center of AdS 4. The partition function resembles the Laplace transform of the wave function of a topological string and with an assumption about the measure for the localization integral yields an Airy function in precise agreement with the computation from the boundary ABJM theory on a 3-sphere. Our bulk quantum gravity computation is nonperturbatively exact in four-dimensional Planck length but ignores corrections due to brane-instantons.
Renormalization, averaging, conservation laws and AdS (in)stability
NASA Astrophysics Data System (ADS)
Craps, Ben; Evnin, Oleg; Vanhoof, Joris
2015-01-01
We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a self-interacting scalar field in a non-dynamical AdS background, and we highlight the similarities of this system to the fully dynamical case of gravitational instability. The nature of these conservation laws is best understood through an appeal to averaging methods which allow one to derive an effective Lagrangian or Hamiltonian description of the slow energy transfer between the normal modes. The conservation laws in question then follow from explicit symmetries of this averaged effective theory.
On holomorphic factorization in asymptotically AdS 3D gravity
NASA Astrophysics Data System (ADS)
Krasnov, Kirill
2003-09-01
This paper studies aspects of 'holography' for Euclidean signature pure gravity on asymptotically AdS 3-manifolds. This theory can be described as SL(2, Bbb C) CS theory. However, not all configurations of CS theory correspond to asymptotically AdS 3-manifolds. We show that configurations that do have the metric interpretation are parametrized by the so-called projective structures on the boundary. The corresponding asymptotic phase space is shown to be the cotangent bundle over the Schottky space of the boundary. This singles out a 'gravitational' sector of the SL(2, Bbb C) CS theory. It is over this sector that the path integral has to be taken to obtain the gravity partition function. We sketch an argument for holomorphic factorization of this partition function.
Massive quiver matrix models for massive charged particles in AdS
NASA Astrophysics Data System (ADS)
Asplund, Curtis T.; Denef, Frederik; Dzienkowski, Eric
2016-01-01
We present a new class of N=4 supersymmetric quiver matrix models and argue that it describes the stringy low-energy dynamics of internally wrapped D-branes in four-dimensional anti-de Sitter (AdS) flux compactifications. The Lagrangians of these models differ from previously studied quiver matrix models by the presence of mass terms, associated with the AdS gravitational potential, as well as additional terms dictated by supersymmetry. These give rise to dynamical phenomena typically associated with the presence of fluxes, such as fuzzy membranes, internal cyclotron motion and the appearance of confining strings. We also show how these models can be obtained by dimensional reduction of four-dimensional supersymmetric quiver gauge theories on a three-sphere.
Symmetry operators of Killing spinors and superalgebras in AdS5
NASA Astrophysics Data System (ADS)
Ertem, Ümit
2016-04-01
We construct the first-order symmetry operators of Killing spinor equation in terms of odd Killing-Yano forms. By modifying the Schouten-Nijenhuis bracket of Killing-Yano forms, we show that the symmetry operators of Killing spinors close into an algebra in AdS5 spacetime. Since the symmetry operator algebra of Killing spinors corresponds to a Jacobi identity in extended Killing superalgebras, we investigate the possible extensions of Killing superalgebras to include higher-degree Killing-Yano forms. We found that there is a superalgebra extension but no Lie superalgebra extension of the Killing superalgebra constructed out of Killing spinors and odd Killing-Yano forms in AdS5 background.
Static strings in global AdS space and quark-antiquark potential
Bayona, C. A. Ballon; Ferreira, Cristine N.
2008-07-15
We investigate the finite temperature quark antiquark problem in a compact space S{sup n-1}xS{sup 1} by considering static strings in global AdS{sub n+1} space with n{>=}3. For high temperatures we work in the black hole metric where two possible solutions show up : the big black hole and the small black hole. Using the AdS/CFT correspondence, we calculate the quark antiquark potential (free energy) as a function of the distance. We show that this potential can be intrepeted as confining for the anti-de Sitter (AdS) space and deconfining for the big black hole. We find for the small black hole a confining limit for the potential but this solution is instable following the Hawking-Page criteria. Our results for the free energy reinforce the Witten interpretation of the confinement/deconfinement transition as the dual of the well-known Hawking-Page transition.
A Jordanian deformation of AdS space in type IIB supergravity
NASA Astrophysics Data System (ADS)
Kawaguchi, Io; Matsumoto, Takuya; Yoshida, Kentaroh
2014-06-01
We consider a Jordanian deformation of the AdS5×S5 superstring action by taking a simple R-operator which satisfies the classical Yang-Baxter equation. The metric and NS-NS two-form are explicitly derived with a coordinate system. Only the AdS part is deformed and the resulting geometry contains the 3D Schrödinger spacetime as a subspace. Then we present the full solution in type IIB supergravity by determining the other field components. In particular, the dilaton is constant and a R-R three-form field strength is turned on. The symmetry of the solution is [SL(2 , ) × U(1)2] × [SU(3) × U(1)] and contains an anisotropic scale symmetry.
Charged and rotating AdS black holes and their CFT duals
NASA Astrophysics Data System (ADS)
Hawking, S. W.; Reall, H. S.
2000-01-01
Black hole solutions that are asymptotic to AdS5×S5 or AdS4×S7 can rotate in two different ways. If the internal sphere rotates, then one can obtain a Reissner-Nordström-AdS black hole. If the asymptotically AdS space rotates, then one can obtain a Kerr-AdS hole. One might expect superradiant scattering to be possible in either of these cases. Superradiant modes reflected off the potential barrier outside the hole would be reamplified at the horizon, and a classical instability would result. We point out that the existence of a Killing vector field timelike everywhere outside the horizon prevents this from occurring for black holes with negative action. Such black holes are also thermodynamically stable in the grand canonical ensemble. The CFT duals of these black holes correspond to a theory in an Einstein universe with a chemical potential and a theory in a rotating Einstein universe. We study these CFTs in the zero coupling limit. In the first case, Bose-Einstein condensation occurs on the boundary at a critical value of the chemical potential. However, the supergravity calculation demonstrates that this is not to be expected at strong coupling. In the second case, we investigate the limit in which the angular velocity of the Einstein universe approaches the speed of light at finite temperature. This is a new limit in which to compare the CFT at strong and weak coupling. We find that the free CFT partition function and supergravity action have the same type of divergence but the usual factor of 4/3 is modified at finite temperature.
Supergravity background of λ-deformed model for AdS2 × S2 supercoset
NASA Astrophysics Data System (ADS)
Borsato, R.; Tseytlin, A. A.; Wulff, L.
2016-04-01
Starting with the F ˆ / G supercoset model corresponding to the AdSn ×Sn superstring one can define the λ-model of arxiv:arXiv:1409.1538 either as a deformation of the F ˆ / F ˆ gauged WZW model or as an integrable one-parameter generalisation of the non-abelian T-dual of the AdSn ×Sn superstring sigma model with respect to the whole supergroup F ˆ . Here we consider the case of n = 2 and find the explicit form of the 4d target space background for the λ-model for the PSU (1 , 1 | 2) / SO (1 , 1) × SO (2) supercoset. We show that this background represents a solution of type IIB 10d supergravity compactified on a 6-torus with only metric, dilaton Φ and the RR 5-form (represented by a 2-form F in 4d) being non-trivial. This implies that the λ-model is Weyl invariant at the quantum level and thus defines a consistent superstring sigma model. The supergravity solution we find is different from the one in arXiv:1410.1886 which should correspond to a version of the λ-model where only the bosonic subgroup of F ˆ is gauged. Still, the two solutions have equivalent scaling limit of arxiv:arXiv:1504.07213 leading to the isometric background for the metric and eΦ F which is related to the η-deformed AdS2 ×S2 sigma model of arXiv:1309.5850. Similar results are expected in the AdS3 ×S3 and AdS5 ×S5 cases.
Yangian of AdS3 / CFT2 and its deformation
NASA Astrophysics Data System (ADS)
Regelskis, Vidas
2016-08-01
We construct highest-weight modules and a Yangian extension of the centrally extended sl(1 | 1) 2 superalgebra, that is a symmetry of the worldsheet scattering associated with the AdS3 / CFT2 duality. We demonstrate that the R-matrix intertwining atypical modules has an elegant trigonometric parametrization. We also consider a quantum deformation of this superalgebra, its modules, and obtain a quantum affine extension of the Drinfeld-Jimbo type that describes a deformed worldsheet scattering.
D-brane on deformed AdS 3 × S 3
NASA Astrophysics Data System (ADS)
Khouchen, Malak; Klusoň, Josef
2015-08-01
We study D1-brane in AdS 3 × S 3 κ-deformed background with non-trivial dilaton and Ramond-Ramond fields. We consider purely time-dependent and spatially-dependent ansatz where we study the solutions of the equations of motion for D1-brane in given background. We find that the behavior of these solutions crucially depends on the value of the parameter a that was introduced in [7].
Gaugings of four-dimensional N =3 supergravity and AdS4/CFT3 holography
NASA Astrophysics Data System (ADS)
Karndumri, Parinya; Upathambhakul, Khem
2016-06-01
We study matter-coupled N =3 gauged supergravity in four dimensions with various semisimple gauge groups. When coupled to n vector multiplets, the gauged supergravity contains 3 +n vector fields and 3 n complex scalars parametrized by S U (3 ,n )/S U (3 )×S U (n )×U (1 ) coset manifold. Semisimple gauge groups take the form of G0×H ⊂S O (3 ,n )⊂S U (3 ,n ) with H being a compact subgroup of S O (n +3 -dim (G0)). The G0 groups considered in this paper are of the form S O (3 ), S O (3 ,1 ), S O (2 ,2 ), S L (3 ,R ) and S O (2 ,1 )×S O (2 ,2 ). We find that S O (3 )×S O (3 ), S O (3 ,1 ) and S L (3 ,R ) gauge groups admit a maximally supersymmetric AdS4 critical point. The S O (2 ,1 )×S O (2 ,2 ) gauge group admits a supersymmetric Minkowski vacuum while the remaining gauge groups admit both half-supersymmetric domain wall vacua and AdS4 vacua with completely broken supersymmetry. For the S O (3 )×S O (3 ) gauge group, there exists another supersymmetric N =3 AdS4 critical point with S O (3 )diag symmetry. We explicitly give a detailed study of various holographic RG flows between AdS4 critical points, flows to nonconformal theories, and supersymmetric domain walls in each gauge group. The results provide gravity duals of N =3 Chern-Simons-matter theories in three dimensions.
Measured Activities of Al and Ni in gamma-(Ni) and gamma'-(Ni)3Al in the Ni-Al-Pt System
NASA Technical Reports Server (NTRS)
Copland, Evan
2007-01-01
Adding Pt to Ni-Al coatings is critical to achieving the required oxidation protection of Ni-based superalloys, but the nature of the Pt effect remains unresolved. This research provides a fundamental part of the answer by measuring the influence of Pt on the activities of Al and Ni in gamma-(Ni), gamma prime-(Ni)3Al and liquid in the Ni-Al-Pt system. Measurements have been made at 25 compositions in the Ni-rich corner over the temperature range, T = 1400-1750 K, by the vapor pressure technique with a multiple effusion-cell mass spectrometer (multi-cell KEMS). These measurements clearly show adding Pt (for X(sub Pt) less than 0.25) decreases a(Al) while increasing a(Ni). This solution behavior supports the idea that Pt increases Al transport to an alloy / Al2O3 interface and also limits the interaction between the coating and substrate alloys in the gamma-(Ni) + gamma prime-(Ni)3Al region. This presentation will review the progress of this study.
Entropy of near-extremal black holes in AdS5
Simon, Joan; Balasubramanian, Vijay; de Boer, Jan; Jejjala, Vishnu; Simon, Joan
2007-07-24
We construct the microstates of near-extremal black holes in AdS_5 x S5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S5, and we show that they dominate the entropy by directly enumerating them and comparing the results with a partition sum calculation. We display new decoupling limits in which the field theory of the lightest open strings on the D-branes becomes dual to a near-horizon region of the black hole geometry. In the single-charge black hole we find evidence for an infrared duality between SU(N) Yang-Mills theories that exchanges the rank of the gauge group with an R-charge. In the two-charge case (where pairs of branes intersect on a line), the decoupled geometry includes an AdS_3 factor with a two-dimensional CFT dual. The degeneracy in this CFT accounts for the black hole entropy. In the three-charge case (where triples of branes intersect at a point), the decoupled geometry contains an AdS_2 factor. Below a certain critical mass, the two-charge system displays solutions with naked timelike singularities even though they do not violate a BPS bound. We suggest a string theoretic resolution of these singularities.
Superradiance and instability of small rotating charged AdS black holes in all dimensions
NASA Astrophysics Data System (ADS)
Aliev, Alikram N.
2016-02-01
Rotating small AdS black holes exhibit the superradiant instability to low-frequency scalar perturbations, which is amenable to a complete analytic description in four dimensions. In this paper, we extend this description to all higher dimensions, focusing on slowly rotating charged AdS black holes with a single angular momentum. We divide the spacetime of these black holes into the near-horizon and far regions and find solutions to the scalar wave equation in each of these regions. Next, we perform the matching of these solutions in the overlap between the regions, by employing the idea that the orbital quantum number ℓ can be thought of as an approximate integer. Thus, we obtain the complete low-frequency solution that allows us to calculate the complex frequency spectrum of quasinormal modes, whose imaginary part is determined by a small damping parameter. Finally, we find a remarkably instructive expression for the damping parameter, which appears to be a complex quantity in general. We show that the real part of the damping parameter can be used to give a universal analytic description of the superradiant instability for slowly rotating charged AdS black holes in all spacetime dimensions.
First order semiclassical thermal string in the AdS spacetime
NASA Astrophysics Data System (ADS)
Belich, Humberto; da Graça, Edison Luiz; dos Santos, Marco Antonio; Vasile Vancea, Ion
2007-02-01
We formulate the finite temperature theory for the free thermal excitations of the bosonic string in the anti-de Sitter (AdS) spacetime in the Thermo Field Dynamics (TFD) approach. The spacetime metric is treated exactly while the string and the thermal reservoir are semiclassically quantized at the first order perturbation theory with respect to the dimensionless parameter epsilon = α'H-2. In the conformal D = 2+1 black-hole AdS background the quantization is exact. The method can be extended to the arbitrary AdS spacetime only in the first order perturbation. This approximation is taken in the center of mass reference frame and it is justified by the fact that at the first order the string dynamics is determined only by the interaction between the free string oscillation modes and the exact background. The first order thermal string is obtained by thermalization of the T = 0 system carried on by the TFD Bogoliubov operator. We determine the free thermal string states and compute the local entropy and free energy in the center of mass reference frame.
On elliptic string solutions in AdS3 and dS3
NASA Astrophysics Data System (ADS)
Bakas, Ioannis; Pastras, Georgios
2016-07-01
Classical string actions in AdS3 and dS3 can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schrödinger problems. Each pair consists of a flat potential and an n = 1 Lamé potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lamé potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS3. New solutions include circular rotating strings in AdS3 with singular time evolution of their radius and angular velocity as well as classical string solutions in dS3.
Cognitive Impact of Banner Ad Characteristics: An Experimental Study.
ERIC Educational Resources Information Center
Li, Hairong; Bukovac, Janice L.
1999-01-01
Finds that (1) animated banner ads (display advertisements hyperlinked to an advertiser's Web site) result in quicker response and better recall (from college students) than non-animated banner ads; (2) larger banner ads lead to better comprehension and more clicks than small banner ads; and (3) user mode (information seeking or Web surfing) did…
37 CFR 2.98 - Adding party to interference.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...
7 CFR 58.727 - Adding optional ingredients.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 3 2013-01-01 2013-01-01 false Adding optional ingredients. 58.727 Section 58.727... Procedures § 58.727 Adding optional ingredients. As each batch is added to the cooker, the predetermined amounts of salt, emulsifiers, color, or other allowable optional ingredients shall be added. However,...
21 CFR 509.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Added poisonous or deleterious substances. 509.6...-PACKAGING MATERIAL General Provisions § 509.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
21 CFR 109.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Added poisonous or deleterious substances. 109.6...-PACKAGING MATERIAL General Provisions § 109.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
21 CFR 509.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Added poisonous or deleterious substances. 509.6...-PACKAGING MATERIAL General Provisions § 509.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
7 CFR 58.727 - Adding optional ingredients.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 3 2011-01-01 2011-01-01 false Adding optional ingredients. 58.727 Section 58.727... Procedures § 58.727 Adding optional ingredients. As each batch is added to the cooker, the predetermined amounts of salt, emulsifiers, color, or other allowable optional ingredients shall be added. However,...
37 CFR 2.98 - Adding party to interference.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...
7 CFR 58.727 - Adding optional ingredients.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 3 2010-01-01 2010-01-01 false Adding optional ingredients. 58.727 Section 58.727... Procedures § 58.727 Adding optional ingredients. As each batch is added to the cooker, the predetermined amounts of salt, emulsifiers, color, or other allowable optional ingredients shall be added. However,...
37 CFR 2.98 - Adding party to interference.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...
7 CFR 58.727 - Adding optional ingredients.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 3 2012-01-01 2012-01-01 false Adding optional ingredients. 58.727 Section 58.727... Procedures § 58.727 Adding optional ingredients. As each batch is added to the cooker, the predetermined amounts of salt, emulsifiers, color, or other allowable optional ingredients shall be added. However,...
21 CFR 109.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Added poisonous or deleterious substances. 109.6...-PACKAGING MATERIAL General Provisions § 109.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
7 CFR 58.727 - Adding optional ingredients.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 3 2014-01-01 2014-01-01 false Adding optional ingredients. 58.727 Section 58.727... Procedures § 58.727 Adding optional ingredients. As each batch is added to the cooker, the predetermined amounts of salt, emulsifiers, color, or other allowable optional ingredients shall be added. However,...
37 CFR 2.98 - Adding party to interference.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...
37 CFR 2.98 - Adding party to interference.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...
21 CFR 109.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Added poisonous or deleterious substances. 109.6...-PACKAGING MATERIAL General Provisions § 109.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
21 CFR 509.6 - Added poisonous or deleterious substances.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Added poisonous or deleterious substances. 509.6...-PACKAGING MATERIAL General Provisions § 509.6 Added poisonous or deleterious substances. (a) Use of an added... approved under the criteria of section 409 of the act, or when the added poisonous or deleterious...
Vacuum currents in braneworlds on AdS bulk with compact dimensions
NASA Astrophysics Data System (ADS)
Bellucci, S.; Saharian, A. A.; Vardanyan, V.
