Stroke dynamics and frequency of 3 phacoemulsification machines.

PubMed

Tognetto, Daniele; Cecchini, Paolo; Leon, Pia; Di Nicola, Marta; Ravalico, Giuseppe

2012-02-01

To measure the working frequency and the stroke dynamics of the phaco tip of 3 phacoemulsification machines. University Eye Clinic of Trieste, Italy. Experimental study. A video wet fixture was assembled to measure the working frequency using a micro camera and a micropulsed strobe-light system. A different video wet fixture was created to measure tip displacement as vectorial movement at different phaco powers using a microscopic video apparatus. The working frequency of the Infiniti Ozil machine was 43.0 kHz in longitudinal mode and 31.6 kHz in torsional mode. The frequency of the Whitestar Signature machine was 29.0 kHz in longitudinal mode and 38.0 kHz with the Ellips FX handpiece. The Stellaris machine had a frequency of 28.8 kHz. The longitudinal stroke of the 3 machines at different phaco powers was statistically significantly different. The Stellaris machine had the highest stroke extent (139 μm). The lateral movement of the Infiniti Ozil and Whitestar Signature machines differed significantly. No movement on the y-axis was observed for the Infiniti Ozil machine in torsional mode. The elliptical path of the Ellips FX handpiece had different x and y components at different phaco powers. The 3 phaco machines performed differently in terms of working frequency and stroke dynamics. The knowledge of the peculiar lateral and elliptical path strokes of Infiniti and Whitestar Signature machines may allow the surgeon to fully use these features for lens removal. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Evaluation of response variables in computer-simulated virtual cataract surgery

NASA Astrophysics Data System (ADS)

Söderberg, Per G.; Laurell, Carl-Gustaf; Simawi, Wamidh; Nordqvist, Per; Skarman, Eva; Nordh, Leif

2006-02-01

We have developed a virtual reality (VR) simulator for phacoemulsification (phaco) surgery. The current work aimed at evaluating the precision in the estimation of response variables identified for measurement of the performance of VR phaco surgery. We identified 31 response variables measuring; the overall procedure, the foot pedal technique, the phacoemulsification technique, erroneous manipulation, and damage to ocular structures. Totally, 8 medical or optometry students with a good knowledge of ocular anatomy and physiology but naive to cataract surgery performed three sessions each of VR Phaco surgery. For measurement, the surgical procedure was divided into a sculpting phase and an evacuation phase. The 31 response variables were measured for each phase in all three sessions. The variance components for individuals and iterations of sessions within individuals were estimated with an analysis of variance assuming a hierarchal model. The consequences of estimated variabilities for sample size requirements were determined. It was found that generally there was more variability for iterated sessions within individuals for measurements of the sculpting phase than for measurements of the evacuation phase. This resulted in larger required sample sizes for detection of difference between independent groups or change within group, for the sculpting phase as compared to for the evacuation phase. It is concluded that several of the identified response variables can be measured with sufficient precision for evaluation of VR phaco surgery.

Efficacy of the SENSIMED Triggerfish® in the postoperative follow-up of PHACO-ExPRESS combined surgery.

PubMed

Osorio-Alayo, V; Pérez-Torregrosa, V T; Clemente-Tomás, R; Olate-Pérez, Á; Cerdà-Ibáñez, M; Gargallo-Benedicto, A; Barreiro-Rego, A; Duch-Samper, A

2017-08-01

To determine the usefulness of the SENSIMED Triggerfish ® system in the postoperative control of combined phacoemulsification and ExPRESS implant (PHACO-ExPRESS) surgery in patients with cataract and chronic open angle glaucoma (COAG) during a 2 months follow-up. A prospective study conducted on 15 eyes that were subjected to PHACO-ExPRESS combined surgery. Using the SENSIMED Triggerfish ® system, two records of the circadian patterns of intraocular pressure (IOP) were performed, one before and one after surgery. A record was made of the best corrected visual acuity (BCVA), comorbidities, previous IOP, and 7-30-60 days after surgery, as well as any hypotensive drugs and complications. The final sample was 12 eyes. The mean pre-operative BCVA (log MAR chart) before surgery was 0.5±0.2, and after surgery 0.14±0.1 (P=.02). The previous IOP was 18.7±3.8mmHg with 2.9±0.7 drugs. The mean IOP at 7, 30, and 60 days after surgery decreased to 13±4.1mmHg (P=.002), 13.5±2mmHg (P=.001), and 13.9±2.5mmHg (P=.001), respectively. The amplitudes of the circadian curves changed significantly after surgery (P=.007). The mean values between daytime and night-time periods decreased significantly from 146.8±80.9 mVeq and 61.2±92.mVeq before surgery to 36.4±36 mVeq (P=.000), and -23,2±47.6mVeq (P=.014) after surgery, respectively. There were complications in one patient. The SENSIMED Triggerfish ® monitoring system showed changes in the curves of the circadian patterns, as well as decreased mean amplitudes after the combined PHACO-ExPRESS technique, suggesting that it may become a useful tool for postoperative follow-up of COAG. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Application of Corvis ST to evaluate the effect of femtosecond laser-assisted cataract surgery on corneal biomechanics.

PubMed

Wei, Yinjuan; Xu, Lingxiao; Song, Hui

2017-08-01

The aim of the present study was to evaluate the effects of femtosecond laser-assisted cataract surgery (FLACS) and phacoemulsification on corneal biomechanics using corneal visualization Scheimpflug technology. The medical records of 50 eyes from 50 patients who received phacoemulsification and intraocular lens implantation because of age-related factors between June 2014 and September 2014 were retrospectively analyzed. FLACS was used in 12 eyes (FLACS group), and conventional phacoemulsification in 38 eyes (PHACO group). The evaluation of corneal biomechanical parameters included the first/second applanation time (A-time1/A-time2), the first/second applanation length (A-length1/A-length2), corneal velocity during the first/second applanation moment (Vin/Vout), highest concavity time, highest concavity-radius (HC-radius), peak distance (PD), deformation amplitude (DA), central corneal thickness (CCT), and intraocular pressure (IOP). The differences in A-length1/A-length2, IOP, CCT, PD, and DA were significant in the PHACO group between those before, 1 week after, and 1 month after surgery. No significant differences in corneal biomechanical parameters were found between those at 1 month after surgery and before surgery. There were significant differences in IOP and CCT in the FLACS group between those before, 1 week after, and 1 month after surgery. There were no significant differences in the other corneal biomechanical parameters. No significant differences were found in corneal biomechanical parameters between those 1 month after surgery and before surgery. There were significant differences in A-length1/A-length2, CCT, PD, and DA between the two groups at 1 week after surgery. There were no significant differences in corneal biomechanical parameters between the two groups at 1 month after surgery. In conclusion, the effect of FLACS on corneal biomechanics is smaller than that of phacoemulsification. The corneal biomechanical parameters are restored to preoperative levels with the healing of the incision, and the reduction of swelling of the tissue near the incision.

Wound and surface temperatures in vivo in torsional and longitudinal modalities of ultrasound in coaxial microincisional cataract surgery

PubMed Central

Nair, Swapna; Nair, Ramachandran Unnikrishnan

2017-01-01

Background To study phacoemulsification probe shaft/wound and corneal surface/tip temperatures in vivo during longitudinal, torsional and combined phacoemulsification modes and their relationship to machine parameters. Design This was a prospective study at Chaithanya Eye Hospital and Research Institute, Trivandrum, India (tertiary). Participants Twenty-two eyes of 22 patients were randomized into six groups depending on the grade of nuclear sclerosis (NS) and the type of ultrasound used: Group 1, torsional in NS2; Group 2, torsional in NS3; Group 3, torsional with intermittent longitudinal in NS2; Group 4, torsional with intermittent longitudinal in NS3; Group 5, longitudinal in NS2; Group 6, longitudinal in NS3. Methods Patients underwent phacoemulsification by torsional, longitudinal or combined modalities. A thermal camera was used to measure phaco probe temperatures. Main outcome measures The mean probe shaft and tip temperatures were documented for different ultrasound modalities. Results The mean shaft and tip temperatures were: Group 1, 29.22°C±0.71°C and 28.4°C±0.88°C; Group 2, 32.12°C±0.62°C and 31.88°C±0.84°C; Group 3, 30.25°C±0.71°C and 29.35°C±0.62°C; Group 4, 31.95°C±0.65°C and 32.01°C±1.31°C; Group 5, 23°C and 27.6°C and Group 6, 23°C and 29.68°C, respectively. In all groups using longitudinal ultrasound, the phaco tip surface temperatures were higher than the shaft temperatures, except in Group 3. Shaft temperatures were higher than tip temperatures in cases using torsional phaco, except in Group 4. The mean temperature difference between groups was significant only for shaft temperatures (P=0.001). On thermal imaging, for torsional phaco, the rise in temperature of the probe from shaft to tip was dependent on the amplitude of ultrasound applied (P=0.009). Conclusion The shaft temperatures were higher than over the phaco tip during torsional phacoemulsification. PMID:28184151

Evaluation of Ophthalmic Surgical Instrument Sterility Using Short-Cycle Sterilization for Sequential Same-Day Use.

PubMed

Chang, David F; Hurley, Nikki; Mamalis, Nick; Whitman, Jeffrey

2018-03-27

The common practice of short-cycle sterilization for ophthalmic surgical instrumentation has come under increased regulatory scrutiny. This study was undertaken to evaluate the efficacy of short-cycle sterilization processing for consecutive same-day cataract procedures. Testing of specific sterilization processing methods by an independent medical device validation testing laboratory. Phaco handpieces from 3 separate manufacturers were tested along with appropriate biologic indicators and controls using 2 common steam sterilizers. A STATIM 2000 sterilizer (SciCan, Canonsburg, PA) with the STATIM metal cassette, and an AMSCO Century V116 pre-vacuum sterilizer (STERIS, Mentor, OH) using a Case Medical SteriTite container (Case Medical, South Hackensack, NJ) rigid container were tested using phaco tips and handpieces from 3 different manufacturers. Biological indicators were inoculated with highly resistant Geobacillus stearothermophilus, and each sterility verification test was performed in triplicate. Both wrapped and contained loads were tested with full dry cycles and a 7-day storage time to simulate prolonged storage. In adherence with the manufacturers' instructions for use (IFU), short cycles (3.0-3.5-minute exposure times) for unwrapped and contained loads were also tested after only 1 minute of dry time to simulate use on a consecutive case. Additional studies were performed to demonstrate whether any moisture present in the load containing phaco handpieces postprocessing was sterile and would affect the sterility of the contents after a 3-minute transit/storage time. This approximated the upper limit of time needed to transfer a containment device to the operating room. Presence or absence of microbial growth from cultured test samples. All inoculated test samples from both sterilizers were negative for growth of the target organism whether the full dry phase was interrupted or not. Pipetted postprocessing moisture samples and swabs of the handpieces were also negative for growth after a 3-minute transit/storage time. These studies support the use of unwrapped, short-cycle sterilization that adheres to the IFU of these 2 popular Food and Drug Administration-cleared sterilizers for sequential same-day cataract surgeries. A full drying phase is not necessary when the instruments are kept within the covered sterilizer containment device for prompt use on a sequential case. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

A study of initial therapy for glaucoma in southern India: India Glaucoma Outcomes and Treatment (INGOT) Study.

PubMed

Congdon, Nathan G; Krishnadas, R; Friedman, David S; Goggins, William; Ramakrishnan, R; Kader, M A; Gilbert, Donna; Tielsch, James; Quigley, Harry A

2012-06-01

To compare initial glaucoma therapy with medications and trabeculectomy in southern India. Patients aged ≥ 30 years newly diagnosed with glaucoma were randomized to trabeculectomy with 5-fluorouracil or medical therapy. Subjects with best-corrected vision <6/18 due to cataract underwent phacoemulsification (phaco/intraocular lens, IOL). Intraocular pressure (IOP), vision and visual function were assessed at 12 months. Patients assigned to medications and surgery received the expected therapy in 86% (172/199) and 64% (126/199) of cases, respectively. Forty patients (20%) assigned to surgery refused any treatment and 33 (17%) received medications. Among 199 patients randomized to medications, 52 (26.1%) underwent phaco/IOL, as did 89/199 (43.7%) of patients randomized to trabeculectomy. Baseline parameters of the two groups did not differ, nor did 1-year follow-up rates (medication 65%, trabeculectomy 58%, P = 0.15). Final IOP was lower with randomization to trabeculectomy (16.3 ± 5.1 mmHg) than medication (18.8 ± 6.7 mmHg, P < 0.0001). In regression models, randomization to trabeculectomy (P < 0.0001) was associated with lower IOP, and simultaneous trabeculectomy and cataract surgery was associated with higher IOP (P = 0.008) than trabeculectomy alone. Subjects receiving Phaco/IOL had significantly better final acuity (P < 0.0001) and visual function (P = 0.035), despite concurrent glaucoma treatment. Final visual acuity was worse in those receiving trabeculectomy in addition to cataract surgery, but this was of borderline significance (P = 0.06). Trabeculectomy lowered IOP significantly more than medical treatment, but with slightly greater loss of visual acuity. Combined phaco/IOL and trabeculectomy improved visual acuity with substantial IOP lowering.

[Preliminary evaluation of the femtosecond laser-assisted cataract surgery in 300 cases].

PubMed

Wang, Yong; Bao, Xianyi; Zhou, Yanli; Xu, Rong; Peng, Tingting; Sun, Ming; Cao, Danmin; He, Ling

2015-09-01

To evaluate the clinical outcome of the femtosecond laser-assisted cataract surgery (FLACS) in our first 300 cases. In this retrospective study, the study group comprised 300 cases (300 eyes) in which FLACS was done. The control group comprised 300 cases (300 eyes) in which phacoemulsification was performed. The steps of the FLACS included capsulotomy, lens fragmentation, corneal incisions, and creation of incisions within the peripheral cornea to aid the correction of pre-existing astigmatism. After the FLACS, 2.2-mm coaxial micro-incision phacoemulsification and implantation of an intraocular lens were operated. The preoperative best corrected visual acuity (BCVA) and postoperative uncorrected visual acuity (UCVA), the cumulative dissipated energy (CDE) of the phacoemulsification, and the parameters of the FLACS, including the docking time, the suction time and the laser time, were recorded. The complications of the FLACS were analyzed. The FLACS was successfully completed in 99.33% of the cases. The docking time was (24.6 ± 16.8) sec, the suction time was (101.27 ± 20.09) sec, and the laser time was (23.3 ± 5.5) sec. The most common complications of the FLACS included suction break (7/300, 2.33%), subconjunctival hemorrhage (58/300, 19.33%), pupillary constriction (47/300, 15.67%), incision at a wrong site (13/300, 4.33%), anterior capsular tag (17/300, 5.67%), decentration of the capsulorhexis (11/300, 3.67%), failure to split the lens nucleus (5/300, 1.67%), and posterior capsular ruptures (1/300, 0.33%). The CDE was 5.52 ± 5.18 in the FLACS group and 8.37 ± 7.91 in the traditional phaco group (P < 0.05). The UCVA was 0.12 ± 0.08 and 0.13 ± 0.11 at 1 month after the FLACS and traditional phaco, respectively (P > 0.05). Compared with the conventional phacoemulsification surgery, the FLACS can achieve less CDE and better early postoperative visual acuity. Long-term effects remain to be investigated.

Patients with Fuchs Endothelial Dystrophy and Cataract Undergoing Descemet Stripping Automated Endothelial Keratoplasty and Phacoemulsification with Intraocular Lens Implant: Staged versus Combined Procedure Outcomes.

PubMed

Sykakis, Evripidis; Lam, Fook Chang; Georgoudis, Panagiotis; Hamada, Samer; Lake, Damian

2015-01-01

Purpose. To compare the surgical outcomes of staged and combined phacoemulsification with intraocular lens implant (phaco+IOL) and Descemet stripping automated endothelial keratoplasty (DSAEK) in patients with Fuchs' endothelial dystrophy and cataract. Setting. Corneoplastic Unit and Eye Bank, Queen Victoria Hospital, East Grinstead, UK. Methods. Retrospective study of patients who had combined phaco+IOL and DSAEK (group 1) or phaco+IOL followed within 2 months by DSAEK (group 2). Patients who had previous eye surgery or any other ocular comorbidities were excluded. Results. There were 28 eyes in group 1 and 31 in group 2. There were no significant differences in the demographics and corneal tissue characteristics of the two groups. The endothelial disc dislocation and rebubbling rate within 1 week in group 1 was 21.42% and in group 2 was 3.2% (P = 0.04), while the endothelial cell density at 12 months was 1510 ± 433 for group 1 and 1535 ± 482 for group 2 (P = 0.89). The mean 12-month logMAR visual acuity was 0.28 ± 0.24 for group 1 and 0.33 ± 0.15 for group 2 (P = 0.38). Conclusions. Although the combined procedure seems to be associated with a higher complication rate the final outcomes seem to be similar to both methods.

Patients with Fuchs Endothelial Dystrophy and Cataract Undergoing Descemet Stripping Automated Endothelial Keratoplasty and Phacoemulsification with Intraocular Lens Implant: Staged versus Combined Procedure Outcomes

PubMed Central

Lam, Fook Chang; Georgoudis, Panagiotis; Hamada, Samer; Lake, Damian

2015-01-01

Purpose. To compare the surgical outcomes of staged and combined phacoemulsification with intraocular lens implant (phaco+IOL) and Descemet stripping automated endothelial keratoplasty (DSAEK) in patients with Fuchs' endothelial dystrophy and cataract. Setting. Corneoplastic Unit and Eye Bank, Queen Victoria Hospital, East Grinstead, UK. Methods. Retrospective study of patients who had combined phaco+IOL and DSAEK (group 1) or phaco+IOL followed within 2 months by DSAEK (group 2). Patients who had previous eye surgery or any other ocular comorbidities were excluded. Results. There were 28 eyes in group 1 and 31 in group 2. There were no significant differences in the demographics and corneal tissue characteristics of the two groups. The endothelial disc dislocation and rebubbling rate within 1 week in group 1 was 21.42% and in group 2 was 3.2% (P = 0.04), while the endothelial cell density at 12 months was 1510 ± 433 for group 1 and 1535 ± 482 for group 2 (P = 0.89). The mean 12-month logMAR visual acuity was 0.28 ± 0.24 for group 1 and 0.33 ± 0.15 for group 2 (P = 0.38). Conclusions. Although the combined procedure seems to be associated with a higher complication rate the final outcomes seem to be similar to both methods. PMID:26064669

A Comparative Study of Clear Corneal Phacoemulsification with Rigid IOL Versus SICS; the Preferred Surgical Technique in Low Socio-economic group Patients of Rural Areas.

PubMed

Devendra, Jaya; Agarwal, Smita; Singh, Pankaj Kumar

2014-11-01

Low socio-economic group patients from rural areas often opt for free cataract surgeries offered by charitable organisations. SICS continues to be a time tested technique for cataract removal in such patients. In recent times, camp patients are sometimes treated by clear corneal phacoemulsification with implantation of a rigid IOL, which being more cost effective is often provided for camp patients. This study was undertaken to find out which surgical technique yielded better outcomes and was more suited for high volume camp surgery. To find the better surgical option- phacoemulsification with rigid IOL or SICS, in poor patients from rural areas. A prospective randomised controlled trial of cataract patients operated by two different techniques. One hundred and twelve eyes were selected and were randomly allocated into two groups of 56 eyes each. At completion of the study, data was analysed for 52 eyes operated by clear corneal phacoemulsification and implantation of a rigid IOL, and 56 eyes operated by SICS. Unpaired t-test was used to calculate the p- value. The results were evaluated on the following criteria. The mean post-operative astigmatism at the end of four weeks - was significantly higher in phacoemulsification group as compared to SICS group The BCVA (best corrected visual acuity) at the end of four weeks - was comparable in both groups. Subjective complaints and/ or complications: In phaco group two patients required sutures and seven had striate keratitis , while none in SICS group. Complaint of irritation was similar in both groups. Surgical time- was less for SICS group as compared to phaco group. SICS by virtue of being a faster surgery with more secure wound and significantly less astigmatism is a better option in camp patients from rural areas as compared to phacoemulsification with rigid IOL.

Dodick laser phacolysis: thermal effects.

PubMed

Alzner, E; Grabner, G

1999-06-01

To gather experimental data on whether Dodick laser phacolysis leads to corneal or scleral burns. The Eye Department, County Hospital Salzburg, Salzburg, Austria. The study was done using a pulsed neodymium:YAG (Nd:YAG) laser with a wavelength of 1064 nm; energy, 10 mJ; and duration of pulses, 14 ns. The light pulse is carried by a 400 microns quartz fiber to the laser phacolysis probe. The laser light hits a titanium target inside the tip, causing an optical breakdown and thus a shock wave. The generation of both plasma and the shock disrupt the nuclear material. The temperature at the ultrasonic phaco and laser phacolysis tip was measured under air and balanced salt solution (BSS) in a test chamber and in the anterior chambers of eye-bank eyes. Ultrasonic phacoemulsification led to a difference in temperature up to 55.3 degrees C under air, 12 degrees C in BSS, and 10.9 degrees C in the anterior chamber. There was no clinical significant heat generated by the laser phacolysis tip. This initial in vitro study demonstrates that the well-known risk of the tissue heating (i.e., phaco burn) does not occur with Dodick laser phacolysis, even when the irrigation flow is slow or discontinued.

Ultrasonic-generated fluid velocity with Sovereign WhiteStar micropulse and continuous phacoemulsification.

PubMed

Steinert, Roger F; Schafer, Mark E

2006-02-01

To evaluate and compare ultrasonic turbulence created by conventional and micropulse ultrasound technology. Sonora Medical Systems, Longmont, Colorado, USA. A high-resolution digital ultrasound probe imaged the zone around a phacoemulsification tip. Doppler analysis allowed determination of flow. The fluid velocity was measured at 4 levels of ultrasound power at a constant flow, comparing the ultrasonic conditions of continuous energy to WhiteStar micropulses. In addition to the normal baseline irrigation and aspiration, fluid movement was detected directly below the phaco tip, produced by a nonlinear effect known as acoustic streaming. Acoustic streaming increased with increased phacoemulsification power for both conditions. At each of the 4 levels of power, fluid velocity away from the tip was less with micropulse technology than with continuous phacoemulsification. The demonstrated decrease in acoustic streaming flow away from the phaco tip with Sovereign WhiteStar micropulse technology compared to conventional ultrasound provides an objective explanation for clinical observations of increased stability of nuclear fragments at the tip and less turbulence in the anterior chamber during phacoemulsification. This methodology can be used to examine and compare fluid flow and turbulence under a variety of clinically relevant conditions.

[Phacoemulsification versus manual small incision cataract surgery: Anatomic and functional results].

PubMed

Ammous, I; Bouayed, E; Mabrouk, S; Boukari, M; Erraies, K; Zhioua, R

2017-06-01

Prospective randomised study to compare the impact of phacoemusification (PHACO) and small incision cataract surgery (SICS) on endothelial structure (cell density and morphology) and refractive results (visual acuity, induced astigmatism). Prospective study of 57 patients (63 eyes) over 20 months (May 2012-January 2014) undergoing surgery by 2 experienced surgeons. We included patients with senile or presenile cataracts, LOCS III class 2, 3 and 4. Patients were randomized into 2 groups based on their birth month (group 1: PHACO [33]; group 2: SICS [30]). All pre- intra- and postoperative data were collected prospectively. The minimum follow-up was 6 months. We used the SPSS 18.0 for statistical analysis. Statistical tests used included the test-t Student, the Anova test, the Mann-Witney non-parametric test and the Khi 2 test. A threshold of significance was set at 0.05. The mean preoperative endothelial cell density was 2447.5±225 c/mm 2 with no significant difference between the two groups (P=0.207). The mean percentage of hexagonality was 55.5±8.2% in groups 1 and 2. The most significant cell loss was during the first immediate postoperative period for both groups. At Day 15 postoperative, the decrease in cell loss was significant (P<0.001) with a mean loss of 312.9±208.9 c/mm 2 (P<10 -2 ). Postoperatively, the mean best-corrected visual acuity was 0.057 log MAR for all of our patients (P=0.170); no patient had an acuity ≤1/10. The mean astigmatism at the conclusion of follow-up was 1.08±0.42 D in group 1 and 1.51±0.55 D in group 2, with a significant difference (P=0.001). Both SICS and PHACO give excellent results, both anatomical and refractive. However, SICS appears to be more advantageous than PHACO in terms of speed, cost, and independence from technology, and appears to be better suited to dense cataracts and mass surgery. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Isolated Capsulorhexis Flap Technique in Femtosecond Laser-Assisted Cataract Surgery to Protect the Corneal Endothelial Cells.

PubMed

Li, Shaowei; Chen, Xu; Zhao, Jun; Xu, Man; Yu, Zhouxing

2017-12-18

To present a novel technique that using capsulorhexis flap to protect corneal endothelial cells during femtosecond laser-assisted cataract surgery. During the procedure, an isolated capsulorhexis flap was used to lift it up carefully by using OVD until the flap attached to the corneal inner layer. It kept steady during the phaco phase, and been removed by I/A tip after intraocular lens implantation. In our pilot study, the damage to the corneal endothelial cells from the phacoemulsification procedure were no more than the traditional phaco procedure, even femtosecond laser assisted cataract surgery. Isolated capsulorhexis flap technique initiate a new approach to protect the endothelial cell. It is a simple technique with a short learning curve, but still need a further investigation to prove the protection of corneal endothelial cells.

Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces.

PubMed

Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

2015-01-01

To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Assil Eye Institute, Beverly Hills, CA, USA. Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (P<0.05 for both). Similarly, mean total balanced salt solution used was significantly less with the transverse system vs torsional (P<0.05). Postoperative safety demonstrated significantly lower endothelial cell loss at 1 day and 1 month (P<0.05) with transverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may translate to a better overall safety profile for the patient.

Eye drops preservative as the cause of corneal band keratopathy in long-term pilocarpine hydrochloride treatment.

PubMed

Pavicić-Astalos, Jasna; Lacmanović-Loncar, Valentina; Petric-Vicković, Ivanka; Sarić, Dean; Mandić, Zdravko; Csik, Tigrena; Susić, Nikola

2012-03-01

The aim is to present a patient with severe bilateral corneal complications after long-term antiglaucoma treatment with 1% pilocarpine hydrochloride (Pilokarpin, Pliva, Zagreb, Croatia) and its management. A patient with narrow-angle glaucoma treated with 1% topical pilocarpine hydrochloride eye drops for the last twenty years complained of impaired vision, intermittent visual haloes and eye redness. Ophthalmologic examination showed bilateral band keratopathy, peripheral laser iridotomy, medicamentous myosis, brown nuclear cataract, and synchysis scintillans of his right eye. Band keratopathy was thought to have resulted from the presence of the preservative phenylmercuric nitrate in the pilocarpine hydrochloride eye drops. Treatment of the patient consisted of two separate procedures for both eyes, i.e. phaco trabeculectomy and six months later corneal procedure including abrasion of corneal epithelium followed by removal of the superficial stromal calcium deposits by means of a 3.75% ethylenediaminetetraacetic (EDTA) solution. After phaco trabeculectomy, visual acuity was 0.8 on both eyes. Bilateral visual improvement with visual acuity 1.0 was recorded after corneal treatment with EDTA. In conclusion, one must be aware of preservative complications in long-term topical use, such as band keratopathy that can be visually incapacitating. Surgical treatment using EDTA is safe and effective treatment for band keratopathy.

Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces

PubMed Central

Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

2015-01-01

Purpose To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Setting Assil Eye Institute, Beverly Hills, CA, USA. Design Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients and methods Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Results Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (P<0.05 for both). Similarly, mean total balanced salt solution used was significantly less with the transverse system vs torsional (P<0.05). Postoperative safety demonstrated significantly lower endothelial cell loss at 1 day and 1 month (P<0.05) with transverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. Conclusion The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may translate to a better overall safety profile for the patient. PMID:26345628

Fluid temperature at the corneal endothelium during phacoemulsification: comparison of an ophthalmic viscosurgical device and balanced salt solution using the finite element method.