2015-11-01
The two-point function and the vacuum expectation value (VEV) of the current density are investigated for a massive charged scalar field with arbitrary curvature coupling in the geometry of a brane on the background of AdS spacetime with partial toroidal compactification. The presence of a gauge field flux, enclosed by compact dimensions, is assumed. On the brane the field obeys Robin boundary condition and along compact dimensions periodicity conditions with general phases are imposed. There is a range in the space of the values for the coefficient in the boundary condition where the Poincaré vacuum is unstable. This range depends on the location of the brane and is different for the regions between the brane and AdS boundary and between the brane and the horizon. In models with compact dimensions the stability condition is less restrictive than that for the AdS bulk with trivial topology. The vacuum charge density and the components of the current along non-compact dimensions vanish. The VEV of the current density along compact dimensions is a periodic function of the gauge field flux with the period equal to the flux quantum. It is decomposed into the boundary-free and brane-induced contributions. The asymptotic behavior of the latter is investigated near the brane, near the AdS boundary and near the horizon. It is shown that, in contrast to the VEVs of the field squared an denergy-momentum tensor, the current density is finite on the brane and vanishes for the special case of Dirichlet boundary condition. Both the boundary-free and brane-induced contributions vanish on the AdS boundary. The brane-induced contribution vanishes on the horizon and for points near the horizon the current is dominated by the boundary-free part. In the near-horizon limit, the latter is connected to the corresponding quantity for a massless field in the Minkowski bulk by a simple conformal relation. Depending on the value of the Robin coefficient, the presence of the brane can either
Planar AdS black holes in Lovelock gravity with a nonminimal scalar field
NASA Astrophysics Data System (ADS)
Gaete, Moisés Bravo; Hassaïne, Mokhtar
2013-11-01
In arbitrary dimension D, we consider a self-interacting scalar field nonminimally coupled with a gravity theory given by a particular Lovelock action indexed by an integer k. To be more precise, the coefficients appearing in the Lovelock expansion are fixed by requiring the theory to have a unique AdS vacuum with a fixed value of the cosmological constant. This yields to k = 1, 2,⋯, inequivalent possible gravity theories; here the case k = 1 corresponds to the standard Einstein-Hilbert Lagrangian. For each par ( D, k), we derive two classes of AdS black hole solutions with planar event horizon topology for particular values of the nonminimal coupling parameter. The first family of solutions depends on a unique constant and is valid only for k ≥ 2. In fact, its GR counterpart k = 1 reduces to the pure AdS metric with a vanishing scalar field. The second family of solutions involves two independent constants and corresponds to a stealth black hole configuration; that is a nontrivial scalar field together with a black hole metric such that both side of the Einstein equations (gravity and matter parts) vanishes identically. In this case, the standard GR case k = 1 reduces to the Schwarzschild-AdS-Tangherlini black hole metric with a trivial scalar field. We show that the two-parametric stealth solution defined in D dimension can be promoted to the uniparametric black hole solution in ( D + 1) dimension by fixing one of the two constants in term of the other and by adding a transversal coordinate. In both cases, the existence of these solutions is strongly inherent of the presence of the higher order curvature terms k ≥ 2 of the Lovelock gravity. We also establish that these solutions emerge from a stealth configuration defined on the pure AdS metric through a Kerr-Schild transformation. Finally, in the last part, we include multiple exact ( D - 1) - forms homogenously distributed and coupled to the scalar field. For a specific coupling, we obtain black hole
'Abd al-Rahman al-Sufi's 3-Step Magnitude System
NASA Astrophysics Data System (ADS)
Hafez, Ihsan; Stephenson, F. Richard; Orchiston, Wayne
'Abd al-Rahmān al-ūfī's Book of the Fixed Stars dates from around AD 964 and is one of the most important medieval Arabic treatises on astronomy. In this paper we begin with a very brief introduction to the Book of the Fixed Stars. This book contains an extensive star catalogue that lists star coordinates and magnitude estimates for all of the Ptolemaic stars. However, in his book al-hūfī utilized three distinct intermediate magnitude values whereas Ptolemy only mentioned two. We believe that al-hūfī used what we have termed a '3-step intermediate magnitude system,' which is more accurate than Ptolemy's 2-step intermediate system. In this paper we examine in detail the accuracy of this unique 3-step system in comparison with Ptolemy's and modern magnitude values.
Interpolated Sounding Value-Added Product
Troyan, D
2013-04-01
The Interpolated Sounding (INTERPSONDE) value-added product (VAP) uses a combination of observations from radiosonde soundings, the microwave radiometer (MWR), and surface meteorological instruments in order to define profiles of the atmospheric thermodynamic state at one-minute temporal intervals and a total of at least 266 altitude levels. This VAP is part of the Merged Sounding (MERGESONDE) suite of VAPs. INTERPSONDE is the profile of the atmospheric thermodynamic state created using the algorithms of MERGESONDE without including the model data from the European Centre for Medium-range Weather Forecasting (ECMWF). More specifically, INTERPSONDE VAP represents an intermediate step within the larger MERGESONDE process.
Noncommutative q -photon-added coherent states
NASA Astrophysics Data System (ADS)
Dey, Sanjib; Hussin, Véronique
2016-05-01
We construct the photon-added coherent states of a noncommutative harmonic oscillator associated to a q -deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher-order quadrature squeezing, namely, the Hillery type and the Hong-Mandel type, and second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. Also, we compare the behavior of different types of quadrature and photon number squeezing of our system with those of the ordinary harmonic oscillator by considering the same set of parameters.
Adding control to arbitrary unknown quantum operations
Zhou, Xiao-Qi; Ralph, Timothy C.; Kalasuwan, Pruet; Zhang, Mian; Peruzzo, Alberto; Lanyon, Benjamin P.; O'Brien, Jeremy L.
2011-01-01
Although quantum computers promise significant advantages, the complexity of quantum algorithms remains a major technological obstacle. We have developed and demonstrated an architecture-independent technique that simplifies adding control qubits to arbitrary quantum operations—a requirement in many quantum algorithms, simulations and metrology. The technique, which is independent of how the operation is done, does not require knowledge of what the operation is, and largely separates the problems of how to implement a quantum operation in the laboratory and how to add a control. Here, we demonstrate an entanglement-based version in a photonic system, realizing a range of different two-qubit gates with high fidelity. PMID:21811242
Ad Hoc Networks: Headline 2000 Communications Analysis
NASA Astrophysics Data System (ADS)
Blair, W. D.; Reynolds, A. B.
2002-06-01
This report examines unit location data and terrain from Headline 2000 to investigate communications networks within the maneuver units. Within the Enhanced Combat Force timeframe, such units would be supported by a Tactical Data Distribution Sub-system (TDDS). This is envisaged as an ad hoc network changing its topology as units maneuver across the battlespace. The report describes approaches that can be applied to Headline 2000 and other data to characterize the nature of the network topology, both statically and as it changes over time, in order to explore the impact on the TDDS network capacity and hence to hence to assist in elucidating consequent requirements of a candidate TDDS.
The future of the cern ad infrastructures in the context of elena machine design and integration
NASA Astrophysics Data System (ADS)
Bartmann, W.; Belochitskii, P.; Butin, F.; Carli, C.; Choisnet, O.; Eriksson, T.; Kersevan, R.; Maridor, S.; Maury, S.; Tranquille, G.
2014-06-01
ELENA will lower the energy of AD antiprotons from 5MeV to 100keV, thus increasing by a factor of up to 100 the number of antiprotons usable by the experiments (Oelert et al. 2014). The AD infrastructures must be adapted to cope with another 20 years of low energy antiproton physics. To fit the ELENA ring in the already crowded AD hall, old kicker generators must be relocated to a new technical building, existing and new services and racks must be re-arranged also at height, preserving access and maintenance capabilities. The ELENA beam will be delivered to existing experiments via new transfer lines without compromising the possibility to maintain a visitors path to this very popular place at CERN.
B₂O₃-added lithium aluminium germanium phosphate solid electrolyte for Li-O₂ rechargeable batteries.
Jadhav, Harsharaj S; Kalubarme, Ramchandra S; Jang, Seong-Yong; Jung, Kyu-Nam; Shin, Kyoung-Hee; Park, Chan-Jin
2014-08-14
B2O3-added Li(1.5)Al(0.5)Ge(1.5)(PO4)3 (LAGP) glass ceramics showing a room temperature ionic conductivity of 0.67 mS cm(-1) have been synthesized by using a melt-quenching method. The prepared glass ceramics are observed to be stable in tetraethylene glycol dimethyl ether containing lithium bis(trifluoromethane) sulfonamide. The augmented conductivity of the B2O3-added LAGP glass ceramic has improved the plateau potential during discharge. Furthermore, the B2O3-added LAGP glass ceramics are successfully employed as a solid electrolyte in a Li-O2 battery to obtain a stable cycling lifetime of up to 15 cycles with the limited capacity protocol. PMID:24953185
López-Campos, Ó; Bodas, R; Prieto, N; Frutos, P; Andrés, S; Giráldez, F J
2011-04-01
Twenty-four Merino lambs (mean BW 15.4 ± 0.13 kg, 6 to 7 wk old) were used to study the effects of the addition of 0 (control), 100 (V10), and 200 (V20) g of vinasse per kilgram of concentrate on intake, animal performance, biochemical blood profile, and carcass and meat characteristics. Lambs were assigned to 1 of 3 experimental diets and fed barley straw and the corresponding concentrate ad libitum. When the animals reached 25 kg of BW, a sample of blood was taken and the lambs were slaughtered. Feed intake, growth rate, biochemical blood profile, and carcass and meat characteristics were assessed. Lambs that received the concentrates with vinasse showed a reduced concentrate intake (linear contrast, P = 0.029) and ADG (linear contrast, P = 0.004) and an increased length of fattening period (linear contrast, P = 0.002) as well as feed:gain ratio (linear contrast P = 0.011). Vinasse enhanced ruminal pH (orthogonal contrast control vs. V10 + V20; P = 0.007). Plasma glucose concentrations declined in lambs fed vinasse (linear contrast, P = 0.003), whereas plasma urea concentration increased in animals fed vinasse (linear contrast, P = 0.036). The plasma concentrations of creatinine, triglycerides, and lactate and the enzyme profile studied (alkaline phosphate, alanine transaminase, glutamate oxal-acetate transaminase, γ-glutamyl transpeptidase, and lactate dehydrogenase) were not modified in response to vinasse inclusion. Lambs in the vinasse groups had less Na(+) and nitrate and greater K(+) and nitrite plasma concentrations (linear contrasts, P < 0.05). None of the carcass characteristics studied was affected by vinasse (P > 0.10). Meat chemical composition and characteristics were unaffected (P > 0.10), but shear force was greater for lambs that received vinasse (orthogonal contrast, control vs. V10 + V20, P = 0.007). The addition of 100 or 200 g vinasse/kg of concentrate for fattening lambs reduced feed intake and growth rate and increased the feed:gain ratio
NASA Astrophysics Data System (ADS)
Sarkar, Madhuchhanda; Dana, Kausik; Das, Sukhen
2015-10-01
This work aims to investigate the microstructural and phase evolution of alkali activated metakaolin products with different activators and added aluminosilicate filler phases. The added filler phases have different reactivity to the alkali activated metakaolin system. Microstructural evolution in the alkali activated products has been investigated by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscope (FESEM). Variation in strength development in alkali activated metakaolin products was followed by compressive strength measurement test. Microstructural study shows that in case of metakaolin with NaOH activator crystalline sodalite formed in all the product samples irrespective of the added filler phases. The microstructure of these NaOH activated products investigated by FESEM showed crystalline and inhomogeneous morphology. Mixed activator containing both NaOH and sodium silicate in a fixed mass ratio formed predominantly amorphous phase. Microstructure of these samples showed more homogeneity than that of NaOH activated metakaolin products. The study further shows that addition of α-Al2O3 powder, non reactive phase to the alkali activated metakaolin system when used in larger amount increased crystalline phase in the matrix. α-Al2O3 powder addition increased the compressive strength of the product samples for both the activator compositions. Added phase of colloidal silica, reactive to the alkali activated metakaolin system when used in larger amount was found to increase amorphous nature of the matrix. Addition of colloidal silica influenced the compressive strength property differently with different activator compositions.
POSSIBLE CHROMOSPHERIC ACTIVITY CYCLES IN AD LEO
Buccino, Andrea P.; Petrucci, Romina; Mauas, Pablo J. D.; Jofré, Emiliano
2014-01-20
AD Leo (GJ 388) is an active dM3 flare star that has been extensively observed both in the quiescent and flaring states. Since this active star is near the fully convective boundary, studying its long-term chromospheric activity in detail could be an appreciable contribution to dynamo theory. Here, using the Lomb-Scargle periodogram, we analyze the Ca II K line-core fluxes derived from CASLEO spectra obtained between 2001 and 2013 and the V magnitude from the ASAS database between 2004 and 2010. From both of these totally independent time series, we obtain a possible activity cycle with a period of approximately seven years and a less significant shorter cycle of approximately two years. A tentative interpretation is that a dynamo operating near the surface could be generating the longer cycle, while a second dynamo operating in the deep convection zone could be responsible for the shorter one. Based on the long duration of our observing program at CASLEO and the fact that we observe different spectral features simultaneously, we also analyze the relation between simultaneous measurements of the Na I index (R{sub D}{sup ′}), Hα, and Ca II K fluxes at different activity levels of AD Leo, including flares.
NASA Astrophysics Data System (ADS)
Fischetti, Sebastian; Marolf, Donald; Santos, Jorge
2013-04-01
We construct stationary non-equilibrium black funnels locally asymptotic to global AdS4 in vacuum Einstein-Hilbert gravity with negative cosmological constant. These are non-compactly-generated black holes in which a single connected bulk horizon extends to meet the conformal boundary. Thus the induced (conformal) boundary metric has smooth horizons as well. In our examples, the boundary spacetime contains a pair of black holes connected through the bulk by a tubular bulk horizon. Taking one boundary black hole to be hotter than the other (δT !=0) prohibits equilibrium. The result is a so-called flowing funnel, a stationary bulk black hole with a non-Killing horizon that may be said to transport heat toward the cooler boundary black hole. While most of our results are numerical, a semi-analytic fluid/gravity description can be obtained by passing to a one-parameter generalization of the above boundary conditions. In the fluid regime, we find excellent agreement with our numerical solutions. In terms of a dual CFT, our solutions describe heat transport via a large N version of Hawking radiation through a deconfined plasma that couples efficiently to both boundary black holes.
Variations of 14C around AD 775 and AD 1795 - due to solar activity
NASA Astrophysics Data System (ADS)
Neuhäuser, R.; Neuhäuser, D. L.
2015-12-01
The motivation for our study is the disputed cause for the strong variation of 14C around AD 775. Our method is to compare the 14C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects, (i) very strong activity in the previous cycles (i.e. very low 14C level), (ii) the declining phase of a very strong Schwabe cycle, and (iii) a phase of very weak activity after the strong 14C rise - very short and/or weak cycle(s) like the suddenly starting Dalton minimum. (d) Furthermore, we can show that the strong change at AD 1795 happened after a pair of two packages of four Schwabe cycles with certain hemispheric leadership (each package consists of two Gnevyshev-Ohl pairs, respectively two Hale-Babcock pairs). We show with several additional arguments that the rise around AD 775 was not that special. We conclude that such large, short-term rises in 14C (around BC 671, AD 775, and 1795) do not need to be explained by highly unlikely solar super-flares nor other rare events, but by extra-solar cosmic rays modulated due to solar activity variations.
From the generalized uncertainty relations on fuzzy AdS 2 to the Poincaré geometry
NASA Astrophysics Data System (ADS)
Fakhri, H.; Hashemi, A.; Lotfizadeh, M.
2012-03-01
The positive and discrete unitary irreps of SU(1,1) are used to construct fuzzy (Euclidean) AdS 2. Two different types of uncertainty relation involving the Weyl-Heisenberg and a weaker type are studied. It is shown that there are no generalized coherent states which simultaneously minimize the Weyl-Heisenberg uncertainty relations among three non-commuting embedding coordinates of the fuzzy AdS 2. However, generalized squeezed states that simultaneously satisfy the three weaker uncertainty relations do exist, and reproduce some properties of the classical AdS 2. Up to a common scaling factor in terms of the irrep label, the expectation values of the non-commuting coordinates over such states are described in the same manner as the classical AdS 2, in terms of the Poincaré coordinates. The expectation values on the fuzzy AdS 2 tend to their corresponding values in the commutative limit.
CFT adapted gauge invariant formulation of arbitrary spin fields in AdS and modified de Donder gauge
NASA Astrophysics Data System (ADS)
Metsaev, R. R.
2009-01-01
Using Poincaré parametrization of AdS space, we study totally symmetric arbitrary spin massless fields in AdS space of dimension greater than or equal to four. CFT adapted gauge invariant formulation for such fields is developed. Gauge symmetries are realized similarly to the ones of Stueckelberg formulation of massive fields. We demonstrate that the curvature and radial coordinate contributions to the gauge transformation and Lagrangian of the AdS fields can be expressed in terms of ladder operators. Realization of the global AdS symmetries in the conformal algebra basis is obtained. Modified de Donder gauge leading to simple gauge fixed Lagrangian is found. The modified de Donder gauge leads to decoupled equations of motion which can easily be solved in terms of the Bessel function. Interrelations between our approach to the massless AdS fields and the Stueckelberg approach to massive fields in flat space are discussed.
NASA Astrophysics Data System (ADS)
Colucci, Frank
1987-10-01
The Advanced Launch System (ALS) development program will avail itself of existing technologies in the short term in order to produce an interim 'core' vehicle that may be operational by 1993; the full, booster-incorporating system objective will then be achieved in 1998. This programmatic 'decoupling' of booster and core vehicle development efforts will separate their funding peaks. The ALS program will cut costs by colocating manufacturing and launch facilities, using Al-Li alloys in booster primary structures, and aggressively applying 'paperless' CIM. The ALS launch vehicle configuration will be primarily determined by both payload requirements and flight frequency.
Duthie, C-A; Rooke, J A; Troy, S; Hyslop, J J; Ross, D W; Waterhouse, A; Roehe, R
2016-05-01
Adding nitrate to the diet or increasing the concentration of dietary lipid are effective strategies for reducing enteric methane emissions. This study investigated their effect on health and performance of finishing beef cattle. The experiment was a two×two×three factorial design comprising two breeds (CHX, crossbred Charolais; LU, Luing); two basal diets consisting of (g/kg dry matter (DM), forage to concentrate ratios) 520 : 480 (Mixed) or 84 : 916 (Concentrate); and three treatments: (i) control with rapeseed meal as the main protein source replaced with either (ii) calcium nitrate (18 g nitrate/kg diet DM) or (iii) rapeseed cake (RSC, increasing acid hydrolysed ether extract from 25 to 48 g/kg diet DM). Steers (n=84) were allocated to each of the six basal diet×treatments in equal numbers of each breed with feed offered ad libitum. Blood methaemoglobin (MetHb) concentrations (marker for nitrate poisoning) were monitored throughout the study in steers receiving nitrate. After dietary adaptation over 28 days, individual animal intake, performance and feed efficiency were recorded for a test period of 56 days. Blood MetHb concentrations were low and similar up to 14 g nitrate/kg diet DM but increased when nitrate increased to 18 g nitrate/kg diet DM (P0.05). Neither basal diet nor treatment affected carcass quality (P>0.05), but CHX steers achieved a greater killing out proportion (P<0.001) than LU steers. Thus, adding nitrate to the diet or increasing the level of dietary lipid through the use of cold-pressed RSC, did not adversely affect health or performance of finishing beef steers when used within the diets studied. PMID:26627142
Mechanism of Corrosion in Al-Si-Cu
NASA Astrophysics Data System (ADS)
Hayasaka, Nobuo; Koga, Yuri; Shimomura, Koji; Yoshida, Yukimasa; Okano, Haruo
1991-07-01
An Al-Cu local cell was formed between the Cu precipitation and adjacent Al in an Al-Si-Cu alloy when Cu was added in excess to the alloy. Once an Al-Cu local cell was formed, corrosion took place simply by dipping the alloy in deionized water without any contamination. Furthermore, it was found that corrosion was enhanced at the Al-Si-Cu lines in contact with the p+-n junction of Si. The reason for this is that holes are injected into Al-Si-Cu from p+-Si due to electromotive force produced by light irradiation and an external circuit connecting the alloy and n-Si formed by the adsorption of moisture on the surface. Furthermore, it was found that the irradiation of light with a wavelength between 320 to 380 nm was most effective in enhancing the corrosion reaction.
Gravitational wave solutions in string and M-theory AdS backgrounds
Kumar, Alok; Kunduri, Hari K.