PubMed

Reepolmaha, Somporn; Limtrakarn, Wiroj; Uthaisang-Tanechpongtamb, Wanlaya; Dechaumphai, Pramote

2010-01-01

The purpose of this study was to estimate and compare the temperatures of two different anterior chamber solutions at the corneal endothelial level during phacoemulsification. An ophthalmic viscosurgical device (OVD) and balanced salt solution (BSS) were compared using the finite element method (FEM). The thermal properties of an OVD (IAL-F) and BSS were studied in an experimental setting. A computer-aided design model of ocular anatomy was created in two dimensions. The phaco needle was considered to be the only source of heat generation. Then, the FEM was used to demonstrate the transient temperature distribution in the two ocular models at 10, 20, 30, 40, 50 and 60 s. In these models, the anterior chamber was filled with IAL-F (IAL-F model) or BSS (BSS model). The heat generation rate of the phaco needle was 0.0004 cal/s/mm(2). The maximum corneal endothelial temperatures for the two models at 60 s were 52.67 and 41.57 degrees C, respectively. The experimental IAL-F model showed fewer changes in temperature for any given time and location. At larger distances from the heat source, less temperature variation was detected. Phacoemulsification is a potential heat-generating procedure performed between the delicate anterior chamber structures. During this procedure, IAL-F protects the endothelium against heat better than BSS. Copyright 2009 S. Karger AG, Basel.

Evaluation of endothelial mucin layer thickness after phacoemulsification with next generation ophthalmic irrigating solution.

PubMed

Ghate, Deepta A; Holley, Glenn; Dollinger, Harli; Bullock, Joseph P; Markwardt, Kerry; Edelhauser, Henry F

2008-10-01

To evaluate human corneal endothelial mucin layer thickness and ultrastructure after phacoemulsification and irrigation-aspiration with either next generation ophthalmic irrigating solution (NGOIS) or BSS PLUS. Paired human corneas were mounted in an artificial anterior chamber, exposed to 3 minutes of continuous ultrasound (US) at 80% power using the Alcon SERIES 20000 LEGACY surgical system (n = 9) or to 2 minutes of pulsed US at 50% power, 50% of the time at 20 pps using the Alcon INFINITI Vision System (n = 5), and irrigated with 250 mL of either NGOIS or BSS PLUS. A control group of paired corneas did not undergo phacoemulsification or irrigation-aspiration (n = 5). Corneas were divided and fixed for mucin staining or transmission electron microscopy. Mucin layer thickness was measured on the transmission electron microscopy prints. The mucin layer thickness in the continuous phaco group was 0.77 +/- 0.02 microm (mean +/- SE) with NGOIS and 0.51 +/- 0.01 microm with BSS PLUS (t test, P < 0.001). The mucin layer thickness in the pulsed phaco group was 0.79 +/- 0.02 microm with NGOIS and 0.54 +/- 0.01 microm with BSS PLUS (P < 0.001). The mucin layer thickness in the untreated control group was 0.72 +/- 0.02 microm. The endothelial ultrastructure was normal in all corneas. In this in vitro corneal model, NGOIS, due to its lower surface tension and higher viscosity, preserved endothelial mucin layer thickness better than BSS PLUS with both the INFINITI Vision System (pulsed US) and the LEGACY surgical system (continuous US).

A Computer Based Cognitive Simulation of Cataract Surgery

DTIC Science & Technology

2011-12-01

for zonular absence, assess for notable lenticular astigmatism ** How and when do you decide to use a capsular tension ring? (Expert) Zonular...INTRODUCTION The Virtual Mentor Cataract Surgery Trainer is a computer based, cognitive simulation of phacoemulsification cataract surgery. It is...the Cataract Trainer. BODY Phacoemulsification cataract surgery (phaco) is a difficult procedure to learn, with little margin for error. As in other

Manual small incision extracapsular cataract surgery in Australia.

PubMed

van Zyl, Lourens; Kahawita, Shyalle; Goggin, Michael

2014-11-01

Examination of the results and describing the technique of manual small incision extracapsular cataract extraction on patients with advanced cataracts in urban Australia. A descriptive case series. Thirty-eight patients at three public hospitals, one tertiary and two secondary ophthalmic units in urban Australia. Forty eyes with dense mature cataracts with hand movement vision or worse underwent a planned manual small incision extracapsular cataract extraction instead of traditional phaco-emulsification. Postoperative visual aquity, surgically induced astigmatism and complications. Seventy-eight per cent of patients had an uncorrected visual acuity of 6/12 or better on the first postoperative day. Eighty-three per cent of patients had a distance corrected visual acuity of 6/9 or better 3 months postoperatively. One case was complicated by a posterior capsule rupture. No cases of endophthalmitis were reported. The summated vector mean of the surgically induced astigmatism was 0.089D at 93°. Manual small incision extracapsular cataract extraction is an efficacious cataract surgery technique with good visual outcome and is a safe alternative to phaco-emulsification in suitable cases in a first-world setting. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Novel Gonioscopy Score and Predictive Factors for Intraocular Pressure Lowering After Phacoemulsification.

PubMed

Perez, Claudio I; Chansangpetch, Sunee; Feinstein, Max; Mora, Marta; Nguyen, Anwell; Badr, Mai; Masis, Marisse; Lin, Shan C

2018-05-04

To evaluate a novel gonioscopy score as a potential predictor for intraocular pressure (IOP) reduction after cataract surgery. Prospective study that included consecutive patients with or without glaucoma, either with open or narrow angles but without peripheral anterior synechiae, who underwent phacoemulsification. Eyes with intraoperative complications and secondary glaucoma were excluded. A preoperative gonioscopy score was created, summing the Shaffer gonioscopy grading in 4 quadrants (range 0-16). To determine variables associated with IOP change at 6 months, univariate and multivariate linear mixed-effects regression analysis was performed adjusting for age, sex, and preoperative IOP. 188 eyes from 137 patients were enrolled. The mean age of the patients was 75.0 (±8.5) years and the average preoperative IOP was 15.6 (±3.6) mm Hg with 0.7 (range 0-4) glaucoma medications. The mean IOP reduction after phaco was 3.0 (±2.6) mm Hg at postoperative month 6. After multivariate analysis, preop IOP (β=0.49 [0.41 - 0.58] P<0.0001), gonioscopy score (β=-0.17 [-0.24 - -0.09] P<0.0001), ACD (β=-0.88 [-1.64 - -0.14] P=0.02) and IOP/ACD ratio (β=0.45 [0.07 - 0.83] P=0.021) were associated with IOP reduction at 6 months. Preoperative predictors for IOP reduction after cataract surgery were preoperative IOP, ACD, gonioscopy score and IOP/ACD ratio. The IOP/ACD ratio and gonioscopy score can be easy parameters to obtain and may help clinicians to estimate the IOP reduction after phaco.

MIGS: therapeutic success of combined Xen Gel Stent implantation with cataract surgery.

PubMed

Hohberger, Bettina; Welge-Lüßen, Ulrich-Christoph; Lämmer, Robert

2018-03-01

Glaucoma, a common disease in the elderly population, is frequently coexistent with cataract. While the combination of filtration surgery and cataract surgery is a challenging topic with limited success, minimal invasive glaucoma surgery (MIGS), such as Xen Gel Stents, seems to provide promising results. The aim of this study was to investigate the complete and qualified therapeutic success of Xen Gel Stent implantation with (XenPhaco) and without cataract surgery. One hundred and eleven open-angle glaucoma eyes underwent implantation of Xen45 Gel Stent (AqueSys, Inc.) with or without cataract operation. Complete therapeutic success was defined as target intraocular pressure (IOP) < 18 mmHg at any time point within 6 months of follow-up without local antiglaucomatous therapy or further surgical interventions. Qualified success was defined as target IOP <18 mmHg with additional 1-2 local antiglaucomatous eye drops. Failure included all cases with the necessity of at least three local antiglaucomatous eye drops or additional glaucoma surgery. Combined implantation of Xen Gel Stent with cataract surgery was performed in 30 eyes and stand-alone Xen Gel Stent implantation was performed in 81 eyes. A complete therapeutic success was achieved in 46.9% of single Xen Gel Stent implantation, whereas 53.3% was reached with combined XenPhaco. Qualified success was seen in 2.5% in the eyes of the single Xen Gel Stent implantation group and in 3.3% of the combined surgery group. Therapeutic failure rate was 49.4% in the stand-alone group vs 46.7% in the combined group. Data were not significantly different for group and subgroup analyses. Complete and qualified therapeutic success is similar for the combination of Xen Gel Stent implantation with and without cataract surgery in open-angle glaucoma patients. MIGS using Xen Gel Stent can be recommended in situations if glaucoma surgery is indicated besides coexisting cataract.

Residency Evaluation and Adherence Design Study III: Ophthalmology residency training in India: Then and now-Improving with time?

PubMed

Biswas, Partha; Gogate, Parikshit Madhav; Maskati, Quresh Badr; Natarajan, Sundaram; Verma, Lalit; Bansal, Payal K

2018-06-01

To gauge the differences in ophthalmology residency training, academic, clinical and surgical, in the last three decades of the 20 th century and the first decade of the 21 st century. A survey was conducted by the Academic and Research Committee of the All India Ophthalmological Society, in 2014-2016, using a prevalidated questionnaire, which was circulated to ophthalmologists to gauge the practicality of the teaching protocols of clinical and surgical skills during postgraduate residency program. Of the 1005 respondents, 320 ophthalmologists who completed residency between 1967 and 2002 (20 th century trained) and 531 who completed a residency in 2003-2012 (21 st century trained) fulfilled the inclusion criteria. The average age was 49.2 years (standard deviation [SD] 4) and 32.6 years (SD 4), respectively. Twenty-first century trained ophthalmologists rated their training significantly better than the 20 th century trained ophthalmologists for slit lamp examination (P = 0.001), indirect ophthalmoscopy, gonioscopy, automated perimetry, optical coherence tomography, and fundus photography (all having P < 0.001), while the 20 th century trained rated their teaching of refraction, synoptophore, diplopia charting better (all P < 0.001). The range of grading was 0-10 in all categories. The median number of surgeries performed independently by 20 th century and 21 st century trained (during their training period) were: intracapsular cataract extraction (ICCE) 10, 0; extracapsular cataract extraction (ECCE) 43, 18; small incision cataract surgery (SICS) 5, 55; phacoemulsification (Phaco) 0, 1; pterygium excision 20, 15; dacryocystectomy 11, 4; dacryocystorhinostomy 11, 2; chalazion 35, 30; trabeculectomies 5, 0; strabismus correction 0, 0; vitrectomy 0, 0; keratoplasty 0, 0; eyelid surgery 6, 2; and ocular emergencies 18, 20. Teaching of many clinical skills had improved over decades. Cataract surgery training has shifted from ICCE and ECCE to SICS and Phaco, but other surgeries were still taught sparingly. There was an enormous variation across the country in residency training which needs immediate attention.

Cell system engineering to produce extracellular polyhydroxyalkanoate depolymerase with targeted applications.

PubMed

Martínez, Virginia; Dinjaski, Nina; de Eugenio, Laura I; de la Peña, Fernando; Prieto, María Auxiliadora

2014-11-01

Novel platforms based on the application of bacterial cell systems as factories for production of new bioproducts open avenues and dramatically expand the catalogue of existing biomaterials. Herein, we designed the strategy based on in vivo production of extracellular Pseudomonas fluorescens GK13 (PhaZGK13) depolymerase to degrade previously biosynthesized polyhydroxyalkanotes (PHAs) or to obtain 3-hydroxyalkanoic acids (HAs). With this aim, extracellular PhaZGK13 was produced in recombinant strains and the optimal conditions for controlled release of HAs and oligomers by growing cells were set up with a particle suspension of (14)C-labelled PHA, being maximal after 24h of incubation. Genetic modification of key factors involved in fatty acids metabolism revealed the influence of an active β-oxidation pathway on the extracellular degradation of PHA and subsequent HAs isolation. The highest HAs production was obtained using Pseudomonas putida KT2442 fadB mutant (0.27mg/mL) due to the reduced ability of this strain to metabolize the degradation products. The system was applied to produce new added value HAs harboring thioester groups in the side chain from the functionalized mcl-PHA, PHACOS. Remarkably, hydrolyzed PHACOS showed greater potential to inhibit Staphylococcus aureus(T) growth when compared to that of degradation products of non functionalized polyhydroxyoctanoate-co-hexanoate P(HO-co-HH). Copyright © 2014 Elsevier B.V. All rights reserved.

The Prospective Health Assessment of Cataract Patients’ Ocular Surface (PHACO) study: the effect of dry eye

PubMed Central

Trattler, William B; Majmudar, Parag A; Donnenfeld, Eric D; McDonald, Marguerite B; Stonecipher, Karl G; Goldberg, Damien F

2017-01-01

Purpose To determine the incidence and severity of dry eye as determined by the International Task Force (ITF) scale in patients being screened for cataract surgery. Patients and methods This was a prospective, multi-center, observational study of 136 patients, at least 55 years of age, who were scheduled to undergo cataract surgery. The primary outcome measure was the incidence of dry eye as evaluated by grade on the ITF scale and secondary outcome measures include tear break-up time (TBUT), ocular surface disease index score, corneal staining with fluorescein, conjunctival staining with lissamine green, and a patient questionnaire to evaluate symptoms of dry eye. Results Mean patient age was 70.7 years. A total of 73.5% of patients were Caucasian and 50% were female. Almost 60% had never complained of a foreign body sensation; only 13% complained of a foreign body sensation half or most of the time. The majority of patients (62.9%) had a TBUT ≤5 seconds, 77% of eyes had positive corneal staining and 50% of the eyes had positive central corneal staining. Eighteen percent had Schirmer’s score with anesthesia ≤5 mm. Conclusion The incidence of dry eye in patients scheduled to undergo cataract surgery in a real-world setting is higher than anticipated. PMID:28848324

[Computer-assisted phacoemulsification for hard cataracts].

PubMed

Zemba, M; Papadatu, Adriana-Camelia; Sîrbu, Laura-Nicoleta; Avram, Corina

2012-01-01

to evaluate the efficiency of new torsional phacoemulsification software (Ozil IP system) in hard nucleus cataract extraction. 45 eyes with hard senile cataract (degree III and IV) underwent phacoemulsification performed by the same surgeon, using the same technique (stop and chop). Infiniti (Alcon) platform was used, with Ozil IP software and Kelman phaco tip miniflared, 45 degrees. The nucleus was split into two and after that the first half was phacoemulsificated with IP-on (group 1) and the second half with IP-off (group 2). For every group we measured: cumulative dissipated energy (CDE), numbers of tip closure that needed manual desobstruction the amount of BSS used. The mean CDE was the same in group 1 and in group 2 (between 6.2 and 14.9). The incidence of occlusion that needed manual desobstruction was lower in group 1 (5 times) than in group 2 (13 times). Group 2 used more BSS compared to group 1. The new torsional software (IP system) significantly decreased occlusion time and balanced salt solution use over standard torsional software, particularly with denser cataracts.

Reprint of: Relationship between cataract severity and socioeconomic status.

PubMed

Wesolosky, Jason D; Rudnisky, Christopher J

2015-06-01

To determine the relationship between cataract severity and socioeconomic status (SES). Retrospective, observational case series. A total of 1350 eyes underwent phacoemulsification cataract extraction by a single surgeon using an Alcon Infiniti system. Cataract severity was measured using phaco time in seconds. SES was measured using area-level aggregate census data: median income, education, proportion of common-law couples, and employment rate. Preoperative best corrected visual acuity was obtained and converted to logarithm of the minimum angle of resolution values. For patients undergoing bilateral surgery, the generalized estimating equation was used to account for the correlation between eyes. Univariate analyses were performed using simple regression, and multivariate analyses were performed to account for variables with significant relationships (p < 0.05) on univariate testing. Sensitivity analyses were performed to assess the effect of including patient age in the controlled analyses. Multivariate analyses demonstrated that cataracts were more severe when the median income was lower (p = 0.001) and the proportion of common-law couples living in a patient's community (p = 0.012) and the unemployment rate (p = 0.002) were higher. These associations persisted even when controlling for patient age. Patients of lower SES have more severe cataracts. Copyright © 2015. Published by Elsevier Inc.

[Original method of extracapsule fragmentation of the lens nucleus during phacoemulsification].

PubMed

Avetisov, S E; Iusef, Iusef Naim; Mamikonian, V R; Vvedenskiĭ, A S; Iusef, Said Naim; Mutonen, N V

2002-01-01

Clinical estimation of different modifications of phacoemulsification revealed the formation of the second tunnel in the nucleus for its division into quadrants in "four-quadrant phaco" increases the required duration of ultrasonography (US) and irrigation, which causes greater endothelial losses associated with the use of nuclear breakdown by means of a chopper tunnel. When the authors used their own methods of "extracapsular half-nuclei" fragmentation, endothelial losses are rather greater than those with the similar method "stop & "chop", which is associated with closer disposition of the US tip to the posterior corneal surface. At the same time nuclear breakdown by means a chapper in the capsular sac by the "stop & chop" method causes dilation of Zinn's ligaments, fraught by their rupture, particularly if latent derangement or defects of the zonular apparatus, and increases the risk of damage to the posterior capsule by the chopper.

Comparison of peristaltic and Venturi pumps in bimanual microincisional cataract surgery.

PubMed

Karaguzel, Hande; Karalezli, Aylin; Aslan, Bekir Sitki

2009-12-01

Comparison of peristaltic and Venturi pumps in bimanual microincision phacoemulsification on the success of the cataract surgery by using sleeveless phaco tip. Bimanual microincision phacoemulsification was done in 49 eyes using a 1.4-mm temporal clear corneal incision. A peristaltic pump was used in 23 eyes, and a Venturi pump was used in 26 eyes for phacoemulsification. Intraoperative complications, anterior chamber stability, and mean duration of surgery were recorded. Duration of surgery was shorter in the Venturi pump group. Anterior chamber stability could not be established in 17 eyes in the peristaltic pump group; it was established in all eyes in the Venturi pump group. Corneal burns were observed in two eyes in the peristaltic pump group and no eyes in the Venturi pump group. Use of a Venturi pump system and a vented gas-forced infusion system can significantly shorten surgery time and reduce risk of thermal burns.

Relationship between cataract severity and socioeconomic status.

PubMed

Wesolosky, Jason D; Rudnisky, Christopher J

2013-12-01

To determine the relationship between cataract severity and socioeconomic status (SES). Retrospective, observational case series. A total of 1350 eyes underwent phacoemulsification cataract extraction by a single surgeon using an Alcon Infiniti system. Cataract severity was measured using phaco time in seconds. SES was measured using area-level aggregate census data: median income, education, proportion of common-law couples, and employment rate. Preoperative best corrected visual acuity was obtained and converted to logarithm of the minimum angle of resolution values. For patients undergoing bilateral surgery, the generalized estimating equation was used to account for the correlation between eyes. Univariate analyses were performed using simple regression, and multivariate analyses were performed to account for variables with significant relationships (p < 0.05) on univariate testing. Sensitivity analyses were performed to assess the effect of including patient age in the controlled analyses. Multivariate analyses demonstrated that cataracts were more severe when the median income was lower (p = 0.001) and the proportion of common-law couples living in a patient's community (p = 0.012) and the unemployment rate (p = 0.002) were higher. These associations persisted even when controlling for patient age. Patients of lower SES have more severe cataracts. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Two-Port Pars Plana Anterior and Central Core Vitrectomy (Lam Floaterectomy) in Combination With Phacoemulsification and Intraocular Lens Implantation Under Topical Anesthesia for Patients with Cataract and Significant Floaters: Results of the First 50 Consecutive Cases.

PubMed

Lam, Dennis S C; Leung, Hiu Ying; Liu, Shu; Radke, Nishant; Yuan, Ye; Lee, Vincent Y W

2017-01-01

To study the safety and efficacy of 2-port pars plana anterior and central core vitrectomy (Lam floaterectomy) in combination with phacoemulsification (phaco) and intraocular lens implantation (IOL) for patients with cataract and significant floaters under topical anesthesia. Retrospective review of the first 50 consecutive cases. A standardized treatment protocol was used for patients with cataract and significant (moderate to severe) floaters (duration > 3 months). Data analysis included intraoperative and postoperative complications, floater status, and patient satisfaction. There were 50 eyes (38 patients) with a male-to-female ratio of 1 to 2.3. Twelve patients had bilateral eye surgeries. Mean age was 58.10 ± 9.85 years (range, 39-83). All patients completed the 3-month follow-up. One eye had mild vitreous hemorrhage at the end of surgery arising from sclerotomy wound oozing. No other intraoperative compli-cations were encountered. Postoperatively, there was 1 case of transient hypotony and 1 case of congestion at sclerotomy wound. No cases of retinal break or detachment, or clinically significant macular edema, were reported. There were 5 cases (10%) of mild residual floaters and 1 case (2%) of floater recurrence. Total floater clearance rate was 88%. Patient satisfaction rates were 80%, 14%, 6%, and 0% for very satisfied, satis-fied, acceptable, and unsatisfied, respectively. The 3-month results in terms of safety and efficacy of the Lam floaterectomy in combination with phaco and IOLfor patients with cataract and significant floaters under topical anesthesia are encouraging. Further larger-scale, prospective, multicenter studies seem warranted. Copyright© 2017 Asia-Pacific Academy of Ophthalmology.

Impact of the Femtosecond Laser in Line with the Femtosecond Laser-Assisted Cataract Surgery (FLACS) on the Anterior Chamber Characteristics in Comparison to the Manual Phacoemulsification.

PubMed

Pahlitzsch, Milena; Torun, Necip; Pahlitzsch, Marie Luise; Klamann, Matthias K J; Gonnermann, Johannes; Bertelmann, Eckart; Pahlitzsch, Thomas

2017-01-01

To assess the alterations of the anterior chamber conditions including laser flare photometry after femtosecond laser-assisted cataract surgery (FLACS) compared to the manual phacoemulsification. Data of n=70 FLACS (mean age 67.2 ± 8.9 years) and n=40 manual phacoemulsification (mean age 69.5 ± 9.6 years) were analyzed. The procedures were performed by LenSx Alcon, USA, and Alcon Infiniti Vision System, USA. The following parameters were recorded: laser flare photometry (Kowa FM 700, Japan), anterior chamber (AC) depth, AC volume, AC angle (Pentacam, Oculus Inc., Germany), lens density, pupil diameter, endothelial cell count and pachymetry. The analysis was performed preoperatively, immediately after femtosecond laser procedure and one day postoperatively. Between FLACS and the phaco control group, there was a significant difference in the AC depth (p=0.023, 3.77 mm vs. 4.05 mm) one day postoperatively. The AC angle (p=0.016) showed a significant difference immediately after the femto laser treatment. The central and thinnest pachymetry and endothelial cell count did not show a significant difference between the two study cohorts (p=0.165, p=0.291, p=0.979). The phaco cohort (n=40) demonstrated a non-statistically significant difference in the flare photometry of 15.80 photons/ms one postoperative day compared to the FLACS group 26.62 photons/ms (p=0.322). In this study population, no evidence for an additive damage caused by the use of the femtosecond laser was demonstrated. Furthermore, no increase in the central and thinnest corneal thickness and no increased endothelial cell loss was demonstrated by the laser energy.

Determining optimal torsional ultrasound power for cataract surgery with automatic longitudinal pulses at maximum vacuum ex vivo.

PubMed

Ronquillo, Cecinio C; Zaugg, Brian; Stagg, Brian; Kirk, Kevin R; Gupta, Isha; Barlow, William R; Pettey, Jeff H; Olson, Randall J

2014-12-01

To determine the optimal longitudinal power settings for Infiniti OZil Intelligent Phaco (IP) at varying torsional amplitude settings; and to test the hypothesis that increasing longitudinal power is more important at lower torsional amplitudes to achieve efficient phacoemulsification. Laboratory investigation. setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. procedure: Individual porcine nuclei were fixed in formalin, then cut into 2.0 mm cubes. Lens cube phacoemulsification was done using OZil IP at 60%, 80%, and 100% torsional amplitude with 0%, 10%, 20%, 30%, 50%, 75%, or 100% longitudinal power. All experiments were done using a 20 gauge 0.9 mm bent reverse bevel phaco tip at constant vacuum (550 mm Hg), aspiration rate (40 mL/min), and bottle height (50 cm). main outcome measure: Complete lens particle phacoemulsification (efficiency). Linear regression analysis showed a significant increase in efficiency with increasing longitudinal power at 60% torsional amplitude (R(2) = 0.7269, P = .01) and 80% torsional amplitude (R(2) = 0.6995, P = .02) but not at 100% amplitude (R(2) = 0.3053, P = .2). Baseline comparison of 60% or 80% vs 100% torsional amplitude without longitudinal power showed increased efficiency at 100% (P = .0004). Increasing longitudinal power to 20% abolished the efficiency difference between 80% vs 100% amplitudes. In contrast, 75% longitudinal power abolished the efficiency difference between 60% vs 100% torsional amplitudes. Results suggest that longitudinal power becomes more critical at increasing phacoemulsification efficiencies at torsional amplitudes less than 100%. Increasing longitudinal power does not further increase efficiency at maximal torsional amplitudes. Copyright © 2014 Elsevier Inc. All rights reserved.

Posterior segment nucleotomy for dislocated sclerotic cataractous lens using chandelier endoilluminator and sharp tipped chopper

PubMed Central

Takkar, Brijesh; Azad, Rajvardhan; Azad, Shorya; Rathi, Anubha

2015-01-01

AIM To describe a new surgical technique for managing dislocated sclerotic cataractous lens. METHODS Six patients with advanced posteriorly dislocated cataracts were operated at a tertiary care centre and analyzed retrospectively. After standard 3 port 23 G pars plana vitrectomy and perfluorocarbon liquid (PFCL) injection, the dislocated white cataract was held with occlusion using phaco fragmatome and then chopped into smaller pieces with a sharp tipped chopper using 25 G chandelier endoilluminator. Each piece was emulsified individually. Following aspiration of PFCL, Fluid Air Exchange was done in all the cases and surgery completed uneventfully. RESULTS Best corrected visual acuity (BCVA) in all the patients was better than 6/12 after one month of follow up. No serious complications were noted till minimum 6mo of follow up. CONCLUSION Four port posterior segment nucleotomy with a chandelier endoilluminator, fragmatome and a chopper appears to be a safe, easy and effective procedure for managing dislocated sclerotic cataractous nuclei. Ultrasonic energy used and adverse thermal effects of the fragmatome on the sclera may be lesser. PMID:26309887

Pericardium Plug in the Repair of the Corneoscleral Fistula After Ahmed Glaucoma Valve Explantation

PubMed Central

Yoo, Chungkwon; Kwon, Sung Wook

2008-01-01

We report four cases in which a pericardium (Tutoplast®) plug was used to repair a corneoscleral fistula after Ahmed Glaucoma Valve (AGV) explantation. In four cases in which the AGV tube had been exposed, AGV explantation was performed using a pericardium (Tutoplast®) plug to seal the defect previously occupied by the tube. After debridement of the fistula, a piece of processed pericardium (Tutoplast®), measured 1 mm in width, was plugged into the fistula and secured with two interrupted 10-0 nylon sutures. To control intraocular pressure, a new AGV was implanted elsewhere in case 1, phaco-trabeculectomy was performed concurrently in case 2, cyclophotocoagulation was performed postoperatively in case 3 and anti-glaucomatous medication was added in case 4. No complication related to the fistula developed at the latest follow-up (range: 12~26 months). The pericardium (Tutoplast®) plug seems to be an effective method in the repair of corneoscleral fistulas resulting from explantation of glaucoma drainage implants. PMID:19096247

Outcomes of torsional microcoaxial phacoemulsification performed by 12-degree and 22-degree bent tips.