2004-11-15
In this paper, we present several gravitational wave solutions in AdS{sub 5}xS{sup 5} string backgrounds, as well as in AdS{sub 7}xS{sup 4} and AdS{sub 4}xS{sup 7} backgrounds in M theory, generalizing the results of Phys. Lett. B 594, 368 (2004).. In each case, we present the general form of such solutions and give explicit examples, preserving certain amount of supersymmetry, by taking limits on known Bogomol'nyi-Prasad-Sommerfield D3 and M2, M5-brane solutions in pp-wave backgrounds. A key feature of our examples is the possibility of a wider variety of wave profiles, than in pure gravity and string/M-theory examples known earlier, coming from the presence of various p-form field strengths appearing in the gravitational wave structure.
3D τ RR -minimization in AdS4 gauged supergravity
NASA Astrophysics Data System (ADS)
Amariti, Antonio; Gnecchi, Alessandra
2016-07-01
In this paper we propose the identification in AdS4 N = 2 gauged supergravity of the coefficient τRR of 3D N = 2 SCFTs. We constrain the structure of this function in supergravity by combining the results from unitarity, holography and localization. We show that our conjectured function is minimized by the exact R-charge, corresponding to a gravitational attractor for the scalars of special geometry. We identify this mechanism with the supergravity dual of τ RR -minimization. We check this proposal in ABJM model, comparing with expectations from localization and AdS/CFT duality. We comment also on possible relations with black hole microstates counting, recently obtained from application of localization techniques.
Non-minimally coupled pseudoscalars in AdS4 for instantons in CFT3
NASA Astrophysics Data System (ADS)
Naghdi, M.
2016-06-01
For the 11-dimensional supergravity over {{{AdS}}}4× {{{S}}}7/{Z}k, beginning with a general four-form ansatz and the main geometry unchanged, we get a tower of massive and tachyonic pseudoscalars. Indeed, the resultant equations can be assigned to the so-called {φ }4 actions of the non-minimally coupled scalar-tensor theories with a cosmological constant. We focus on a well-known tachyonic and a new massive bulk mode, which are singlet under the internal group and break all supersymmetries, associated with skew-whiffing and Wick-rotating of the background four-form flux, respectively. The first one is the conformally coupled {m}2=-2 pseudoscalar in the bulk of Euclidean AdS4, where an exact instanton solution is found and a marginally triple-trace deformation with a proper dimension-1 operator produces an agreeing boundary solution with finite action. From the action evaluated on the solution, we estimate the decay rate of the vacuum tunneling mediated by the instanton. Another massive {m}2=+4 mode, with the so-called non-minimal coupling parameter ξ =-1/3, also breaks the conformal invariance and so there is no exact solution. Then, based on the AdS4/CFT3 correspondence rules, we propose the dimension-4 ({{{Δ }}}+=+4) boundary operator in the skew-whiffed (anti-M2-branes) theory with which to deform the boundary action—consisting of a singlet fermion, an original scalar and U(1) gauges fields—and find some solutions to be matched with the bulk solutions.
Ehrenfest's scheme and thermodynamic geometry in Born-Infeld AdS black holes
NASA Astrophysics Data System (ADS)
Lala, Arindam; Roychowdhury, Dibakar
2012-10-01
In this paper, we analyze the phase transition phenomena in Born-Infeld anti-de Sitter (BI AdS) black holes using Ehrenfest’s scheme of standard thermodynamics. The critical points are marked by the divergences in the heat capacity. In order to investigate the nature of the phase transition, we analytically check both Ehrenfest equations near the critical points. Our analysis reveals that this is indeed a second order phase transition. Finally, we analyze the nature of the phase transition using the state space geometry approach. This is found to be compatible with Ehrenfest’s scheme.
Warped AdS3 black holes in higher derivative gravity theories
NASA Astrophysics Data System (ADS)
Detournay, Stéphane; Douxchamps, Laure-Anne; Ng, Gim Seng; Zwikel, Céline
2016-06-01
We consider warped AdS3 black holes in generic higher derivatives gravity theories in 2+1 dimensions. The asymptotic symmetry group of the phase space containing these black holes is the semi-direct product of a centrally extended Virasoro algebra and an affine u(1) Kac-Moody algebra. Previous works have shown that in some specific theories, the entropy of these black holes agrees with a Cardy-like entropy formula derived for warped conformal field theories. In this paper, we show that this entropy matching continues to hold for the most general higher derivative theories of gravity. We also discuss the existence of phase transitions.
Small black holes in AdS5 × S5
NASA Astrophysics Data System (ADS)
Buchel, Alex; Lehner, Luis
2015-07-01
We consider small black holes in {{AdS}}5× {S}5, smeared on S5. We compute the spectrum of {\\ell } \\in [1, 10] S5-quasinormal modes corresponding to fluctuations leading to localization of these black holes on S5. We recover the zero mode found by Hubeny and Rangamani previously (Hubeny and Rangamani 2002 J. High Energy Phys. JHEP05(2002)027), and explicitly demonstrate that a Gregory-Laflamme type instability is at play in this system. The instability is associated with the expectation value of a dimension-5 operator.
Giant magnon on deformed AdS3×S3
NASA Astrophysics Data System (ADS)
Khouchen, Malak; KlusoÅ, Josef
2014-09-01
We study giant magnon solutions for strings moving on a deformed AdS3×S3 background. We impose a conformal gauge on the Polyakov action and proceed with solving the Virasoro constraints. The expressions of the conserved charge J and the energy of a single magnon excitation are then computed. Then we determine the dispersion relation of a giant magnon in the infinite J limit configuration and we find that for κ =0 it reduces to the celebrated Hofman-Maldacena dispersion relation.
- criticality of AdS black hole in the Einstein-Maxwell-power-Yang-Mills gravity
NASA Astrophysics Data System (ADS)
Zhang, Ming; Yang, Zhan-Ying; Zou, De-Cheng; Xu, Wei; Yue, Rui-Hong
2015-02-01
We study the - critical behaivor of N-dimensional AdS black holes in Einstein-Maxwell-power-Yang-Mills gravity. Our results show the existence of the Van der Waals like small-large black hole phase transitions when taking some special values of charges of the Maxwell and Yang-Mills fields. Further to calculate the critical exponents of the black holes at the critical point, we find that they are the same as those in the Van der Waals liquid-gas system.
Emergent AdS3 in the zero entropy extremal black holes
NASA Astrophysics Data System (ADS)
Azeyanagi, Tatsuo; Ogawa, Noriaki; Terashima, Seiji
2011-03-01
We investigate the zero entropy limit of the near horizon geometries of D = 4 and D = 5 general extremal black holes with {text{SL}}left( {2,mathbb{R}} right) × {text{U}}{(1)^{D - 3}} symmetry. We derive some conditions on the geometries from expectation of regularity. We then show that an AdS3 structure emerges in a certain scaling limit, though the periodicity shrinks to zero. We present some examples to see the above concretely. We also comment on some implications to the Kerr/CFT correspondence.
Integrable λ-deformations: squashing coset CFTs and AdS5 × S 5
NASA Astrophysics Data System (ADS)
Demulder, Saskia; Sfetsos, Konstantinos; Thompson, Daniel C.
2015-07-01
We examine integrable λ-deformations of SO( n + 1) /SO( n) coset CFTs and their analytic continuations. We provide an interpretation of the deformation as a squashing of the corresponding coset σ-model's target space. We realise the λ-deformation for n = 5 case as a solution to supergravity supported by non-vanishing five-form and dilaton. This interpolates between the coset CFT SO(4 , 2) /SO(4 , 1) × SO(6) /SO(5) constructed as a gauged WZW model and the non-Abelian T-dual of the AdS5 × S 5 spacetime.
Art as an Evolutionary Adaptation: Inspiration from the Visible Supernovae of AD 1054 and AD 3054
NASA Astrophysics Data System (ADS)
Corbally, C. J.; Rappaport, M. B.
2016-01-01
The authors, an astronomer/priest and an anthropologist/biologist, describe their use of the dramatic arts at the INSAP VIII meeting in their performance of two short skits on the sighting of a supernova in AD 1054 (creating the beautiful Crab Nebula) and a future “Rho Cas” stellar explosion in the constellation Cassiopeia, in AD 3054. They speculate on the emergence of science, religion, and art as bona fide adaptations, responding to natural selection, which served early hominins well in their struggle for existence. They draw parallels to the continued functions of science, religion, and art in modern society.
Spin Filtering Studies at COSY and AD
Nass, Alexander
2009-08-04
The high physics potential of experiments with stored high-energy polarized antiprotons led to the proposal of PAX (Polarized Antiproton eXperiment) for the High Energy Storage Ring (HESR) of the FAIR at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin filtering with a polarized H (D) gas target. The feasibility of spin filtering has been demonstrated in the FILTEX experiment. The current interpretation foresees a self-cancellation of the electron contribution to the filtering process and only the hadronic contribution is effective. Several experimental studies with protons (at COSY/Juelich) as well as antiprotons (at AD/CERN) will be carried out to test the principle and measure p-barp-vector and p-bard-vector cross sections. A polarized internal gas target (PIT) with surrounding Silicon detectors immersed into a low-beta section has to be set up.
Scientific Publishing: Adding Value, Delivering Impact
NASA Astrophysics Data System (ADS)
Mayes, Beth
2015-08-01
Publishers are developing new services and applying new technologies to improve publication and reading experiences for the scholarly community. This needs to be implemented with care to avoid adding technology-driven complexity. Our publishing processes need to be widely accessible to both authors and readers and to maintain the scientific record. Beth Mayes will outline new developments at IOP Publishing delivering (1) improvements to the presentation of articles and their commitment to formats that go beyond the PDF, improving the understanding of research. (2) How IOP Publishing is responding to the growing calls for metadata and linking that involve being central to the shared information ecosystem for astronomy. (3) After publication, discuss how publishers invest in metrics and new initiatives for discovery that improve the impact of published research.
Worm epidemics in wireless ad hoc networks
NASA Astrophysics Data System (ADS)
Nekovee, Maziar
2007-06-01
A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.
[Did Henrik Wergeland have AD/HD?].
Aanonsen, Nils Olav
2008-12-18
Henrik Wergeland (1808 - 45) is one of Norwegian cultural history's most notable figures. He is honoured as a national symbol during this year's 200-year jubilee for his birth. Biographies and numerous academic publications have been written about him for more than 100 years. His life was short and diverse; on one hand he continuously worked to give people general education, he was an author and a poet and on the other hand he was always in a dispute with someone and involved in endless court cases and scandals. After his death it was said that Wergeland was one who
Adding fuel to the fire: immunogenic intensification.
O'Sullivan Coyne, Geraldine; Gulley, James L
2014-01-01
The durable long term clinical benefits seen for certain patients treated with immunotherapy agents has suggested there is significant therapeutic potential to be derived from these agents, as shown by the increasing prominence of this treatment strategy in upcoming clinical trials. There has been a renewed interest and focus on the drivers of tumoral antigen recognition, and the pathways by which various cells of the immune system can stimulate, propagate and execute an effective anti-tumor response. Various challenges lie ahead in the further development of these treatments, including induction of an endogenous anti-tumor response, tumor microenvironment modulation, and T-cell response amplification. Novel treatment combinations may prove of significant added benefit by immunogenic intensification. PMID:25483630
Aerosol Best Estimate Value-Added Product
Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C
2012-07-19
The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.
Droplet Number Concentration Value-Added Product
Riihimaki, L.; McFarlane, S.; Sivaraman, C.
2014-06-01
The ndrop_mfrsr value-added product (VAP) provides an estimate of the cloud droplet number concentration of overcast water clouds retrieved from cloud optical depth from the multi-filter rotating shadowband radiometer (MFRSR) instrument and liquid water path (LWP) retrieved from the microwave radiometer (MWR). When cloud layer information is available from vertically pointing lidar and radars in the Active Remote Sensing of Clouds (ARSCL) product, the VAP also provides estimates of the adiabatic LWP and an adiabatic parameter (beta) that indicates how divergent the LWP is from the adiabatic case. quality control (QC) flags (qc_drop_number_conc), an uncertainty estimate (drop_number_conc_toterr), and a cloud layer type flag (cloud_base_type) are useful indicators of the quality and accuracy of any given value of the retrieval. Examples of these major input and output variables are given in sample plots in section 6.0.
MR enterography: how to deliver added value.
Dillman, Jonathan R; Trout, Andrew T; Smith, Ethan A
2016-05-01
MR enterography (MRE) is increasingly vital to the diagnosis and follow-up of children with Crohn disease. This diagnostic test, which can provide valuable information regarding the presence of intestinal inflammation, intestinal and intra-abdominal complications, and extra-intestinal disease-related manifestations, has the potential to directly impact both medical and surgical decision-making. Consequently, it is imperative that the interpretation and reporting of these examinations provide as much clinical information as possible. This article reviews specific ways radiologists can provide added value when interpreting MRE examinations in the setting of pediatric Crohn disease by (1) establishing the true extent of disease involvement, (2) subjectively and objectively assessing response to medical treatment and (3) accurately characterizing disease-related complications. PMID:26939974
Chhabildas, L.C.; Furnish, M.D.; Reinhart, W.D.; Grady, D.E.
1997-10-01
Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.
Declarative ad-hoc sensor networking
NASA Astrophysics Data System (ADS)
Coffin, Daniel A.; Van Hook, Daniel J.; McGarry, Stephen M.; Kolek, Stephen R.
2000-11-01
Networking protocols for distributed collaborative ad-hoc wireless sensing are constrained by requirements such as energy efficiency, scalability, and support for greater variations in topology than traditional fully wired or last- hop wireless (remote to base station) networks. In such a highly constrained and dynamic environment, conventional networking approaches are generally not adequate. A declarative approach to network configuration and organization appears to offer significant benefits. Declarative networking exploits application-supplied data descriptions to control network routing and resource allocation in such a way as to enhance energy efficiency and scalability. An implementation of this approach, called the Declarative Routing Protocol (DRP) has been developed as part of DARPA's Sensor Information Technology program. This paper introduces the concept of declarative networking and what distinguishes it from more conventional networking approaches, describes the Declarative Routing Protocol, and presents performance results from initial experiments.
Frozen yogurt with added inulin and isomalt.
Isik, U; Boyacioglu, D; Capanoglu, E; Erdil, D Nilufer
2011-04-01
The objective of this study was to produce a frozen yogurt containing low fat and no added sugar. Samples containing 5% polydextrose, 0.065% aspartame and acesulfame-K mixture, and different levels of inulin and isomalt (5.0, 6.5, and 8.0%) were produced at pilot scale and analyzed for their physical and chemical properties including proximate composition, viscosity, acidity, overrun, melting rate, heat shock stability, as well as sensory characteristics, and viability of lactic acid bacteria. With the addition of inulin and isomalt, viscosity increased by 19 to 52% compared with that of sample B (reduced-fat control). The average calorie values of samples substituted with sweeteners were about 43% lower than that of original sample. Low-calorie frozen yogurt samples melted about 33 to 48% slower than the reduced-fat control sample at 45 min. Based on quantitative descriptive profile test results, statistically significant differences among products were observed for hardness, iciness, foamy melting, whey separation, and sweetness characteristics. The results of principal component analysis showed that the sensory properties of the sample containing 6.5% inulin and 6.5% isomalt were similar to those of control. Lactic acid bacteria counts of frozen yogurt were found to be between 8.12 and 8.49 log values, 3 mo after the production. The overall results showed that it is possible to produce an attractive frozen yogurt product with the incorporation of inulin and isomalt with no added sugar and reduced fat. PMID:21426952
NASA Astrophysics Data System (ADS)
Fischetti, Sebastian; Marolf, Donald; Santos, Jorge E.
2013-04-01
We construct stationary non-equilibrium black funnels locally asymptotic to global AdS4 in vacuum Einstein-Hilbert gravity with a negative cosmological constant. These are non-compactly-generated black holes in which a single connected bulk horizon extends to meet the conformal boundary. Thus the induced (conformal) boundary metric has smooth horizons as well. In our examples, the boundary spacetime contains a pair of black holes connected through the bulk by a tubular bulk horizon. Taking one boundary black hole to be hotter than the other (ΔT ≠ 0) prohibits equilibrium. The result is a so-called flowing funnel, a stationary bulk black hole with a non-Killing horizon that may be said to transport heat toward the cooler boundary black hole. While generators of the bulk future horizon evolve toward zero expansion in the far future, they begin at finite affine parameter with infinite expansion on a singular past horizon characterized by power-law divergences with universal exponents. We explore both the horizon generators and the boundary stress tensor in detail. While most of our results are numerical, a semi-analytic fluid/gravity description can be obtained by passing to a one-parameter generalization of the above boundary conditions. The new parameter detunes the temperatures Tbulk BH and Tbndy BH of the bulk and boundary black holes, and we may then take α = {T_{bndy \\ BH}/{T_{bulk \\ BH}} and ΔT small to control the accuracy of the fluid-gravity approximation. In the small α, ΔT regime, we find excellent agreement with our numerical solutions. For our cases the agreement also remains quite good even for α ˜ 0.8. In terms of a dual CFT, our α = 1 solutions describe heat transport via a large N version of Hawking radiation through a deconfined plasma that couples efficiently to both boundary black holes.
Cloud Condensation Nuclei Profile Value-Added Product
McFarlane, S; Sivaraman, C; Ghan, S
2012-10-08
The cloud condensation nuclei (CCN) concentration at cloud base is the most relevant measure of the aerosol that influences droplet formation in clouds. Since the CCN concentration depends on supersaturation, a more general measure of the CCN concentration is the CCN spectrum (values at multiple supersaturations). The CCN spectrum is now measured at the surface at several fixed ARM sites and by the ARM Mobile Facility (AMF), but is not measured at the cloud base. Rather than rely on expensive aircraft measurements for all studies of aerosol effects on clouds, a way to project CCN measurements at the surface to cloud base is needed. Remote sensing of aerosol extinction provides information about the vertical profile of the aerosol, but cannot be directly related to the CCN concentration because the aerosol extinction is strongly influenced by humidification, particularly near cloud base. Ghan and Collins (2004) and Ghan et al. (2006) propose a method to remove the influence of humidification from the extinction profiles and tie the “dry extinction” retrieval to the surface CCN concentration, thus estimating the CCN profile. This methodology has been implemented as the CCN Profile (CCNPROF) value-added product (VAP).
Lagrangian modelling tool for IAGOS database added-value products
NASA Astrophysics Data System (ADS)
Fontaine, Alain; Auby, Antoine; Petetin, Hervé; Sauvage, Bastien; Thouret, Valérie; Boulanger, Damien
2015-04-01
Since 1994, the IAGOS (In-Service Aircraft for a Global Observing System, http://www.iagos.fr) project has produced in-situ measurements of chemical as ozone, carbon monoxide or nitrogen oxides species through more than 40000 commercial aircraft flights. In order to help analysing these observations a tool which links the observed pollutants to their sources was developped based on the Stohl et al. (2003) methodology. Build on the lagrangian particle dispersion model FLEXPART coupled with ECMWF meteorological fields, this tool simulates contributions of anthropogenic and biomass burning emissions from the ECCAD database, to the measured carbon monoxide mixing ratio along each IAGOS flight. Thanks to automated processes, 20-days backward simulation are run from the observation, separating individual contributions from the different source regions. The main goal is to supply added-value product to the IAGOS database showing pollutants geographical origin and emission type and link trends in the atmospheric composition to changes in the transport pathways and to the evolution of emissions. This tool may also be used for statistical validation for intercomparisons of emission inventories, where they can be compared to the in-situ observations from the IAGOS database.
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Crystalline Al1 - x Ti x phases in the hydrogen cycled NaAlH4 + 0.02TiCl3 system
NASA Astrophysics Data System (ADS)
Pitt, M. P.; Vullum, P. E.; Sørby, M. H.; Emerich, H.; Paskevicius, M.; Buckley, C. E.; Gray, E. MacA.; Walmsley, J. C.; Holmestad, R.; Hauback, B. C.
2013-03-01
The hydrogen (H) cycled planetary milled (PM) NaAlH4 + 0.02TiCl3 system has been studied by high resolution synchrotron X-ray diffraction and transmission electron microscopy during the first 10 H cycles. After the first H absorption, we observe the formation of four nanoscopic crystalline (c-) Ti-containing phases embedded on the NaAlH4 surface, i.e. Al2Ti, Al3Ti, Al82Ti18 and Al89Ti11, with 100% of the originally added Ti atoms accounted for. Al2Ti and Al3Ti are observed morphologically as a mechanical couple on the NaAlH4 surface, with a moderately strained interface. Electron diffraction shows that the Al82Ti18 phase retains some ordering from the L12 structure type, with the observation of forbidden (100) ordering reflections in the fcc Al82Ti18 lattice. After 2 H cycles the NaAlH4 + 0.02TiCl3 system displays only two crystalline Ti-containing phases, Al3Ti and Al89Ti11. After 10 H cycles, the Al89Ti11 is completely converted to Al85Ti15. Al89Ti11, Al85Ti15 and Al3Ti do not display any ordering reflections, and they are modeled in the A1 structure type. Quantitative phase analysis indicates that the Al3Ti proportion continues to increase with further H cycles. The formation of Ti-poor Al1 - x Ti x (x < 0.25) phases in later H cycles is detrimental to hydrogenation kinetics, compared to the starting Ti-richer near-surface Al2Ti/NaAlH4 interface present during the first absorption of hydrogen.
Rabies in medieval Persian literature – the Canon of Avicenna (980–1037 AD)
2014-01-01
Ibn Sina (980–1037 AD), known by his full name Abu Ali al-Hussain ibn Abdallah ibn Sina and the Latin name ‘Avicenna’, was a Persian scholar who is primarily remembered for his contributions to the science of medicine. He authored Al-Qanun fi al-Tibb (The Canon of Medicine). Sections of his work are devoted to detailed descriptions of a number of infectious illnesses, particularly rabies. Avicenna described rabies in humans and animals and explained its clinical manifestations, route of transmission, and treatment methods. In this article, our goal is to discuss Avicenna’s 11th-century points of view on rabies and compare them with modern medical knowledge. PMID:24533686
Secret symmetries of type IIB superstring theory on Ad{{S}_{3}} × {{S}^{3}} × {{M}^{4}}
NASA Astrophysics Data System (ADS)
Pittelli, Antonio; Torrielli, Alessandro; Wolf, Martin
2014-11-01
We establish features of so-called Yangian secret symmetries for AdS3 type IIB superstring backgrounds, thus verifying the persistence of such symmetries to this new instance of the AdS/CFT correspondence. Specifically, we find two a priori different classes of secret symmetry generators. One class of generators, anticipated from the previous literature, is more naturally embedded in the algebra governing the integrable scattering problem. The other class of generators is more elusive and somewhat closer in its form to its higher-dimensional AdS5 counterpart. All of these symmetries respect left-right crossing. In addition, by considering the interplay between left and right representations, we gain a new perspective on the AdS5 case. We also study the RTT-realisation of the Yangian in AdS3 backgrounds, thus establishing a new incarnation of the Beisert-de Leeuw construction.
CFT dual of charged AdS black hole in the large dimension limit
NASA Astrophysics Data System (ADS)
Guo, Er-Dong; Li, Miao; Sun, Jia-Rui
2016-05-01
We study the dual CFT description of the d + 1-dimensional Reissner-Nordström-Anti de Sitter (RN-AdSd+1) black hole in the large dimension (large d) limit, both for the extremal and nonextremal cases. The central charge of the dual CFT2 (or chiral CFT1) is calculated for the near-horizon near extremal geometry which possesses an AdS2 structure. Besides, the Q-picture hidden conformal symmetry in the nonextremal background can be naturally obtained by a probe charged scalar field in the large d limit, without the need to input the usual limits to probe the hidden conformal symmetry. Furthermore, a new dual CFT description of the nonextremal RN-AdSd+1 black hole is found in the large d limit and the duality is analyzed by comparing the entropies, the absorption cross-sections and the retarded Green’s functions obtained both from the gravity and the dual CFT sides.
Quantum compositeness of gravity: black holes, AdS and inflation
Dvali, Gia; Gomez, Cesar
2014-01-14
Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.
Quartic AdS interactions in higher-spin gravity from Conformal Field Theory
NASA Astrophysics Data System (ADS)
Bekaert, X.; Erdmenger, J.; Ponomarev, D.; Sleight, C.
2015-11-01
Clarifying the locality properties of higher-spin gravity is a pressing task, but notoriously difficult due to the absence of a weakly-coupled flat regime. The simplest non-trivial case where this question can be addressed is the quartic self-interaction of the AdS scalar field present in the higher-spin multiplet. We investigate this issue in the context of the holographic duality between the minimal bosonic higher-spin theory on AdS4 and the free O( N) vector model in three dimensions. In particular, we determine the exact explicit form of the derivative expansion of the bulk scalar quartic vertex. The quartic vertex is obtained from the field theory four-point function of the operator dual to the bulk scalar, by making use of our previous results for the Witten diagrams of higher-spin exchanges. This is facilitated by establishing the conformal block expansions of both the boundary four-point function and the dual bulk Witten diagram amplitudes. We show that the vertex we find satisfies a generalised notion of locality.
Exact results for the low energy AdS 4 × 3 string theory
NASA Astrophysics Data System (ADS)
Fabbri, Alessandro; Fioravanti, Davide; Piscaglia, Simone; Tateo, Roberto
2013-11-01
We derive the Thermodynamic Bethe Ansatz equations for the relativistic sigma model describing the AdS 4 × 3 string II A theory at strong coupling (i.e. in the Alday-Maldacena decoupling limit). The corresponding Y -system involves an infinite number of Y functions and is of a new type, although it shares a peculiar feature with the Y -system for AdS 4 × 3. A truncation of the equations at level p and a further generalisation to generic rank N allow us an alternative description of the theory as the N =4, p = ∞ representative in an infinite family of models corresponding to the conformal cosets ( N -1) p × U(1), perturbed by a relevant composite field ϕ ( N,p) = ϕ[( N -1) p ] × ϕ [U(1)] that couples the two independent conformal field theories. The calculation of the ultraviolet central charge confirms the conjecture by Basso and Rej and the conformal dimension of the perturbing operator, at every N and p, is obtained using the Y-system periodicity. The conformal dimension of ϕ[( N -1) p ] matches that of the field identified by Fendley while discussing integrability issues for the purely bosonic N -1 sigma model.
Quasinormal modes and holographic correlators in a crunching AdS geometry
NASA Astrophysics Data System (ADS)
Kumar, S. Prem; Vaganov, Vladislav
2016-02-01
We calculate frequency space holographic correlators in an asymptotically AdS crunching background, dual to a relevant deformation of the M2-brane CFT placed in de Sitter spacetime. For massless bulk scalars, exploiting the connection to a solvable supersymmetric quantum mechanical problem, we obtain the exact frequency space correlator for the dual operator in the deformed CFT. Controlling the shape of the crunching surface in the Penrose diagram by smoothly dialling the deformation from zero to infinity, we observe that in the large deformation limit the Penrose diagram becomes a `square', and the exact holographic correlators display striking similarities to their counterparts in the BTZ black hole and its higher dimensional generalisations. We numerically determine quasinormal poles for relevant and irrelevant operators, and find an intricate pattern of these in the complex frequency plane. In the case of relevant operators, the deformation parameter has an infinite sequence of critical values, each one characterised by a pair of poles colliding and moving away from the imaginary frequency axis with increasing deformation. In the limit of infinite deformation all scalar operators have identical quasinormal spectra. We compare and contrast our strongly coupled de Sitter QFT results with strongly coupled thermal correlators from AdS black holes.
Quantum compositeness of gravity: black holes, AdS and inflation
Dvali, Gia; Gomez, Cesar E-mail: cesar.gomez@uam.es
2014-01-01
Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.
Baldcypress tree ring elemental concentrations at Reelfoot Lake, Tennessee from AD 1795 to AD 1820
Van Arsdale, R.; Hall, G.
1995-11-01
Many two hundred year old baldcypress trees in Reelfoot Lake, Tennessee, lived through the great New Madrid earthquakes of 1811--1812. This study was undertaken to determine if the elemental composition of baldcypress tree rings showed any systematic variation through the earthquake period of AD 1795 through AD 1820. Multiple cores were collected from two Reelfoot Lake baldcypress trees and analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Individual yearly rings and five-year ring segments were analyzed to determine their elemental compositions. The cores were analyzed for Li through U but only Ba, Ce, Cs, Cu, I, La, Mg, Mn, Nd, Rb, Sm, Sr, and Zn were found to be in appropriate concentrations for this study. Of these elements only Ce, I, La, Nd, Rb, and Sm showed any systematic changes within individual cores. Comparison of three cores taken from one tree reveal that tree-ring elemental concentrations and changes in tree-ring elemental concentration through time are very different among the cores. When comparing the elemental concentrations of tree rings for the same years in the two different trees neither elemental concentrations nor changes in elemental concentration through time were similar. We conclude that the elemental concentrations in the tree rings of the two baldcypress trees analyzed in this study show no systematic change through the earthquake period of AD 1795 through AD 1820.
Interpolating solution from AdS5 to hyperscaling violating Lifshitz spacetime
NASA Astrophysics Data System (ADS)
Dey, Parijat; Roy, Shibaji
2015-01-01
We construct two interpolating solutions in type II string theory which interpolate between AdS5 in the UV and a hyperscaling-violating three (spatial)-dimensional Lifshitz spacetime in the IR. The first solution is nonsupersymmetric and is obtained from a known intersecting nonsupersymmetric D3-brane with a chargeless D0-brane solution of type IIB string theory, by restricting some parameters characterizing the solution and going to a new coordinate. In the IR the dilaton is nonconstant in general and the metric is three (spatial)-dimensional hyperscaling-violating Lifshitz spacetime with dynamical critical exponent z =(3 +3 γ )/(3 -γ ) and hyperscaling-violation exponent θ =12 /(3 -γ ), where γ is a real parameter and can take continuous values from -1 to +1 . At the two extreme values, i.e., for γ =±1 , the dilaton is constant. On physical grounds it is found that γ must be restricted to lie in the range -1 ≤γ ≤0 . The second solution is supersymmetric and is obtained from the known F-D2 bound-state solution of type IIA string theory by zooming into a particular region of space. In the UV, the proper description is given in a T -dual frame which is AdS5, whereas in the IR, it gives a three-dimensional hyperscaling-violating Lifshitz spacetime with z =3 and θ =2 =d -1 .
RG flow and thermodynamics of causal horizons in higher-derivative AdS gravity
NASA Astrophysics Data System (ADS)
Banerjee, Shamik; Bhattacharyya, Arpan
2016-05-01
In
[Environmental factors in ALS].
Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William
2014-05-01
ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk. PMID:24703731
Full vector archaeomagnetic data and Bayesian modelling for 1300 to 1750 AD
NASA Astrophysics Data System (ADS)
Schnepp, E.; Lanos, P.; Chauvin, A.
2009-04-01
The data base of geomagnetic palaeointensities obtained from archaeological artefacts is poor and very scattered for Western and Central Europe. High precision palaeointensities have been determined from a single archaeological site in Lübeck (Germany) where a sequence of 25 bread-oven-floors has been preserved in a bakery from medieval times until today. Age dating confines the time interval from about 1300 AD to about 1750 AD. Palaeomagnetic directions have been determined from each oven-floor (Schnepp et al., JGR, 2003). Palaeointensity was measured from selected specimens with the double-heating Thellier method and reliable palaeointensity results have been obtained. Tests for thermoremanent magnetisation anisotropy have been performed, but did not show a significant change, while a cooling rate correction was not necessary. 22 mean palaeointensity values derived from the oven-floors show maxima in the 15th and early 17th century AD, followed by a decrease of palaeointensity of about 25% until 1750 AD. The Thellier experiments provided also new characteristic remanent magnetisation directions which were included in the data set. Mean directions have been recalculated. Palaeointensity together with the directions represent a record of about 450 years full vector secular variation. From this full vector data set a secular variation curve has been calculated using a Bayesian modelling taking dating errors, all errors on the field vector and stratigraphy into account. A smooth curve with an error envelope was obtained which compares very well with the gufm1 geomagnetic model (Jackson et al., Phil. Trans. R. Soc. Lond. A, 2000) obtained from historical observations starting at 1600 AD. Comparison of the marginal curve obtained for palaeointensity with a selected data set of archaeomagnetic intensities from Western and Central Europe will be discussed.
B Removal by Zr Addition in Electromagnetic Solidification Refinement of Si with Si-Al Melt
NASA Astrophysics Data System (ADS)
Lei, Yun; Ma, Wenhui; Sun, Luen; Dai, Yongnian; Morita, Kazuki
2016-02-01
This study investigated a new process of enhancing B removal by adding small amounts of Zr in the electromagnetic solidification refinement of Si with Si-Al melt. B in Si was removed by as much as 97.2 pct by adding less than 1057 ppma Zr, and the added Zr was removed by as much as 99.7 pct. In addition, Zr is more effective in enhancing B removal than Ti in the same electromagnetic solidification refining process.
76 FR 71430 - Automatic Dependent Surveillance Broadcast (ADS-B)
Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-17
... Federal Aviation Administration Automatic Dependent Surveillance Broadcast (ADS-B) AGENCY: Department of Transportation, Federal Aviation Administration. ACTION: Notice of availability--Recommendations from the ADS-B... the ADS-B In Aviation Rulemaking Committee, Recommendations to Define a Strategy for Incorporating...
Determining Positions and Desired Applicant Characteristics in Sports Job Ads
ERIC Educational Resources Information Center
Atali, Levent
2015-01-01
The purpose of this study is to determine the diversity of positions occurring in sports job ads and reveal the characteristics requested from applicants for each position. This study examined 103 sports-related job ads obtained from four human resources websites. Using content analysis, job ads were examined in terms of job titles, and the…
Leica ADS40 Sensor for Coastal Multispectral Imaging
NASA Technical Reports Server (NTRS)
Craig, John C.
2007-01-01
The Leica ADS40 Sensor as it is used for coastal multispectral imaging is presented. The contents include: 1) Project Area Overview; 2) Leica ADS40 Sensor; 3) Focal Plate Arrangements; 4) Trichroid Filter; 5) Gradient Correction; 6) Image Acquisition; 7) Remote Sensing and ADS40; 8) Band comparisons of Satellite and Airborne Sensors; 9) Impervious Surface Extraction; and 10) Impervious Surface Details.
2 CFR 200.470 - Taxes (including Value Added Tax).
Code of Federal Regulations, 2014 CFR
2014-01-01
... Federal government for the taxes, interest, and penalties. (c) Value Added Tax (VAT) Foreign taxes charged... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Taxes (including Value Added Tax). 200.470... Cost § 200.470 Taxes (including Value Added Tax). (a) For states, local governments and Indian...
14 CFR 1203.903 - Ad hoc committees.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Ad hoc committees. 1203.903 Section 1203... NASA Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as may be necessary in the conduct of the...
14 CFR 1203.903 - Ad hoc committees.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Ad hoc committees. 1203.903 Section 1203.903... Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as may be necessary in the conduct of the Committee's work....
21 CFR 14.90 - Ad hoc advisory committee members.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Ad hoc advisory committee members. 14.90 Section... PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Members of Advisory Committees § 14.90 Ad hoc advisory committee members. In selecting members of an ad hoc advisory committee, the Commissioner may use...
21 CFR 14.90 - Ad hoc advisory committee members.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Ad hoc advisory committee members. 14.90 Section... PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Members of Advisory Committees § 14.90 Ad hoc advisory committee members. In selecting members of an ad hoc advisory committee, the Commissioner may use...
21 CFR 14.90 - Ad hoc advisory committee members.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Ad hoc advisory committee members. 14.90 Section... PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Members of Advisory Committees § 14.90 Ad hoc advisory committee members. In selecting members of an ad hoc advisory committee, the Commissioner may use...
14 CFR § 1203.803 - Ad hoc committees.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Ad hoc committees. Â§ 1203.803 Section Â... PROGRAM Delegation of Authority To Make Determinations in Original Classification Matters § 1203.803 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as...
14 CFR 1203.903 - Ad hoc committees.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Ad hoc committees. 1203.903 Section 1203... NASA Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as may be necessary in the conduct of the...
21 CFR 14.90 - Ad hoc advisory committee members.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Ad hoc advisory committee members. 14.90 Section... PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Members of Advisory Committees § 14.90 Ad hoc advisory committee members. In selecting members of an ad hoc advisory committee, the Commissioner may use...
14 CFR 1203.903 - Ad hoc committees.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Ad hoc committees. 1203.903 Section 1203... NASA Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as may be necessary in the conduct of the...
14 CFR § 1203.903 - Ad hoc committees.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Ad hoc committees. Â§ 1203.903 Section Â... PROGRAM NASA Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to establish such ad hoc panels or subcommittees as may be necessary in the conduct of...
21 CFR 14.90 - Ad hoc advisory committee members.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Ad hoc advisory committee members. 14.90 Section... PUBLIC HEARING BEFORE A PUBLIC ADVISORY COMMITTEE Members of Advisory Committees § 14.90 Ad hoc advisory committee members. In selecting members of an ad hoc advisory committee, the Commissioner may use...
Evaluating Teachers: The Important Role of Value-Added
ERIC Educational Resources Information Center
Glazerman, Steven; Loeb, Susanna; Goldhaber, Dan; Staiger, Douglas; Raudenbush, Stephen; Whitehurst, Grover
2010-01-01
The evaluation of teachers based on the contribution they make to the learning of their students, "value-added", is an increasingly popular but controversial education reform policy. In this report, the authors highlight and try to clarify four areas of confusion about value-added. The first is between value-added information and the uses to which…
Spontaneous Ad Hoc Mobile Cloud Computing Network
Lacuesta, Raquel; Sendra, Sandra; Peñalver, Lourdes
2014-01-01
Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes. PMID:25202715
Adding crumb rubber into exterior wall materials.
Zhu, Han; Thong-On, Norasit; Zhang, Xiong
2002-10-01
In Arizona US, most houses are built with walls covered by stuccos/coatings/mortars. This paper presents an explorative investigation of adding crumb rubber into stuccos/coatings/mortars. A series of experiments are conducted to examine the thermal and mechanical performance of the crumb rubber mixes. The results show that, the mixes with crumb rubber do exhibit more desirable performances like being high in crack-resistance and thermal insulation, and low in thermal expansion/contraction. The drawback for the crumb rubber mixes is the reduction in compressive strength, but which can be compensated by other means. As a site experiment, an area of 100 square-feet of crumb rubber coatings for two mix designs is sprayed on a tire-adobe wall. After being sprayed more than 14 months, the coatings apparently are in good condition. Significance of this study is that this practice, if accepted, will yield improved products that consume large quantities of crumb rubber. PMID:12498477
Snacks, sweetened beverages, added sugars, and schools.
2015-03-01
Concern over childhood obesity has generated a decade-long reformation of school nutrition policies. Food is available in school in 3 venues: federally sponsored school meal programs; items sold in competition to school meals, such as a la carte, vending machines, and school stores; and foods available in myriad informal settings, including packed meals and snacks, bake sales, fundraisers, sports booster sales, in-class parties, or other school celebrations. High-energy, low-nutrient beverages, in particular, contribute substantial calories, but little nutrient content, to a student's diet. In 2004, the American Academy of Pediatrics recommended that sweetened drinks be replaced in school by water, white and flavored milks, or 100% fruit and vegetable beverages. Since then, school nutrition has undergone a significant transformation. Federal, state, and local regulations and policies, along with alternative products developed by industry, have helped decrease the availability of nutrient-poor foods and beverages in school. However, regular access to foods of high energy and low quality remains a school issue, much of it attributable to students, parents, and staff. Pediatricians, aligning with experts on child nutrition, are in a position to offer a perspective promoting nutrient-rich foods within calorie guidelines to improve those foods brought into or sold in schools. A positive emphasis on nutritional value, variety, appropriate portion, and encouragement for a steady improvement in quality will be a more effective approach for improving nutrition and health than simply advocating for the elimination of added sugars. PMID:25713277
NASA Astrophysics Data System (ADS)
Zhukov, I. A.; Garkushin, G. V.; Vorozhtsov, S. A.; Khrustalyov, A. P.; Razorenov, S. V.; Kvetinskaya, A. V.; Promakhov, V. V.; Zhukov, A. S.