PubMed

Helvacioglu, Firat; Yeter, Celal; Tunc, Zeki; Sencan, Sadik

2013-08-01

To compare the safety and efficacy of Ozil Intelligent Phaco torsional microcoaxial phacoemulsification surgeries performed with 12-degree and 22-degree bent tips using the Infiniti Vision System. Maltepe University School of Medicine Department of Ophthalmology, Istanbul, Turkey. Comparative case series. Eyes were assigned to 2.2 mm microcoaxial phacoemulsification using the torsional mode with a 22-degree bent tip (Group 1) or a 12-degree bent tip (Group 2). The primary outcome measures were ultrasound time (UST), cumulative dissipated energy (CDE), longitudinal and torsional ultrasound (US) amplitudes, mean surgical time, mean volume of balanced salt solution used, and surgical complications. Both groups included 45 eyes. The mean UST, CDE, longitudinal US amplitude, and torsional US amplitude were 65 seconds ± 27.23 (SD), 11.53 ± 6.99, 0.22 ± 0.26, and 42.86 ± 15.64, respectively, in Group 1 and 84 ± 45.04 seconds, 16.68 ± 10.66, 0.48 ± 0.68, and 46.27 ± 14.74, respectively, in Group 2. The mean UST, CDE, and longitudinal amplitudes were significantly lower in Group 1 (P=.003, P=.008, and P=.022, respectively). The mean volume of balanced salt solution was 73.33 ± 28.58 cc in Group 1 and 82.08 ± 26.21 cc in Group 2 (P=.134). Torsional phacoemulsification performed with 22-degree bent tips provided more effective lens removal than 12-degree bent tips, with a lower UST and CDE. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Ozil IP torsional mode versus combined torsional/longitudinal microcoaxial phacoemulsification.

PubMed

Helvacioglu, Firat; Tunc, Zeki; Yeter, Celal; Oguzhan, Hasan; Sencan, Sadik

2012-01-01

To compare the safety and efficacy of microcoaxial phacoemulsification surgeries performed with the Ozil Intelligent Phaco (IP) torsional mode and combined torsional/longitudinal ultrasound (US) mode using the Infiniti Vision System (Alcon Laboratories). In this prospective randomized comparative study, 60 eyes were assigned to 2.2-mm microcoaxial phacoemulsification using the Ozil IP torsional mode (group 1) or combined torsional/longitudinal US mode (group 2). The primary outcome measures were US time (UST), cumulative dissipated energy (CDE), longitudinal and torsional ultrasound amplitudes, mean operation time, mean volume of balanced salt solution (BSS) used, and surgical complications. Both groups included 30 eyes. Mean UST, CDE, and longitudinal and torsional ultrasound amplitudes in group 1 were 1 minute 15±34.33 seconds, 8.74±5.64, 0.43±0.74, and 25.56±8.56, respectively, and these parameters in group 2 were 1 minute 40±51.44 seconds, 9.28±5.99, 3.64±1.55, and 3.71±1.34, respectively. UST and longitudinal amplitudes were found to be significantly low in group 1 (p<0.001, p<0.001), whereas torsional amplitude was found to be significantly high in this group (p=0.001). Mean volumes of BSS used in groups 1 and 2 were 63.30±18.00 cc and 84.50±28.65 cc, respectively (p=0.001). The Ozil IP torsional mode may provide more effective lens removal than the combined torsional/longitudinal US mode with a lower UST and volume of BSS used.

Eye health care in the Czech Republic.

PubMed

Kocur, Ivo; Kuchynka, Pavel

2002-01-01

An analysis of eye health care in the Czech Republic as of 1998 was performed. A questionnaire was used to obtain information from all 59 in-patient eye departments. The number of ophthalmologists per 1 million inhabitants was 95. The number of cataract operations per 1 million inhabitants was 4,209: phaco-emulsification (36,926 surgeries, 85.2%), extracapsular extraction (6,094 surgeries, 14.1%) and intracapsular extraction (90 surgeries, 0.2%). Intra-ocular lenses were implanted in 99% of cases; 404 corneal transplantations and 1,220 operations for retinal detachment were performed. The number of pars plana vitrectomies for diabetic eye complications was 661. Selected regional clinical centres should be equipped and preferred by health insurance companies to provide comprehensive eye health care services and training. Copyright 2002 S. Karger AG, Basel

Torsional ultrasound mode versus combined torsional and conventional ultrasound mode phacoemulsification for eyes with hard cataract.

PubMed

Fakhry, Mohamed A; El Shazly, Malak I

2011-01-01

To compare torsional versus combined torsional and conventional ultrasound modes in hard cataract surgery regarding ultrasound energy and time and effect on corneal endothelium. Kasr El Aini hospital, Cairo University, and International Eye Hospital, Cairo, Egypt. Ninety-eight eyes of 63 patients were enrolled in this prospective comparative randomized masked clinical study. All eyes had nuclear cataracts of grades III and IV using the Lens Opacities Classification System III (LOCS III). Two groups were included, each having an equal number of eyes (49). The treatment for group A was combined torsional and conventional US mode phacoemulsification, and for group B torsional US mode phacoemulsification only. Pre- and post-operative assessments included best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp evaluation, and fundoscopic evaluation. Endothelial cell density (ECD) and central corneal thickness (CCT) were measured preoperatively, 1 day, 7 days, and 1 month postoperatively. All eyes were operated on using the Alcon Infiniti System (Alcon, Fort Worth, TX) with the quick chop technique. All eyes were implanted with AcrySof SA60AT (Alcon) intraocular lens (IOL). The main phaco outcome parameters included the mean ultrasound time (UST), the mean cumulative dissipated energy (CDE), and the percent of average torsional amplitude in position 3 (%TUSiP3). Improvement in BCVA was statistically significant in both groups (P < 0.001). Comparing UST and CDE for both groups revealed results favoring the pure torsional group (P = 0.002 and P < 0.001 for UST; P = 0.058 and P = 0.009 for CDE). As for %TUSiP3, readings were higher for the pure torsional group (P = 0.03 and P = 0.01). All changes of CCT, and ECD over time were found statistically significant using one-way ANOVA testing (P < 0.001). Both modes are safe in hard cataract surgery, however the pure torsional mode showed less US energy used.

Torsional ultrasound mode versus combined torsional and conventional ultrasound mode phacoemulsification for eyes with hard cataract

PubMed Central

Fakhry, Mohamed A; Shazly, Malak I El

2011-01-01

Purpose To compare torsional versus combined torsional and conventional ultrasound modes in hard cataract surgery regarding ultrasound energy and time and effect on corneal endothelium. Settings Kasr El Aini hospital, Cairo University, and International Eye Hospital, Cairo, Egypt. Methodology Ninety-eight eyes of 63 patients were enrolled in this prospective comparative randomized masked clinical study. All eyes had nuclear cataracts of grades III and IV using the Lens Opacities Classification System III (LOCS III). Two groups were included, each having an equal number of eyes (49). The treatment for group A was combined torsional and conventional US mode phacoemulsification, and for group B torsional US mode phacoemulsification only. Pre- and post-operative assessments included best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp evaluation, and fundoscopic evaluation. Endothelial cell density (ECD) and central corneal thickness (CCT) were measured preoperatively, 1 day, 7 days, and 1 month postoperatively. All eyes were operated on using the Alcon Infiniti System (Alcon, Fort Worth, TX) with the quick chop technique. All eyes were implanted with AcrySof SA60AT (Alcon) intraocular lens (IOL). The main phaco outcome parameters included the mean ultrasound time (UST), the mean cumulative dissipated energy (CDE), and the percent of average torsional amplitude in position 3 (%TUSiP3). Results Improvement in BCVA was statistically significant in both groups (P < 0.001). Comparing UST and CDE for both groups revealed results favoring the pure torsional group (P = 0.002 and P < 0.001 for UST; P = 0.058 and P = 0.009 for CDE). As for %TUSiP3, readings were higher for the pure torsional group (P = 0.03 and P = 0.01). All changes of CCT, and ECD over time were found statistically significant using one-way ANOVA testing (P < 0.001). Conclusion Both modes are safe in hard cataract surgery, however the pure torsional mode showed less US energy used. PMID:21792288

Topical anesthesia without intracameral lidocaine in cataract surgery.

PubMed

Spiritus, A; Huygens, M; Callebaut, F

2000-01-01

To evaluate the efficacy of topical anesthesia with oxybuprocaïne 0.4% without intracameral lidocaïne as an alternative to peribulbar or retrobulbar anesthesia in cataract surgery. Fifty-eight patients (eighty-two eyes) were included in this study. All patients received topical anesthesia with oxybuprocaïne 0.4%. No intracameral lidocaïne was used at the start of the intervention. Seventy-five per cent of patients received oral sedation with lorazepam 2.5 mg. All surgery was done using a superior corneal incision and phacoemulsification followed by a foldable IOL implantation. Subjective pain was assessed at 4 intervals during surgery using a 4-point pain scale. All patients were evaluated for intraoperative eye motility and blepharospasm. Patient and surgeon satisfaction was measured with a 4-point satisfaction scale. 15% of patients experienced mild pain during phaco and 43% had mild pain during corneal suturing. No patient had severe pain during the operation. In 4% of patients, intracameral lidocaïne was used to relieve pain. The surgeon and patient satisfaction was high. No eye movements or blepharospasm were recorded in 75% and 62% of cases respectively. No serious complications occurred. Topical anesthesia is a safe and effective alternative to peribulbar and retrobulbar anesthesia in corneal cataract surgery for the experienced surgeon.

Impact of cataract surgery in reducing visual impairment: a review.

PubMed

Khandekar, Rajiv; Sudhan, Anand; Jain, B K; Deshpande, Madan; Dole, Kuldeep; Shah, Mahul; Shah, Shreya

2015-01-01

The aim was to assess the impact of cataract surgeries in reducing visual disabilities and factors influencing it at three institutes of India. A retrospective chart review was performed in 2013. Data of 4 years were collected on gender, age, residence, presenting a vision in each eye, eye that underwent surgery, type of surgery and the amount the patient paid out of pocket for surgery. Visual impairment was categorized as; absolute blindness (no perception of light); blind (<3/60); severe visual impairment (SVI) (<6/60-3/60); moderate visual impairment (6/18-6/60) and; normal vision (≥6/12). Statistically analysis was performed to evaluate the association between visual disabilities and demographics or other possible barriers. The trend of visual impairment over time was also evaluated. We compared the data of 2011 to data available about cataract cases from institutions between 2002 and 2009. There were 108,238 cataract cases (50.6% were female) that underwent cataract surgery at the three institutions. In 2011, 71,615 (66.2%) cases underwent surgery. There were 45,336 (41.9%) with presenting vision < 3/60 and 75,393 (69.7%) had SVI in the fellow eye. Blindness at presentation for cataract surgery was associated to, male patients, Institution 3 (Dristi Netralaya, Dahod) surgeries after 2009, cataract surgeries without Intra ocular lens implant implantation, and patients paying <25 US $ for surgery. Predictors of SVI at time of cataract surgery were, male, Institution 3 (OM), phaco surgeries, those opting to pay 250 US $ for cataract surgeries. Patients with cataract seek eye care in late stages of visual disability. The goal of improving vision related quality of life for cataract patients during the early stages of visual impairment that is common in industrialized countries seems to be non-attainable in the rural India.

Novel extracellular medium-chain-length polyhydroxyalkanoate depolymerase from Streptomyces exfoliatus K10 DSMZ 41693: a promising biocatalyst for the efficient degradation of natural and functionalized mcl-PHAs.

PubMed

Martínez, Virginia; de Santos, Patricia Gómez; García-Hidalgo, Javier; Hormigo, Daniel; Prieto, M Auxiliadora; Arroyo, Miguel; de la Mata, Isabel

2015-11-01

Cloning and biochemical characterization of a novel extracellular medium-chain-length polyhydroxyalkanoate (mcl-PHA) depolymerase from Streptomyces exfoliatus K10 DSMZ 41693 are described. The primary structure of the depolymerase (PhaZSex2) includes the lipase consensus sequence (serine-histidine-aspartic acid) which is known for serine hydrolases. Secondary structure analysis shows 7.9 % α-helix, 43.9 % β-sheet, 19.4 % β-turns, and 31.2 % random coil, suggesting that this enzyme belongs to the α/β hydrolase fold family, in agreement with other PHA depolymerases and lipases. The enzyme was efficiently produced as an extracellular active form in Rhodococcus and purified by two consecutive hydrophobic chromatographic steps. Matrix-assisted laser desorption-time-of-flight (MALDI-TOF) analysis of the purified enzyme revealed a monomer of 27.6 kDa with a midpoint transition temperature of 44.2 °C. Remarkably, the activity is significantly enhanced by low concentrations of nonionic and anionic detergents and thermal stability is improved by the presence of 10 % glycerol. PhaZSex2 is an endo-exohydrolase that cleaves both large and small PHA molecules, producing (R)-3-hydroxyoctanoic acid monomers as the main reaction product. Markedly, PhaZSex2 is able to degrade functionalized polymers containing thioester groups in the side chain (PHACOS), releasing functional thioester-based monomers and oligomers demonstrating the potentiality of this novel biocatalyst for the industrial production of enantiopure (R)-3-hydroxyalkanoic acids.

Femtosecond laser-assisted cataract surgery with bimanual technique: learning curve for an experienced cataract surgeon.

PubMed

Cavallini, Gian Maria; Verdina, Tommaso; De Maria, Michele; Fornasari, Elisa; Volpini, Elisa; Campi, Luca

2017-11-29

To describe the intraoperative complications and the learning curve of microincision cataract surgery assisted by femtosecond laser (FLACS) with bimanual technique performed by an experienced surgeon. It is a prospective, observational, comparative case series. A total of 120 eyes which underwent bimanual FLACS by the same experienced surgeon during his first experience were included in the study; we considered the first 60 cases as Group A and the second 60 cases as Group B. In both groups, only nuclear sclerosis of grade 2 or 3 was included; an intraocular lens was implanted through a 1.4-mm incision. Best-corrected visual acuity (BCVA), surgically induced astigmatism (SIA), central corneal thickness and endothelial cell loss (ECL) were evaluated before and at 1 and 3 months after surgery. Intraoperative parameters, and intra- and post-operative complications were recorded. In Group A, we had femtosecond laser-related minor complications in 11 cases (18.3%) and post-operative complications in 2 cases (3.3%); in Group B, we recorded 2 cases (3.3%) of femtosecond laser-related minor complications with no post-operative complications. Mean effective phaco time (EPT) was 5.32 ± 3.68 s in Group A and 4.34 ± 2.39 s in Group B with a significant difference (p = 0.046). We recorded a significant mean BCVA improvement at 3 months in both groups (p < 0.05) and no significant SIA nor corneal pachymetry changes in the two groups during the follow-up (p > 0.05). Finally, we found significant ECL in both groups with a significant difference between the two groups (p = 0.042). FLACS with bimanual technique and low-energy LDV Z8 is associated with a necessary initial learning curve. After the first adjustments in the surgical technique, this technology seems to be safe and effective with rapid visual recovery and it helps surgeons to standardize the crucial steps of cataract surgery.

Performance index for virtual reality phacoemulsification surgery

NASA Astrophysics Data System (ADS)

Söderberg, Per; Laurell, Carl-Gustaf; Simawi, Wamidh; Skarman, Eva; Nordqvist, Per; Nordh, Leif

2007-02-01

We have developed a virtual reality (VR) simulator for phacoemulsification (phaco) surgery. The current work aimed at developing a performance index that characterizes the performance of an individual trainee. We recorded measurements of 28 response variables during three iterated surgical sessions in 9 subjects naive to cataract surgery and 6 experienced cataract surgeons, separately for the sculpting phase and the evacuation phase of phacoemulsification surgery. We further defined a specific performance index for a specific measurement variable and a total performance index for a specific trainee. The distribution function for the total performance index was relatively evenly distributed both for the sculpting and the evacuation phase indicating that parametric statistics can be used for comparison of total average performance indices for different groups in the future. The current total performance index for an individual considers all measurement variables included with the same weight. It is possible that a future development of the system will indicate that a better characterization of a trainee can be obtained if the various measurements variables are given specific weights. The currently developed total performance index for a trainee is statistically an independent observation of that particular trainee.

Results of endocapsular phacofracture debulking of hard cataracts.

PubMed

Davison, James A

2015-01-01

To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip.

The Comparison between Torsional and Conventional Mode Phacoemulsification in Moderate and Hard Cataracts

PubMed Central

Kim, Dong-Hyun; Wee, Won-Ryang; Lee, Jin-Hak

2010-01-01

Purpose To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. Methods Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30. Results Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30. Conclusions Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage. PMID:21165231

The comparison between torsional and conventional mode phacoemulsification in moderate and hard cataracts.

PubMed

Kim, Dong-Hyun; Wee, Won-Ryang; Lee, Jin-Hak; Kim, Mee-Kum

2010-12-01

To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30. Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30. Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage.

Meta-analysis of the efficacy and safety of combined surgery in the management of eyes with coexisting cataract and open angle glaucoma.

PubMed

Jiang, Nan; Zhao, Gui-Qiu; Lin, Jing; Hu, Li-Ting; Che, Cheng-Ye; Wang, Qian; Xu, Qiang; Li, Cui; Zhang, Jie

2018-01-01

To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma. We performed a systematic search of the related literature in the Cochrane Library, PubMed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction (IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre- to post-operation, and the secondary efficacy evaluations were performed by odds ratio (OR) and 95% confidence interval (CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using RevMan software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi 2 test and the I 2 measure. Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification. Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.

Determining the local origin of hydroxyl radical generation during phacoemulsification.

PubMed

Aust, Steven D; Terry, Scott; Hebdon, Thomas; Gunderson, Broc; Terry, Michael; Dimalanta, Ramon

2011-06-01

To determine the local origin of hydroxyl radicals during phacoemulsification using an ultrasonic phacoemulsification device that includes longitudinal and torsional modalities. Chemistry and Biochemistry Department, Utah State University, Logan, Utah, USA. Experimental study. Experiments were conducted using the Infiniti Vision System and Ozil handpiece. Hydroxyl radical concentrations during longitudinal and torsional phacoemulsification were quantitated as malondialdehyde (MDA) determined spectrophotometrically using the deoxyribose assay. The difference between the total concentration found in the aspirated solution at steady-state concentrations and the pre-aspirate levels deductively determined the concentration of MDA formed along the interior of the sonicating tip. The time to reach 50% of steady state as a function of reaction vessel volume was determined. The mean maximum for torsional ultrasound at 100% amplitude was 7.70 nM ± 0.38 (SD), 91.1% of which was generated outside the tip. During longitudinal ultrasound at 100% power, MDA concentration in the aspirated solution was 29.5 ± 0.3 nM, 71.6% of which was generated outside the tip. The time (seconds) to reach 50% of maximum for longitudinal ultrasound using 5 mL, 10 mL, and 20 mL reaction vessels was 12.6 ± 1.5, 21.0 ± 1.5, and 25.3 ± 3.4, respectively. Although a significantly greater proportion of the hydroxyl radicals generated during ultrasound modality were formed outside the phaco tip (91.1% torsional; 71.6% longitudinal), torsional ultrasound generated only about one-fourth the amount of MDA as longitudinal ultrasound in total and about one-third that generated outside the tip (7.02 nM versus 21.1 nM). No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

A systematic review of phacoemulsification cataract surgery in virtual reality simulators.

PubMed

Lam, Chee Kiang; Sundaraj, Kenneth; Sulaiman, Mohd Nazri

2013-01-01

The aim of this study was to review the capability of virtual reality simulators in the application of phacoemulsification cataract surgery training. Our review included the scientific publications on cataract surgery simulators that had been developed by different groups of researchers along with commercialized surgical training products, such as EYESI® and PhacoVision®. The review covers the simulation of the main cataract surgery procedures, i.e., corneal incision, capsulorrhexis, phacosculpting, and intraocular lens implantation in various virtual reality surgery simulators. Haptics realism and visual realism of the procedures are the main elements in imitating the actual surgical environment. The involvement of ophthalmology in research on virtual reality since the early 1990s has made a great impact on the development of surgical simulators. Most of the latest cataract surgery training systems are able to offer high fidelity in visual feedback and haptics feedback, but visual realism, such as the rotational movements of an eyeball with response to the force applied by surgical instruments, is still lacking in some of them. The assessment of the surgical tasks carried out on the simulators showed a significant difference in the performance before and after the training.

Results of endocapsular phacofracture debulking of hard cataracts

PubMed Central

Davison, James A

2015-01-01

Purpose/aim of the study To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. Materials and methods A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. Results No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. Conclusion The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip. PMID:26203213

Development of a virtual reality training curriculum for phacoemulsification surgery.

PubMed

Spiteri, A V; Aggarwal, R; Kersey, T L; Sira, M; Benjamin, L; Darzi, A W; Bloom, P A

2014-01-01

Training within a proficiency-based virtual reality (VR) curriculum may reduce errors during real surgical procedures. This study used a scientific methodology to develop a VR training curriculum for phacoemulsification surgery (PS). Ten novice-(n) (performed <10 cataract operations), 10 intermediate-(i) (50-200), and 10 experienced-(e) (>500) surgeons were recruited. Construct validity was defined as the ability to differentiate between the three levels of experience, based on the simulator-derived metrics for two abstract modules (four tasks) and three procedural modules (five tasks) on a high-fidelity VR simulator. Proficiency measures were based on the performance of experienced surgeons. Abstract modules demonstrated a 'ceiling effect' with construct validity established between groups (n) and (i) but not between groups (i) and (e)-Forceps 1 (46, 87, and 95; P<0.001). Increasing difficulty of task showed significantly reduced performance in (n) but minimal difference for (i) and (e)-Anti-tremor 4 (0, 51, and 59; P<0.001), Forceps 4 (11, 73, and 94; P<0.001). Procedural modules were found to be construct valid between groups (n) and (i) and between groups (i) and (e)-Lens-cracking (0, 22, and 51; P<0.05) and Phaco-quadrants (16, 53, and 87; P<0.05). This was also the case with Capsulorhexis (0, 19, and 63; P<0.05) with the performance decreasing in the (n) and (i) group but improving in the (e) group (0, 55, and 73; P<0.05) and (0, 48, and 76; P<0.05) as task difficulty increased. Experienced/intermediate benchmark skill levels are defined allowing the development of a proficiency-based VR training curriculum for PS for novices using a structured scientific methodology.

[Posterior capsule opacification, capsular bag distension syndrome, and anterior capsular phimosis: A retrospective cohort study].

PubMed

González-Martín-Moro, J; González-López, J J; Gómez-Sanz, F; Zarallo-Gallardo, J; Cobo-Soriano, R

2015-02-01

To determine the incidence and the risk factors involved in the development of the three main postoperative capsular complications: posterior capsule opacification (PCO), capsular bag distension syndrome (CBDS), and anterior capsular phimosis syndrome (ACP). A retrospective cohort study was conducted on 801 patients submitted to cataract surgery in the ophthalmology unit of Hospital del Henares (Madrid) from March 2, 2009 to February 28, 2010. Computerized clinical charts were reviewed during July 2012. PCO was studied using the Kaplan-Meier method (log rank test). A total of 167 patients developed PCO. No association could be demonstrated between PCO and age, sex, diabetes mellitus, phaco technique, IOL model, tamsulosin intake, glaucoma, and age-related macular degeneration. Three patients developed CBDS, all of them have received and Akreos Adapt AO(®) (Bausch & Lomb). Two of them were young men who had received surgery for posterior subcapsular cataracts. Three patients developed ACP, 2 of whom had received a MicroSlim(®) IOL (PhysIOL). No association was found between PCO and any of the studied variables. Male gender, young age, subcapsular cataract and large non-angulated lens such as Akreos Adapt AO(®) could be associated with CBDS. ACP could be more frequent when microincision IOLs (like MicroSlim(®)) are implanted. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

High correlation between performance on a virtual-reality simulator and real-life cataract surgery.

PubMed

Thomsen, Ann Sofia Skou; Smith, Phillip; Subhi, Yousif; Cour, Morten la; Tang, Lilian; Saleh, George M; Konge, Lars

2017-05-01

To investigate the correlation in performance of cataract surgery between a virtual-reality simulator and real-life surgery using two objective assessment tools with evidence of validity. Cataract surgeons with varying levels of experience were included in the study. All participants performed and videorecorded three standard cataract surgeries before completing a proficiency-based test on the EyeSi virtual-reality simulator. Standard cataract surgeries were defined as: (1) surgery performed under local anaesthesia, (2) patient age >60 years, and (3) visual acuity >1/60 preoperatively. A motion-tracking score was calculated by multiplying average path length and average number of movements from the three real-life surgical videos of full procedures. The EyeSi test consisted of five abstract and two procedural modules: intracapsular navigation, antitremor training, intracapsular antitremor training, forceps training, bimanual training, capsulorhexis and phaco divide and conquer. Eleven surgeons were enrolled. After a designated warm-up period, the proficiency-based test on the EyeSi simulator was strongly correlated to real-life performance measured by motion-tracking software of cataract surgical videos with a Pearson correlation coefficient of -0.70 (p = 0.017). Performance on the EyeSi simulator is significantly and highly correlated to real-life surgical performance. However, it is recommended that performance assessments are made using multiple data sources. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Laser welding of biological tissue: experimental studies in ophthalmology

NASA Astrophysics Data System (ADS)

Pini, Roberto; Rossi, Francesca; Menabuoni, Luca

2006-04-01

In this paper we present an original approach to laser welding of ocular media. Attention is focused on laser welding of the cornea and lens capsule. The process is based on the interaction of near infrared diode laser radiation (at 810 nm) with tissue that was previously stained with an Indocyanine Green solution in sterile water. The topical application of the chromophore makes possible a selective heating of the tissue, which results in a homogenous welding effect with low thermal damage to the surrounding tissue. Experimental tests were performed ex vivo on both capsule and cornea, and in vivo (rabbits) only on the cornea, in order to characterize the process as a whole. Spectrophotometric, biomechanical, and thermal measurements were carried out in order to study the laser-tissue interaction, while morphological, histological and auto-florescence microscopy analyses made during a follow-up study provided information on the healing process in welded rabbit corneas. The welding procedure was set up according to the type of tissue, with the staining procedure and irradiation conditions being optimized in each case. Our test indicated that: 1) laser welding of corneal wounds, which is a non contact technique performed at low continuous wave laser power (12 W/cm2), can be proposed as a support to or substitute for the standard suturing technique in cataract surgery and in penetrating keratoplasty (in corneal transplants); 2) laser welding of the lens capsule requires a "contact irradiating technique" in order to be efficiently performed, since the tissue is in underwater conditions, with single spot pulses of about 100 J/cm2 fluence and pulse duration around 100 ms. In the latter case, laser welding was proposed as a tool for assisting closure of the lens capsule after the lens refilling procedure (Phaco-ersatz), or for repairing capsular breaks induced by accidental traumas or produced intraoperatively.

Combined analysis of trabectome and phaco-trabectome outcomes by glaucoma severity

PubMed Central

Bussel, Igor I.; Loewen, Ralitsa T.; Parikh, Hardik; Loewen, Nils A.

2016-01-01

Prior glaucoma severity staging systems were mostly concerned with visual field function and retinal nerve fiber layer, but did not include intraocular pressure or medications to capture resistance to treatment. We recently introduced a simple index that combines pressure, medications, and visual field damage and applied it to stratify outcomes of trabectome surgery. In the analysis presented here, we combined data of trabectome alone and trabectome with same session cataract surgery to increase testing power and chances of effect discovery. This microincisional glaucoma surgery removes the primary resistance to outflow in glaucoma, the trabecular meshwork, and has been mostly used in mild glaucoma. Traditional glaucoma surgeries have a relatively high complication rate and have been reserved for more advanced disease stages. In the analysis presented here we include our data of trabectome combined with cataract surgery. This is a common practice pattern as both occur in the same age group with increasing frequency. For patients in higher glaucoma index (GI) groups, the intraocular pressure (IOP) reduction was 2.34+/-0.19 mmHg more than those in a GI group one level lower while holding everything else constant. Those who had undergone trabectome combined with phacoemulsification had an IOP reduction that was 1.29+/-0.39 mmHg less compared to those with trabectome alone. No statistically significant difference was found between genders and age groups while holding everything else constant. Hispanics had a 3.81+/-1.08 mmHg greater IOP reduction. Pseudoexfoliation and steroid glaucoma patients had an IOP reduction that was greater by 2.91+/-0.56 and 3.86+/-0.81 mmHg, respectively, than those with primary open angle glaucoma. These results suggest a role for trabectome-mediated ab interno trabeculectomy beyond mild forms of glaucoma. Additionally, the multifactorial glaucoma index demonstrates a role in staging patients when comparing glaucoma surgical modalities. PMID:27239278

A clinical study to evaluate the results after toric intraocular lens implantation in cases of corneal astigmatism.

PubMed

Moulick, P S; Mohindra, V K; Gurunadh, V S; Patel, Parth; Gupta, Sandeep; Khan, M A

2018-04-01

Modern day cataract surgery aims at a spectacle free vision which becomes difficult in cases with pre-operative astigmatism more than 1.5 D. Implantation of toric intra-ocular lenses (IOL) after phacoemulsification in such eyes is one of the ways to counteract this problem. Thirty eyes with pre-operative astigmatism between 1.5 D and 4.5 D were implanted with toric IOLs following uneventful phaco-emulsification. The estimation of the axis of implantation of this toric IOL included calculating the surgically induced astigmatism (SIA) of the surgeon. Post-operatively, 20 (66.67%) patients had a visual acuity 6/9 or better and 17 (57%) had a visual acuity of 6/6 at 12 weeks. The mean postoperative uncorrected visual acuity (UCVA) was 0.12 ± 0.15 at 12 weeks. The difference between means of preoperative best corrected visual acuity (BCVA) LogMAR and postoperative UCVA at 12 wk LogMAR was found to be statistically significant at p  = 0.001. Mean (SD) scores of pre-op astigmatism of study group was -2.20 (0.67) and residual astigmatism was -0.32 (0.44). The difference between means of pre-op astigmatism and residual astigmatism in the study group was significant at p  = 0.001 with 95% CI -2.22 to -1.50. This significant difference was because of the toric IOL implantation.

Comparison of different types of phacoemulsification tips. I. Quantitative analysis of elemental composition and tip surface microroughness.

PubMed

Tsaousis, Konstantinos T; Werner, Liliana; Perez, Jesus Paulo; Li, He J; Reiter, Nicholas; Guan, Jia J; Mamalis, Nick

2016-09-01

To evaluate the elemental composition of phacoemulsification tips and their surface roughness in the microscale. John A. Moran Eye Center and Utah Nanofab, College of Engineering, University of Utah, Salt Lake City, Utah, USA. Experimental study. Seven types of phacoemulsification tips were studied. The phaco tips were examined through energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) for elemental composition. In addition, the roughness of the opening in all tips was assessed through 3-dimensional white-light interferometry. Elemental analysis showed considerable differences in the surface layers between manufacturers. Alcon tips had a thinner oxidized titanium (Ti) layer in their surface. Through XPS, vanadium was not detected in the superficial layers of any tip, but only in deeper levels. The microroughness surface analysis showed comparable results regarding their root-mean-square (RMS) metric. Maximum peak valley distance values varied and appeared to be dependent on the quality of material process rather than the material itself. Phacoemulsification tips are made of Ti alloys and showed differences between models, especially regarding their composition in the superficial layers. Their opening end roughness showed an overall appropriate RMS value of less than 1.0 μm in all cases. The existence of small defected areas highlights the importance of adequate quality control of these critical surgical instruments. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Comparison of Methodologies Using Estimated or Measured Values of Total Corneal Astigmatism for Toric Intraocular Lens Power Calculation.

PubMed

Ferreira, Tiago B; Ribeiro, Paulo; Ribeiro, Filomena J; O'Neill, João G

2017-12-01

To compare the prediction error in the calculation of toric intraocular lenses (IOLs) associated with methods that estimate the power of the posterior corneal surface (ie, Barrett toric calculator and Abulafia-Koch formula) with that of methods that consider real measures obtained using Scheimpflug imaging: a software that uses vectorial calculation (Panacea toric calculator: http://www.panaceaiolandtoriccalculator.com) and a ray tracing software (PhacoOptics, Aarhus Nord, Denmark). In 107 eyes of 107 patients undergoing cataract surgery with toric IOL implantation (Acrysof IQ Toric; Alcon Laboratories, Inc., Fort Worth, TX), predicted residual astigmatism by each calculation method was compared with manifest refractive astigmatism. Prediction error in residual astigmatism was calculated using vector analysis. All calculation methods resulted in overcorrection of with-the-rule astigmatism and undercorrection of against-the-rule astigmatism. Both estimation methods resulted in lower mean and centroid astigmatic prediction errors, and a larger number of eyes within 0.50 diopters (D) of absolute prediction error than methods considering real measures (P < .001). Centroid prediction error (CPE) was 0.07 D at 172° for the Barrett toric calculator and 0.13 D at 174° for the Abulafia-Koch formula (combined with Holladay calculator). For methods using real posterior corneal surface measurements, CPE was 0.25 D at 173° for the Panacea calculator and 0.29 D at 171° for the ray tracing software. The Barrett toric calculator and Abulafia-Koch formula yielded the lowest astigmatic prediction errors. Directly evaluating total corneal power for toric IOL calculation was not superior to estimating it. [J Refract Surg. 2017;33(12):794-800.]. Copyright 2017, SLACK Incorporated.

[Superficial sponge anesthesia in cataract surgery (with scleral tunnel incision)].

PubMed

Pham, D T; Scherer, V; Wollensak, J

1996-12-01

The successful development of cataract operation and IOL implantation in the last decade has resulted in progressive shortening of the incision length as well as in developing safer and simpler anesthetic techniques. The purpose of the present study was to evaluate whether cataract surgery with scleral incision is possible using only topical sponge anesthesia with oxybuprocaine 0.4%. This method was compared with retrobulbar injection. 150 patients (3 groups each consisting 50 eyes) underwent phaco with scleral incision. 1st group: oxybuprocaine sponge anesthesia. 2nd group: oxybuprocaine sponge anesthesia combined with mild systemic analgesia (tramadol p.o.). 3rd group: retrobulbar injection (prilocaine/etidocaine mixture). All patients received medazolam premedication (Dormicum, 3/10 of 1 cc). Pain and discomfort during and after operation were investigated and statistically analyzed. Neither in group 1, 2 or 3 an additional subconjunctival injection was necessary. Pain or discomfort during operation was felt in 14 percent of the patients anesthetized with the oxybuprocaine sponge but only in 6 percent of the patients additionally premedicated with tramadol (2nd group). Also 6 percent of the patients after retrobulbar injection felt pain during operation. Postoperatively no significant differences between group 1 and 2 were obtained: 6 percent felt pain, 30 percent had a short term foreign body sensation. After retrobulbar injection (group 3) only 10 percent felt postoperative pain or discomfort. Topically applied oxybuprocaine provides sufficient anesthesia during cataract surgery with scleral incision. A combination with mild systemic analgesia (tramadol) helps to minimize pain and discomfort. Retrobulbur injection yielded only in the postoperative period significantly better analgesia. In the operating room full cooperation of the patient is required. Therefore we recommend not to use sponge anesthesia in cases when communication between surgeon and patient is insufficient.

Thermal characterization of phacoemulsification probes operated in axial and torsional modes.

PubMed

Zacharias, Jaime

2015-01-01

To analyze temperature increases and identify potential sources of heat generated when sleeved and sleeveless phacoemulsification probes were operated in axial and torsional modes using the Infiniti Vision System with the Ozil torsional handpiece. Phacodynamics Laboratory, Pasteur Ophthalmic Clinic, Santiago, Chile. Experimental study. Two computer-controlled thermal transfer systems were developed to evaluate the contribution of internal metal stress and tip-to-sleeve friction on heat generation during phacoemulsification using axial and torsional ultrasound modalities. Both systems incorporated infrared thermal imaging and used a black-body film to accurately capture temperature measurements. Axial mode was consistently associated with greater temperature increases than torsional mode whether tips were operated with or without sleeves. In tests involving bare tips, axial mode and torsional mode peaked at 51.7°C and 34.2°C, respectively. In an example using sleeved tips in which a 30.0 g load was applied for 1 second, temperatures for axial mode reached 45°C and for torsional mode, 38°C. Friction between the sleeved probe and the incisional wall contributed more significantly to the temperature increase than internal metal stress regardless of the mode used. In all experiments, the temperature increase observed with axial mode was greater than that observed with torsional mode, even when conditions such as power or amplitude and flow rate were varied. Tip-to-sleeve friction was a more dominant source of phaco probe heating than internal metal stress. The temperature increase due to internal metal stress was greater with axial mode than with torsional mode. Dr. Zacharias received research funding from Alcon Laboratories, Inc., to conduct this study. He has no financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Microinterventional endocapsular nucleus disassembly: novel technique and results of first-in-human randomised controlled study.

PubMed

Ianchulev, Tsontcho; Chang, David F; Koo, Edward; MacDonald, Susan; Calvo, Ernesto; Tyson, Farrell Toby; Vasquez, Andrea; Ahmed, Iqbal Ike K

2018-04-18

To assess the safety and efficacy of microinterventional endocapsular nuclear fragmentation in moderate to severe cataracts. This was a prospective single-masked multisurgeon interventional randomised controlled trial (ClinicalTrials.gov NCT02843594) where 101 eyes of 101 subjects with grade 3-4+ nuclear cataracts were randomised to torsional phacoemulsification alone (controls) or torsional phacoemulsification with adjunctive endocapsular nuclear fragmentation using a manual microinterventional nitinol filament loop device (miLOOP group). Outcome measures were phacoemulsification efficiency as measured by ultrasound energy (cumulative dispersed energy (CDE) units) and fluidics requirements (total irrigation fluid used) as well as incidence of intraoperative and postoperative complications. Only high-grade advanced cataracts were enrolled with more than 85% of eyes with baseline best corrected visual acuity (BCVA) of 20/200 or worse in either group. Mean CDE was 53% higher in controls (32.8±24.9 vs 21.4±13.1 with miLOOP assistance) (p=0.004). Endothelial cell loss after surgery was low and similar between groups (7-8%, p=0.561) One-month BCVA averaged 20/27 Snellen in miLOOP eyes and 20/24 in controls. No direct complications were caused by the miLOOP. In two cases, capsular tears occurred during IOL implantation and in all remaining cases during phacoemulsification, with none occurring during the miLOOP nucleus disassembly part of the procedure. Microinterventional endocapsular fragmentation with the manual, disposable miLOOP device achieved consistent, ultrasound-free, full-thickness nucleus disassembly and significantly improved overall phaco efficiency in advanced cataracts. NCT02843594. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparing the Effect of Topical Anesthesia and Retrobulbar Block With Intravenous Sedation on Hemodynamic Changes and Satisfaction in Patients Undergoing Cataract Surgery (Phaco Method)

PubMed Central

Haddadi, Soudabeh; Marzban, Shideh; Fazeli, Baharak; Heidarzadeh, Abtin; Parvizi, Arman; Naderinabi, Bahram; Panjtan Panah, Mohamad Reza

2015-01-01

Background: Cataract is one of the most common surgical procedures in the elderly. In most cases, the elderly have cardiac ischemia or chronic coronary diseases, which would lead to more ischemic events during general anesthesia. Therefore, surgeons and anesthetists prefer regional aesthesia to the general one owing to its more advantages and less complications. Objectives: Therefore, this study aimed to compare topical method and retrobulbar block for pain intensity, patient’s satisfaction, hemodynamic changes and intra and postoperative complications. Patients and Methods: In a single-blinded clinical trial, 114 patients scheduled for cataract surgery, aged 50 to 90 years with ASA physical status of I-III, were randomly assigned to two groups under monitored anesthesia care as topical anesthesia and retrobulbar block. After the injection of intravenous sedation, which was the combination of midazolam 0.5-1 mg with fentanyl 0.5-1 µ/kg, patients received retro bulbar block or topical anesthesia. During the operation, heart rate, systolic and diastolic blood pressure, mean arterial blood pressure and arterial saturation of O2were measured every five minutes. In addition, pain (VAS) and satisfaction (ISAS) scores were recorded every 15 minutes, then at recovery and one hour after the ending of operation in the ward. Findings were statistically analyzed using SPSS 16. Results: In this study, no significant association was found between age, gender, education and physical condition of patients in both topical and retro bulbar block groups. Comparison of pain based on VAS, satisfaction based on ISAS score and MAP in the studied periods had no significant differences between the two groups of patients undergoing cataract surgery. However, significant differences were found between the two groups (P = 0.045, 0.02, 0.042 and P < 0.05) regarding heart rate, systolic and diastolic blood pressure and arterial oxygen saturation percentage after 20-30 minutes of the operation. Conclusions: Both methods, topical and retro bulbar block had similar impression in cataract surgery regarding analgesia and patient satisfaction. However, in non-complicated cataract surgeries with short duration, topical anesthesia may be the preferable method, because of non-invasiveness, appropriate analgesia, patient satisfaction and hemodynamic stability. PMID:25918686

Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phacoemulsification in a Hispanic Population.

PubMed

L Jung, Jennifer; Isida-Llerandi, Cristina G; Lazcano-Gomez, Gabriel; SooHoo, Jeffrey R; Kahook, Malik Y

2014-01-01

To compare the efficacy of different surgical strategies for intraocular pressure (IOP) control in Hispanic glaucoma patients with and without visually significant cataracts. Comparative retrospective consecutive case series. The charts of 153 consecutive patients with primary open angle glaucoma who underwent either trabeculectomy alone (n = 51), phacotrabeculectomy (n = 51), or phacoemulsification alone (n = 51) were reviewed to compare IOP control, the number of glaucoma medications required postoperatively, and the inci dence of surgical complications. Preoperative IOP was 17.5 ± 5.2 mm Hg in the trabe-culectomy group, 15.4 ± 4.5 mm Hg in the phacotrabeculectomy group and 13.9 ± 2.9 mm Hg in the phacoemulsification group (p < 0.001 for all comparisons). Mean IOP reduction from baseline was 4.2 ± 6.9 (24.6%) for the trabeculectomy group, 2.9 ± 5.0 (20.8%) for the phacotrabeculectomy group, and 0.9 ± 3.4 (6.5%) for the phacoemulsification group (p = 0.009). The number of IOP-lowering medications required postoperatively decreased significantly in all three groups (p = 0.001). The rate of early and late postoperative complications was similar between the trabeculectomy and phacotrabeculectomy groups and less for the phacoemulsification group. Trabeculectomy and phacotrabeculectomy are both viable surgical options for managing open angle glau coma. Both resulted in similar rates of success, IOP reduction, decrease in use of IOP-lowering medications and post operative complication rates. Phacoemulsification alone had a lower success rate and greater need for postoperative IOP-lowering medications compared to trabeculectomy alone or phacotrabeculectomy. Phacoemulsification alone may be a reasonable option for patients with visually significant cataract and lower baseline IOP. How to cite this article: Jung JL, Isida-Llerandi CG, Lazcano-Gomez G, SooHoo JR, Kahook MY. Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phaco-emulsification in a Hispanic Population. J Curr Glaucoma Pract 2014;8(2):67-74.

Prevalence of blindness and cataract surgery in Gandaki Zone, Nepal

PubMed Central

Sapkota, Y D; Pokharel, G P; Nirmalan, P K; Dulal, S; Maharjan, I M; Prakash, K

2006-01-01

Background/aim Himalaya Eye Hospital (HEH), established in 1993, is rendering eye care services in the Gandaki and Dhaulagiri zones. The hospital has extensive community outreach activities along with services for outpatients, emergencies, and subspecialties such as vitreoretinal, paediatric, and low vision. The operation theatre is well equipped to match the surgical needs including phaco surgery for cataract. The hospital has performed more than 14 000 cataract surgeries and 250 000 treatment services during this period. The aim of this study was to estimate the prevalence of blindness, visual impairment, and cataract surgical coverage among the older adult population of three districts of Gandaki Zone, where 80% of the hospital's service recipients reside. Methods People aged 45 years and older were enrolled in the study using a stratified cluster design. Subjects in 25 randomly selected clusters from the listed 806 were recruited through door to door visits. Each recruited subject had visual acuity (VA) and clinical examination conducted by an ophthalmologist. The survey was preceded by pre‐pilot and pilot studies to refine the operational method. To assess quality assurance the interobserver variation in VA measurement was also carried out in five different clusters. Results Out of 5863 selected subjects 85.3% were examined. Blindness defined as presenting VA <6/60 in both eyes was found in 2.6% (95% confidence interval (CI): 2.2 to 3.9), whereas 16.8% individuals examined had vision <6/19 in one or both eyes. Cataract was the principal cause of blindness in 60.5%, and refractive error was the dominant cause of vision impairment (<6/19) 83.3%. Cataract surgical coverage was 59.5% among the cataract blind and associated with younger age, literacy, and male sex. Conclusion The finding suggests a positive impact of the HEH programme on the prevalence of blindness and cataract surgical services in the survey area. Strategies to further improve access and utilisation of facilities and increase cataract surgical coverage need to be developed. PMID:16547315

Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phacoemulsification in a Hispanic Population

PubMed Central

L Jung, Jennifer; Isida-Llerandi, Cristina G; Lazcano-Gomez, Gabriel; SooHoo, Jeffrey R

2014-01-01

ABSTRACT Purpose: To compare the efficacy of different surgical strategies for intraocular pressure (IOP) control in Hispanic glaucoma patients with and without visually significant cataracts. Design: Comparative retrospective consecutive case series. Methods: The charts of 153 consecutive patients with primary open angle glaucoma who underwent either trabeculectomy alone (n = 51), phacotrabeculectomy (n = 51), or phacoemulsification alone (n = 51) were reviewed to compare IOP control, the number of glaucoma medications required postoperatively, and the inci dence of surgical complications. Results: Preoperative IOP was 17.5 ± 5.2 mm Hg in the trabe-culectomy group, 15.4 ± 4.5 mm Hg in the phacotrabeculectomy group and 13.9 ± 2.9 mm Hg in the phacoemulsification group (p < 0.001 for all comparisons). Mean IOP reduction from baseline was 4.2 ± 6.9 (24.6%) for the trabeculectomy group, 2.9 ± 5.0 (20.8%) for the phacotrabeculectomy group, and 0.9 ± 3.4 (6.5%) for the phacoemulsification group (p = 0.009). The number of IOP-lowering medications required postoperatively decreased significantly in all three groups (p = 0.001). The rate of early and late postoperative complications was similar between the trabeculectomy and phacotrabeculectomy groups and less for the phacoemulsification group. Conclusion: Trabeculectomy and phacotrabeculectomy are both viable surgical options for managing open angle glau coma. Both resulted in similar rates of success, IOP reduction, decrease in use of IOP-lowering medications and post operative complication rates. Phacoemulsification alone had a lower success rate and greater need for postoperative IOP-lowering medications compared to trabeculectomy alone or phacotrabeculectomy. Phacoemulsification alone may be a reasonable option for patients with visually significant cataract and lower baseline IOP. How to cite this article: Jung JL, Isida-Llerandi CG, Lazcano-Gomez G, SooHoo JR, Kahook MY. Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phaco-emulsification in a Hispanic Population. J Curr Glaucoma Pract 2014;8(2):67-74. PMID:26997812

Corneal endothelial cell loss and corneal biomechanical characteristics after two-step sequential or combined phaco-vitrectomy surgery for idiopathic epiretinal membrane.

PubMed

Hamoudi, Hassan; Christensen, Ulrik Correll; La Cour, Morten

2017-08-01

To assess the impact of sequential and combined surgery [cataract surgery and 23-gauge pars plana vitrectomy (PPV) with peeling] on corneal endothelium cell density (CED) and corneal biomechanical characteristics. Phakic eyes with epiretinal membrane (ERM) were prospectively allocated to (i) cataract surgery and subsequent PPV (CAT group), (ii) PPV and subsequent cataract surgery (VIT group) or (iii) phacovitrectomy (COMBI group). Eyes were examined at baseline, 1 month after each surgery, and at 3 and 12 months follow-up. Corneal endothelium cell density (CED) was assessed with non-contact specular microscopy. Pachymetry [central cornea thickness (CCT)], keratometry and cornea volume (CV) were measured with Pentacam Scheimpflug camera. Primary outcome was change in CED after 12 months; secondary outcomes were changes in CCT and CV after 12 months. Sixty-two eyes were enrolled and allocated to the three groups. The mean preoperative CED was 2776, 2794 and 2653 cells/mm 2, which decreased significantly at 12 months by 15.3, 20.0 and 19.3% in the CAT, VIT and COMBI group. There was no significant difference in percentage cell loss between the groups at final follow-up. The CED decreased significantly after cataract surgery, but was unaffected by PPV. Central cornea thickness (CCT) increased by 10 μm (p = 0.005) and CV by 1.38 mm 3 (2.3%, p < 0.001) in the COMBI group. There were no significant differences in CCT or CV between the groups at final follow-up. Combined and sequential surgery in ERM leads to a small decrease in CED. Performing cataract surgery before, after or in combination with vitrectomy did not make any significant difference with respect to final CED, CCT or CV. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision.

PubMed

Assaf, Ahmed; Roshdy, Maged Maher

2013-01-01

This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification. This study includes 139 consecutive cataractous eyes (nuclear color 2-4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature(®) system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti(®) system with the OZil(®) Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated. All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm(2) vs 2315.6 ± 83.1 cell/mm(2), P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm(2) vs 2270.3 ± 89.9 cell/mm(2), P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 μm and 24.0 ± 24.0 μm in groups I and II, respectively (P = 0.1). Ellips™ FX transversal and OZil(®) IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision

PubMed Central

Assaf, Ahmed; Roshdy, Maged Maher

2013-01-01

Purpose This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification. Patients and methods This study includes 139 consecutive cataractous eyes (nuclear color 2–4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature® system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti® system with the OZil® Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated. Results All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm2 vs 2315.6 ± 83.1 cell/mm2, P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm2 vs 2270.3 ± 89.9 cell/mm2, P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 μm and 24.0 ± 24.0 μm in groups I and II, respectively (P = 0.1). Conclusion Ellips™ FX transversal and OZil® IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes. PMID:23326184

Functionalised Polysiloxanes as Injectable, In Situ Curable Accommodating Intraocular Lenses

PubMed Central

Hao, Xiaojuan; Jeffery, Justine L.; Wilkie, John S.; Meijs, Gordon; Clayton, Anthony; Watling, Jason; Ho, Arthur; Fernandez, Viviana; Acosta, Carolina; Yamamoto, Hideo; Aly, Mohamed G. M.; Parel, Jean-Marie; Hughes, Timothy C.

2010-01-01

The aged eye’s ability to change focus (accommodation) may be restored by replacing the hardened natural lens with a soft gel. Functionalised polysiloxane macromonomers, designed for application as an injectable, in situ curable accommodating intraocular lens (A-IOL), were prepared via a two-step synthesis. Prepolymers were synthesised via ring opening polymerisation (ROP) of octamethylcyclotetrasiloxane (D4) and 2,4,6,8-tetramethylcyclotetrasiloxane (D4H) in toluene using trifluoromethanesulfonic acid (TfOH) as catalyst. Hexaethyldisiloxane (HEDS) was used as the end group to control the molecular weight of the prepolymers, which were then converted to macromonomers by hydrosilylation of the SiH groups with allyl methacrylate (AM) to introduce polymerisable groups. The resulting macromonomers had an injectable consistency and thus, were able to be injected into and refill the empty lens capsular bag. The macromonomers also contained a low ratio of polymerisable groups so that they may be cured on demand, in situ, under irradiation of blue light, in the presence of a photo-initiator, to form a soft polysiloxane gel (an intraocular lens) in the eye. The pre-cure viscosity and post-cure modulus of the polysiloxanes, which are crucial factors for an injectable, in situ curable A-IOL application, were controlled by adjusting the end group and D4H concentrations, respectively, in the ROP. The macromonomers were fully cured within 5 minutes under light irradiation, as shown by the rapid change in modulus monitored by photorheology. Ex vivo primate lens stretching experiments on an Ex Vivo Accommodation Simulator (EVAS) showed that the polysiloxane gel refilled lenses achieved over 60% of the accommodation amplitude of the natural lens. An in vivo biocompatibility study in rabbits using the lens refilling (Phaco-Ersatz) procedure demonstrated that the soft gels were biocompatible with the ocular tissue. The polysiloxane macromonomers meet the targeted optical and mechanical properties of a young natural crystalline lens and show promise as candidate materials for use as injectable, in situ curable A-IOLs for lens refilling procedures. PMID:20692702

Coarsened Exact Matching of Phaco-Trabectome to Trabectome in Phakic Patients: Lack of Additional Pressure Reduction from Phacoemulsification

PubMed Central

Parikh, Hardik A.; Bussel, Igor I.; Schuman, Joel S.; Brown, Eric N.; Loewen, Nils A.

2016-01-01

Purpose To compare intraocular pressure (IOP) after trabectome-mediated ab interno trabeculectomy surgery in phakic patients (T) and trabectome with same session phacoemulsification (PT) using Coarsened Exact Matching. Although phacoemulsification is associated with IOP reduction when performed on its own, it is not known how much it contributes in PT. Methods Subjects were divided into phakic T and PT. Exclusion criteria were follow-up for <12 months and additional glaucoma surgery. Demographics were compared by the Mann-Whitney U test and chi-squared test for continuous and categorical variables, respectively. Multiple imputation was utilized to avoid eliminating data with missing values. Groups were then matched using Coarsened Exact Matching based on age, race, type of glaucoma, baseline IOP, and number of preoperative glaucoma medications. Univariate linear regression was used to examine IOP reduction after surgery; those variables that were statistically significant were included in the final multivariate regression model. Results A total of 753 cases were included (T: 255, PT: 498). When all variables except for age were kept constant, there was an additional IOP reduction of 0.05±0.01 mmHg conferred for every yearly increment in age. Every 1 mmHg increase in baseline IOP correlated to an additional IOP reduction of 0.80±0.02 mmHg. Phacoemulsification was not found to be a statistically significant contributor to IOP when comparing T and PT (p≥0.05). T had a 21% IOP reduction to 15.9±3.5 mmHg (p<0.01) while PT had an 18% reduction to 15.5±3.6 mmHg (p<0.01). Number of medications decreased (p<0.01) in both groups from 2.4±1.2 to 1.9±1.3 and from 2.3±1.1 to 1.7±1.3, respectively. Conclusion Phacoemulsification does not make a significant contribution to postoperative IOP or number of medications when combined with trabectome surgery in phakic patients. PMID:26895293

7 CFR 953.65 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 953.65 Section 953.65 Agriculture... STATES Order Regulating Handling Effective Time and Termination § 953.65 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature...

7 CFR 946.62 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

7 CFR 947.70 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

7 CFR 946.62 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

7 CFR 953.65 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 953.65 Section 953.65 Agriculture... STATES Order Regulating Handling Effective Time and Termination § 953.65 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature...

7 CFR 953.65 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 953.65 Section 953.65 Agriculture... STATES Order Regulating Handling Effective Time and Termination § 953.65 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature...

7 CFR 947.70 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

7 CFR 947.70 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

7 CFR 947.70 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

7 CFR 947.70 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

7 CFR 946.62 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

7 CFR 946.62 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

7 CFR 946.62 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

7 CFR 953.65 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 953.65 Section 953.65 Agriculture... STATES Order Regulating Handling Effective Time and Termination § 953.65 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature...

Improving productivity through more effective time management.

PubMed

Arnold, Edwin; Pulich, Marcia

2004-01-01

Effective time management has become increasingly important for managers as they seek to accomplish objectives in today's organizations, which have been restructured for efficiency while employing fewer people. Managers can improve their ability to manage time effectively by examining their attitudes toward time, analyzing time-wasting behaviors, and developing better time management skills. Managers can improve their performance and promotion potential with more effective time utilization. Strategies for improving time management skills are presented.

Effects of Helicity on Lagrangian and Eulerian Time Correlations in Turbulence

NASA Technical Reports Server (NTRS)

Rubinstein, Robert; Zhou, Ye

1998-01-01

Taylor series expansions of turbulent time correlation functions are applied to show that helicity influences Eulerian time correlations more strongly than Lagrangian time correlations: to second order in time, the helicity effect on Lagrangian time correlations vanishes, but the helicity effect on Eulerian time correlations is nonzero. Fourier analysis shows that the helicity effect on Eulerian time correlations is confined to the largest inertial range scales. Some implications for sound radiation by swirling flows are discussed.

The influence of time units on the flexibility of the spatial numerical association of response codes effect.