2016-01-01
The results obtained from investigations into the special features inherent in the mechanical characteristics (Hugoniot elastic limit and spall strength) observed under shock-wave loading of Al-Al2O3 composite samples produced by an explosive powder compaction technique are presented. Embedding 10 wt.% of aluminum oxide in the aluminum matrix has been found to increase the Hugoniot elastic limit as opposed to the commercialgrade AD1(Al 1013) aluminum alloy.
... External link, please review our exit disclaimer . Subscribe All About ALS Understanding a Devastating Disorder In the ... a coffee pot, or button a shirt. Eventually, all muscles under voluntary control are affected, and people ...
Amyotrophic Lateral Sclerosis (ALS)
... Pictures of ALS Mutant Proteins Support Two Major Theories About How the Disease is Caused May 2003 ... All NINDS-prepared information is in the public domain and may be freely copied. Credit to the ...
... Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic ... guarantee a person will develop symptoms of ALS. Genetic Counseling If there is more than one person ...
ALS synchrotron radiation shielding
Donahue, R.J.
1995-10-01
This note discusses the assumptions and results of synchrotron radiation shielding estimates for ALS bend magnet and wiggler beamlines. Estimates of gas bremsstrahlung production are not included and are dealt with elsewhere.
... scarring or hardening ("sclerosis") in the region. Motor neurons reach from the brain to the spinal cord ... the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise. When ...
Minimal surfaces in q-deformed AdS5xS5
NASA Astrophysics Data System (ADS)
Kameyama, Takashi
2016-01-01
We study minimal surfaces in q-deformed AdS5×S5. For this purpose, it is convenient to introduce a coordinate system which describes the spacetime only inside the singularity surface and treat the singularity surface as the holographic screen. In particular, we consider minimal surfaces whose boundary shapes are 1) a straight line and 2) a circle. In the q → 1 limit, the solutions correspond to a 1/2 BPS straight line Wilson loop and a 1/2 BPS circular one, respectively. A remarkable point is that the classical Euclidean actions have no linear divergence unlike the original ones. This finiteness indicates that the q-deformation may be regarded as a UV regularization.
Holographic cusped Wilson loops in q-deformed AdS5 × S5 spacetime
NASA Astrophysics Data System (ADS)
Bai, Nan; Chen, Hui-Huang; Wu, Jun-Bao
2015-10-01
In this paper, a minimal surface in q-deformed AdS5×S5 with a cusp boundary is studied in detail. This minimal surface is dual to a cusped Wilson loop in dual field theory. We find that the area of the minimal surface has both logarithmic squared divergence and logarithmic divergence. The logarithmic squared divergence cannot be removed by either Legendre transformation or the usual geometric subtraction. We further make an analytic continuation to the Minkowski signature, taking the limit such that the two edges of the cusp become light-like, and extract the anomalous dimension from the coefficient of the logarithmic divergence. This anomalous dimension goes back smoothly to the results in the undeformed case when we take the limit that the deformation parameter goes to zero. Supported by National Natural Science Foundation of China (11105154, 11222549, 11275207), K. C. Wong Education Foundation and Youth Innovation Promotion Association of CAS
Masses of higher spin fields on AdS4 and conformal perturbation theory
NASA Astrophysics Data System (ADS)
Hikida, Yasuaki
2016-07-01
We study the breaking of gauge symmetry for higher spin theory on AdS4 dual to the 3d critical O (N ) vector model. It was argued that the breaking is due to the change of boundary condition for a scalar field through a loop effect and the Goldstone modes are bound states of a scalar field and higher spin field. The masses of higher spin fields were obtained from the anomalous dimensions of dual currents at the leading order in 1 /N , and we reproduce them from the O (N ) vector model in the conformal perturbation theory. The anomalous dimensions can be computed from the bulk theory using Witten diagrams, and we show that the bulk computation reduces to the boundary one in the conformal perturbation theory. With this fact our computation provides an additional support for the bulk interpretation.
Wake potential in a strong coupling plasma from the AdS /CFT correspondence
NASA Astrophysics Data System (ADS)
Liu, Lian; Liu, Hui
2016-04-01
With the dielectric function computed from the AdS /CFT correspondence, we studied the wake potential induced by a fast moving charge in a strong-coupling plasma and compared it with the weak-coupling wake potential for different particle velocities as v =0.55 c and v =0.99 c . The most prominent difference between strong and weak wake potential is that, when v =0.99 c , the remarkable oscillation due to Cerenkov-like radiation and the Mach cone in weak coupling disappears in strong coupling, which implies that the plasmon mode with phase velocity lower than the speed of light dose not exist in the strong-coupling plasma.
Holographic fermionic spectrum from Born-Infeld AdS black hole
NASA Astrophysics Data System (ADS)
Wu, Jian-Pin
2016-07-01
In this letter, we systematically explore the holographic (non-)relativistic fermionic spectrum without/with dipole coupling dual to Born-Infeld anti-de Sitter (BI-AdS) black hole. For the relativistic fermionic fixed point, this holographic fermionic system exhibits non-Fermi liquid behavior. Also, with the increase of BI parameter γ, the non-Fermi liquid becomes even "more non-Fermi". When the dipole coupling term is included, we find that the BI term makes it a lot tougher to form the gap. While for the non-relativistic fermionic system with large dipole coupling in BI-AdS background, with the increase of BI parameter, the gap comes into being again.
Multi-spike strings in AdS3 with mixed three-form fluxes
NASA Astrophysics Data System (ADS)
Banerjee, Aritra; Sadhukhan, Abhishake
2016-05-01
The string sigma model in AdS3 × S 3 supported by mixed three-form fluxes has recently been proved to be integrable which led to a plethora of work in this background including proposals for S matrix and study of semiclassical string profiles. Motivated by this, in this paper, we present a study of `spiky' strings in this background. We analyze the string profiles in detail and also find the dispersion relation between the charges in the `long' string limit after solving the equations of motion perturbatively upto the leading order in the Neveu-Schwarz flux b. We find that the dispersion for 2 spikes gets corrected by the term -b^2/2 log S. We also discuss the fate of the solution in the limit of pure NS-NS flux.
Boundary conditions and partition functions in higher spin AdS3/CFT2
NASA Astrophysics Data System (ADS)
de Boer, Jan; Jottar, Juan I.
2016-04-01
We discuss alternative definitions of the semiclassical partition function in two-dimensional CFTs with higher spin symmetry, in the presence of sources for the higher spin currents. Theories of this type can often be described via Hamiltonian reduction of current algebras, and a holographic description in terms of three-dimensional Chern-Simons theory with generalized AdS boundary conditions becomes available. By studying the CFT Ward identities in the presence of sources, we determine the appropriate choice of boundary terms and boundary conditions in Chern-Simons theory for the various types of partition functions considered. In particular, we compare the Chern-Simons description of deformations of the field theory Hamiltonian versus those encoding deformations of the CFT action. Our analysis clarifies various issues and confusions that have permeated the literature on this subject.
Contractions of AdS brane algebra and superGalileon Lagrangians
Kamimura, Kiyoshi; Onda, Seiji
2013-06-15
We examine AdS Galileon Lagrangians using the method of nonlinear realization. By contractions (1) flat curvature limit, (2) non-relativistic brane algebra limit, and (3) (1) + (2) limits we obtain DBI, Newton-Hoock, and Galilean Galileons, respectively. We make clear how these Lagrangians appear as invariant 4-forms and/or pseudo-invariant Wess-Zumino (WZ) terms using Maurer-Cartan (MC) equations on the coset G/SO(3, 1). We show the equations of motion are written in terms of the MC forms only and explain why the inverse Higgs condition is obtained as the equation of motion for all cases. The supersymmetric extension is also examined using a supercoset SU(2, 2 Double-Vertical-Line 1)/(SO(3, 1) Multiplication-Sign U(1)) and five WZ forms are constructed. They are reduced to the corresponding five Galileon WZ forms in the bosonic limit and are candidates for supersymmetric Galileon action.
AdS4 solutions of massive IIA from dyonic ISO(7) supergravity
NASA Astrophysics Data System (ADS)
Varela, Oscar
2016-03-01
Explicit formulae are given for the consistent truncation of massive type IIA supergravity on the six-sphere to the SU(3)-invariant sector of D = 4 {N}=8 supergravity with dyonic ISO(7) gauging. These formulae are then used to construct AdS4 solutions of massive type IIA via uplift on S 6 of the critical points of the D = 4 supergravity with at least SU(3) symmetry. We find a new {N}=1 solution with SU(3) symmetry, a new non-supersymmetric solution with SO(6) symmetry, and recover previously known solutions. We quantise the fluxes, calculate the gravitational free energies of the solutions and discuss the stability of the non-supersymmetric ones. Among these, a (previously known) G2-invariant solution is found to be stable.
Mizuno, Yuji; Fujita, Yukio; Takatama, Masamitsu; Okamoto, Koichi
2012-04-15
TDP-43 has been identified as a major component of the pathological inclusions in most forms of frontotemporal lobar degeneration with ubiquitin-positive inclusions and in amyotrophic lateral sclerosis (ALS). In the present study, paraffin sections of the midbrain in 112 patients with various non-ALS disorders and 27 patients with sporadic ALS were immunostained with antibody against phosphorylated TDP-43 (pTDP-43). pTDP-43-positive inclusions in oculomotor neurons were detected in 18 of 112 patients with non-ALS disorders (16.1%). The appearance of the inclusions showed fine filamentous structures rather than the skein-like inclusions seen in the anterior horn cells of ALS spinal cords. The incidence was increased in the age range of 80-89 years old (10/37 cases; 27.0%), in which 6 of 10 cases demonstrated AD pathology in the temporal lobes. Twenty-seven ALS patients were examined and the findings were compared with those of non-ALS patients. There were 13 cases demonstrating pTDP-43-positive inclusions (48.1%) which showed stronger immunoreactivities in ALS cases. This is the first report demonstrating fine filamentous pTDP-43-positive inclusions in oculomotor neurons in non-ALS disorders. Although the mechanisms underlying pTDP-43 in oculomotor neurons are currently unknown, its detection is of interest, and the expression may occur not only in ALS but also during the aging process. PMID:22257502
Boundary conditions for General Relativity on AdS3 and the KdV hierarchy
NASA Astrophysics Data System (ADS)
Pérez, Alfredo; Tempo, David; Troncoso, Ricardo
2016-06-01
It is shown that General Relativity with negative cosmological constant in three spacetime dimensions admits a new family of boundary conditions being labeled by a nonnegative integer k. Gravitational excitations are then described by "boundary gravitons" that fulfill the equations of the k-th element of the KdV hierarchy. In particular, k = 0 corresponds to the Brown-Henneaux boundary conditions so that excitations are described by chiral movers. In the case of k = 1, the boundary gravitons fulfill the KdV equation and the asymptotic symmetry algebra turns out to be infinite-dimensional, abelian and devoid of central extensions. The latter feature also holds for the remaining cases that describe the hierarchy ( k > 1). Our boundary conditions then provide a gravitational dual of two noninteracting left and right KdV movers, and hence, boundary gravitons possess anisotropic Lifshitz scaling with dynamical exponent z = 2 k + 1. Remarkably, despite spacetimes solving the field equations are locally AdS, they possess anisotropic scaling being induced by the choice of boundary conditions. As an application, the entropy of a rotating BTZ black hole is precisely recovered from a suitable generalization of the Cardy formula that is compatible with the anisotropic scaling of the chiral KdV movers at the boundary, in which the energy of AdS spacetime with our boundary conditions depends on z and plays the role of the central charge. The extension of our boundary conditions to the case of higher spin gravity and its link with different classes of integrable systems is also briefly addressed.
First-principles thermochemistry for the combustion of a TiCl4 and AlCl3 mixture.
Shirley, Raphael; Liu, Yaoyao; Totton, Tim S; West, Richard H; Kraft, Markus
2009-12-10
AlCl(3) is added in small quantities to TiCl(4) fed to industrial reactors during the combustion synthesis of titanium dioxide nanoparticles in order to promote the rutile crystal phase. Despite the importance of this process, a detailed mechanism including AlCl(3) is still not available. This work presents the thermochemistry of many of the intermediates in the early stages of the mechanism, computed using quantum chemistry. The enthalpies of formation and thermochemical data for AlCl, AlO, AlOCl, AlOCl(2), AlO(2), AlO(2)Cl, AlOCl(3), AlO(2)Cl(2), AlO(3)ClTi, AlO(2)Cl(2)Ti, AlO(2)Cl(4)Ti, AlOCl(5)Ti, AlO(2)Cl(3)Tia (isomer-a), AlO(3)Cl(2)Ti, AlO(2)Cl(5)Ti, AlOCl(4)Ti, AlO(2)Cl(3)Tib (isomer-b), AlCl(7)Ti, AlCl(6)Ti, Al(2)Cl(6), Al(2)O(2)Cl, Al(2)O(2)Cl(3), Al(2)O(3)Cl(2), Al(2)O(2)Cl(2), Al(2)OCl(4), Al(2)O(3), and Al(2)OCl(3) were calculated using density functional theory (DFT). A full comparison between a number of methods is made for one of the important species, AlOCl, to validate the use of DFT and gauge the magnitude of errors involved with this method. Finally, equilibrium calculations are performed to try to identify which intermediates are likely to be most prevalent in the high temperature industrial process and as a first attempt to characterize the nucleation process. PMID:19888740
Holographic superconductors in the AdS black hole with a magnetic charge
NASA Astrophysics Data System (ADS)
Setare, M. R.; Momeni, D.; Myrzakulov, R.; Raza, Muhammad
2012-10-01
In this work, we study the analytical properties of a 2 + 1-dimensional magnetically charged holographic superconductor in AdS4. We obtain the critical chemical potential μc analytically, using the Sturm-Liouville variational approach. Further, by applying the perturbation scheme, we obtain the electrical conductivity of the model. We observe that the real part of the σ increases and the imaginary part of the conductivity decreases monotonously versus the frequency ω. Each module of σ has a minimum value, which is similar to the case of the uncharged Schwarachild-AdS background. Further, we also conclude that the value of \\frac {\\omega _g}{T_{ {c}}} increases. For the condensate operator {O}_2 we find that, as the frequency ω increases for fixed H, the real part has a common behavior. However, the imaginary part possesses a minimum value in this case and the location of this minimum value changes along right when H increases. We find that at ω = 0, the real part of conductivity behaves as a delta function and the imaginary part exists as a pole in the background. This pole may be related to the existence of a magnetic monopole. Also, the obtained analytic result can be used to back up numerical computations in the holographic superconductor in the probe limit.
Three dimensional nonlinear magnetic AdS solutions through topological defects
NASA Astrophysics Data System (ADS)
Hendi, S. H.; Panah, B. Eslam; Momennia, M.; Panahiyan, S.
2015-09-01
Inspired by large applications of topological defects in describing different phenomena in physics, and considering the importance of three dimensional solutions in AdS/CFT correspondence, in this paper we obtain magnetic anti-de Sitter solutions of nonlinear electromagnetic fields. We take into account three classes of nonlinear electrodynamic models; first two classes are the well-known Born-Infeld like models including logarithmic and exponential forms and third class is known as the power Maxwell invariant nonlinear electrodynamics. We investigate the effects of these nonlinear sources on three dimensional magnetic solutions. We show that these asymptotical AdS solutions do not have any curvature singularity and horizon. We also generalize the static metric to the case of rotating solutions and find that the value of the electric charge depends on the rotation parameter. Finally, we consider the quadratic Maxwell invariant as a correction of Maxwell theory and we investigate the effects of nonlinearity as a correction. We study the behavior of the deficit angle in presence of these theories of nonlinearity and compare them with each other. We also show that some cases with negative deficit angle exists which are representing objects with different geometrical structure. We also show that in case of the static only magnetic field exists whereas by boosting the metric to rotating one, electric field appears too.
Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks
Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha
2016-01-01
Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013
Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.
Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha
2016-01-01
Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013
Nearly Conformal QCD and AdS/CFT
de Teramond, Guy F.; Brodsky, Stanley J.; /Costa Rica U. /SLAC
2005-08-08
The AdS/CFT correspondence is a powerful tool to study the properties of conformal QCD at strong coupling in terms of a higher dimensional dual gravity theory. The power-law falloff of scattering amplitudes in the non-perturbative regime and calculable hadron spectra follow from holographic models dual to QCD with conformal behavior at short distances and confinement at large distances. String modes and fluctuations about the AdS background are identified with QCD degrees of freedom and orbital excitations at the AdS boundary limit. A description of form factors in space and time-like regions and the behavior of light-front wave functions can also be understood in terms of a dual gravity description in the interior of AdS.
Comment on ‘Critical scalar field collapse in AdS3: an analytical approach’
NASA Astrophysics Data System (ADS)
Clément, Gérard; Fabbri, Alessandro
2014-05-01
We comment on the derivation of an analytical solution presented in Baier et al (2014 Class. Quantum Grav. 31 025007), show that it belongs to a family of separable solutions previously constructed in Clément and Fabbri (2002 Nucl. Phys. B 630 269), and question its relevance to critical collapse.
A tribute to Zakariya Razi (865 - 925 AD), an Iranian pioneer scholar.
Modanlou, Houchang D
2008-11-01
The resurgence of Islamic Civilization in the Near East in the 7th century AD and its expansion to Persian Empire and Westward provided opportunities of access Persian, Hellenic, and Roman writings in philosophy and medicine. Based on their observations and experiences, Islamic physician-philosophers expanded upon those writings and at times challenged them. Among these physician-philosophers admiring and challenging Galen was Zakariya Razi described as the greatest physician of Islam and Medieval Ages.A search of electronic and written materials about early Islamic Medicine was carried out focusing on Persian physician-philosophers Zakariya Razi. Abu Bakr Mohammad Ibn Zakariya al-Razi, known in the West as Rhazes, was born in 865 AD in the ancient city of Rey, Near Tehran. A musician during his youth he became an alchemist. He discovered alcohol and sulfuric acid. He classified substances as plants, organic, and inorganic. At age 30, he undertook the study of medicine. He was a prolific writer with more than 184 texts in medicine attributed to him with 40 of them currently available. Among them are Kitab al-Mansoori, Kitab al-Hawi, and Kitab al -Judari wa al-Hasabah. The latter is the first scientific description for the recognition and differentiation of smallpox and measles. The Bulletin of the World Health Organization of May 1970 pays tribute to Razi by stating "His writings on smallpox and measles show originality and accuracy, and his essay on infectious diseases was the first scientific treatise on the subject". Razi established qualifications and ethical standards for the practice of medicine. Zakariya Razi was not only one of the most important Persian physician-philosophers of his era, but for centuries his writings became fundamental teaching texts in European medical schools. Some important aspects of his contributions to medicine are reviewed. PMID:18976043
Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of re-discovery
NASA Astrophysics Data System (ADS)
Hafez, Ihsan
2010-10-01
Al-Şūfı's Book of the Fixed Stars, dating from around AD 964, is one of the most important medieval Arabic treatises on astronomy. This major work contains an extensive star catalog, which lists star co-ordinates and magnitude estimates, as well as detailed star charts. Other topics include descriptions of nebulae, colors of stars and Arabic folk astronomy. Al-Şūfı's book was based on Ptolemy's classical work called the Almagest which was written around A.D. 137. Al-Şūfı updated Ptolemy's stellar longitudes from A.D. 137 to 964 by adding 12 degrees and 42 minutes on Ptolemy's longitude values to allow for precession. However, it is surprising that at present no English translation of al-Şūfı's treatise exists. Therefore this is a Doctorate thesis which includes for the first time a complete English translation of the main parts of al-Şūfı's work as well as a detailed study of this important book. The main topics which have been discussed in this study include a brief biography on al-Şūfı, the extant manuscripts of al-Şūfı's treatise, the structure of the book and star catalogue, and the star maps and charts. One of al-Şūfı's innovations in charting the stars was the production of dual illustrations for each of Ptolemy's constellations. One illustration was as portrayed on a celestial globe. The other illustration was as viewed directly in the night sky. Al-Şūfı's contribution to astronomy was not only limited to writing this book but he was also instrumental in developing the science of astronomy for a very long time. He also contributed to the building of an important observatory in the city of Shiraz as well as constructing many astronomical instruments such as astrolabes and celestial globes. His influence reverberated throughout history reaching as far as the end of the 19th century. This study also includes a major finding which is al-Şūfı's magnitude unique 3-step intermediate magnitude system. Al-Şūfı identified more than one
Quasinormal modes of self-dual warped AdS3 black hole in topological massive gravity
NASA Astrophysics Data System (ADS)
Li, Ran; Ren, Ji-Rong
2011-03-01
We consider the scalar, vector and spinor field perturbations in the background of self-dual warped AdS3 black hole of topological massive gravity. The corresponding exact expressions for quasinormal modes are obtained by analytically solving the perturbation equations and imposing the vanishing Dirichlet boundary condition at asymptotic infinity. It is expected that the quasinormal modes agree with the poles of retarded Green’s functions of the CFT dual to self-dual warped AdS3 black hole. Our results provide a quantitative test of the warped AdS/CFT correspondence.
Efficacy of adding folic acid to foods.
Fajardo, Violeta; Varela-Moreiras, Gregorio
2012-06-01
In the past, food fortification along with nutritional education and the decrease in food costs relative to income have proven successful in eliminating common nutritional deficiencies. These deficiencies such as goiter, rickets, beriberi, and pellagra have been replaced with an entirely new set of "emergent deficiencies" that were not previously considered a problem [e.g., folate and neural tube defects (NTDs)]. In addition, the different nutrition surveys in so-called affluent countries have identified "shortfalls" of nutrients specific to various age groups and/or physiological status. Complex, multiple-etiology diseases, such as atherosclerosis, diabetes, cancer, and obesity have emerged. Food fortification has proven an effective tool for tackling nutritional deficiencies in populations; but today a more reasonable approach is to use food fortification as a means to support but not replace dietary improvement strategies (i. e. nutritional education campaigns). Folic acid (FA) is a potential relevant factor in the prevention of a number of pathologies. The evidence linking FA to NTD prevention led to the introduction of public health strategies to increase folate intakes: pharmacological supplementation, mandatory or voluntary fortification of staple foods with FA, and the advice to increase the intake of folate-rich foods. It is quite contradictory to observe that, regardless of these findings, there is only limited information on food folate and FA content. Data in Food Composition Tables and Databases are scarce or incomplete. Fortification of staple foods with FA has added difficulty to this task. Globally, the decision to fortify products is left up to individual food manufacturers. Voluntary fortification is a common practice in many countries. Therefore, the "worldwide map of vitamin fortification" may be analyzed. It is important to examine if fortification today really answers to vitamin requirements at different ages and/or physiological states. The
What makes an ad a cigarette ad? Commercial tobacco imagery in the lesbian, gay, and bisexual press
Smith, E.; Offen, N.; Malone, R.
2005-01-01
Objectives: To determine the extent of commercial tobacco imagery in the lesbian, gay, and bisexual (LGB) press. Methods: Content analysis of all advertising containing tobacco related text or imagery in 20 LGB community periodicals, published between January 1990 and December 2000. Results: 3428 ads were found: 689 tobacco product ads, 1607 ads for cessation products or services, 99 ads with a political message about tobacco, and 1033 non-tobacco ads that showed tobacco (NAST). Although cessation ads were numerically dominant, tobacco product ads and NAST occupied more space and were more likely to use images. NAST almost never had an anti-tobacco message. Formal sponsorship between tobacco and other companies was very rare. Lesbian periodicals had proportionally more NAST and fewer cessation ads. Conclusions: Cigarette ads were outnumbered by NAST. Although these ads do not usually show brands, and are unlikely to be the result of formal sponsorship agreements, they may be "selling" smoking. Tobacco control advocates should persuade editors to refuse tobacco product ads and those with gratuitous tobacco imagery. PMID:16286500
Remote wildcat added to Mississippi search
Petzet, G.A.
1991-03-06
A Canadian operator conducting a broad exploration and development program in the U.S. has staked a remote Lower Cretaceous Washita-Fredericksburg wildcat in southeastern Mississippi. Norcen Explorer Inc., Houston, plans to drill the 1 Exxon Corp. et al., NW NW NW 25-3n-8w, in western Greene County, Miss. Projected total depth is 11,000 ft. The location is 1 3/4 miles southwest of Byrd, Miss., and 8 miles south of Avera field, which produces oil from several Cretaceous formations. Petroleum Information notes that the nearest previous drilling is a 13,520 ft wildcat, 1 Neely-Jackson, in 35-3n-8w abandoned more than 30 years ago by King Petroleum Co. King recovered 53 sidewall cores at 7,441-13,493 ft but found no shows. The only other work scheduled in lightly drilled Greene County as of mid- April was a planned 8,600 ft Upper Cretaceous Lower Tuscaloosa wildcat permitted in late 1990 by Fina Oil and Chemical Co., Dallas. That attempt is 1 Glen Neubert 5-9, NW NE SE 5-4n-8w, 3/4 mile west of North Sand Hill field, which produces oil from Tuscaloosa. Fina in November 1989 abandoned 1 Freeman 33-13, NE SW SW 33-5n-8w, the last well drilled in the county. This 12,500 ft Lower Cretaceous Sligo wildcat 1 1/2 miles west of North Sand Hill field found no shows in 30 sidewall cores taken in Lower Cretaceous Rodessa sand.
Rapidly solidified NiAl and FeAl
NASA Technical Reports Server (NTRS)
Gaydosh, D. J.; Crimp, M. A.
1984-01-01
Melt spinning was used to produce rapidly solidified ribbons of the B2 intermetallics NiAl and FeAl. Both Fe-40Al and Fe-45Al possessed some bend ductility in the as spun condition. The bend ductility of Fe-40Al, Fe-45Al, and equiatomic NiAl increased with subsequent heat treatment. Heat treatment at approximately 0.85 T (sub m) resulted in significant grain growth in equiatomic FeAl and in all the NiAl compositions. Low bend ductility in both FeAl and NiAl generally coincided with intergranular failure, while increased bend ductility was characterized by increasing amounts of transgranular cleavage fracture.
Introduction to the AdS/CFT Correspondence
NASA Astrophysics Data System (ADS)
Nąstase, Horaǧiu
2015-09-01
Preface; Introduction; Part I. Background: 1. Elements of quantum field theory and gauge theory; 2. Basics of general relativity. Anti-de Sitter space; 3. Basics of supersymmetry; 4. Basics of supergravity; 5. Kaluza-Klein dimensional reduction; 6. Black holes and p-branes; 7. String theory actions and spectra; 8. Elements of conformal field theory; 9. D-branes; Part II. Basics of AdS/CFT for N = 4 SYM vs AdS5 × S5: 10. The AdS/CFT correspondence: motivation, definition and spectra; 11. Witten prescription and 3-point correlator calculations; 12. Holography in Lorentzian signature: Poincaré and global; 13. Solitonic objects in AdS/CFT; 14. Quarks and the Wilson loop; 15. Finite temperature and N = 4 SYM plasmas; 16. Scattering processes and gravitational shockwave limit; 17. The pp-wave correspondence; 18. Spin chains; Part III. AdS/CFT Developments and Gauge-Gravity Dualities: 19. Other conformal cases; 20. The 3 dimensional ABJM model vs. AdS4 × CP3; 21. Gravity duals; 22. Holographic renormalization; 23. RG flow between fixed points; 24. Phenomenological gauge-gravity duality I: AdS/QCD; 25. Phenomenological gauge-gravity duality II: AdS/CMT; 26. Gluon scattering: the Alday-Maldacena prescription; 27. Holographic entanglement entropy: the Ryu-Takayanagi prescription.
Super-Galilean conformal algebra in AdS/CFT
Sakaguchi, Makoto
2010-04-15
Galilean conformal algebra (GCA) is an Inoenue-Wigner (IW) contraction of a conformal algebra, while Newton-Hooke string algebra is an IW contraction of an Anti-de Sitter (AdS) algebra, which is the isometry of an AdS space. It is shown that the GCA is a boundary realization of the Newton-Hooke string algebra in the bulk AdS. The string lies along the direction transverse to the boundary, and the worldsheet is AdS{sub 2}. The one-dimensional conformal symmetry so(2,1) and rotational symmetry so(d) contained in the GCA are realized as the symmetry on the AdS{sub 2} string worldsheet and rotational symmetry in the space transverse to the AdS{sub 2} in AdS{sub d+2}, respectively. It follows from this correspondence that 32 supersymmetric GCAs can be derived as IW contractions of superconformal algebras, psu(2,2|4), osp(8|4), and osp(8*|4). We also derive less supersymmetric GCAs from su(2,2|2), osp(4|4), osp(2|4), and osp(8*|2)
NASA Astrophysics Data System (ADS)
Neuhäuser, D. L.; Neuhäuser, R.
2015-12-01
The interpretation of the strong 14C variation around AD 775 as one (or several) solar super-flare(s) by, e.g., Usoskin et al. (2013) is based on alleged aurora sightings in the mid AD 770s in Europe: A red cross/crucifix in AD 773/4/6 from the Anglo-Saxon Chronicle, inflamed shields in AD 776 (both listed in the aurora catalogue of Link 1962), and riders on white horses in AD 773 (newly proposed as aurora in Usoskin et al. 2013), the two latter from the Royal Frankish Annals. We discuss the reports about these three sightings in detail here. We can show that all three can be interpreted convincingly as halo displays: The red cross or crucifix is formed by the horizontal arc and a vertical pillar of light (either with the Sun during sunset or with the moon after sunset); the inflamed shields and the riders on white horses were both two mock suns, especially the latter narrated in form of a Christian adaptation of the antique dioscuri motive. While the latter event took place early in AD 774 (dated AD 773 in Usoskin et al. 2013), the two other sightings have to be dated AD 776, i.e. anyway too late for being in connection with a 14C rise that started before AD 775. We also sketch the ideological background of those sightings and there were many similar reports throughout that time. In addition, we present a small drawing of a lunar halo display with horizontal arc and vertical pillar forming a cross for shortly later, namely AD 806 June 4, the night of full moon, also from the Anglo-Saxon Chronicle; we also show historic observations of halo phenomena (mock suns and crosses) from G. Kirch and Hevelius - and a modern photograph.
Matrix model maps and reconstruction of AdS supergravity interactions
Cremonini, Sera; Mello Koch, Robert de; Jevicki, Antal
2008-05-15
We consider the question of reconstructing (cubic) SUGRA interactions in AdS/CFT. The method we introduce is based on the matrix model maps (MMP) which were previously successfully employed at the linearized level. The strategy is to start with the map for 1/2 BPS configurations, which is exactly known (to all orders) in the Hamiltonian framework. We then use the extension of the matrix model map with the corresponding Ward identities to completely specify the interaction. A central point in this construction is the nonvanishing of off-shell interactions (even for highest-weight states)
Effect of added mass on the interaction of bubbles in a low-Reynolds-number shear flow.
Lavrenteva, Olga; Prakash, Jai; Nir, Avinoam
2016-02-01
Equal size air bubbles that are entrapped by a Taylor vortex of the secondary flow in a Couette device, thereby defying buoyancy, slowly form a stable ordered ring with equal separation distances between all neighbors. We present two models of the process dynamics based on force balance on a bubble in the presence of other bubbles positioned on the same streamline in a simple shear flow. The forces taken into account are the viscous resistance, the added mass force, and the inertia-induced repulsing force between two bubbles in a low-Reynolds-number shear flow obtained in Prakash et al. [J. Prakash et al., Phys. Rev. E 87, 043002 (2013)]. The first model of the process assumes that each bubble interacts solely with its nearest neighbors. The second model takes into account pairwise interactions among all the bubbles in the ring. The performed dynamic simulations were compared to the experimental results reported in Prakash et al. [J. Prakash et al., Phys. Rev. E 87, 043002 (2013)] and to the results of quasistationary models (ignoring the added mass effect) suggested in that paper. It is demonstrated that taking into account the effect of added mass, the models describe the major effect of the bubbles' ordering, provide good estimation of the relaxation time, and also predict nonmonotonic behavior of the separation distance between the bubbles, which exhibit over- and undershooting of equilibrium separations. The latter effects were observed in experiments, but are not predicted by the quasistationary models. PMID:26986411
The forecaster's added value in QPF
NASA Astrophysics Data System (ADS)
Turco, M.; Milelli, M.
2010-03-01
: - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use: the subjective HQPF continues to offer the best performance for the period +24 h/+48 h (i.e. the warning period in the Piemonte system); - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterization and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.
Modulus measurements in ordered Co-Al, Fe-Al, and Ni-Al alloys
NASA Technical Reports Server (NTRS)
Harmouche, M. R.; Wolfenden, A.
1985-01-01
The composition and/or temperature dependence of the dynamic Young's modulus for the ordered B2 Co-Al, Fe-Al, and Ni-Al aluminides has been investigated using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The modulus has been measured in the composition interval 48.49 to 52.58 at. pct Co, 50.87 to 60.2 at. pct Fe, and 49.22 to 55.95 at. pct Ni for Co-Al, Fe-Al, and Ni-Al, respectively. The measured values for Co-Al are in the temperature interval 300 to 1300 K, while those for the other systems are for ambient temperature only. The data points show that Co-Al is stiffer than Fe-Al, which is stiffer than Ni-Al. The data points for Fe-Al and Ni-Al are slightly higher than those reported in the literature.
Explanations of AD in ethnic minority participants undergoing cognitive screening.
Tappen, Ruth M; Gibson, Sandra E; Williams, Christine L
2011-06-01
The purpose of this study was to describe and compare explanations of Alzheimer's disease (AD) of African American, Afro-Caribbean, and European American older adults undergoing cognitive screening. Participants were asked a series of open-ended questions regarding what they knew about AD and if they were experiencing memory problems. Responses were coded and quantized for analysis. Forty percent reported experiencing memory problems. Afro-Caribbeans made significantly more incorrect statements about AD and were less likely to identify memory loss as a symptom. Half the participants said they would seek their physician's advice if the screening was positive; none mentioned a memory disorder center. Misconceptions about AD included the effect of aluminum, brain collapse, relaxed brain, shaking, tremors, and physical illness. More Afro-Caribbeans, all of whom were first generation, had misconceptions about AD. Campaigns to educate the public about AD need to provide culturally sensitive and appropriate information to ethnic minority populations. PMID:21697141
Long-term variations in natural, terrestrial VOC emissions: 1000-1990 AD
NASA Astrophysics Data System (ADS)
Acosta, J. C.; Struthers, H.; Zorita, E.; Ekman, A. M.; Riipinen, I.
2012-12-01
). We evaluate the long-term response of terrestrial BVOC emission activity to variations in land-use change and climatic factors, and find that compared to preindustrial times (1000-1800 A.D.), global isoprene emissions have decreased 8%, monoterpenes emissions have increased 10% and sesquiterpenes emissions have increased 15% during the time period 1950-1990 A.D.. The results suggest that the variation of isoprene emissions is governed by land-use changes, while monoterpenenes and sesquiterpenes variations are dominated by climate variability. Adams, J.M. (2001). Chemosphere - Global Change Science, 3, 73-91 J.H. Seinfeld and S. N. Pandis. (1998). Atmospheric Chemistry and Physics . Wiley, New York Jimenez, J. L. et al. (2009). Science, 326, 1525-1529 Kaplan, J. O. et al (2010). The Holocene 21(5), 775-791 Guenther, A. et al. (1995). J. Geophys. Res., 100, 8873-8892 Hoyle, C. R. et al. (2011). Atmos. Chem. Phys., 11, 321-343 A. Guenther et al. (2006). Atmospheric Chemistry and Physics, 6:3181-3210 J. H. Jungclaus et al. (2010). Climate of the Past, 6:723-737
40Ar/39Ar ages of the AD 79 eruption of Vesuvius, Italy
Lanphere, M.; Champion, D.; Melluso, L.; Morra, V.; Perrotta, A.; Scarpati, C.; Tedesco, D.; Calvert, A.
2007-01-01
The Italian volcano, Vesuvius, erupted explosively in AD 79. Sanidine from pumice collected at Casti Amanti in Pompeii and Villa Poppea in Oplontis yielded a weighted-mean 40Ar/39Ar age of 1925??66 years in 2004 (1?? uncertainty) from incremental-heating experiments of eight aliquants of sanidine. This is the calendar age of the eruption. Our results together with the work of Renne et al. (1997) and Renne and Min (1998) demonstrate the validity of the 40Ar/39Ar method to reconstruct the recent eruptive history of young, active volcanoes. ?? Springer-Verlag 2006.
Gribov ambiguity in asymptotically AdS three-dimensional gravity
Anabalon, Andres; Canfora, Fabrizio; Giacomini, Alex; Oliva, Julio
2011-03-15
In this paper the zero modes of the de Donder gauge Faddeev-Popov operator for three-dimensional gravity with negative cosmological constant are analyzed. It is found that the AdS{sub 3} vacuum produces (infinitely many) normalizable smooth zero modes of the Faddeev-Popov operator. On the other hand, it is found that the Banados-Teitelboim-Zanelli black hole (including the zero mass black hole) does not generate zero modes. This differs from the usual Gribov problem in QCD where, close to the maximally symmetric vacuum, the Faddeev-Popov determinant is positive definite while 'far enough' from the vacuum it can vanish. This suggests that the zero mass Banados-Teitelboim-Zanelli black hole could be a suitable ground state of three-dimensional gravity with negative cosmological constant. Because of the kinematic origin of this result, it also applies for other covariant gravity theories in three dimensions with AdS{sub 3} as maximally symmetric solution, such as new massive gravity and topologically massive gravity. The relevance of these results for supersymmetry breaking is pointed out.
Area spectrum of extremal black holes with warped AdS near-horizon geometry
NASA Astrophysics Data System (ADS)
Wen, Wen-Yu
2014-06-01
In this paper, we provide an alternative method to study the area spectrum of certain classes of extremal black holes which have near-horizon geometry as warped AdS. We argue that previous methods which are based on the existence of quasinormal modes may not be applicable in the extremal limit. The topology difference of the near-horizon geometry between non-extremal and extremal black holes implies a separate treatment is needed to study the area discreteness in the extremal limit. To be specific, we will study area spectrum of supersymmetric BMPV black holes/black rings and Reissner-Nordström (RN) black holes at the extremal limit. Inspired by the recently established Kerr/CFT and RN/CFT correspondence, we propose a new way to quantize the area regardless of the (non-)existence of quasinormal modes or zero Hawking temperature. At last, we propose a dilute gas model and harmonic oscillator model which have same degrees of freedom as the dual CFT.
Warped AdS 6 × S 2 in Type IIB supergravity I: local solutions
NASA Astrophysics Data System (ADS)
D'Hoker, Eric; Gutperle, Michael; Karch, Andreas; Uhlemann, Christoph F.