PubMed

Zhao, Tingting; He, Xianyou; Zhao, Xueru; Huang, Jianrui; Zhang, Wei; Wu, Shuang; Chen, Qi

2018-05-01

The Spatial Numerical/Temporal Association of Response Codes (SNARC/STEARC) effects are considered evidence of the association between number or time and space, respectively. As the SNARC effect was proposed by Dehaene, Bossini, and Giraux in 1993, several studies have suggested that different tasks and cultural factors can affect the flexibility of the SNARC effect. This study explored the influence of time units on the flexibility of the SNARC effect via materials with Arabic numbers, which were suffixed with time units and subjected to magnitude comparison tasks. Experiment 1 replicated the SNARC effect for numbers and the STEARC effect for time units. Experiment 2 explored the flexibility of the SNARC effect when numbers were attached to time units, which either conflicted with the numerical magnitude or in which the time units were the same or different. Experiment 3 explored whether the SNARC effect of numbers was stable when numbers were near the transition of two adjacent time units. The results indicate that the SNARC effect was flexible when the numbers were suffixed with time units: Time units influenced the direction of the SNARC effect in a way which could not be accounted for by the mathematical differences between the time units and numbers. This suggests that the SNARC effect is not obligatory and can be easily adapted or inhibited based on the current context. © 2017 The Authors. British Journal of Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Time-of-day effects in implicit racial in-group preferences are likely selection effects, not circadian rhythms

PubMed Central

2016-01-01

Time-of-day effects in human psychological functioning have been known of since the 1800s. However, outside of research specifically focused on the quantification of circadian rhythms, their study has largely been neglected. Moves toward online data collection now mean that psychological investigations take place around the clock, which affords researchers the ability to easily study time-of-day effects. Recent analyses have shown, for instance, that implicit attitudes have time-of-day effects. The plausibility that these effects indicate circadian rhythms rather than selection effects is considered in the current study. There was little evidence that the time-of-day effects in implicit attitudes shifted appropriately with factors known to influence the time of circadian rhythms. Moreover, even variables that cannot logically show circadian rhythms demonstrated stronger time-of-day effects than did implicit attitudes. Taken together, these results suggest that time-of-day effects in implicit attitudes are more likely to represent processes of selection rather than circadian rhythms, but do not rule out the latter possibility. PMID:27114886

Time-of-day effects in implicit racial in-group preferences are likely selection effects, not circadian rhythms.

PubMed

Schofield, Timothy P

2016-01-01

Time-of-day effects in human psychological functioning have been known of since the 1800s. However, outside of research specifically focused on the quantification of circadian rhythms, their study has largely been neglected. Moves toward online data collection now mean that psychological investigations take place around the clock, which affords researchers the ability to easily study time-of-day effects. Recent analyses have shown, for instance, that implicit attitudes have time-of-day effects. The plausibility that these effects indicate circadian rhythms rather than selection effects is considered in the current study. There was little evidence that the time-of-day effects in implicit attitudes shifted appropriately with factors known to influence the time of circadian rhythms. Moreover, even variables that cannot logically show circadian rhythms demonstrated stronger time-of-day effects than did implicit attitudes. Taken together, these results suggest that time-of-day effects in implicit attitudes are more likely to represent processes of selection rather than circadian rhythms, but do not rule out the latter possibility.

Identification and Sensitivity Analysis for Average Causal Mediation Effects with Time-Varying Treatments and Mediators: Investigating the Underlying Mechanisms of Kindergarten Retention Policy.

PubMed

Park, Soojin; Steiner, Peter M; Kaplan, David

2018-06-01

Considering that causal mechanisms unfold over time, it is important to investigate the mechanisms over time, taking into account the time-varying features of treatments and mediators. However, identification of the average causal mediation effect in the presence of time-varying treatments and mediators is often complicated by time-varying confounding. This article aims to provide a novel approach to uncovering causal mechanisms in time-varying treatments and mediators in the presence of time-varying confounding. We provide different strategies for identification and sensitivity analysis under homogeneous and heterogeneous effects. Homogeneous effects are those in which each individual experiences the same effect, and heterogeneous effects are those in which the effects vary over individuals. Most importantly, we provide an alternative definition of average causal mediation effects that evaluates a partial mediation effect; the effect that is mediated by paths other than through an intermediate confounding variable. We argue that this alternative definition allows us to better assess at least a part of the mediated effect and provides meaningful and unique interpretations. A case study using ECLS-K data that evaluates kindergarten retention policy is offered to illustrate our proposed approach.

7 CFR 945.82 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

7 CFR 922.63 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 948.83 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

7 CFR 958.70 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 958.70 Section 958.70 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Effective Time and Termination § 958.70 Effective time. The provisions of this subpart, or any amendment thereto, shall become...

7 CFR 922.63 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 958.70 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 958.70 Section 958.70 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Effective Time and Termination § 958.70 Effective time. The provisions of this subpart, or any amendment thereto, shall become...

7 CFR 922.63 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 922.63 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 922.63 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 945.82 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

7 CFR 945.82 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

7 CFR 948.83 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

7 CFR 945.82 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

7 CFR 948.83 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

7 CFR 958.70 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 958.70 Section 958.70 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Effective Time and Termination § 958.70 Effective time. The provisions of this subpart, or any amendment thereto, shall become...

7 CFR 945.82 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

7 CFR 948.83 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

7 CFR 948.83 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

7 CFR 958.70 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 958.70 Section 958.70 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Effective Time and Termination § 958.70 Effective time. The provisions of this subpart, or any amendment thereto, shall become...

7 CFR 929.68 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

7 CFR 906.54 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

7 CFR 932.67 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

7 CFR 985.71 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 985.71 Section 985.71 Agriculture....71 Effective time. The provisions of this subpart, and of any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in force until terminated or...

7 CFR 993.89 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 993.89 Section 993.89 Agriculture... Order Regulating Handling Miscellaneous Provisions § 993.89 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary...

7 CFR 959.83 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 959.83 Section 959.83 Agriculture... Regulating Handling Miscellaneous Provisions § 959.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 927.77 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

7 CFR 915.63 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

7 CFR 917.60 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

7 CFR 966.83 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 966.83 Section 966.83 Agriculture... Regulating Handling Miscellaneous Provisions § 966.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 923.63 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 916.63 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 916.63 Section 916.63 Agriculture... Regulating Handling Miscellaneous Provisions § 916.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and...

7 CFR 924.63 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 924.63 Section 924.63 Agriculture... § 924.63 Effective time. The provisions of this part and any amendments thereto shall become effective at such time as the Secretary may declare above his signature, and shall continue in force until...

7 CFR 989.90 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 989.90 Section 989.90 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.90 Effective time. The provisions of this amended subpart, as well as any amendments to this amended subpart shall become effective at such time as...

7 CFR 930.82 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

7 CFR 917.60 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

7 CFR 927.77 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

7 CFR 966.83 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 966.83 Section 966.83 Agriculture... Regulating Handling Miscellaneous Provisions § 966.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 906.54 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

7 CFR 989.90 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 989.90 Section 989.90 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.90 Effective time. The provisions of this amended subpart, as well as any amendments to this amended subpart shall become effective at such time as...

7 CFR 959.83 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 959.83 Section 959.83 Agriculture... Regulating Handling Miscellaneous Provisions § 959.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 930.82 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

7 CFR 906.54 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

7 CFR 916.63 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 916.63 Section 916.63 Agriculture... Regulating Handling Miscellaneous Provisions § 916.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and...

7 CFR 993.89 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 993.89 Section 993.89 Agriculture... Order Regulating Handling Miscellaneous Provisions § 993.89 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary...

7 CFR 906.54 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

7 CFR 915.63 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

7 CFR 930.82 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

7 CFR 985.71 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 985.71 Section 985.71 Agriculture....71 Effective time. The provisions of this subpart, and of any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in force until terminated or...

7 CFR 917.60 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

7 CFR 993.89 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 993.89 Section 993.89 Agriculture... Order Regulating Handling Miscellaneous Provisions § 993.89 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary...

7 CFR 927.77 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

7 CFR 927.77 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

7 CFR 932.67 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

7 CFR 924.63 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 924.63 Section 924.63 Agriculture... § 924.63 Effective time. The provisions of this part and any amendments thereto shall become effective at such time as the Secretary may declare above his signature, and shall continue in force until...

7 CFR 930.82 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

7 CFR 915.63 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

7 CFR 993.89 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 993.89 Section 993.89 Agriculture... Order Regulating Handling Miscellaneous Provisions § 993.89 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary...

7 CFR 929.68 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

7 CFR 932.67 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

7 CFR 932.67 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

7 CFR 917.60 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

7 CFR 959.83 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 959.83 Section 959.83 Agriculture... Regulating Handling Miscellaneous Provisions § 959.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 983.87 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 983.87 Section 983.87 Agriculture..., ARIZONA, AND NEW MEXICO Miscellaneous Provisions § 983.87 Effective time. The provisions of this part, as well as any amendments, shall become effective at such time as the Secretary may declare, and shall...

7 CFR 983.87 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 983.87 Section 983.87 Agriculture..., ARIZONA, AND NEW MEXICO Miscellaneous Provisions § 983.87 Effective time. The provisions of this part, as well as any amendments, shall become effective at such time as the Secretary may declare, and shall...

7 CFR 929.68 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

7 CFR 923.63 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 915.63 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

7 CFR 917.60 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

7 CFR 932.67 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

7 CFR 966.83 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 966.83 Section 966.83 Agriculture... Regulating Handling Miscellaneous Provisions § 966.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 966.83 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 966.83 Section 966.83 Agriculture... Regulating Handling Miscellaneous Provisions § 966.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 923.63 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 915.63 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

7 CFR 923.63 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

7 CFR 927.77 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

7 CFR 985.71 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 985.71 Section 985.71 Agriculture....71 Effective time. The provisions of this subpart, and of any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in force until terminated or...

7 CFR 989.90 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 989.90 Section 989.90 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.90 Effective time. The provisions of this amended subpart, as well as any amendments to this amended subpart shall become effective at such time as...

7 CFR 989.90 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 989.90 Section 989.90 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.90 Effective time. The provisions of this amended subpart, as well as any amendments to this amended subpart shall become effective at such time as...

7 CFR 983.87 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 983.87 Section 983.87 Agriculture..., ARIZONA, AND NEW MEXICO Miscellaneous Provisions § 983.87 Effective time. The provisions of this part, as well as any amendments, shall become effective at such time as the Secretary may declare, and shall...

7 CFR 906.54 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

7 CFR 929.68 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

7 CFR 929.68 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

7 CFR 930.82 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

7 CFR 985.71 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 985.71 Section 985.71 Agriculture....71 Effective time. The provisions of this subpart, and of any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in force until terminated or...

7 CFR 959.83 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 959.83 Section 959.83 Agriculture... Regulating Handling Miscellaneous Provisions § 959.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

7 CFR 923.63 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

[Accumulative effects and long-term persistence of subliminal mere exposure].

PubMed

Kawakami, Naoaki; Yoshida, Fujio

2011-10-01

We examined the accumulative effects and long-term persistence of subliminal mere exposure. An accumulative exposure condition (100 exposures distributed over five days) and a massed exposure condition (100 exposures in one day) were used in a Go/No-go Association Task (GNAT), with assessments of likability from Time 1 (just after) to Time 6 (after three months). First, a single stimulus was shown subliminally for a total of 100 times. The results indicated that mere exposure effects occurred equally often at Time 1. However, after Time 2, likability gradually decreased under the massed exposure condition, while it did not decrease under the accumulative exposure condition until Time 6. Second, in order to investigate the effect of multiple exposure, five stimuli belonging to a common category were shown 20 times each, for a total of 100 times. An ANOVA suggested that massed exposure had an instantaneous effect on likability, whereas accumulative exposure had a long-term persistence effect. Also, multiple exposures strengthened the mere exposure effect.

Intravascular low-intensity He-Ne laser irradiation therapy on idiopathic edema

NASA Astrophysics Data System (ADS)

Gao, Yunqing; Liu, T. C.; Tang, Xiang-Jun

1998-11-01

194 patients with psoriasis were treated by intravascular low level laser irradiation combined with Vit C 2.0g iv and O2 inhale to the nose. An hour once a day, for 5-40 times, and 13.06 times in average, ten times with 4-7 days intervals. The results: cured 23 cases, good effected 61 cases, improved 110 cases, relapsed 10 cases. Curative effect was related to treatment times, cured and good effected 5 times 12.5 percent, 10 times 31 percent, 15 times 94 percent. A matched control group in 17 patients was treated by drug. The results: good effected 1 case, improved 13 cases, not effected 3 cases.

The Effect of the Activities Enhanced Concerning Time Concept on Time Concept Acquisition of Children

ERIC Educational Resources Information Center

Birgül, Arzu Ergisi; Zeteroglu, Elvan Sahin; Derman, Meral Taner

2017-01-01

The aim of this study is to examine the effect of the activities enhanced concerning time concept on time concept acquisition of children. The research is a quantitative study in experimental model with pretest-posttest control group aiming to examine the effect of the activities enhanced concerning time concept on time concept acquisition of…

17 CFR 232.13 - Date of filing; adjustment of filing date.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed filed on.... Eastern Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed... Daylight Savings Time, whichever is currently in effect, shall be deemed filed on the same business day. (4...

17 CFR 232.13 - Date of filing; adjustment of filing date.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed filed on.... Eastern Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed... Daylight Savings Time, whichever is currently in effect, shall be deemed filed on the same business day. (4...

17 CFR 232.13 - Date of filing; adjustment of filing date.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed filed on.... Eastern Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed... Daylight Savings Time, whichever is currently in effect, shall be deemed filed on the same business day. (4...

17 CFR 232.13 - Date of filing; adjustment of filing date.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed filed on.... Eastern Standard Time or Eastern Daylight Saving Time, whichever is currently in effect, shall be deemed... Daylight Savings Time, whichever is currently in effect, shall be deemed filed on the same business day. (4...

Materialism Moderates the Effect of Accounting for Time on Prosocial Behaviors.

PubMed

Li, Jibo; Chen, Yingying; Huang, Xiting

2015-01-01

Accounting for time is defined as putting a price on time. Researchers have demonstrated that accounting for time reduces the time individuals spend on others; however, its association with monetary donations has not been examined. We hypothesized that accounting for time will activate a utility mindset that would affect one's allocation of time and money. In Study 1, the mediating effect of utility mindsets on the relationship between accounting for time and prosocial behavior was examined. In Study 2, we examined the effect of accounting for time on time spent helping and donating money, and the moderating role of material values on the relationship between accounting for time and prosocial behavior. Results showed that accounting for time activated a mindset of utility maximization that, in turn, reduced participants' prosocial behavior; moreover, materialism moderated the effect of accounting for time on prosocial behavior.

When time is more than money: the allocation of time between work and leisure in HIV-infected patients.

PubMed

Sendi, Pedram; Brouwer, Werner B F; Bucher, Heiner C; Weber, Rainer; Battegay, Manuel

2007-06-01

Time is a limited resource and individuals have to decide how many hours they should allocate to work and to leisure activities. Differences in wage rate or availability of non-labour income (financial support from families and savings) may influence how individuals allocate their time between work and leisure. An increase in wage rate may induce income effects (leisure time demanded increases) and substitution effects (leisure time demanded decreases) whereas an increase in non-labour income only induces income effects. We explored the effects of differences in wage rate and non-labour income on the allocation of time in HIV-infected patients. Patients enrolled in the Swiss HIV Cohort Study (SHCS) provided information on their time allocation, i.e. number of hours worked in 1998. A multinomial logistic regression model was used to test for income and substitution effects. Our results indicate that (i) the allocation of time in HIV-infected patients does not differ with level of education (i.e., wage rate), and that (ii) availability of non-labour income induces income effects, i.e. individuals demand more leisure time.

Thinking Fast Increases Framing Effects in Risky Decision Making.

PubMed

Guo, Lisa; Trueblood, Jennifer S; Diederich, Adele

2017-04-01

Every day, people face snap decisions when time is a limiting factor. In addition, the way a problem is presented can influence people's choices, which creates what are known as framing effects. In this research, we explored how time pressure interacts with framing effects in risky decision making. Specifically, does time pressure strengthen or weaken framing effects? On one hand, research has suggested that framing effects evolve through the deliberation process, growing larger with time. On the other hand, dual-process theory attributes framing effects to an intuitive, emotional system that responds automatically to stimuli. In our experiments, participants made decisions about gambles framed in terms of either gains or losses, and time pressure was manipulated across blocks. Results showed increased framing effects under time pressure in both hypothetical and incentivized choices, which supports the dual-process hypothesis that these effects arise from a fast, intuitive system.

Moderating Effects of Mathematics Anxiety on the Effectiveness of Explicit Timing

ERIC Educational Resources Information Center

Grays, Sharnita D.; Rhymer, Katrina N.; Swartzmiller, Melissa D.

2017-01-01

Explicit timing is an empirically validated intervention to increase problem completion rates by exposing individuals to a stopwatch and explicitly telling them of the time limit for the assignment. Though explicit timing has proven to be effective for groups of students, some students may not respond well to explicit timing based on factors such…

Positive smoking outcome expectancies mediate the association between negative affect and smoking urge among women during a quit attempt.

PubMed

Cano, Miguel Ángel; Lam, Cho Y; Chen, Minxing; Adams, Claire E; Correa-Fernández, Virmarie; Stewart, Diana W; McClure, Jennifer B; Cinciripini, Paul M; Wetter, David W

2014-08-01

Ecological momentary assessment was used to examine associations between negative affect, positive smoking outcome expectancies, and smoking urge during the first 7 days of a smoking quit attempt. Participants were 302 female smokers who enrolled in an individually tailored smoking cessation treatment study. Multilevel mediation analysis was used to examine the temporal relationship among the following: (a) the effects of negative affect and positive smoking outcome expectancies at 1 assessment point (e.g., time j) on smoking urge at the subsequent time point (e.g., time j + 1) in Model 1; and, (b) the effects of negative affect and smoking urge at time j on positive smoking outcome expectancies at time j + 1 in Model 2. The results from Model 1 showed a statistically significant effect of negative affect at time j on smoking urge at time j + 1, and this effect was mediated by positive smoking outcome expectancies at time j, both within- and between-participants. In Model 2, the within-participant indirect effect of negative affect at time j on positive smoking outcome expectancies at time j + 1 through smoking urge at time j was nonsignificant. However, a statistically significant indirect between-participants effect was found in Model 2. The findings support the hypothesis that urge and positive smoking outcome expectancies increase as a function of negative affect, and suggest a stronger effect of expectancies on urge as opposed to the effect of urge on expectancies.

Positive Smoking Outcome Expectancies Mediate the Association between Negative Affect and Smoking Urge among Women During a Quit Attempt

PubMed Central

Cano, Miguel Ángel; Lam, Cho Y.; Chen, Minxing; Adams, Claire E.; Correa-Fernández, Virmarie; Stewart, Diana W.; McClure, Jennifer B.; Cinciripini, Paul M.; Wetter, David W.

2014-01-01

Ecological momentary assessment was used to examine associations between negative affect, positive smoking outcome expectancies, and smoking urge during the first 7 days of a smoking quit attempt. Participants were 302 female smokers who enrolled in an individually tailored smoking cessation treatment study. Multilevel mediation analysis was used to examine the temporal relationship among: 1) the effects of negative affect and positive smoking outcome expectancies at one assessment point (e.g., time j) on smoking urge at the subsequent time point (e.g., time j + 1) in Model 1; and, 2) the effects of negative affect and smoking urge at time j on positive smoking outcome expectancies at time j + 1 in Model 2. The results from Model 1 showed a statistically significant effect of negative affect at time j on smoking urge at time j + 1, and this effect was mediated by positive smoking outcome expectancies at time j, both within- and between-participant. In Model 2, the within-participant indirect effect of negative affect at time j on positive smoking outcome expectancies at time j + 1 through smoking urge at time j was nonsignificant. However, a statistically significant indirect between-participant effect was found in Model 2. The findings support the hypothesis that urge and positive smoking outcome expectancies increase as a function of negative affect, and suggest a stronger effect of expectancies on urge as opposed to the effect of urge on expectancies. PMID:24796849

How visual timing and form information affect speech and non-speech processing.

PubMed

Kim, Jeesun; Davis, Chris

2014-10-01

Auditory speech processing is facilitated when the talker's face/head movements are seen. This effect is typically explained in terms of visual speech providing form and/or timing information. We determined the effect of both types of information on a speech/non-speech task (non-speech stimuli were spectrally rotated speech). All stimuli were presented paired with the talker's static or moving face. Two types of moving face stimuli were used: full-face versions (both spoken form and timing information available) and modified face versions (only timing information provided by peri-oral motion available). The results showed that the peri-oral timing information facilitated response time for speech and non-speech stimuli compared to a static face. An additional facilitatory effect was found for full-face versions compared to the timing condition; this effect only occurred for speech stimuli. We propose the timing effect was due to cross-modal phase resetting; the form effect to cross-modal priming. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance of time-varying predictors in multilevel models under an assumption of fixed or random effects.

PubMed

Baird, Rachel; Maxwell, Scott E

2016-06-01

Time-varying predictors in multilevel models are a useful tool for longitudinal research, whether they are the research variable of interest or they are controlling for variance to allow greater power for other variables. However, standard recommendations to fix the effect of time-varying predictors may make an assumption that is unlikely to hold in reality and may influence results. A simulation study illustrates that treating the time-varying predictor as fixed may allow analyses to converge, but the analyses have poor coverage of the true fixed effect when the time-varying predictor has a random effect in reality. A second simulation study shows that treating the time-varying predictor as random may have poor convergence, except when allowing negative variance estimates. Although negative variance estimates are uninterpretable, results of the simulation show that estimates of the fixed effect of the time-varying predictor are as accurate for these cases as for cases with positive variance estimates, and that treating the time-varying predictor as random and allowing negative variance estimates performs well whether the time-varying predictor is fixed or random in reality. Because of the difficulty of interpreting negative variance estimates, 2 procedures are suggested for selection between fixed-effect and random-effect models: comparing between fixed-effect and constrained random-effect models with a likelihood ratio test or fitting a fixed-effect model when an unconstrained random-effect model produces negative variance estimates. The performance of these 2 procedures is compared. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Microrandomized trials: An experimental design for developing just-in-time adaptive interventions.

PubMed

Klasnja, Predrag; Hekler, Eric B; Shiffman, Saul; Boruvka, Audrey; Almirall, Daniel; Tewari, Ambuj; Murphy, Susan A

2015-12-01

This article presents an experimental design, the microrandomized trial, developed to support optimization of just-in-time adaptive interventions (JITAIs). JITAIs are mHealth technologies that aim to deliver the right intervention components at the right times and locations to optimally support individuals' health behaviors. Microrandomized trials offer a way to optimize such interventions by enabling modeling of causal effects and time-varying effect moderation for individual intervention components within a JITAI. The article describes the microrandomized trial design, enumerates research questions that this experimental design can help answer, and provides an overview of the data analyses that can be used to assess the causal effects of studied intervention components and investigate time-varying moderation of those effects. Microrandomized trials enable causal modeling of proximal effects of the randomized intervention components and assessment of time-varying moderation of those effects. Microrandomized trials can help researchers understand whether their interventions are having intended effects, when and for whom they are effective, and what factors moderate the interventions' effects, enabling creation of more effective JITAIs. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Micro-Randomized Trials: An Experimental Design for Developing Just-in-Time Adaptive Interventions

PubMed Central

Klasnja, Predrag; Hekler, Eric B.; Shiffman, Saul; Boruvka, Audrey; Almirall, Daniel; Tewari, Ambuj; Murphy, Susan A.

2015-01-01

Objective This paper presents an experimental design, the micro-randomized trial, developed to support optimization of just-in-time adaptive interventions (JITAIs). JITAIs are mHealth technologies that aim to deliver the right intervention components at the right times and locations to optimally support individuals’ health behaviors. Micro-randomized trials offer a way to optimize such interventions by enabling modeling of causal effects and time-varying effect moderation for individual intervention components within a JITAI. Methods The paper describes the micro-randomized trial design, enumerates research questions that this experimental design can help answer, and provides an overview of the data analyses that can be used to assess the causal effects of studied intervention components and investigate time-varying moderation of those effects. Results Micro-randomized trials enable causal modeling of proximal effects of the randomized intervention components and assessment of time-varying moderation of those effects. Conclusions Micro-randomized trials can help researchers understand whether their interventions are having intended effects, when and for whom they are effective, and what factors moderate the interventions’ effects, enabling creation of more effective JITAIs. PMID:26651463

Time-varying effect moderation using the structural nested mean model: estimation using inverse-weighted regression with residuals

PubMed Central

Almirall, Daniel; Griffin, Beth Ann; McCaffrey, Daniel F.; Ramchand, Rajeev; Yuen, Robert A.; Murphy, Susan A.

2014-01-01

This article considers the problem of examining time-varying causal effect moderation using observational, longitudinal data in which treatment, candidate moderators, and possible confounders are time varying. The structural nested mean model (SNMM) is used to specify the moderated time-varying causal effects of interest in a conditional mean model for a continuous response given time-varying treatments and moderators. We present an easy-to-use estimator of the SNMM that combines an existing regression-with-residuals (RR) approach with an inverse-probability-of-treatment weighting (IPTW) strategy. The RR approach has been shown to identify the moderated time-varying causal effects if the time-varying moderators are also the sole time-varying confounders. The proposed IPTW+RR approach provides estimators of the moderated time-varying causal effects in the SNMM in the presence of an additional, auxiliary set of known and measured time-varying confounders. We use a small simulation experiment to compare IPTW+RR versus the traditional regression approach and to compare small and large sample properties of asymptotic versus bootstrap estimators of the standard errors for the IPTW+RR approach. This article clarifies the distinction between time-varying moderators and time-varying confounders. We illustrate the methodology in a case study to assess if time-varying substance use moderates treatment effects on future substance use. PMID:23873437

Effects of Social Constraints on Career Maturity: The Mediating Effect of the Time Perspective

ERIC Educational Resources Information Center

Kim, Kyung-Nyun; Oh, Se-Hee

2013-01-01

Previous studies have provided mixed results for the effects of social constraints on career maturity. However, there has been growing interest in these effects from the time perspective. Few studies have examined the effects of social constraints on the time perspective which in turn influences career maturity. This study examines the mediating…

Is time to peak effect of neuromuscular blocking agents dependent on dose? Testing the concept of buffered diffusion.

PubMed

Proost, J H; Houwertjes, M C; Wierda, J M K H

2008-07-01

For neuromuscular blocking agents, an inverse relationship between potency and time to peak effect has been observed. To test the hypothesis that this relationship is due to buffered diffusion, we investigated the influence of dose on time to peak effect. Pharmacokinetic-pharmacodynamic simulations were performed to support the expected relationships between potency, dose, peak effect and time to peak effect. Pigs (20-28 kg body weight) were anaesthetized with ketamine and midazolam, followed by pentobarbital and fentanyl intravenously. Neuromuscular block was measured by stimulating the peroneal nerve supramaximally at 0.1 Hz and measuring the response of the tibialis anterior muscle mechanomyographically. After an initial dose to establish the individual ED90 of a neuromuscular blocking agent (rocuronium, vecuronium, pipecuronium or d-tubocurarine), five different doses of the same compound were administered to each animal, aiming at 20%, 40%, 60%, 75% or 90% block, in a random order. Doses were given 45 min after complete recovery of the twitch response. For rocuronium and pipecuronium, time to peak effect increased with dose, whereas dose did not affect time to peak effect of vecuronium and d-tubocurarine. Simulations predict that time to peak effect decreases with dose if buffered diffusion is taken into account. The results suggest that buffered diffusion does not play a dominant role in the time to peak effect of neuromuscular blocking agents. Therefore it is unlikely that the observed inverse relationship between potency and time to peak effect of neuromuscular blocking agents in the clinical range is due to buffered diffusion.

Early to Rise? The Effect of Daily Start Times on Academic Performance

ERIC Educational Resources Information Center

Edwards, Finley

2012-01-01

Local school districts often stagger daily start times for their schools in order to reduce busing costs. This paper uses data on all middle school students in Wake County, NC from 1999 to 2006 to identify the causal effect of daily start times on academic performance. Using variation in start times within schools over time, the effect is a two…

Effective time-independent analysis for quantum kicked systems.