2016-08-01
We investigate the existence of solutions with 16 residual supersymmetries to Type IIB supergravity on a space-time of the formc AdS 6× S 2 warped over a two-dimensional Riemann surface Σ. The SO(2 , 5) × SO(3) isometry extends to invariance under the exceptional Lie superalgebra F (4). In the present paper, we construct the general Ansatz compatible with these symmetries, derive the corresponding reduced BPS equations, and obtain their complete local solution in terms of two locally holomorphic functions {A}_{± } on Σ, subject to certain positivity and regularity conditions. Globally, ( {A}+ , {A}- ) are allowed to be multiple-valued on Σ and be holomorphic sections of a holomorphic bundle over Σ with structure group contained in SU(1,1)× C . Globally regular solutions are expected to provide the near-horizon geometry of ( p, q) 5-brane and 7-brane webs which are holographic duals to five-dimensional conformal field theories. A preliminary analysis of the positivity and regularity conditions will be presented here, leaving the construction of globally regular solutions to a subsequent paper.
Static black holes with axial symmetry in asymptotically AdS4 spacetime
NASA Astrophysics Data System (ADS)
Kichakova, Olga; Kunz, Jutta; Radu, Eugen; Shnir, Yasha
2016-02-01
The known static electrovacuum black holes in a globally AdS4 background have an event horizon which is geometrically a round sphere. In this work we argue that the situation is different in models with matter fields possessing an explicit dependence on the azimuthal angle φ , which, however, does not manifest at the level of the energy-momentum tensor. As a result, the full solutions are axially symmetric only, possessing a single (timelike) Killing vector field. Explicit examples of such static black holes are constructed in Einstein-(complex) scalar field and Einstein-Yang-Mills theories. The basic properties of these solutions are discussed, looking for generic features. For example, we notice that the horizon has an oblate spheroidal shape for solutions with a scalar field and a prolate one for black holes with Yang-Mills fields. The deviation from sphericity of the horizon geometry manifests itself in the holographic stress tensor. Finally, based on the results obtained in the probe limit, we conjecture the existence in Einstein-Maxwell theory of static black holes with axial symmetry only.
S -matrix algebra of the AdS2×S2 superstring
NASA Astrophysics Data System (ADS)
Hoare, Ben; Pittelli, Antonio; Torrielli, Alessandro
2016-03-01
In this paper, we find the Yangian algebra responsible for the integrability of the AdS2×S2×T6 superstring in the planar limit. We demonstrate the symmetry of the corresponding exact S matrix in the massive sector, including the presence of the secret symmetry. We give two alternative presentations of the Hopf algebra. The first takes the usual canonical form, which, as the relevant representations are long, leads to a Yangian representation that is not of evaluation type. After investigating the relationship between cocommutativity, evaluation representations and the shortening condition, we find an alternative realization of the Yangian whose representation is of the evaluation type. Finally, we explore two limits of the S matrix. The first is the classical r matrix, where we rediscover the need for a secret symmetry also in this context. The second is the simplifying zero-coupling limit. In this limit, taking the S matrix as a generating R matrix for the algebraic Bethe ansatz, we obtain an effective model of free fermions on a periodic spin-chain. This limit should provide hints to the one-loop anomalous dimension of the mysterious superconformal quantum mechanics dual to the superstring theory in this geometry.
Asymptotic structure of the Einstein-Maxwell theory on AdS3
NASA Astrophysics Data System (ADS)
Pérez, Alfredo; Riquelme, Miguel; Tempo, David; Troncoso, Ricardo
2016-02-01
The asymptotic structure of AdS spacetimes in the context of General Relativity coupled to the Maxwell field in three spacetime dimensions is analyzed. Although the fall-off of the fields is relaxed with respect to that of Brown and Henneaux, the variation of the canonical generators associated to the asymptotic Killing vectors can be shown to be finite once required to span the Lie derivative of the fields. The corresponding surface integrals then acquire explicit contributions from the electromagnetic field, and become well-defined provided they fulfill suitable integrability conditions, implying that the leading terms of the asymptotic form of the electromagnetic field are functionally related. Consequently, for a generic choice of boundary conditions, the asymptotic symmetries are broken down to {R}⊗ U(1)⊗ U(1) . Nonetheless, requiring compatibility of the boundary conditions with one of the asymptotic Virasoro symmetries, singles out the set to be characterized by an arbitrary function of a single variable, whose precise form depends on the choice of the chiral copy. Remarkably, requiring the asymptotic symmetries to contain the full conformal group selects a very special set of boundary conditions that is labeled by a unique constant parameter, so that the algebra of the canonical generators is given by the direct sum of two copies of the Virasoro algebra with the standard central extension and U (1). This special set of boundary conditions makes the energy spectrum of electrically charged rotating black holes to be well-behaved.
Puzzles of η-deformed AdS5 × S5
NASA Astrophysics Data System (ADS)
Arutyunov, Gleb; Borsato, Riccardo; Frolov, Sergey
2015-12-01
We derive the part of the Lagrangian for the sigma model on the η-deformed AdS5 × S5 space which is quadratic in fermions and has the full dependence on bosons. We then show that there exists a field redefinition which brings the corresponding La-grangian to the standard form of type IIB Green-Schwarz superstring. Reading off the corresponding RR couplings, we observe that they fail to satisfy the supergravity equations of motion, despite the presence of κ-symmetry. However, in a special scaling limit our solution reproduces the supergravity background found by Maldacena and Russo. Further, using the fermionic Lagrangian, we compute a number of new matrix elements of the tree level world-sheet scattering matrix. We then show that after a unitary transformation on the basis of two-particle states which is not one-particle factorisable, the corresponding T-matrix factorises into two equivalent parts. Each part satisfies the classical Yang-Baxter equation and coincides with the large tension limit of the q-deformed S-matrix.
Coherent cascade conjecture for collapsing solutions in global AdS
NASA Astrophysics Data System (ADS)
Freivogel, Ben; Yang, I.-Sheng
2016-05-01
We analyze the gravitational dynamics of a classical scalar field coupled to gravity in asymptotically AdS spacetime, which leads to black hole formation on the shortest nonlinear time scale for some initial conditions. We show that the observed collapse cannot be described by the well-known process of a random-phase cascade in the theory of weak turbulence. This implies that the dynamics on this time scale is highly sensitive to the phases of modes. We explore the alternative possibility of a coherent phase cascade and analytically find stationary solutions with completely coherent phases and power-law energy spectra. We show that these power-law spectra lead to diverging geometric backreaction, which is the likely precursor to black hole formation. In 4 +1 dimensions, our stationary solution has the same power-law energy spectrum as the final state right before collapse observed in numerical simulations. We conjecture that our stationary solutions describe the system shortly before collapse in other dimensions, and predict the energy spectrum.
1-loop partition function in AdS 3/ CFT 2
NASA Astrophysics Data System (ADS)
Chen, Bin; Wu, Jie-qiang
2015-12-01
The 1-loop partition function of the handlebody solutions in the AdS3 gravity have been derived some years ago using the heat kernel techniques and the method of images. In the semiclassical limit, such partition function should correspond to the order O( c 0) part in the partition function of dual conformal field theory(CFT) on the boundary Riemann surface. The higher genus partition function could be computed by the multi-point functions in the Riemann sphere via sewing prescription. In the large central charge limit, the CFT is effectively free in the sense that to the leading order of c the multi-point function is further simplified to be a summation over the products of two-point functions of single-particle states. Correspondingly in the bulk, the graviton is freely propagating without interaction. Furthermore the product of the two-point functions may define the links, each of which is in one-to-one correspondence with the conjugacy class of the Schottky group of the Riemann surface. Moreover, the value of a link is determined by the multiplier of the element in the conjugacy class. This allows us to reproduce exactly the gravitational 1-loop partition function. The proof can be generalized to the higher spin gravity and its dual CFT.
Progress report for the ASCI AD resistance weld process modeling project AD2003-15.
Brown, Arthur A.; Winters, William S.; Bammann, Douglas J.; Ortega, Arthur R.; Foulk, James W., III
2005-05-01
This report documents activities related to the ASCI AD Resistance Weld Process Modeling Project AD2003-15. Activities up to and including FY2004 are discussed. This was the third year for this multi year project, the objective of which is to position the SIERRA computational tools for the solution of resistance welding problems. The process of interest is a three-way coupled problem involving current flow, temperature buildup and large plastic deformation. The DSW application is the reclamation stem weld used in the manufacture of high pressure gas bottles. This is the first year the CALAGIO suite of codes (eCALORE, CALORE, and ADAGIO) was used to successfully solve a three-way coupled problem in SIERRA. This report discusses the application of CALAGIO to the tapered bar acceptance problem and a similar but independent tapered bar simulation of a companion C6 experiment. New additions to the EMMI constitutive model and issues related to CALAGIO performance are also discussed.
Bosonic excitations of the AdS 4 Reissner-Nordstrom black hole
NASA Astrophysics Data System (ADS)
Davison, Richard A.; Kaplis, Nikolaos K.
2011-12-01
We study the long-lived modes of the charge density and energy density correla- tors in the strongly-coupled, finite density field theory dual to the AdS 4 Reissner-Nordstrom black hole. For small momenta q ≪ μ , these correlators contain a pole due to sound propagation, as well as a pole due to a long-lived, purely imaginary mode analogous to the μ = 0 hydrodynamic charge diffusion mode. As the temperature is raised in the range T{\\underset{raise0.3emsmashriptscriptstylethicksim}{ < }}μ , the sound attenuation shows no significant temperature dependence. When T{\\underset{raise0.3emsmashriptscriptstylethicksim}{ > }}μ , it quickly approaches the μ = 0 hydrodynamic result where it decreases like 1/ T. It does not share any of the temperature-dependent properties of the `zero sound' of Landau Fermi liquids observed in the strongly-coupled D3/D7 field theory. For such small momenta, the energy density spectral function is dominated by the sound mode at all temperatures, whereas the charge density spectral function undergoes a crossover from being dominated by the sound mode at low temperatures to being dominated by the diffusion mode when T ˜ {μ^2}/q . This crossover occurs due to the changing residue at each pole. We also compute the momentum dependence of these spectral functions and their corresponding long-lived poles at fixed, low temperatures T ≪ μ.
Analytic self-gravitating Skyrmions, cosmological bounces and AdS wormholes
NASA Astrophysics Data System (ADS)
Ayón-Beato, Eloy; Canfora, Fabrizio; Zanelli, Jorge
2016-01-01
We present a self-gravitating, analytic and globally regular Skyrmion solution of the Einstein-Skyrme system with winding number w = ± 1, in presence of a cosmological constant. The static spacetime metric is the direct product R ×S3 and the Skyrmion is the self-gravitating generalization of the static hedgehog solution of Manton and Ruback with unit topological charge. This solution can be promoted to a dynamical one in which the spacetime is a cosmology of the Bianchi type-IX with time-dependent scale and squashing coefficients. Remarkably, the Skyrme equations are still identically satisfied for all values of these parameters. Thus, the complete set of field equations for the Einstein-Skyrme-Λ system in the topological sector reduces to a pair of coupled, autonomous, nonlinear differential equations for the scale factor and a squashing coefficient. These equations admit analytic bouncing cosmological solutions in which the universe contracts to a minimum non-vanishing size, and then expands. A non-trivial byproduct of this solution is that a minor modification of the construction gives rise to a family of stationary, regular configurations in General Relativity with negative cosmological constant supported by an SU (2) nonlinear sigma model. These solutions represent traversable AdS wormholes with NUT parameter in which the only "exotic matter" required for their construction is a negative cosmological constant.
Light-Front Holography and AdS/QCD Correspondence
Brodsky, Stanley J.; de Teramond, Guy F.
2008-04-23
Light-Front Holography is a remarkable consequence of the correspondence between string theory in AdS space and conformal field theories in physical-space time. It allows string modes {Phi}(z) in the AdS fifth dimension to be precisely mapped to the light-front wavefunctions of hadrons in terms of a specific light-front impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron. This mapping was originally obtained by matching the exact expression for electromagnetic current matrix elements in AdS space with the corresponding exact expression for the current matrix element using light-front theory in physical space-time. More recently we have shown that one obtains the identical holographic mapping using matrix elements of the energy-momentum tensor, thus providing an important consistency test and verification of holographic mapping from AdS to physical observables defined on the light-front. The resulting light-front Schrodinger equations predicted from AdS/QCD give a good representation of the observed meson and baryon spectra and give excellent phenomenological predictions for amplitudes such as electromagnetic form factors and decay constants.
Search for SmAd-SmAdscript transitions
NASA Astrophysics Data System (ADS)
Wu, Lei; Garland, C. W.; Shashidhar, R.
1993-03-01
High-resolution heat capacity measurements have been made on two mixtures of 4-nonyloxybenzoyloxy-4'-cyanoazobenzene (9OBCAB) and 4-nitrophenyl-4'-(4`-n-hexyloxybenzoyloxybenzoate) (6ONPBB). The goal of this work was to establish the thermal behavior near a proposed SmAd-SmAd' transition between two different partial bilayer smectic-A phases. Although nematic-smectic-A transitions with small Cp peaks were observed, there was no calorimetric evidence of smectic-smectic transitions. Any SmAd-SmAd' transition must be first order due to symmetry, and it seems doubtful that true thermodynamic transitions of this type exist.
Are restrictive guidelines for added sugars science based?
Erickson, Jennifer; Slavin, Joanne
2015-01-01
Added sugar regulations and recommendations have been proposed by policy makers around the world. With no universal definition, limited access to added sugar values in food products and no analytical difference from intrinsic sugars, added sugar recommendations present a unique challenge. Average added sugar intake by American adults is approximately 13% of total energy intake, and recommendations have been made as low 5% of total energy intake. In addition to public health recommendations, the Food and Drug Administration has proposed the inclusion of added sugar data to the Nutrition and Supplemental Facts Panel. The adoption of such regulations would have implications for both consumers as well as the food industry. There are certainly advantages to including added sugar data to the Nutrition Facts Panel; however, consumer research does not consistently show the addition of this information to improve consumer knowledge. With excess calorie consumption resulting in weight gain and increased risk of obesity and obesity related co-morbidities, added sugar consumption should be minimized. However, there is currently no evidence stating that added sugar is more harmful than excess calories from any other food source. The addition of restrictive added sugar recommendations may not be the most effective intervention in the treatment and prevention of obesity and other health concerns. PMID:26652250
Functional communication with AD patients: a caregiver training program.
Ripich, D N
1994-01-01
The loss of functional communication in Alzheimer disease (AD) results from the disproportionate breakdowns in the pragmatic and semantic areas of language in these patients. Communication breakdown is regularly listed among the top four stressors in measures of stress and burden of AD caregivers. A caregiver training program designed around seven specific communication strategies can be used to alter communication interactions. As a pilot program, the acronym FOCUSED organized the seven strategies for easy recall (Face-to-face, Orientation, Continuity, Unsticking, Structure, Exchanges, and Direct). Significant differences in both attitude toward AD patients, knowledge of AD, and knowledge of communication strategies were shown in comparisons of pre- and posttraining assessments. PMID:7999352
Necessary conditions for an AdS-type instability
NASA Astrophysics Data System (ADS)
Menon, Dhanya S.; Suneeta, Vardarajan
2016-01-01
In this work, we analyze the necessary conditions for a nonlinear anti-de Sitter (AdS)-type instability in the gravity-scalar field system. In particular, we discuss the necessary conditions for a cascade of energy to higher modes by applying results in Kolmogorov-Arnold-Moser theory. Our analytical framework explains numerical observations of instability of spacetimes even when the spectrum is only asymptotically resonant, and the fact that a minimum field amplitude is needed to trigger it. Our framework can be applied for similar stability analyses of fields in (locally) asymptotically AdS spacetimes. We illustrate this with the example of the AdS soliton. Further, we conjecture on the possible reasons for quasiperiodic behavior observed in perturbations of AdS spacetime. Certain properties of the eigenfunctions of the linear system dictate whether there will be localization in space leading to black hole formation. These properties are examined using the asymptotics of Jacobi polynomials. Finally we discuss recent results on the AdS instability in Einstein-Gauss-Bonnet gravity in light of our work.
Improved Correction of IR Loss in Diffuse Shortwave Measurements: An ARM Value-Added Product
Younkin, K; Long, CN
2003-11-01
Simple single black detector pyranometers, such as the Eppley Precision Spectral Pyranometer (PSP) used by the Atmospheric Radiation Measurement (ARM) Program, are known to lose energy via infrared (IR) emission to the sky. This is especially a problem when making clear-sky diffuse shortwave (SW) measurements, which are inherently of low magnitude and suffer the greatest IR loss. Dutton et al. (2001) proposed a technique using information from collocated pyrgeometers to help compensate for this IR loss. The technique uses an empirically derived relationship between the pyrgeometer detector data (and alternatively the detector data plus the difference between the pyrgeometer case and dome temperatures) and the nighttime pyranometer IR loss data. This relationship is then used to apply a correction to the diffuse SW data during daylight hours. We developed an ARM value-added product (VAP) called the SW DIFF CORR 1DUTT VAP to apply the Dutton et al. correction technique to ARM PSP diffuse SW measurements.
NASA Astrophysics Data System (ADS)
Kalligeris, N.; Flouri, E.; Okal, E.; Synolakis, C.
2012-04-01
In the eastern Mediterranean, historical and archaeological records document major earthquake and tsunami events in the past 2000 year (Ambraseys and Synolakis, 2010). The 1200km long Hellenic Arc has allegedly caused the strongest reported earthquakes and tsunamis in the region. Among them, the AD 365 and AD 1303 tsunamis have been extensively documented. They are likely due to ruptures of the Central and Eastern segments of the Hellenic Arc, respectively. Both events had widespread impact due to ground shaking, and e triggered tsunami waves that reportedly affected the entire eastern Mediterranean. The seismic mechanism of the AD 365 earthquake, located in western Crete, has been recently assigned a magnitude ranging from 8.3 to 8.5 by Shaw et al., (2008), using historical, sedimentological, geomorphic and archaeological evidence. Shaw et al (2008) have inferred that such large earthquakes occur in the Arc every 600 to 800 years, with the last known the AD 1303 event. We report on a full-scale simulation exercise that took place in Crete on 24-25 October 2011, based on a scenario sufficiently large to overwhelm the emergency response capability of Greece and necessitating the invocation of the Monitoring and Information Centre (MIC) of the EU and triggering help from other nations . A repeat of the 365 A.D. earthquake would likely overwhelm the civil defense capacities of Greece. Immediately following the rupture initiation it will cause substantial damage even to well-designed reinforced concrete structures in Crete. Minutes after initiation, the tsunami generated by the rapid displacement of the ocean floor would strike nearby coastal areas, inundating great distances in areas of low topography. The objective of the exercise was to help managers plan search and rescue operations, identify measures useful for inclusion in the coastal resiliency index of Ewing and Synolakis (2011). For the scenario design, the tsunami hazard for the AD 365 event was assessed for
ERIC Educational Resources Information Center
American Educator, 2000
2000-01-01
In a 1996 interview shortly before his death, Al Shanker, longtime president of the American Federation of Teachers, discussed such topics as: his own educational experiences; how he learned about political fighting in the Boy Scouts; the appeal of socialism; multinational corporations and the nation state; teaching tough students; and John Dewey…
NASA Astrophysics Data System (ADS)
Falcone, R. W.; Feinberg, B.; Hussain, Z.; Kirz, J.; Krebs, G. F.; Padmore, H. A.; Robin, D. S.; Robinson, A. L.
2007-11-01
As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates.
Integrated Risk Information System (IRIS)
Fosetyl - al ; CASRN 39148 - 24 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef
Massless Lüscher terms and the limitations of the AdS3 asymptotic Bethe ansatz
NASA Astrophysics Data System (ADS)
Abbott, Michael C.; Aniceto, Inês
2016-05-01
In AdS5/CFT4 integrability the Bethe ansatz gives the spectrum of long strings, accurate up to exponentially small corrections. This is no longer true in three-dimensional anti-de Sitter (AdS3 ) space, as we demonstrate here by studying Lüscher F-terms with a massless particle running in the loop. We apply this to the classic test of Hernández and López, in which the s u (2 ) sector Bethe equations (including the one-loop dressing phase) should match the semiclassical string theory result for a circular spinning string. These calculations do not agree in AdS3×S3×T4 , and we show that the sum of all massless Lüscher F-terms can reproduce the difference.
Fermions Tunnelling from Black String and Kerr AdS Black Hole with Consideration of Quantum Gravity
NASA Astrophysics Data System (ADS)
Li, Zhong-hua; Zhang, Li-mei
2016-01-01
In this paper, using the Hamilton-Jacobi Ansatz, we discuss the tunnelling of fermions when effects of quantum gravity are taken into account. We investigate two cases, black string and Kerr AdS black hole. For black string, the uncharged and un-rotating case, we find that the correction of Hawking temperature is only affected by the mass of emitted fermions and the quantum gravitational corrections slow down the increases of the temperature, which naturally leads to remnants left in the evaporation. For another case, the Kerr AdS black hole, we find that the quantum gravitational corrections are not only determined by the mass of the emitted fermions but also affected by the rotating properties of the AdS black hole. So with consideration of the quantum gravity corrections, an offset around the standard temperature always exists.
Universal slow fall-off to the unique AdS infinity in Einstein-Gauss-Bonnet gravity
Maeda, Hideki
2008-08-15
In this paper, the following two propositions are proven under the dominant energy condition for the matter field in the higher-dimensional spherically symmetric spacetime in Einstein-Gauss-Bonnet gravity in the presence of a cosmological constant {lambda}. First, for {lambda}{<=}0 and {alpha}{>=}0 without a fine-tuning to give a unique anti-de Sitter (AdS) vacuum, where {alpha} is the Gauss-Bonnet coupling constant, vanishing generalized Misner-Sharp mass is equivalent to the maximally symmetric spacetime. Under the fine-tuning, it is equivalent to the vacuum class I spacetime. Second, under the fine-tuning with {alpha}>0, the asymptotically AdS spacetime in the higher-dimensional Henneaux-Teitelboim sense is only a special class of the vacuum class I spacetime. This means the universal slow fall-off to the unique AdS infinity in the presence of physically reasonable matter.
Technology Transfer Automated Retrieval System (TEKTRAN)
We have observed that lactating mouse dams nursed 4 times per day (4X) maintained lactation, but had lower milk yields by the weigh-suckle-weigh method, than dams nursed ad libitum (AL). Therefore, we hypothesized that decreased nursing frequency would also decrease lactation persistence, increase m...
Technology Transfer Automated Retrieval System (TEKTRAN)
Background: Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR. Methods: To determine CRs feasibility, safety, and effects on predictors of longevity, di...
Very low archeointensities found for Suriname from 670 to 960 AD
NASA Astrophysics Data System (ADS)
de Groot, L. V.; Ramcharan, W.; Langereis, C. G.
2015-12-01
Geomagnetic field models predict dipole moments higher than today for the past ~3000 years (e.g. Korte et al., 2011). These models are based on data that is geographically biased towards certain regions on the Northern hemisphere; the Southern hemisphere and equatorial regions are currently underrepresented. Here we present archeointensity data obtained from potsherds from the Wageningen-1 mound on the Northwest coast of Suriname (5.8°N 56.7°W); this settlement of the Hertenrits culture was excavated in the 1970s. We obtained potsherds from six levels between 0.75 - 3 meter below the surface, corresponding to 960 and 670 AD respectively (Versteeg, 2003, p. 269-270) based on four radiocarbon datings. The remanent magnetization is carried by small pseudo-single domain grains, is stable, and small overprints are typically removed below 150 °C. Archeointensities were obtained using the IZZI-Thellier protocol; laboratory alteration was monitored by pTRM checks and pTRM Tail checks. All 23 technically acceptable archeointensities (out of 52 samples measured) are very low: between 8.0 and 18.5 μT. A trend is suggested from an average of 10-12 μT at ~700 AD, to ~18 μT at ~950 AD. This corresponds to VADMs from ~28 at ~700 AD to ~47 ZAm2 at ~950 AD. This dramatically contradicts field model predictions that range from 38-39 μT (PFM9K.1b) to 38-46 μT (SHA.DIF.14k) for this location and the same ages. Our results predate the occurrence of the South Atlantic Anomaly (SAA) by 500-1000 years; without a longer record it is difficult to decide whether our reported lows are a different discrete geomagnetic feature, or whether they are a precursor of the South Atlantic Anomaly.
Presymptomatic ALS genetic counseling and testing: Experience and recommendations.
Benatar, Michael; Stanislaw, Christine; Reyes, Eliana; Hussain, Sumaira; Cooley, Anne; Fernandez, Maria Catalina; Dauphin, Danielle D; Michon, Sara-Claude; Andersen, Peter M; Wuu, Joanne
2016-06-14
Remarkable advances in our understanding of the genetic contributions to amyotrophic lateral sclerosis (ALS) have sparked discussion and debate about whether clinical genetic testing should routinely be offered to patients with ALS. A related, but distinct, question is whether presymptomatic genetic testing should be offered to family members who may be at risk for developing ALS. Existing guidelines for presymptomatic counseling and testing are mostly based on small number of individuals, clinical judgment, and experience from other neurodegenerative disorders. Over the course of the last 8 years, we have provided testing and 317 genetic counseling sessions (including predecision, pretest, posttest, and ad hoc counseling) to 161 first-degree family members participating in the Pre-Symptomatic Familial ALS Study (Pre-fALS), as well as testing and 75 posttest counseling sessions to 63 individuals with familial ALS. Based on this experience, and the real-world challenges we have had to overcome in the process, we recommend an updated set of guidelines for providing presymptomatic genetic counseling and testing to people at high genetic risk for developing ALS. These recommendations are especially timely and relevant given the growing interest in studying presymptomatic ALS. PMID:27194384
Supersymmetric partition functions in the AdS/CFT conjecture
NASA Astrophysics Data System (ADS)
Raju, Suvrat
We study supersymmetric partition functions in several versions of the AdS/CFT correspondence. We present an Index for superconformal field theories in d = 3, 4, 5, 6. This captures all information about the spectrum that is protected, under continuous deformations of the theory, purely by group theory. We compute our Index in N = 4 SYM at weak coupling using gauge theory and at strong coupling using supergravity and find perfect agreement at large N. We also compute this Index for supergravity on AdS4 x S7 and AdS7 x S4 and for the recently constructed Chern Simons matter theories. We count 1/16 BPS states in the free gauge theory and find qualitative agreement with the entropy of big black holes in AdS5. We note that the near horizon geometry of some small supersymmetric black holes is an extremal BTZ black holes fibered on a compact base and propose a possible explanation for this, based on giant gravitons. We also find the partition function of the chiral ring of the N = 4 SYM theory at finite coupling and finite N. Turning to AdS3, we study the low energy 1/4 and 1/2 BPS partition functions by finding all classical supersymmetric probe brane solutions of string theory on this background. If the background BNS field and theta angle vanish, AdS3 x S 3 x T4/K3 supports supersymmetric probes: D1 branes, D5 branes and bound states of D5 and D1 branes. In global AdS, upon quantization, these solutions give rise to states in discrete representations of the SL(2,R) WZW model on AdS 3. We conclude that (a) the 1/4 BPS partition function jumps if we turn on a theta angle or NS-NS field (b) generic 1/2 BPS states are protected. We successfully compare our 1/2 BPS partition function with that of the symmetric product. We also discuss puzzles, and their possible resolutions, in reproducing the elliptic genus of the symmetric product. Finally, we comment on the spectrum of particles in the theory of gravity dual to non-supersymmetric Yang Mills theory on S3 x time.
Dichter, Martin Nikolaus; Wolschon, Eva-Maria; Meyer, Gabriele; Köpke, Sascha
2016-08-01
Dementia is a chronic and currently incurable syndrome. Therefore, quality of life (QoL) is a major goal when caring for people with dementia (Gibson et al., 2010) and a major outcome in dementia research (Moniz-Cook et al., 2008). The measurement of QoL, especially proxy-rating, is challenging because of the proxy-perspective (Pickard and Knight, 2005), reliability (Dichter et al., 2016), validity (O'Rourke et al., 2015), and responsiveness (Perales et al., 2013). Probably due to these challenges, it has not been possible to show positive effects for QoL in almost all non-pharmacological interventions for people with dementia (Cooper et al., 2012). One recommended (Moniz-Cook et al., 2008) and frequently used instrument is the Quality of Life in Alzheimer's Disease scale (QoL-AD), which was originally developed in the US for community-dwelling people with dementia. The QoL-AD consists of 13 items based on a 4-point Likert scale ranging from "1"=poor to "4"=excellent (Logsdon et al., 1999). The original instrument has been adapted for people living in nursing homes (NH) by Edelmann et al. (2005). PMID:26863077
Want Ads, Job Skills, and Curriculum: A Survey of 1998 Chemistry Help-Wanted Ads
NASA Astrophysics Data System (ADS)
Headrick, Kurt L.
2001-09-01
Employer surveys are useful checks on how well we are preparing students for the working world. Employer surveys are also useful because they put curriculum deficiencies into terms that are readily understood; they can thus be a catalyst for curriculum reform. This study classified 2035 chemistry jobs advertized in newspapers across the USA in the fall of 1998 according to job type, employment sector, industry, type of chemistry principally involved, and academic background and experience desired. Job ads were also searched for keywords denoting a broad range of instrumentation and techniques, personality traits, and general work skills and experience. The total of 7872 keywords, an average of 3.9 per job, indicates that employers are looking for more than just a B.S. in chemistry.
NASA Astrophysics Data System (ADS)
Kouprianova, E. G.; Stepanov, A. V.; Zaitsev, V. V.
2006-08-01
Using pulsations characteristics from AD Leo radio flares observed with Arecibo (Bastian et al., 1990) and Effelsberg (Stepanov et al. , 2001) radio telescopes, the values of electric currents (7-40)×10 ^11 A and plasma parameters in stellar flares are determined. It was shown that radio pulsations can be due to both sausage oscillations of as well as current RLC-oscillations in a flare loop (Zaitsev et al ., 1988, 2004). Explanation of very intense radio bursts (T[b ]≥ 10^15 K) in terms of coherent plasma emission gives the magnetic field value (100-300 G) and the electron number density (10^10^ - 10^11 cm^-3) in the flares. The energy of electric current stored in flares was estimated as (1-50) ×10^25 J. It is shown that <10% of stored energy was released in the flares. References Bastian, T., Bookbinder, J., Dulk, G.A., Davis, M. 1990, ApJ, 353, 265 Stepanov, A.V., Kliem, B., Zaitsev, V.V. et al. 2001, A&A, 374, 1072 Zaitsev, V.V., Stepanov, A.V., Urpo, S., Pohjolainen, S., 1998, A& A, 337, 887. Zaitsev, V.V., Kislyakov, A.G., Stepanov, A.V., Kliem, B., Fuerst, E. 2004, Astron. Lett. 30, 319
On conserved charges and thermodynamics of the AdS4 dyonic black hole
NASA Astrophysics Data System (ADS)
Cárdenas, Marcela; Fuentealba, Oscar; Matulich, Javier
2016-05-01
We consider four-dimensional gravity in the presence of a dilatonic scalar field and an Abelian gauge field. This theory corresponds to the bosonic sector of a Kaluza-Klein reduction of eleven-dimensional supergravity which induces a specific self-interacting potential for the scalar field. We compute the conserved charges and carry out the thermodynamics of an anti-de Sitter (AdS) dyonic black hole solution that was proposed recently. The charges coming from symmetries of the action are computed using the Regge-Teitelboim Hamiltonian approach. They correspond to the mass, which acquires contributions from the scalar field, and the electric charge. We introduce integrability conditions because the scalar field leads to non-integrable terms in the variation of the mass. These conditions are generically solved by introducing boundary conditions that relate the leading and subleading terms of the scalar field fall-off. The Hamiltonian Euclidean action, computed in the grand canonical ensemble, is obtained by demanding the action to have an extremum. Its value is given by a radial boundary term plus an additional polar angle boundary term due to the presence of a magnetic monopole. Remarkably, the magnetic charge can be identified from the variation of the additional polar angle boundary term, confirming that the first law of black hole thermodynamics is a consequence of having a well-defined and finite Hamiltonian action principle, even if the charge does not come from a symmetry of the action. The temperature and electrostatic potential are determined by demanding regularity of the black hole solution, whereas the value of the magnetic potential is determined by the variation of the additional polar angle boundary term. Consequently, the first law of black hole thermodynamics is identically satisfied by construction.
Stable p-branes in Chern-Simons AdS supergravities
Edelstein, Jose D.; Garbarz, Alan; Miskovic, Olivera; Zanelli, Jorge
2010-08-15
We construct static codimension-two branes in any odd dimension D, with a negative cosmological constant, and show that they are exact solutions of Chern-Simons (super)gravity theory for (super)AdS{sub D} coupled to external sources. The stability of these solutions is analyzed by counting the number of preserved supersymmetries. It is shown that static massive (D-3)-branes are unstable unless some suitable gauge fields are added and the brane is extremal. In particular, in three dimensions, a 0-brane is recognized as the negative mass counterpart of the Banados-Teitelboim-Zanelli black hole. For these 0-branes, we write explicitly magnetically charged Bogomol'nyi-Prasad-Sommerfield states with various numbers of preserved supersymmetries within the OSp(p|2)xOSp(q|2) supergroups. In five dimensions, we prove that stable 2-branes with magnetic charge always exist for the generic supergroup SU(2,4|N), where N{ne}4. For the special case N=4, in which Chern-Simons supergravity requires the addition of a nontrivial gauge field configuration in order to preserve the maximal number of degrees of freedom, we show for two different static 2-branes that they are Bogomol'nyi-Prasad-Sommerfield states (one of which is the ground state), and from the corresponding algebra of charges we show that the energy is bounded from below. In higher dimensions, our results admit a straightforward generalization, although there are presumably more solutions corresponding to different intersections of the elementary objects.
Stellar survivor from explosion in 1572 AD
NASA Astrophysics Data System (ADS)
2004-10-01
burned-out 'white dwarf' star. The normal star spills material onto the dwarf, eventually triggering an explosion. The results of this research, led by Pilar Ruiz-Lapuente of the University of Barcelona, Spain, are published in the 28 October issue of the British science journal Nature. "There was no previous evidence pointing to any specific kind of companion star out of the many that had been proposed. Here we have identified a clear path: the feeding star is similar to our sun, but slightly older," said Ruiz-Lapuente. "The high speed of the star called our attention to it," she added. Type Ia supernovae are used to measure the history of the expansion rate of the Universe and so are fundamental in helping astronomers understand the behaviour of 'dark energy', an unknown force that is accelerating the expansion of the Universe. Finding evidence to confirm the theory as to how Type Ia supernovae explode is critical to assuring astronomers that the objects can be better understood as reliable calibrators of the expansion of space. Although today's astronomers are looking at this event 432 years too late, they were still able to see a star rushing away from the location of the explosion (which is now enveloped in a vast bubble of hot gas called 'Tycho's Supernova Remnant'). The runaway star and its surroundings have been studied with a variety of telescopes for the past seven years. The NASA/ESA Hubble Space Telescope played a key role in the process by measuring the star's motion against the sky background precisely. The star is breaking the speed limit for that particular region of the Milky Way Galaxy by moving three times faster than the surrounding stars. When the system was disrupted by the white dwarf's explosion, the companion star went hurtling off into space, like a stone thrown by a sling, retaining the velocity of its orbital motion. However there are alternative explanations for this motion. It could be falling into the region from the galactic halo that
17 CFR 240.17Ad-7 - Record retention.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Record retention. 240.17Ad-7 Section 240.17Ad-7 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL RULES AND REGULATIONS, SECURITIES EXCHANGE ACT OF 1934 Rules and Regulations Under the Securities Exchange Act of 1934 Supervised...
Beyond the Job Ad: Employers and Library Instruction
ERIC Educational Resources Information Center
Hall, Russell A.
2013-01-01
Many content analyses of job ads have revealed the skills and experience needed in academic library jobs and show that library instruction is an important job duty. This study moves beyond the content of the job ads and surveys the employers themselves (in the person of the supervisor). The survey revealed that supervisors highly value library…
Secure ADS-B authentication system and method
NASA Technical Reports Server (NTRS)
Viggiano, Marc J (Inventor); Valovage, Edward M (Inventor); Samuelson, Kenneth B (Inventor); Hall, Dana L (Inventor)
2010-01-01
A secure system for authenticating the identity of ADS-B systems, including: an authenticator, including a unique id generator and a transmitter transmitting the unique id to one or more ADS-B transmitters; one or more ADS-B transmitters, including a receiver receiving the unique id, one or more secure processing stages merging the unique id with the ADS-B transmitter's identification, data and secret key and generating a secure code identification and a transmitter transmitting a response containing the secure code and ADSB transmitter's data to the authenticator; the authenticator including means for independently determining each ADS-B transmitter's secret key, a receiver receiving each ADS-B transmitter's response, one or more secure processing stages merging the unique id, ADS-B transmitter's identification and data and generating a secure code, and comparison processing comparing the authenticator-generated secure code and the ADS-B transmitter-generated secure code and providing an authentication signal based on the comparison result.
Value-Added Models for the Pittsburgh Public Schools
ERIC Educational Resources Information Center
Johnson, Matthew; Lipscomb, Stephen; Gill, Brian; Booker, Kevin; Bruch, Julie
2012-01-01
At the request of Pittsburgh Public Schools (PPS) and the Pittsburgh Federation of Teachers (PFT), Mathematica has developed value-added models (VAMs) that aim to estimate the contributions of individual teachers, teams of teachers, and schools to the achievement growth of their students. The authors' work in estimating value-added in Pittsburgh…
Healthy Skepticism's new AdWatch: understanding drug promotion.
Mansfield, Peter R
The AdWatch section of the Healthy Skepticism website (http://www.healthyskepticism.org/adwatch.asp) aims to improve medical decision-making by illuminating the techniques used in drug advertising. AdWatch draws on 20 years of dialogue about drug promotion plus ideas from many disciplines, especially logic, psychology and marketing. PMID:14636142
Assured Information Sharing for Ad-Hoc Collaboration
ERIC Educational Resources Information Center
Jin, Jing
2009-01-01
Collaborative information sharing tends to be highly dynamic and often ad hoc among organizations. The dynamic natures and sharing patterns in ad-hoc collaboration impose a need for a comprehensive and flexible approach to reflecting and coping with the unique access control requirements associated with the environment. This dissertation…
The Validity of Value-Added Models: An Allegory
ERIC Educational Resources Information Center
Martineau, Joseph A.
2010-01-01
Value-added models have become popular fixes for various accountability schemes aimed at measuring teacher effectiveness. Value-added models may resolve some of the issues in accountability models, but they bring their own set of challenges to the table. Unfortunately, political and emotional considerations sometimes keep one from examining…
Methodological Concerns about the Education Value-Added Assessment System
ERIC Educational Resources Information Center
Amrein-Beardsley, Audrey
2008-01-01
Value-added models help to evaluate the knowledge that school districts, schools, and teachers add to student learning as students progress through school. In this article, the well-known Education Value-Added Assessment System (EVAAS) is examined. The author presents a practical investigation of the methodological issues associated with the…