PubMed

Bandyopadhyay, Jayendra N; Guha Sarkar, Tapomoy

2015-03-01

We present a mapping of potentially chaotic time-dependent quantum kicked systems to an equivalent approximate effective time-independent scenario, whereby the system is rendered integrable. The time evolution is factorized into an initial kick, followed by an evolution dictated by a time-independent Hamiltonian and a final kick. This method is applied to the kicked top model. The effective time-independent Hamiltonian thus obtained does not suffer from spurious divergences encountered if the traditional Baker-Cambell-Hausdorff treatment is used. The quasienergy spectrum of the Floquet operator is found to be in excellent agreement with the energy levels of the effective Hamiltonian for a wide range of system parameters. The density of states for the effective system exhibits sharp peaklike features, pointing towards quantum criticality. The dynamics in the classical limit of the integrable effective Hamiltonian shows remarkable agreement with the nonintegrable map corresponding to the actual time-dependent system in the nonchaotic regime. This suggests that the effective Hamiltonian serves as a substitute for the actual system in the nonchaotic regime at both the quantum and classical level.

Effective time-independent analysis for quantum kicked systems

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Jayendra N.; Guha Sarkar, Tapomoy

2015-03-01

We present a mapping of potentially chaotic time-dependent quantum kicked systems to an equivalent approximate effective time-independent scenario, whereby the system is rendered integrable. The time evolution is factorized into an initial kick, followed by an evolution dictated by a time-independent Hamiltonian and a final kick. This method is applied to the kicked top model. The effective time-independent Hamiltonian thus obtained does not suffer from spurious divergences encountered if the traditional Baker-Cambell-Hausdorff treatment is used. The quasienergy spectrum of the Floquet operator is found to be in excellent agreement with the energy levels of the effective Hamiltonian for a wide range of system parameters. The density of states for the effective system exhibits sharp peaklike features, pointing towards quantum criticality. The dynamics in the classical limit of the integrable effective Hamiltonian shows remarkable agreement with the nonintegrable map corresponding to the actual time-dependent system in the nonchaotic regime. This suggests that the effective Hamiltonian serves as a substitute for the actual system in the nonchaotic regime at both the quantum and classical level.

Time series momentum and contrarian effects in the Chinese stock market

NASA Astrophysics Data System (ADS)

Shi, Huai-Long; Zhou, Wei-Xing

2017-10-01

This paper concentrates on the time series momentum or contrarian effects in the Chinese stock market. We evaluate the performance of the time series momentum strategy applied to major stock indices in mainland China and explore the relation between the performance of time series momentum strategies and some firm-specific characteristics. Our findings indicate that there is a time series momentum effect in the short run and a contrarian effect in the long run in the Chinese stock market. The performances of the time series momentum and contrarian strategies are highly dependent on the look-back and holding periods and firm-specific characteristics.

The effect of interventions targeting screen time reduction: A systematic review and meta-analysis.

PubMed

Wu, Lei; Sun, Samio; He, Yao; Jiang, Bin

2016-07-01

Previous studies have evaluated the effectiveness of interventions aimed at screen time reduction, but the results have been inconsistent. We therefore conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize the accumulating evidence of the impact of interventions targeting screen time reduction on body mass index (BMI) reduction and screen time reduction. The PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for RCTs on the effect of interventions targeting screen time reduction. The primary and secondary outcomes were the mean difference between the treatment and control groups in the changes in BMI and changes in screen viewing time. A random effects model was used to calculate the pooled mean differences. Fourteen trials including 2238 participants were assessed. The pooled analysis suggested that interventions targeting screen time reduction had a significant effect on BMI reduction (-0.15 kg/m, P < 0.001, I = 0) and on screen time reduction (-4.63 h/w, P = 0.003, I = 94.6%). Subgroup analysis showed that a significant effect of screen time reduction was observed in studies in which the duration of intervention was <7 months and that the types of interventions in those studies were health promotion curricula or counseling. Interventions for screen time reduction might be effective in reducing screen time and preventing excess weight. Further rigorous investigations with larger samples and longer follow-up periods are still needed to evaluate the efficacy of screen time reduction both in children and in adults.

Time course of effects of emotion on item memory and source memory for Chinese words.

PubMed

Wang, Bo; Fu, Xiaolan

2011-05-01

Although many studies have investigated the effect of emotion on memory, it is unclear whether the effect of emotion extends to all aspects of an event. In addition, it is poorly understood how effects of emotion on item memory and source memory change over time. This study examined the time course of effects of emotion on item memory and source memory. Participants learned intentionally a list of neutral, positive, and negative Chinese words, which were presented twice, and then took test of free recall, followed by recognition and source memory tests, at one of eight delayed points of time. The main findings are (within the time frame of 2 weeks): (1) Negative emotion enhances free recall, whereas there is only a trend that positive emotion enhances free recall. In addition, negative and positive emotions have different points of time at which their effects on free recall reach the greatest magnitude. (2) Negative emotion reduces recognition, whereas positive emotion has no effect on recognition. (3) Neither positive nor negative emotion has any effect on source memory. The above findings indicate that effect of emotion does not necessarily extend to all aspects of an event and that valence is a critical modulating factor in effect of emotion on item memory. Furthermore, emotion does not affect the time course of item memory and source memory, at least with a time frame of 2 weeks. This study has implications for establishing the theoretical model regarding the effect of emotion on memory. Copyright © 2011 Elsevier Inc. All rights reserved.

Investigating the Effect of Voltage-Switching on Low-Energy Task Scheduling in Hard Real-Time Systems

DTIC Science & Technology

2005-01-01

We investigate the effect of voltage-switching on task execution times and energy consumption for dual-speed hard real - time systems , and present a...scheduling algorithm and apply it to two real-life task sets. Our results show that energy can be conserved in embedded real - time systems using energy...aware task scheduling. We also show that switching times have a significant effect on the energy consumed in hard real - time systems .

Effects of a job crafting intervention program on work engagement among Japanese employees: a pretest-posttest study.

PubMed

Sakuraya, Asuka; Shimazu, Akihito; Imamura, Kotaro; Namba, Katsuyuki; Kawakami, Norito

2016-10-24

Job crafting, an employee-initiated job design/redesign, has become important for employees' well-being such as work engagement. This study examined the effectiveness of a newly developed job crafting intervention program on work engagement (as primary outcome), as well as job crafting and psychological distress (as secondary outcomes), using a pretest-posttest study design among Japanese employees. Participants were managers of a private company and a private psychiatric hospital in Japan. The job crafting intervention program consisted of two 120-min sessions with a two-week interval between them. Outcomes were assessed at baseline (Time 1), post-intervention (Time 2), and a one-month follow-up (Time 3). The mixed growth model analyses were conducted using time (Time 1, Time 2, and Time 3) as an indicator of intervention effect. Effect sizes were calculated using Cohen's d. The program showed a significant positive effect on work engagement (t = 2.20, p = 0.03) in the mixed growth model analyses, but with only small effect sizes (Cohen's d = 0.33 at Time 2 and 0.26 at Time 3). The program also significantly improved job crafting (t = 2.36, p = 0.02: Cohen's d = 0.36 at Time 2 and 0.47 at Time 3) and reduced psychological distress (t = -2.06, p = 0.04: Cohen's d = -0.15 at Time 2 and -0.31 at Time 3). The study indicated that the newly developed job crafting intervention program was effective in increasing work engagement, as well as in improving job crafting and decreasing psychological distress, among Japanese managers. UMIN Clinical Trials Registry UMIN000024062 . Retrospectively registered 15 September 2016.

Estimating the effect of immortal-time bias in urological research: a case example of testosterone-replacement therapy.

PubMed

Wallis, Christopher J D; Saskin, Refik; Narod, Steven A; Law, Calvin; Kulkarni, Girish S; Seth, Arun; Nam, Robert K

2017-10-01

To quantify the effect of immortal-time bias in an observational study examining the effect of cumulative testosterone exposure on mortality. We used a population-based matched cohort study of men aged ≥66 years, newly treated with testosterone-replacement therapy (TRT), and matched-controls from 2007 to 2012 in Ontario, Canada to quantify the effects of immortal-time bias. We used generalised estimating equations to determine the association between cumulative TRT exposure and mortality. Results produced by models using time-fixed and time-varying exposures were compared. Further, we undertook a systematic review of PubMed to identify studies addressing immortal-time bias or time-varying exposures in the urological literature and qualitatively summated these. Among 10 311 TRT-exposed men and 28 029 controls, the use of a time-varying exposure resulted in the attenuation of treatment effects compared with an analysis that did not account for immortal-time bias. While both analyses showed a decreased risk of death for patients in the highest tertile of TRT exposure, the effect was overestimated when using a time-fixed analysis (adjusted hazard ratio [aHR] 0.56, 95% confidence interval [CI]: 0.52-0.61) when compared to a time-varying analysis (aHR 0.67, 95% CI: 0.62-0.73). Of the 1 241 studies employing survival analysis identified in the literature, nine manuscripts met criteria for inclusion. Of these, five used a time-varying analytical method. Each of these was a large, population-based retrospective cohort study assessing potential harms of pharmacological agents. Where exposures vary over time, a time-varying exposure is necessary to draw meaningful conclusions. Failure to use a time-varying analysis will result in overestimation of a beneficial effect. However, time-varying exposures are uncommonly utilised among manuscripts published in prominent urological journals. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Methodological Issues in Design and Analysis of a Matched Case-Control Study of a Vaccine’s Effectiveness

PubMed Central

Niccolai, Linda M.; Ogden, Lorraine G.; Muehlenbein, Catherine E.; Dziura, James D.; Vázquez, Marietta; Shapiro, Eugene D.

2007-01-01

Objective Case-control studies of the effectiveness of a vaccine are useful to answer important questions, such as the effectiveness of a vaccine over time, that usually are not addressed by pre-licensure clinical trials of the vaccine’s efficacy. This report describes methodological issues related to design and analysis that were used to determine the effects of time since vaccination and age at the time of vaccination. Study Design and Setting A matched case-control study of the effectiveness of varicella vaccine. Results Sampling procedures and conditional logistic regression models including interaction terms are described. Conclusion Use of these methods will allow investigators to assess the effects of a wide range of variables, such as time since vaccination and age at the time of vaccination, on the effectiveness of a vaccine. PMID:17938054

[Psychological time, definition and challenges].

PubMed

Droit-Volet, Sylvie

2012-10-01

Psychological time comprises different forms of time. Each form of time corresponds to different psychological mechanisms. The human being is subject to distortions of time under the effect of emotions. The effectiveness of social interaction depends on our aptitude to synchronise ourselves with others.

Single machine total completion time minimization scheduling with a time-dependent learning effect and deteriorating jobs

NASA Astrophysics Data System (ADS)

Wang, Ji-Bo; Wang, Ming-Zheng; Ji, Ping

2012-05-01

In this article, we consider a single machine scheduling problem with a time-dependent learning effect and deteriorating jobs. By the effects of time-dependent learning and deterioration, we mean that the job processing time is defined by a function of its starting time and total normal processing time of jobs in front of it in the sequence. The objective is to determine an optimal schedule so as to minimize the total completion time. This problem remains open for the case of -1 < a < 0, where a denotes the learning index; we show that an optimal schedule of the problem is V-shaped with respect to job normal processing times. Three heuristic algorithms utilising the V-shaped property are proposed, and computational experiments show that the last heuristic algorithm performs effectively and efficiently in obtaining near-optimal solutions.

Investigating Factors Related to the Effects of Time-Out on Stuttering in Adults

ERIC Educational Resources Information Center

Franklin, Diane E.; Taylor, Catherine L.; Hennessey, Neville W.; Beilby, Janet M.

2008-01-01

Background: Response-contingent time-out has been shown to be an effective technique for enhancing fluency in people who stutter. However, the factors that determine individual responsiveness to time-out are not well understood. Aims: The study investigated the effectiveness of using response-contingent time-out to reduce stuttering frequency in…

Investigating the Effects of Planning Time on the Complexity of L2 Argumentative Writing

ERIC Educational Resources Information Center

Tabari, Mahmoud Abdi

2017-01-01

Much research has investigated the role of planning time in second language writing; however, the results show that there are inconsistent findings about the effects of planning time conditions on the complexity of the EFL learners' textual output. The current study attempted to consider the differential effects of planning time conditions in…

Effects of experiment start time and duration on measurement of standard physiological variables.

PubMed

Page, Amanda J; Cooper, Christine E; Withers, Philip C

2011-07-01

Duration and start time of respirometry experiments have significant effects on the measurement of basal values for several commonly measured physiological variables (metabolic rate, evaporative water loss and body temperature). A longer measurement duration reduced values for all variables for all start times, and this was an effect of reduced animal activity rather than random sampling. However, there was also an effect of circadian rhythm on the timing of minimal physiological values. Experiment start time had a significant effect on time taken to reach minimal values for all variables, ranging from 0400 hours ± 38 min (body temperature, start time 2300 hours) to 0854 hours ± 52 min (evaporative water loss, start time 1700 hours). It also influenced the time of day that minimal values were obtained, ranging from 2224 hours ± 40 min (carbon dioxide production, start time 1500 hours) to 0600 hours ± 57 min (oxygen consumption, start time 2300 hours), and the minimum values measured. Consequently, both the measurement duration and the experiment start time should be considered in experimental design to account for both a handling and a circadian effect on the animal's physiology. We suggest that experiments to measure standard physiological variables for small diurnal birds should commence between 1700 and 2100 hours, and measurement duration should be at least 9 h.

Effects of parent drug use and personality on toddler adjustment.

PubMed

Brook, J S; Whiteman, M; Shapiro, J; Cohen, P

1996-03-01

The interrelation between parental drug use and parental personality and the effects on 18-month-old children's adjustment were examined. Data on the parents were available at four points in time: Time 1 at mean age 6.1 years, Time 2 at mean age 13.7 years, Time 3 at mean age 16.4 years, and at Time 4 at mean age 22.2 years. Data on their toddlers at 18 months of age were also available. Structured interviews were used to assess personality and drug use and the toddlers' adjustment. Time 3 parental personality traits were related to Time 4 personality traits, which in turn were related to toddler adjustment. The influence of parental alcohol involvement (Time 3) on toddler adjustment was mediated by parental personality (Times 3 and 4) and parental alcohol problems (Time 4). Interactive effects demonstrated that protective parental personality traits (nondrug conducive) enhanced the effects of low parental drug use, resulting in the highest amounts of toddler adjustment. There are significant pathways between parental personality and drug use and toddler adjustment. Parental protective factors enhance the effect of parental low drug use on toddler adjustment.

As time passes by: Observed motion-speed and psychological time during video playback.

PubMed

Nyman, Thomas Jonathan; Karlsson, Eric Per Anders; Antfolk, Jan

2017-01-01

Research shows that psychological time (i.e., the subjective experience and assessment of the passage of time) is malleable and that the central nervous system re-calibrates temporal information in accordance with situational factors so that psychological time flows slower or faster. Observed motion-speed (e.g., the visual perception of a rolling ball) is an important situational factor which influences the production of time estimates. The present study examines previous findings showing that observed slow and fast motion-speed during video playback respectively results in over- and underproductions of intervals of time. Here, we investigated through three separate experiments: a) the main effect of observed motion-speed during video playback on a time production task and b) the interactive effect of the frame rate (frames per second; fps) and motion-speed during video playback on a time production task. No main effect of video playback-speed or interactive effect between video playback-speed and frame rate was found on time production.

As time passes by: Observed motion-speed and psychological time during video playback

PubMed Central

Karlsson, Eric Per Anders; Antfolk, Jan

2017-01-01

Research shows that psychological time (i.e., the subjective experience and assessment of the passage of time) is malleable and that the central nervous system re-calibrates temporal information in accordance with situational factors so that psychological time flows slower or faster. Observed motion-speed (e.g., the visual perception of a rolling ball) is an important situational factor which influences the production of time estimates. The present study examines previous findings showing that observed slow and fast motion-speed during video playback respectively results in over- and underproductions of intervals of time. Here, we investigated through three separate experiments: a) the main effect of observed motion-speed during video playback on a time production task and b) the interactive effect of the frame rate (frames per second; fps) and motion-speed during video playback on a time production task. No main effect of video playback-speed or interactive effect between video playback-speed and frame rate was found on time production. PMID:28614353

Time-lag effects of global vegetation responses to climate change.

PubMed

Wu, Donghai; Zhao, Xiang; Liang, Shunlin; Zhou, Tao; Huang, Kaicheng; Tang, Bijian; Zhao, Wenqian

2015-09-01

Climate conditions significantly affect vegetation growth in terrestrial ecosystems. Due to the spatial heterogeneity of ecosystems, the vegetation responses to climate vary considerably with the diverse spatial patterns and the time-lag effects, which are the most important mechanism of climate-vegetation interactive effects. Extensive studies focused on large-scale vegetation-climate interactions use the simultaneous meteorological and vegetation indicators to develop models; however, the time-lag effects are less considered, which tends to increase uncertainty. In this study, we aim to quantitatively determine the time-lag effects of global vegetation responses to different climatic factors using the GIMMS3g NDVI time series and the CRU temperature, precipitation, and solar radiation datasets. First, this study analyzed the time-lag effects of global vegetation responses to different climatic factors. Then, a multiple linear regression model and partial correlation model were established to statistically analyze the roles of different climatic factors on vegetation responses, from which the primary climate-driving factors for different vegetation types were determined. The results showed that (i) both the time-lag effects of the vegetation responses and the major climate-driving factors that significantly affect vegetation growth varied significantly at the global scale, which was related to the diverse vegetation and climate characteristics; (ii) regarding the time-lag effects, the climatic factors explained 64% variation of the global vegetation growth, which was 11% relatively higher than the model ignoring the time-lag effects; (iii) for the area with a significant change trend (for the period 1982-2008) in the global GIMMS3g NDVI (P < 0.05), the primary driving factor was temperature; and (iv) at the regional scale, the variation in vegetation growth was also related to human activities and natural disturbances. Considering the time-lag effects is quite important for better predicting and evaluating the vegetation dynamics under the background of global climate change. © 2015 John Wiley & Sons Ltd.

Hydra effects in discrete-time models of stable communities.

PubMed

Cortez, Michael H

2016-12-21

A species exhibits a hydra effect when, counter-intuitively, increased mortality of the species causes an increase in its abundance. Hydra effects have been studied in many continuous time (differential equation) multispecies models, but only rarely have hydra effects been observed in or studied with discrete time (difference equation) multispecies models. In addition most discrete time theory focuses on single-species models. Thus, it is unclear what unifying characteristics determine when hydra effects arise in discrete time models. Here, using discrete time multispecies models (where total abundance is the single variable describing each population), I show that a species exhibits a hydra effect in a stable system only when fixing that species' density at its equilibrium density destabilizes the system. This general characteristic is referred to as subsystem instability. I apply this result to two-species models and identify specific mechanisms that cause hydra effects in stable communities, e.g., in host--parasitoid models, host Allee effects and saturating parasitoid functional responses can cause parasitoid hydra effects. I discuss how the general characteristic can be used to identify mechanisms causing hydra effects in communities with three or more species. I also show that the condition for hydra effects at stable equilibria implies the system is reactive (i.e., density perturbations can grow before ultimately declining). This study extends previous work on conditions for hydra effects in single-species models by identifying necessary conditions for stable systems and sufficient conditions for cyclic systems. In total, these results show that hydra effects can arise in many more communities than previously appreciated and that hydra effects were present, but unrecognized, in previously studied discrete time models. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dressing effects on the occurrence scattering time retardation and advance in a dusty plasma

NASA Astrophysics Data System (ADS)

Lee, Myoung-Jae; Jung, Young-Dae; Hanyang Plasma Team

2017-10-01

The dressing effects on the occurrence scattering time for the dust-dust interaction are investigated in a complex plasma. The first-order eikonal analysis is applied to obtain the scattering amplitude and the occurrence scattering time for the dust-dust interaction. The result shows that dressing effect enhances the retardation phenomena of the occurrence scattering time in the forward scattering domain. It is shown that the oscillatory behavior of the scaled occurrence scattering time is getting more significant with an increase of the Debye length. It is also found that the retardation domain of the occurrence scattering time increases with a decrease of the Debye length. The variation of the occurrence scattering time retardation and advance due to the dressing effect is also discussed.

15 CFR 930.151 - Interstate coastal effect.

Code of Federal Regulations, 2010 CFR

2010-01-01

... management program. Effects are not just environmental effects, but include effects on coastal uses. Effects include both direct effects which result from the activity and occur at the same time and place as the... time or farther removed in distance, but are still reasonably foreseeable. Indirect effects are effects...

7 CFR 905.82 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

7 CFR 905.82 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

7 CFR 905.82 - Effective time.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

7 CFR 905.82 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

7 CFR 905.82 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

Buy now, saved later? The critical impact of time-to-pandemic uncertainty on pandemic cost-effectiveness analyses.

PubMed

Drake, Tom; Chalabi, Zaid; Coker, Richard

2015-02-01

Investment in pandemic preparedness is a long-term gamble, with the return on investment coming at an unknown point in the future. Many countries have chosen to stockpile key resources, and the number of pandemic economic evaluations has risen sharply since 2009. We assess the importance of uncertainty in time-to-pandemic (and associated discounting) in pandemic economic evaluation, a factor frequently neglected in the literature to-date. We use a probability tree model and Monte Carlo parameter sampling to consider the cost effectiveness of antiviral stockpiling in Cambodia under parameter uncertainty. Mean elasticity and mutual information (MI) are used to assess the importance of time-to-pandemic compared with other parameters. We also consider the sensitivity to choice of sampling distribution used to model time-to-pandemic uncertainty. Time-to-pandemic and discount rate are the primary drivers of sensitivity and uncertainty in pandemic cost effectiveness models. Base case cost effectiveness of antiviral stockpiling ranged between is US$112 and US$3599 per DALY averted using historical pandemic intervals for time-to-pandemic. The mean elasticities for time-to-pandemic and discount rate were greater than all other parameters. Similarly, the MI scores for time to pandemic and discount rate were greater than other parameters. Time-to-pandemic and discount rate were key drivers of uncertainty in cost-effectiveness results regardless of time-to-pandemic sampling distribution choice. Time-to-pandemic assumptions can "substantially" affect cost-effectiveness results and, in our model, is a greater contributor to uncertainty in cost-effectiveness results than any other parameter. We strongly recommend that cost-effectiveness models include probabilistic analysis of time-to-pandemic uncertainty. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2013; all rights reserved.

Time-local equation for exact time-dependent optimized effective potential in time-dependent density functional theory

NASA Astrophysics Data System (ADS)

Liao, Sheng-Lun; Ho, Tak-San; Rabitz, Herschel; Chu, Shih-I.

2017-04-01

Solving and analyzing the exact time-dependent optimized effective potential (TDOEP) integral equation has been a longstanding challenge due to its highly nonlinear and nonlocal nature. To meet the challenge, we derive an exact time-local TDOEP equation that admits a unique real-time solution in terms of time-dependent Kohn-Sham orbitals and effective memory orbitals. For illustration, the dipole evolution dynamics of a one-dimension-model chain of hydrogen atoms is numerically evaluated and examined to demonstrate the utility of the proposed time-local formulation. Importantly, it is shown that the zero-force theorem, violated by the time-dependent Krieger-Li-Iafrate approximation, is fulfilled in the current TDOEP framework. This work was partially supported by DOE.

An anisotropic universe due to dimension-changing vacuum decay

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

Scargill, James H.C., E-mail: james.scargill@physics.ox.ac.uk

In this paper we consider the question of observational signatures of a false vacuum decay event in the early universe followed by a period of inflation; in particular, motivated by the string landscape, we consider decays in which the parent vacuum has a smaller number of large dimensions than the current vacuum, which leads to an anisotropic universe. We go beyond previous studies, and examine the effects on the CMB temperature and polarisation power spectra, due to both scalar and tensor modes, and consider not only late-time effects but also the full cosmological perturbation theory at early times. We findmore » that whilst the scalar mode behaves as one would expect, and the effects of anisotropy at early times are sub-dominant to the late-time effects already studied, for the tensor modes in fact the the early-time effects grow with multipole and can become much larger than one would expect, even dominating over the late-time effects. Thus these effects should be included if one is looking for such a signal in the tensor modes.« less

Effects of lead time of verbal collision warning messages on driving behavior in connected vehicle settings.

PubMed

Wan, Jingyan; Wu, Changxu; Zhang, Yiqi

2016-09-01

Under the connected vehicle environment, vehicles will be able to exchange traffic information with roadway infrastructure and other vehicles. With such information, collision warning systems (CWSs) will be able to warn drivers with potentially hazardous situations within or out of sight and reduce collision accidents. The lead time of warning messages is a crucial factor in determining the effectiveness of CWSs in the prevention of traffic accidents. Accordingly, it is necessary to understand the effects of lead time on driving behaviors and explore the optimal lead time in various collision scenarios. The present driving simulator experiment studied the effects of controlled lead time at 16 levels (predetermined time headway from the subject vehicle to the collision location when the warning message broadcasted to a driver) on driving behaviors in various collision scenarios. Maximum effectiveness of warning messages was achieved when the controlled lead time was within the range of 5s to 8s. Specifically, the controlled lead time ranging from 4s to 8s led to the optimal safety benefit; and the controlled lead time ranging from 5s to 8s led to more gradual braking and shorter reaction time. Furthermore, a trapezoidal distribution of warning effectiveness was found by building a statistic model using curve estimation considering lead time, lifetime driving experience, and driving speed. The results indicated that the controlled lead time significantly affected driver performance. The findings have implications for the design of collision warning systems. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

Evaluation of arm-leg coordination in flat breaststroke.

PubMed

Chollet, D; Seifert, L; Leblanc, H; Boulesteix, L; Carter, M

2004-10-01

This study proposes a new method to evaluate arm-leg coordination in flat breaststroke. Five arm and leg stroke phases were defined with a velocity-video system. Five time gaps quantified the time between arm and leg actions during three paces of a race (200 m, 100 m and 50 m) in 16 top level swimmers. Based on these time gaps, effective glide, effective propulsion, effective leg insweep and effective recovery were used to identify the different stroke phases of the body. A faster pace corresponded to increased stroke rate, decreased stroke length, increased propulsive phases, shorter glide phases, and a shorter T1 time gap, which measured the effective body glide. The top level swimmers showed short time gaps (T2, T3, T4, measuring the timing of arm-leg recoveries), which reflected the continuity in arm and leg actions. The measurement of these time gaps thus provides a pertinent evaluation of swimmers' skill in adapting their arm-leg coordination to biomechanical constraints.

45 CFR 1303.7 - Effect of failure to file or serve documents in a timely manner.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Effect of failure to file or serve documents in a... PROSPECTIVE DELEGATE AGENCIES General § 1303.7 Effect of failure to file or serve documents in a timely manner... requisite deadlines or time frames if it exceeds them by any amount. (d) The time to file an appeal...

Effect of Hydrofluoric Acid Etching Time on Titanium Topography, Chemistry, Wettability, and Cell Adhesion

PubMed Central

Zahran, R.; Rosales Leal, J. I.; Rodríguez Valverde, M. A.; Cabrerizo Vílchez, M. A.

2016-01-01

Titanium implant surface etching has proven an effective method to enhance cell attachment. Despite the frequent use of hydrofluoric (HF) acid, many questions remain unresolved, including the optimal etching time and its effect on surface and biological properties. The objective of this study was to investigate the effect of HF acid etching time on Ti topography, surface chemistry, wettability, and cell adhesion. These data are useful to design improved acid treatment and obtain an improved cell response. The surface topography, chemistry, dynamic wetting, and cell adhesiveness of polished Ti surfaces were evaluated after treatment with HF acid solution for 0, 2; 3, 5, 7, or 10 min, revealing a time-dependent effect of HF acid on their topography, chemistry, and wetting. Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time. Highest cell adhesion was achieved after 5–7 min of etching time. Wetting and cell adhesion were reduced on the highly rough surfaces obtained after 10-min etching time. PMID:27824875

Effecting aging time of epoxy molding compound to molding process for integrated circuit packaging

NASA Astrophysics Data System (ADS)

Tachapitunsuk, Jirayu; Ugsornrat, Kessararat; Srisuwitthanon, Warayoot; Thonglor, Panakamon

2017-09-01

This research studied about effecting aging time of epoxy molding compound (EMC) that effect to reliability performance of integrated circuit (IC) package in molding process. Molding process is so important of IC packaging process for protecting IC chip (or die) from temperature and humidity environment using encapsulated EMC. For general molding process, EMC are stored in the frozen at 5°C and left at room temperature at 25 °C for aging time on self before molding of die onto lead frame is 24 hours. The aging time effect to reliability performance of IC package due to different temperature and humidity inside the package. In experiment, aging time of EMC were varied from 0 to 24 hours for molding process of SOIC-8L packages. For analysis, these packages were tested by x-ray and scanning acoustic microscope to analyze properties of EMC with an aging time and also analyzed delamination, internal void, and wire sweep inside the packages with different aging time. The results revealed that different aging time of EMC effect to properties and reliability performance of molding process.

Drop-on-demand drop formation of polyethylene oxide solutions

NASA Astrophysics Data System (ADS)

Yan, Xuejia; Carr, Wallace W.; Dong, Hongming

2011-10-01

The dynamics of drop-on-demand (DOD) drop formation for solutions containing polyethylene oxide (PEO) have been studied experimentally. Using a piezoelectrical actuated inkjet printhead with the nozzle orifice diameter of 53 μm, experiments were conducted for a series of PEO aqueous solutions with molecular weights ranging from 14 to 1000 kg/mol, polydispersity from 1.02 to 2.5, and concentrations from 0.005 to 10 wt. %. The addition of a small amount of PEO can have a significant effect on the DOD drop formation process, increasing breakup time, decreasing primary drop speed, and decreasing the number of satellite drops in some cases. The effects depend on both molecular weight and concentration. At lower molecular weights (14 and 35 kg/mol), the effect of PEO over the dilute solution regime is insignificant even at concentrations large enough that the solution does not fall in the dilute regime. As PEO molecular weight increased, the effects became significant. For monodispersed PEO solutions, breakup time and primary drop speed closely correlated with effective relaxation time but not for polydispersed PEO. Effective relaxation time depended greatly on molecular weight distribution. Viscosity-average molecular weight, used in calculating effective relaxation time for polydispersed PEO solutions, did not adequately account for high molecular fractions in the molecular weight distribution of the polydispersed PEOs. A mixture rule was developed to calculate the effective relaxation times for aqueous solutions containing mixtures of monodispersed PEO, and breakup times and primary drop speeds correlated well with effective relaxation times. For our experiments, DOD drop formation was limited to Deborah number ≲ 23.

The Effect of Time of Day on the Reaction to Stress. Final Report.

ERIC Educational Resources Information Center

Osborne, Francis H.

This study obtains evidence for the effect of time of day on learning in a stressful situation. A series of five experiments were performed to assess the effects of this variable on learning using albino rat subjects. None of the experiments provide overwhelming evidence for the effect of time of day when taken alone and each leaves questions…

44 CFR 61.11 - Effective date and time of coverage under the Standard Flood Insurance Policy-New Business...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Effective date and time of... RATES § 61.11 Effective date and time of coverage under the Standard Flood Insurance Policy—New Business Applications and Endorsements. (a) During the 13-month period beginning on the effective date of a revised...

Effects of color combination and ambient illumination on visual perception time with TFT-LCD.

PubMed

Lin, Chin-Chiuan; Huang, Kuo-Chen

2009-10-01

An empirical study was carried out to examine the effects of color combination and ambient illumination on visual perception time using TFT-LCD. The effect of color combination was broken down into two subfactors, luminance contrast ratio and chromaticity contrast. Analysis indicated that the luminance contrast ratio and ambient illumination had significant, though small effects on visual perception. Visual perception time was better at high luminance contrast ratio than at low luminance contrast ratio. Visual perception time under normal ambient illumination was better than at other ambient illumination levels, although the stimulus color had a confounding effect on visual perception time. In general, visual perception time was better for the primary colors than the middle-point colors. Based on the results, normal ambient illumination level and high luminance contrast ratio seemed to be the optimal choice for design of workplace with video display terminals TFT-LCD.

Accounting for time-dependent effects in biofuel life cycle greenhouse gas emissions calculations.

PubMed

Kendall, Alissa; Chang, Brenda; Sharpe, Benjamin

2009-09-15

This paper proposes a time correction factor (TCF) to properly account for the timing of land use change-derived greenhouse gas emissions in the biofuels life cycle. Land use change emissions occur at the outset of biofuel feedstock production, and are typically amortized over an assumed time horizon to assign the burdens of land use change to multiple generations of feedstock crops. Greenhouse gas intensity calculations amortize emissions by dividing them equally over a time horizon, overlooking the fact that the effect of a greenhouse gas increases with the time it remains in the atmosphere. The TCF is calculated based on the relative climate change effect of an emission occurring at the outset of biofuel feedstock cultivation versus one amortized over a time horizon. For time horizons between 10 and 50 years, the TCF varies between 1.7 and 1.8 for carbon dioxide emissions, indicating that the actual climate change effect of an emission is 70-80% higher than the effect of its amortized values. The TCF has broad relevance for correcting the treatment of emissions timing in other life cycle assessment applications, such as emissions from capital investments for production systems or manufacturing emissions for renewable energy technologies.

7 CFR 996.75 - Effective time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 996.75 Section 996.75 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Effective time. The provisions of this part, as well as any amendments, shall apply to 2003-04 and...

7 CFR 996.75 - Effective time.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Effective time. 996.75 Section 996.75 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Effective time. The provisions of this part, as well as any amendments, shall apply to 2003-04 and...

7 CFR 996.75 - Effective time.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Effective time. 996.75 Section 996.75 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Effective time. The provisions of this part, as well as any amendments, shall apply to 2003-04 and...

7 CFR 996.75 - Effective time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Effective time. 996.75 Section 996.75 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Effective time. The provisions of this part, as well as any amendments, shall apply to 2003-04 and...

A special case of reduced rank models for identification and modelling of time varying effects in survival analysis.

PubMed

Perperoglou, Aris

2016-12-10

Flexible survival models are in need when modelling data from long term follow-up studies. In many cases, the assumption of proportionality imposed by a Cox model will not be valid. Instead, a model that can identify time varying effects of fixed covariates can be used. Although there are several approaches that deal with this problem, it is not always straightforward how to choose which covariates should be modelled having time varying effects and which not. At the same time, it is up to the researcher to define appropriate time functions that describe the dynamic pattern of the effects. In this work, we suggest a model that can deal with both fixed and time varying effects and uses simple hypotheses tests to distinguish which covariates do have dynamic effects. The model is an extension of the parsimonious reduced rank model of rank 1. As such, the number of parameters is kept low, and thus, a flexible set of time functions, such as b-splines, can be used. The basic theory is illustrated along with an efficient fitting algorithm. The proposed method is applied to a dataset of breast cancer patients and compared with a multivariate fractional polynomials approach for modelling time-varying effects. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The effects of nitric oxide synthase inhibitors on the sedative effect of clonidine.

PubMed

Soares de Moura, R; Rios, A A; de Oliveira, L F; Resende, A C; de Lemos Neto, M; Santos, E J; Correia, M L; Tano, T

2001-11-01

The mechanism underlying the Niteroi, Rio de Janeiro sedative effect of clonidine, an alpha2-adrenoceptor agonist, remains uncertain. Because activation of alpha2-adrenoceptors induces release of nitric oxide (NO), we tested the hypothesis that the sedative effect of clonidine depends on NO-related mechanisms. The effect of 7-nitro indazole on the sleeping time induced by clonidine was studied in Wistar rats. In addition, we examined the effect of clonidine, alpha-methyldopa, and midazolam on the thiopental-induced sleeping time in rats pretreated with N(G)-nitro-L-arginine-methyl-ester (L-NAME). The sleeping time induced by clonidine was significantly decreased by 7-nitro indazole. Thiopental sleeping time was increased by clonidine, alpha-methyldopa, and midazolam. L-NAME reduced the prolongation effect of clonidine and alpha-methyldopa, but did not alter the effect of midazolam on the thiopental-induced sleeping time. The inhibitory effect of L-NAME on clonidine-dependent prolongation of thiopental-induced sleeping time was reversed by L-arginine. These results suggest that NO-dependent mechanisms are involved in the sedative effect of clonidine. In addition, this effect seems to be specific for the sedative action of alpha2-adrenoceptors agonists. Clonidine, an antihypertensive drug, is also a sedative. This sedative effect, although an adverse event in the treatment of hypertensive patients, can be helpful for sedation of surgical patients. The mechanism of this effect, however, is unknown. In this study, we show that the sedative effect of clonidine is mediated by nitric oxide, because it could be prevented by pretreatment with nitric oxide synthase inhibitors.

Does Vitamin D Supplementation Enhance Musculoskeletal Performance in Individuals Identified as Vitamin D Deficient through Blood Spot Testing?

NASA Astrophysics Data System (ADS)

Murphy, Kellie A.

This thesis investigated possible changes in performance after one month of vitamin D supplementation in individuals found to be vitamin D deficient or insufficient through blood spot testing. Thirty-two males, ages 18-32, participated. Each subject visited the lab three times in one-month, completing four performance tests each session, including an isometric mid-thigh pull and a vertical jump on a force plate, a isometric 90-degree elbow flexion test using a load cell, and a psychomotor vigilance test on a palm pilot. The initial lab included blood spot tests to find vitamin D levels. In a single blind manner, 16 subjects were assigned vitamin D and 16 the placebo. Repeated measures ANOVA analysis did not reveal any main effects for time (F=2.626, p=0.364), treatment (vitamin D3 vs placebo; F=1.282, p=0.999), or interaction effects for treatment by time (F=0.304, p=0.999) for maximum force production during an isometric mid-thigh pull. Repeated measures ANOVA analysis did not reveal any main effects for time (F=1.323, p=0.999), treatment (vitamin D3 vs placebo; F=0.510, p=0.999), or interaction effects for treatment by time (F= 1.625, p=0.860) for rate of force production during a vertical jump. Repeated measures ANOVA analysis did not reveal any main effects for time (F=0.194, p=0.999), treatment (vitamin D3 vs placebo; F=2.452, p=0.513), or interaction effects for treatment by time (F= 1.179, p=0.999) for maximal force production during a 90-degree isometric elbow flexion. Repeated measures ANOVA analysis did not reveal any main effects for time (F=1.710, p=0.804), treatment (vitamin D3 vs placebo; F=1.471, p=0.94), or interaction effects for treatment by time (F= 0.293, p=0.999) for mean reaction time to random stimuli during the psychomotor vigilance test. Repeated measures ANOVA analysis did not reveal any main effects for time (F=0.530, p=0.999), treatment (vitamin D3 vs placebo; F=0.141, p=0.999), or interaction effects for treatment by time (F=0.784 p=0.999) for incidence of minor lapses during the psychomotor vigilance test.

The culture of time in neuropsychological assessment: exploring the effects of culture-specific time attitudes on timed test performance in Russian and American samples.

PubMed

Agranovich, Anna V; Panter, A T; Puente, Antonio E; Touradji, Pegah

2011-07-01

Cultural differences in time attitudes and their effect on timed neuropsychological test performance were examined in matched non-clinical samples of 100 Russian and American adult volunteers using 8 tests that were previously reported to be relatively free of cultural bias: Color Trails Test (CTT); Ruff Figural Fluency Test (RFFT); Symbol Digit Modalities Test (SDMT); and Tower of London-Drexel Edition (ToL(Dx)). A measure of time attitudes, the Culture of Time Inventory (COTI-33) was used to assess time attitudes potentially affecting time-limited testing. Americans significantly outscored Russians on CTT, SDMT, and ToL(Dx) (p,.05) while differences in RFFT scores only approached statistical significance. Group differences also emerged in COTI-33 factor scores, which partially mediated differences in performance on CTT-1, SDMT, and ToL(Dx) initiation time, but did not account for the effect of culture on CTT-2. Significant effect of culture was revealed in ratings of familiarity with testing procedures that was negatively related to CTT, ToL(Dx), and SDMT scores. Current findings indicated that attitudes toward time may influence results of time limited testing and suggested that individuals who lack familiarity with timed testing procedures tend to obtain lower scores on timed tests.

The Effect of Student Time Allocation on Academic Achievement

ERIC Educational Resources Information Center

Grave, Barbara S.

2011-01-01

There is a large literature on the influence of institutional characteristics on student academic achievement. In contrast, relatively little research focusses on student time allocation and its effects on student performance. This paper contributes to the literature by investigating the effect of student time allocation on the average grade of…

29 CFR 1405.10 - Effect on employment ceilings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE PART-TIME EMPLOYMENT Part-time Employment Program § 1405.10 Effect on employment ceilings. Effective October 1, 1980, part-time employees will be counted on the basis of the fractional part of the 40-hour week actually...

Effects of daylight savings time changes on stock market volatility.

PubMed

Berument, M Hakan; Dogan, Nukhet; Onar, Bahar

2010-04-01

The presence of daylight savings time effects on stock returns and on stock volatility was investigated using an EGARCH specification to model the conditional variance. The evidence gathered from the major United States stock markets for the period between 1967 and 2007 did not support the existence of the daylight savings time effect on stock returns or on volatility. Returns on the first business day following daylight savings time changes were not lower nor was the volatility higher, as would be expected if there were an effect.

Evaluation of skin moisturizer effects using terahertz time domain imaging

NASA Astrophysics Data System (ADS)

Martinez-Meza, L. H.; Rojas-Landeros, S. C.; Castro-Camus, E.; Alfaro-Gomez, M.

2018-02-01

We use terahertz time domain imaging for the evaluation of the effects of skin-moisturizers in vivo. We evaluate three principal substances used in commercial moisturizers: glycerin, hyaluronic acid and lanolin. We image the interaction of the forearm with each of the substances taking terahertz spectra at sequential times. With this, we are able to measure the effect of the substances on the hydration level of the skin in time, determining the feasibility of using THz imaging for the evaluation of the products and their effects on the hydration levels of the skin.

Effects of interest-major congruence, motivation, and academic performance on timely degree attainment.

PubMed

Allen, Jeff; Robbins, Steve

2010-01-01

Using longitudinal student data from 15 four-year (n = 3,072) and 13 (n = 788) two-year postsecondary institutions, the authors tested the effects of interest-major congruence, motivation, and 1st-year academic performance on timely degree completion. Findings suggest that interest-major congruence has a direct effect on timely degree completion at both institutional settings and that motivation has indirect effects (via 1st-year academic performance). The total effects of both interest-major congruence and motivation on timely degree completion underscore the importance of both constructs in understanding student adjustment and postsecondary success. Implications for theory and counseling practice are discussed.

Adolescents' Time Use: Effects on Substance Use, Delinquency and Sexual Activity

ERIC Educational Resources Information Center

Barnes, Grace M.; Hoffman, Joseph H.; Welte, John W.; Farrell, Michael P.; Dintcheff, Barbara A.

2007-01-01

Using an integration of social control theory and the routine activity perspective, adolescent time use was examined for effects on problem behaviors. We examined a wide variety of time use categories, including homework, extracurricular activities, sports time, alone time, paid work, housework, television watching, as well as indices of family…

Quantifying the behavior of price dynamics at opening time in stock market

NASA Astrophysics Data System (ADS)

Ochiai, Tomoshiro; Takada, Hideyuki; Nacher, Jose C.

2014-11-01

The availability of huge volume of financial data has offered the possibility for understanding the markets as a complex system characterized by several stylized facts. Here we first show that the time evolution of the Japan’s Nikkei stock average index (Nikkei 225) futures follows the resistance and breaking-acceleration effects when the complete time series data is analyzed. However, in stock markets there are periods where no regular trades occur between the close of the market on one day and the next day’s open. To examine these time gaps we decompose the time series data into opening time and intermediate time. Our analysis indicates that for the intermediate time, both the resistance and the breaking-acceleration effects are still observed. However, for the opening time there are almost no resistance and breaking-acceleration effects, and volatility is always constantly high. These findings highlight unique dynamic differences between stock markets and forex market and suggest that current risk management strategies may need to be revised to address the absence of these dynamic effects at the opening time.

Differential Selection or Differential Socialization? Examining the Effects of Part-Time Work on School Disengagement Behaviors among South Korean Adolescents

ERIC Educational Resources Information Center

Lee, Moosung; Ju, Eunsu

2016-01-01

Reflecting on the fast-growing number of adolescents involved in part-time work in South Korea, we pay special attention to the effects of part-time work on school disengagement in this age group. While research on this issue in Korea is still scarce, a handful of existing studies have documented the undesirable effects of part-time work on…

Time perspective and positivity effects in Alzheimer's disease.

PubMed

Bohn, Linzy; Kwong See, Sheree T; Fung, Helene H

2016-09-01

This study tested whether time perspective, a central tenant of socioemotional selectivity theory (Carstensen, 2006), moderates positivity effects in emotional memory. To provide measures of time perspective, young (YA; M = 22.48 years), young-old (YO; M = 67.56 years), old-old adults (OO; M = 80.24 years), and participants with moderate severity Alzheimer's disease (PAD; M = 84.28 years) completed a line task and reported subjective age. As expected, YA, YO, and OO reported successively more constrained future time perspectives. PAD showed distortion in time perspective, envisioning a future comparable with the YO, although closer matched in chronological age to OO adults. To evince positivity effects, participants were oriented to pairs of emotional images and were then tested for memory (recall and recognition) of the images. Recall and recognition memory for the images indicated an age-related advantage for positive over negative material (positivity effects). Time perspective, however, did not moderate these age effects. In memory performance, PAD were more comparable with OO adults with whom they shared a similar chronological age, rather than YO adults, who had a corresponding time perspective. These results suggest that age correlates that are shared by PAD and OO, such as reduced processing resources, rather than time perspective, may drive the age associated positivity effects. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Pollinator effectiveness varies with experimental shifts in flowering time

PubMed Central

Rafferty, Nicole E.; Ives, Anthony R.

2013-01-01

The earlier flowering times exhibited by many plant species are a conspicuous sign of climate change. Altered phenologies have caused concern that species could suffer population declines if they flower at times when effective pollinators are unavailable. For two perennial wildflowers, Tradescantia ohiensis and Asclepias incarnata, we used an experimental approach to explore how changing phenology affects the taxonomic composition of the pollinator assemblage and the effectiveness of individual pollinator taxa. After finding in the previous year that fruit set varied with flowering time, we manipulated flowering onset in greenhouses, placed plants in the field over the span of five weeks, and measured pollinator effectiveness as the number of seeds produced after a single visit to a flower. The average effectiveness of pollinators and the expected rates of pollination success were lower for plants of both species flowering earlier than for plants flowering at historical times, suggesting there could be reproductive costs to earlier flowering. Whereas for A. incarnata, differences in average seed set among weeks were due primarily to changes in the composition of the pollinator assemblage, the differences for T. ohiensis were driven by the combined effects of compositional changes and increases over time in the effectiveness of some pollinator taxa. Both species face the possibility of temporal mismatch between the availability of the most effective pollinators and the onset of flowering, and changes in the effectiveness of individual pollinator taxa through time may add an unexpected element to the reproductive consequences of such mismatches. PMID:22690631

Pollinator effectiveness varies with experimental shifts in flowering time.

PubMed

Rafferty, Nicole E; Ives, Anthony R

2012-04-01

The earlier flowering times exhibited by many plant species are a conspicuous sign of climate change. Altered phenologies have caused concern that species could suffer population declines if they flower at times when effective pollinators are unavailable. For two perennial wildflowers, Tradescantia ohiensis and Asclepias incarnata, we used an experimental approach to explore how changing phenology affects the taxonomic composition of the pollinator assemblage and the effectiveness of individual pollinator taxa. After finding in the previous year that fruit set varied with flowering time, we manipulated flowering onset in greenhouses, placed plants in the field over the span of five weeks, and measured pollinator effectiveness as the number of seeds produced after a single visit to a flower. The average effectiveness of pollinators and the expected rates of pollination success were lower for plants of both species flowering earlier than for plants flowering at historical times, suggesting there could be reproductive costs to earlier flowering. Whereas for A. incarnata, differences in average seed set among weeks were due primarily to changes in the composition of the pollinator assemblage, the differences for T. ohiensis were driven by the combined effects of compositional changes and increases over time in the effectiveness of some pollinator taxa. Both species face the possibility of temporal mismatch between the availability of the most effective pollinators and the onset of flowering, and changes in the effectiveness of individual pollinator taxa through time may add an unexpected element to the reproductive consequences of such mismatches.

Metformin and the Risk of Cancer

PubMed Central

Suissa, Samy; Azoulay, Laurent

2012-01-01

OBJECTIVE Time-related biases in observational studies of drug effects have been described extensively in different therapeutic areas but less so in diabetes. Immortal time bias, time-window bias, and time-lag bias all tend to greatly exaggerate the benefits observed with a drug. RESEARCH DESIGN AND METHODS These time-related biases are described and shown to be prominent in observational studies that have associated metformin with impressive reductions in the incidence of and mortality from cancer. As a consequence, metformin received much attention as a potential anticancer agent; these observational studies sparked the conduction of randomized, controlled trials of metformin as cancer treatment. However, the spectacular effects reported in these studies are compatible with time-related biases. RESULTS We found that 13 observational studies suffered from immortal time bias; 9 studies had not considered time-window bias, whereas other studies did not consider inherent time-lagging issues when comparing the first-line treatment metformin with second- or third-line treatments. These studies, subject to time-related biases that are avoidable with proper study design and data analysis, led to illusory extraordinarily significant effects, with reductions in cancer risk with metformin ranging from 20 to 94%. Three studies that avoided these biases reported no effect of metformin use on cancer incidence. CONCLUSIONS Although observational studies are important to better understand the effects of drugs, their proper design and analysis is essential to avoid major time-related biases. With respect to metformin, the scientific evidence of its potential beneficial effects on cancer would need to be reassessed critically before embarking on further long and expensive trials. PMID:23173135

How Was the Weekend? How the Social Context Underlies Weekend Effects in Happiness and Other Emotions for US Workers.

PubMed

Helliwell, John F; Wang, Shun

2015-01-01

In this paper we estimate the size of weekend effects for seven emotions and then explore their main determinants for the working population in the United States, using the Gallup/Healthways US Daily Poll 2008-2012. We first find that weekend effects exist for all emotions, and that these effects are not explained by sample selection bias. Full-time workers have larger weekend effects than do part-time workers. We then explore the sources of weekend effects and find that workplace trust and workplace social relations, combined with differences in social time spent with family and friends, together almost fully explain the weekend effects for happiness, laughter, enjoyment and sadness, for both full-time and part-time workers, with significant but smaller proportions explained for the remaining three emotions-worry, anger and stress. Finally, we show that workplace trust and social relations significantly improve emotions and life evaluations on both weekends and weekdays for all workers.

Ambient temperature and coronary heart disease mortality in Beijing, China: a time series study

PubMed Central

2012-01-01

Background Many studies have examined the association between ambient temperature and mortality. However, less evidence is available on the temperature effects on coronary heart disease (CHD) mortality, especially in China. In this study, we examined the relationship between ambient temperature and CHD mortality in Beijing, China during 2000 to 2011. In addition, we compared time series and time-stratified case-crossover models for the non-linear effects of temperature. Methods We examined the effects of temperature on CHD mortality using both time series and time-stratified case-crossover models. We also assessed the effects of temperature on CHD mortality by subgroups: gender (female and male) and age (age > =65 and age < 65). We used a distributed lag non-linear model to examine the non-linear effects of temperature on CHD mortality up to 15 lag days. We used Akaike information criterion to assess the model fit for the two designs. Results The time series models had a better model fit than time-stratified case-crossover models. Both designs showed that the relationships between temperature and group-specific CHD mortality were non-linear. Extreme cold and hot temperatures significantly increased the risk of CHD mortality. Hot effects were acute and short-term, while cold effects were delayed by two days and lasted for five days. The old people and women were more sensitive to extreme cold and hot temperatures than young and men. Conclusions This study suggests that time series models performed better than time-stratified case-crossover models according to the model fit, even though they produced similar non-linear effects of temperature on CHD mortality. In addition, our findings indicate that extreme cold and hot temperatures increase the risk of CHD mortality in Beijing, China, particularly for women and old people. PMID:22909034

Negative impact of prolonged cold storage time before machine perfusion preservation in donation after circulatory death kidney transplantation.

PubMed

Paloyo, Siegfredo; Sageshima, Junichiro; Gaynor, Jeffrey J; Chen, Linda; Ciancio, Gaetano; Burke, George W

2016-10-01

Kidney grafts are often preserved initially in static cold storage (CS) and subsequently on hypothermic machine perfusion (MP). However, the impact of CS/MP time on transplant outcome remains unclear. We evaluated the effect of prolonged CS/MP time in a single-center retrospective cohort of 59 donation after circulatory death (DCD) and 177 matched donation after brain death (DBD) kidney-alone transplant recipients. With mean overall CS/MP times of 6.0 h/30.0 h, overall incidence of delayed graft function (DGF) was higher in DCD transplants (30.5%) than DBD transplants (7.3%, P < 0.0001). In logistic regression, DCD recipient (P < 0.0001), longer CS time (P = 0.0002), male recipient (P = 0.02), and longer MP time (P = 0.08) were associated with higher DGF incidence. In evaluating the joint effects of donor type (DBD vs. DCD), CS time (<6 vs. ≥6 h), and MP time (<36 vs. ≥36 h) on DGF incidence, one clearly sees an unfavorable effect of MP time ≥36 h (P = 0.003) across each donor type and CS time stratum, whereas the unfavorable effect of CS time ≥6 h (P = 0.01) is primarily seen among DCD recipients. Prolonged cold ischemia time had no unfavorable effect on renal function or graft survival at 12mo post-transplant. Long CS/MP time detrimentally affects early DCD/DBD kidney transplant outcome when grafts were mainly preserved by MP; prolonged CS time before MP has a particularly negative impact in DCD kidney transplantation. © 2016 Steunstichting ESOT.

The stingy hour: how accounting for time affects volunteering.

PubMed

DeVoe, Sanford E; Pfeffer, Jeffrey

2010-04-01

These studies examined how the practice of accounting for one's time-so that work can be billed or charged to specific clients or projects-affects the decision to allocate time to volunteer activities. Using longitudinal data collected from law students transitioning to their first jobs, Study 1 showed that exposure to billing time diminished individuals' willingness to volunteer, even after controlling for attitudes about volunteering held before entering the workforce as well as the individual's specific opportunity costs of volunteering time. Studies 2-5 experimentally manipulated billing time and confirmed its causal effect on individuals' willingness to volunteer and actual volunteering behavior. Study 5 showed that the effect of exposure to billing time on volunteering occurred above and beyond any effects on general self-efficacy or self-determination. Individual differences moderated the effects of billing, such that people who did not value money as much were less affected.

Effects of computing time delay on real-time control systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Cui, Xianzhong

1988-01-01

The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

[Complexity and its integrative effects of the time lags of environment factors affecting Larix gmelinii stem sap flow].

PubMed

Wang, Hui-Mei; Sun, Wei; Zu, Yuan-Gang; Wang, Wen-Jie

2011-12-01

Based on the one-year (2005) observations with a frequency of half hour on the stem sap flow of Larix gmelinii plantation trees planted in 1969 and the related environmental factors air humidity (RH), air temperature (T(air)), photosynthetic components active radiation (PAR), soil temperature (T(soil)), and soil moisture (TDR), principal analysis (PCA) and correction analysis were made on the time lag effect of the stem flow in different seasons (26 days of each season) and in a year via dislocation analysis, with the complexity and its integrative effects of the time lags of environment factors affecting the stem sap flow approached. The results showed that in different seasons and for different environmental factors, the time lag effect varied obviously. In general, the time lag of PAR was 0.5-1 hour ahead of sap flow, that of T(air) and RH was 0-2 hours ahead of or behind the sap flow, and the time lags of T(soil) and TDR were much longer or sometimes undetectable. Because of the complexity of the time lags, no evident improvements were observed in the linear correlations (R2, slope, and intercept) when the time lags based on short-term (20 days) data were used to correct the time lags based on whole year data. However, obvious improvements were found in the standardized and non-standardized correlation coefficients in stepwise multiple regressions, i.e., the time lag corrections could improve the effects of RH, but decreased the effects of PAR, T(air), and T(soil). PCA could be used to simplify the complexity. The first and the second principal components could stand for over 75% information of all the environmental factors in different seasons and in whole year. The time lags of both the first and the second principal components were 1-1.5 hours in advance of the sap flow, except in winter (no time lag effect).

Effect of fatigue on reaction time, response time, performance time, and kick impact in taekwondo roundhouse kick.

PubMed

Sant'Ana, Jader; Franchini, Emerson; da Silva, Vinicius; Diefenthaeler, Fernando

2017-06-01

Reaction time and response time are considered important abilities and can potentially affect combat performance. This study investigated the effect of a specific fatigue protocol on reaction time, response time, performance time, and kick impact. Seven male athletes reported to the laboratory on two different days. During day one, athletes performed a specific progressive taekwondo test, and on day two, a protocol for determining reaction time, response time, performance time, and kick impact before and after a time to exhaustion test at an intensity level corresponding to the maximal kick frequency obtained during the specific progressive taekwondo test. Muscle activation from rectus femoris and kick impact of the preferred limb were assessed. No differences were observed for response time and performance time. However, kick impact decreased (43 ± 27 to 13 ± 10 g, p < 0.01) while reaction time increased (145 ± 51 to 223 ± 133 ms, p < 0.05). Moderate correlation was observed between kick impact and response time (r = 0.565; p < 0.01), and kick impact and performance time (r = 0.494; p < 0.05). Results indicate that coaches and athletes may use taekwondo training programmes on coordination-based exercises leading to improve response time and to reduce fatigue effects in order to improve technique effectiveness and enhance the possibilities of scoring in a competitive situation.

The influence of prior experience and expected timing on vibrotactile discrimination

PubMed Central

Karim, Muhsin; Harris, Justin A.; Langdon, Angela; Breakspear, Michael

2013-01-01

Vibrotactile discrimination tasks involve perceptual judgements on stimulus pairs separated by a brief interstimulus interval (ISI). Despite their apparent simplicity, decision making during these tasks is biased by prior experience in a manner that is not well understood. A striking example is when participants perform well on trials where the first stimulus is closer to the mean of the stimulus-set than the second stimulus, and perform comparatively poorly when the first stimulus is further from the stimulus mean. This “time-order effect” suggests that participants implicitly encode the mean of the stimulus-set and use this internal standard to bias decisions on any given trial. For relatively short ISIs, the magnitude of the time-order effect typically increases with the distance of the first stimulus from the global mean. Working from the premise that the time-order effect reflects the loss of precision in working memory representations, we predicted that the influence of the time-order effect, and this superimposed “distance” effect, would monotonically increase for trials with longer ISIs. However, by varying the ISI across four intervals (300, 600, 1200, and 2400 ms) we instead found a complex, non-linear dependence of the time-order effect on both the ISI and the distance, with the time-order effect being paradoxically stronger at short ISIs. We also found that this relationship depended strongly on participants' prior experience of the ISI (from previous task titration). The time-order effect not only depends on participants' expectations concerning the distribution of stimuli, but also on the expected timing of the trials. PMID:24399927

Generalized semiparametric varying-coefficient models for longitudinal data

NASA Astrophysics Data System (ADS)

Qi, Li

In this dissertation, we investigate the generalized semiparametric varying-coefficient models for longitudinal data that can flexibly model three types of covariate effects: time-constant effects, time-varying effects, and covariate-varying effects, i.e., the covariate effects that depend on other possibly time-dependent exposure variables. First, we consider the model that assumes the time-varying effects are unspecified functions of time while the covariate-varying effects are parametric functions of an exposure variable specified up to a finite number of unknown parameters. The estimation procedures are developed using multivariate local linear smoothing and generalized weighted least squares estimation techniques. The asymptotic properties of the proposed estimators are established. The simulation studies show that the proposed methods have satisfactory finite sample performance. ACTG 244 clinical trial of HIV infected patients are applied to examine the effects of antiretroviral treatment switching before and after HIV developing the 215-mutation. Our analysis shows benefit of treatment switching before developing the 215-mutation. The proposed methods are also applied to the STEP study with MITT cases showing that they have broad applications in medical research.

Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

PubMed

Ermis, E E; Celiktas, C

2012-12-01

Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. Copyright © 2012 Elsevier Ltd. All rights reserved.

Time Out for Time Management.

ERIC Educational Resources Information Center

Herr, Judy; And Others

1995-01-01

Offers early childhood program administrators time management strategies to increase available time, efficiency, and effectiveness. To manage paper, directors should clear the desk top, use in-out baskets, create a filing system, and handle mail effectively. Tips for managing meetings include preparing an agenda, scheduling meetings for…

29 CFR 1405.11 - Effect on employee benefits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE PART-TIME EMPLOYMENT Part-time Employment Program § 1405.11 Effect on employee benefits. Career part-time employees are entitled... Programs. The Government contribution for health insurance of eligible part-time employees will be prorated...

Angular dependence of EWS time delay for photoionization of @Xe

NASA Astrophysics Data System (ADS)

Mandal, Ankur; Deshmukh, Pranawa; Kheifets, Anatoli; Dolmatov, Valeriy; Manson, Steven

2017-04-01

Interference between photoionization channels leads to angular dependence in photoionization time delay. Angular dependence is found to be a common effect for two-photon absorption experiments very recently. The effect of confinement on the time delay where each partial wave contributions to the ionization are studied. In this work we report angular dependence and confinement effects on Eisenbud-Wigner-Smith (EWS) time delay in atomic photoionization. Using and we computed the EWS time delay for free and confined Xe atom for photoionization from inner 4d3/2 and 4d5/2 and outer 5p1/2 and 5p3/2 subshells at various angles. The calculated EWS time delay is few tens to few hundreds of attoseconds (10-18 second). The photoionization time delay for @Xe follows that in the free Xe atom on which the confinement oscillations are built. The present work reveals the effect of confinement on the photoionization time delay at different angles between photoelectron ejection and the photon polarization.

Indicators of Institutional Effectiveness at NVCC: 1992-1997. Performance Indicators Series.

ERIC Educational Resources Information Center

Northern Virginia Community Coll., Annandale. Office of Institutional Research.

This is a report on the measurements of institutional effectiveness indicators at Northern Virginia Community College from 1992 to 1997. The report looks at the following indicators: (1) persistence rate of first-time students; (2) persistence rate of full-time first-time students; (3) persistence rate of part-time first-time students; (4)…

49 CFR 393.11 - Lamps and reflective devices.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture..., meet the requirements of subpart B of part 393 in effect at the time of manufacture. (2) Exceptions... devices and electrical equipment in effect at the time of manufacture. Trailers which are equipped with...

Effects of Aging-Time Reference on the Long Term Behavior of the IM7/K3B Composite

NASA Technical Reports Server (NTRS)

Veazie, David R.; Gates, Thomas S.

1998-01-01

An analytical study was undertaken to investigate the effects of the time-based shift reference on the long term behavior of the graphite reinforced thermoplastic polyimide composite IM7/K3B at elevated temperature. Creep compliance and the effects of physical aging on the time dependent response was measured for uniaxial loading at several isothermal conditions below the glass transition temperature (T(sub g). Two matrix dominated loading modes, shear and transverse, were investigated in tension and compression. The momentary sequenced creep/aging curves were collapsed through a horizontal (time) shift using the shortest, middle and longest aging time curve as the reference curve. Linear viscoelasticity was used to characterize the creep/recovery behavior and superposition techniques were used to establish the physical aging related material constants. The use of effective time expressions in a laminated plate model allowed for the prediction of long term creep compliance. The effect of using different reference curves with time/aging-time superposition was most sensitive to the physical aging shift rate at lower test temperatures. Depending on the loading mode, the reference curve used can result in a more accurate long term prediction, especially at lower test temperatures.

The prevalence of upright non-stepping time in comparison to stepping time in 11-13 year old school children across seasons.

PubMed

McCrorie, P Rw; Duncan, E; Granat, M H; Stansfield, B W

2012-11-01

Evidence suggests that behaviours such as standing are beneficial for our health. Unfortunately, little is known of the prevalence of this state, its importance in relation to time spent stepping or variation across seasons. The aim of this study was to quantify, in young adolescents, the prevalence and seasonal changes in time spent upright and not stepping (UNSt(time)) as well as time spent upright and stepping (USt(time)), and their contribution to overall upright time (U(time)). Thirty-three adolescents (12.2 ± 0.3 y) wore the activPAL activity monitor during four school days on two occasions: November/December (winter) and May/June (summer). UNSt(time) contributed 60% of daily U(time) at winter (Mean = 196 min) and 53% at summer (Mean = 171 min); a significant seasonal effect, p < 0.001. USt(time) was significantly greater in summer compared to winter (153 min versus 131 min, p < 0.001). The effects in UNSt(time) could be explained through significant seasonal differences during the school hours (09:00-16:00), whereas the effects in USt(time) could be explained through significant seasonal differences in the evening period (16:00-22:00). Adolescents spent a greater amount of time upright and not stepping than they did stepping, in both winter and summer. The observed seasonal effects for both UNSt(time) and USt(time) provide important information for behaviour change intervention programs.

The effects of publishing emergency department wait time on patient utilization patterns in a community with two emergency department sites: a retrospective, quasi-experiment design.

PubMed

Xie, Bin; Youash, Sabrina

2011-06-14

Providing emergency department (ED) wait time information to the public has been suggested as a mechanism to reduce lengthy ED wait times (by enabling patients to select the ED site with shorter wait time), but the effects of such a program have not been evaluated. We evaluated the effects of such a program in a community with two ED sites. Descriptive statistics for wait times of the two sites before and after the publication of wait time information were used to evaluate the effects of the publication of wait time information on wait times. Multivariate logistical regression was used to test whether or not individual patients used published wait time to decide which site to visit. We found that the rates of wait times exceeding 4 h, and the 95th percentile of wait times in the two sites decreased after the publication of wait time information, even though the average wait times experienced a slight increase. We also found that after controlling for other factors, the site with shorter wait time had a higher likelihood of being selected after the publication of wait time information, but there was no such relationship before the publication. These findings were consistent with the hypothesis that the publication of wait time information leads to patients selecting the site with shorter wait time. While publishing ED wait time information did not improve average wait time, it reduced the rates of lengthy wait times.

Allocating time to future tasks: the effect of task segmentation on planning fallacy bias.

PubMed

Forsyth, Darryl K; Burt, Christopher D B

2008-06-01

The scheduling component of the time management process was used as a "paradigm" to investigate the allocation of time to future tasks. In three experiments, we compared task time allocation for a single task with the summed time allocations given for each subtask that made up the single task. In all three, we found that allocated time for a single task was significantly smaller than the summed time allocated to the individual subtasks. We refer to this as the segmentation effect. In Experiment 3, we asked participants to give estimates by placing a mark on a time line, and found that giving time allocations in the form of rounded close approximations probably does not account for the segmentation effect. We discuss the results in relation to the basic processes used to allocate time to future tasks and the means by which planning fallacy bias might be reduced.

A METHOD TO INCORPORATE ECOLOGY INTO RESIDENCE TIME OF CHEMICALS IN EMBAYMENTS: LOCAL EFFECT TIME

EPA Science Inventory

Residence times are classically defined by the physical and chemical aspects of water bodies rather than by their ecological implications. Therefore, a more clear and direct connection between the residence times and ecological effects is necessary to quantitatively relate these ...

Time Management. Revised.

ERIC Educational Resources Information Center

Halverson, Don E.

This booklet presents concepts and applications of effective time management to help administrators learn to utilize their time most effectively, thereby accomplishing their most worthwhile objectives in the shortest amount of time. Although the booklet is designed to be self-administered, the greatest benefits should be derived in a group setting…

Time-Indexed Effect Size for P-12 Reading and Math Program Evaluation

ERIC Educational Resources Information Center

Lee, Jaekyung; Finn, Jeremy; Liu, Xiaoyan

2012-01-01

This study contextualizes an effect-size-like index of educational treatment effects or any group mean differences in academic achievement by referencing time. The new effect size metric can enrich effect size interpretations while serving as a supplement (but not substitute) for conventional standardized effect size measures. Specifically, the…

Improving care and efficiency: appointment times in a haemodialysis unit.

PubMed

Lunts, P

2002-01-01

Shortage of nurses and dialysis spaces and the desire to improve patient care are the two main driving forces in the dialysis field today. This paper suggests that these issues can be addressed by organisational change. We describe a simple, dramatically effective but rarely used example - the effect on a haemodialysis unit of the introduction of patient appointment times. This paper will demonstrate that appointment times can be highly effective in reducing waiting times for patients and in utilizing staff and resources more efficiently, as long as there is commitment from key staff to implement and maintain them effectively

Delay time and Hartman effect in strain engineered graphene

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

Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong; Ban, Yue, E-mail: yban@shu.edu.cn

2014-05-07

Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect.

Time management for today's workplace demands.

PubMed

Thomack, Bill

2012-05-01

As the work force decreases, the workload remains the same or, in many cases, increases. An effective employee must arrange work time to accomplish what needs to be done in the time available. The best way to manage time is to set a goal, develop a plan, and measure the outcome. To manage time requires determining where time is currently spent, taking time at the end of the day to prepare for the next morning, managing appointments, carefully planning projects, and managing phone, electronic, and paper mail. Organization is another step in effectively managing time. An organizational system decreases wasted time. Keeping the desk clear and creating a system to organize mail improves efficiency. Time management also focuses on balance, an overall purpose, and supporting principles. Personal or professional effectiveness does not depend solely on the effort expended, but whether the effort is in the right direction. The challenge of time management is to manage not only time, but also oneself. Copyright 2012, SLACK Incorporated.

Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

PubMed

Dukic, T; Hanson, L; Falkmer, T

2006-01-15

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

Contact to Nature Benefits Health: Mixed Effectiveness of Different Mechanisms.

PubMed

Hofmann, Mathias; Young, Christopher; Binz, Tina M; Baumgartner, Markus R; Bauer, Nicole

2017-12-25

How can urban nature contribute to the reduction of chronic stress? We twice measured the concentration of the "stress hormone" cortisol in the hair of 85 volunteer gardeners (six months apart), relating cortisol level change to (self-reported) characteristics of their recreational activities. Both time spent in nature and physical activity led to decreases in cortisol, while time spent being idle led to an increase. At high levels of present stressors, however, the relationship for time spent in nature and for idleness was reversed. Time spent with social interaction had no effect on cortisol levels. Our results indicate that physical activity is an effective means of mitigating the negative effects of chronic stress. The results regarding the time spent in nature and time spent being idle are less conclusive, suggesting the need for more research. We conclude that if chronic stress cannot be abolished by eradicating its sources, public health may take to measures to reduce it-providing urban nature being one effective possibility.

Contact to Nature Benefits Health: Mixed Effectiveness of Different Mechanisms

PubMed Central

2017-01-01

How can urban nature contribute to the reduction of chronic stress? We twice measured the concentration of the “stress hormone” cortisol in the hair of 85 volunteer gardeners (six months apart), relating cortisol level change to (self-reported) characteristics of their recreational activities. Both time spent in nature and physical activity led to decreases in cortisol, while time spent being idle led to an increase. At high levels of present stressors, however, the relationship for time spent in nature and for idleness was reversed. Time spent with social interaction had no effect on cortisol levels. Our results indicate that physical activity is an effective means of mitigating the negative effects of chronic stress. The results regarding the time spent in nature and time spent being idle are less conclusive, suggesting the need for more research. We conclude that if chronic stress cannot be abolished by eradicating its sources, public health may take to measures to reduce it—providing urban nature being one effective possibility. PMID:29295586

Circadian type and bed-timing regularity in 654 retired seniors: correlations with subjective sleep measures.

PubMed

Monk, Timothy H; Buysse, Daniel J; Billy, Bart D; Fletcher, Mary E; Kennedy, Kathy S; Schlarb, Janet E; Beach, Scott R

2011-02-01

Using telephone interview data from retired seniors to explore how inter-individual differences in circadian type (morningness) and bed-timing regularity might be related to subjective sleep quality and quantity. MANCOVA with binary measures of morningness, stability of bedtimes, and stability of rise-times as independent variables; sleep measures as dependent variables; age, former shift work, and gender as covariates. Telephone interviews using a pseudo-random age-targeted sampling process. 654 retired seniors (65 y+, 363M, 291F). none. (1) circadian type (from Composite Scale of Morningness [CSM]), and stability of (2) bedtime and (3) rise-time from the Sleep Timing Questionnaire (STQ). Pittsburgh Sleep Quality Index (PSQI) score, time in bed, time spent asleep, and sleep efficiency, from Sleep Timing Questionnaire (STQ). Morning-type orientation, stability in bedtimes, and stability in rise-times were all associated with better sleep quality (P < 0.001, for all; effect sizes: 0.43, 0.33, and 0.27). Morningness was associated with shorter time in bed (P < 0.0001, effect size 0.45) and time spent asleep (P < 0.005, effect size 0.26). For bedtime and rise-time stability the direction of effect was similar but mostly weaker. In retired seniors, a morning-type orientation and regularity in bedtimes and rise-times appear to be correlated with improved subjective sleep quality and with less time spent in bed.

Gender differences in science attitude-achievement relationships over time among white middle-school students

NASA Astrophysics Data System (ADS)

Mattern, Nancy; Schau, Candace

2002-04-01

Four causal models describing the longitudinal relationships between attitudes and achievement have been proposed in the literature. These models feature: (a) cross-effects over time between attitudes and achievement, (b) influence of achievement predominant over time, (c) influence of attitudes predominant over time, or (d) no cross-effects over time between attitudes and achievement. In an examin-ation of the causal relationships over time between attitudes toward science and science achievement for White rural seventh- and eighth-grade students, the cross-effects model was the best fitting model form for students overall. However, when examined by gender, the no cross-effects model exhibited the most accurate fit for White rural middle-school girls, whereas a new model called the no attitudes-path model exhibited the best fit for these boys.

Time-on-task effects in children with and without ADHD: depletion of executive resources or depletion of motivation?

PubMed

Dekkers, Tycho J; Agelink van Rentergem, Joost A; Koole, Alette; van den Wildenberg, Wery P M; Popma, Arne; Bexkens, Anika; Stoffelsen, Reino; Diekmann, Anouk; Huizenga, Hilde M

2017-12-01

Children with attention-deficit/hyperactivity disorder (ADHD) are characterized by deficits in their executive functioning and motivation. In addition, these children are characterized by a decline in performance as time-on-task increases (i.e., time-on-task effects). However, it is unknown whether these time-on-task effects should be attributed to deficits in executive functioning or to deficits in motivation. Some studies in typically developing (TD) adults indicated that time-on-task effects should be interpreted as depletion of executive resources, but other studies suggested that they represent depletion of motivation. We, therefore, investigated, in children with and without ADHD, whether there were time-on-task effects on executive functions, such as inhibition and (in)attention, and whether these were best explained by depletion of executive resources or depletion of motivation. The stop-signal task (SST), which generates both indices of inhibition (stop-signal reaction time) and attention (reaction time variability and errors), was administered in 96 children (42 ADHD, 54 TD controls; aged 9-13). To differentiate between depletion of resources and depletion of motivation, the SST was administered twice. Half of the participants was reinforced during second task performance, potentially counteracting depletion of motivation. Multilevel analyses indicated that children with ADHD were more affected by time-on-task than controls on two measures of inattention, but not on inhibition. In the ADHD group, reinforcement only improved performance on one index of attention (i.e., reaction time variability). The current findings suggest that time-on-task effects in children with ADHD occur specifically in the attentional domain, and seem to originate in both depletion of executive resources and depletion of motivation. Clinical implications for diagnostics, psycho-education, and intervention are discussed.

Time-Dependent Effects of Inosine on Competence Development in Haemophilus influenzae

PubMed Central

Miller, Donald H.; Huang, P. C.

1970-01-01

The effect of inosine on the development of competence is dependent upon the time at which it is added to the competence medium. Competence is inhibited if inosine is added within 15 min after the development begins, but is stimulated if the addition is made at later times. Protein synthesis is stimulated by the addition of inosine, but the effect is quantitatively similar regardless of the time at which inosine is added. PMID:5312691

Color, dispersion, and exposure time in performance on rotated figure recognition.

PubMed

Huang, Kuo-Chen; Lee, Shin-Tsann; Chang, Chun-Chieh

2008-10-01

This study investigated the effects of dispersion, color, and rotation of figures on recognition under varied exposure times. A total of 30 women and 15 men, Taiwanese college students ages 18 to 20 years (M = 19.1, SD = 1.2), participated. Subjects were to recognize a target figure and respond with its location in each stimulus by pressing a mouse button. Analysis showed that the effect of rotation on accuracy was significant. Accuracy for the rotation of 180 degrees was greater than those for 60 degrees and 300 degrees. Exposure time also significantly influenced accuracy. The accuracy was greater for 2 and 3 sec. than for 1 sec. No significant effects on accuracy were associated with dispersion and color, and neither had any interactive effect on accuracy. Dispersion significantly affected the response time as response time for dispersion under 0.4 and 0.5 conditions were shorter than those under 0.2 and 0.3 conditions. Significantly less response time was needed for rotation of 180 degrees than for 60 degrees and 300 degrees conditions. Response time was longer for red figures than for blue, green, and yellow figures. No significant effect on response time was associated with duration of exposure. Two interactive two-way effects were found: dispersion x color of figure and dispersion x rotation. Implications for figure or icon design are discussed.

The Importance of Time Management Skills for the Child or Adolescent with Learning Disabilities.

ERIC Educational Resources Information Center

Pisarchick, Sally E.

This document discusses the importance of time management for learning-disabled students and techniques to enhance the teaching of time management skills. Teaching effective time management calls for consideration of the student's readiness to learn new material, effective transitions between activities, clear prioritization of educational…

Seasonal manure application timing and storage effects on field and watershed level phosphorus losses

USDA-ARS?s Scientific Manuscript database

The timing of manure application to agricultural soils remains a contentious area of nutrient management, particularly with regard to the impact of timing on nutrient loss in runoff and downstream water quality. We examined the effect of seasonal manure application timing and manure storage capacity...

Effects of morphological Family Size for young readers.

PubMed

Perdijk, Kors; Schreuder, Robert; Baayen, R Harald; Verhoeven, Ludo

2012-09-01

Dutch children, from the second and fourth grade of primary school, were each given a visual lexical decision test on 210 Dutch monomorphemic words. After removing words not recognized by a majority of the younger group, (lexical) decisions were analysed by mixed-model regression methods to see whether morphological Family Size influenced decision times over and above several other covariates. The effect of morphological Family Size on decision time was mixed: larger families led to significantly faster decision times for the second graders but not for the fourth graders. Since facilitative effects on decision times had been found for adults, we offer a developmental account to explain the absence of an effect of Family Size on decision times for fourth graders. ©2011 The British Psychological Society.

The Effects of Morphine on the Production and Discrimination of Interresponse Times

ERIC Educational Resources Information Center

Odum, Amy L.; Ward, Ryan D.

2004-01-01

Recent experiments suggest that the effects of drugs of abuse on the discrimination of the passage of time may differ for experimenter-imposed and subject-produced events. The current experiment examined this suggestion by determining the effects of morphine on the discrimination of interresponse times (IRTs). Pigeons pecked a center key on a…

Effects of Interest-Major Congruence, Motivation, and Academic Performance on Timely Degree Attainment

ERIC Educational Resources Information Center

Allen, Jeff; Robbins, Steve

2010-01-01

Using longitudinal student data from 15 four-year (n = 3,072) and 13 (n = 788) two-year postsecondary institutions, the authors tested the effects of interest-major congruence, motivation, and 1st-year academic performance on timely degree completion. Findings suggest that interest-major congruence has a direct effect on timely degree completion…

The Effects of Barycentric and Asymmetric Transverse Velocities on Eclipse and Transit Times

NASA Astrophysics Data System (ADS)

Conroy, Kyle E.; Prša, Andrej; Horvat, Martin; Stassun, Keivan G.

2018-02-01

It has long been recognized that the finite speed of light can affect the observed time of an event. For example, as a source moves radially toward or away from an observer, the path length and therefore the light travel time to the observer decreases or increases, causing the event to appear earlier or later than otherwise expected, respectively. This light travel time effect has been applied to transits and eclipses for a variety of purposes, including studies of eclipse timing variations and transit timing variations that reveal the presence of additional bodies in the system. Here we highlight another non-relativistic effect on eclipse or transit times arising from the finite speed of light—caused by an asymmetry in the transverse velocity of the two eclipsing objects, relative to the observer. This asymmetry can be due to a non-unity mass ratio or to the presence of external barycentric motion. Although usually constant, this barycentric and asymmetric transverse velocity (BATV) effect can vary between sequential eclipses if either the path length between the two objects or the barycentric transverse velocity varies in time. We discuss this BATV effect and estimate its magnitude for both time-dependent and time-independent cases. For the time-dependent cases, we consider binaries that experience a change in orbital inclination, eccentric systems with and without apsidal motion, and hierarchical triple systems. We also consider the time-independent case which, by affecting the primary and secondary eclipses differently, can influence the inferred system parameters, such as the orbital eccentricity.

Acute effects of THC on time perception in frequent and infrequent cannabis users.

PubMed

Sewell, R Andrew; Schnakenberg, Ashley; Elander, Jacqueline; Radhakrishnan, Rajiv; Williams, Ashley; Skosnik, Patrick D; Pittman, Brian; Ranganathan, Mohini; D'Souza, D Cyril

2013-03-01

Cannabinoids have been shown to alter time perception, but existing literature has several limitations. Few studies have included both time estimation and production tasks, few control for subvocal counting, most had small sample sizes, some did not record subjects' cannabis use, many tested only one dose, and used either oral or inhaled administration of Δ⁹-tetrahydrocannabinol (THC), leading to variable pharmacokinetics, and some used whole-plant cannabis containing cannabinoids other than THC. Our study attempted to address these limitations. This study aims to characterize the acute effects of THC and frequent cannabis use on seconds-range time perception. THC was hypothesized to produce transient, dose-related time overestimation and underproduction. Frequent cannabis smokers were hypothesized to show blunted responses to these alterations. IV THC was administered at doses from 0.015 to 0.05 mg/kg to 44 subjects who participated in several double-blind, randomized, counterbalanced, crossover, placebo-controlled studies. Visual time estimation and production tasks in the seconds range were presented to subjects three times on each test day. All doses induced time overestimation and underproduction. Chronic cannabis use had no effect on baseline time perception. While infrequent/nonsmokers showed temporal overestimation at medium and high doses and temporal underproduction at all doses, frequent cannabis users showed no differences. THC effects on time perception were not dose related. A psychoactive dose of THC increases internal clock speed as indicated by time overestimation and underproduction. This effect is not dose related and is blunted in chronic cannabis smokers who did not otherwise have altered baseline time perception.

The effect of visual-motion time delays on pilot performance in a pursuit tracking task

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1976-01-01

A study has been made to determine the effect of visual-motion time delays on pilot performance of a simulated pursuit tracking task. Three interrelated major effects have been identified: task difficulty, motion cues, and time delays. As task difficulty, as determined by airplane handling qualities or target frequency, increases, the amount of acceptable time delay decreases. However, when relatively complete motion cues are included in the simulation, the pilot can maintain his performance for considerably longer time delays. In addition, the number of degrees of freedom of motion employed is a significant factor.

Effects of time ordering in quantum nonlinear optics

NASA Astrophysics Data System (ADS)

Quesada, Nicolás; Sipe, J. E.

2014-12-01

We study time-ordering corrections to the description of spontaneous parametric down-conversion (SPDC), four-wave mixing (SFWM), and frequency conversion using the Magnus expansion. Analytic approximations to the evolution operator that are unitary are obtained. They are Gaussian preserving, and allow us to understand order-by-order the effects of time ordering. We show that the corrections due to time ordering vanish exactly if the phase-matching function is sufficiently broad. The calculation of the effects of time ordering on the joint spectral amplitude of the photons generated in SPDC and SFWM are reduced to quadrature.

Timed picture naming in seven languages

PubMed Central

BATES, ELIZABETH; D’AMICO, SIMONA; JACOBSEN, THOMAS; SZÉKELY, ANNA; ANDONOVA, ELENA; DEVESCOVI, ANTONELLA; HERRON, DAN; LU, CHING CHING; PECHMANN, THOMAS; PLÉH, CSABA; WICHA, NICOLE; FEDERMEIER, KARA; GERDJIKOVA, IRINI; GUTIERREZ, GABRIEL; HUNG, DAISY; HSU, JEANNE; IYER, GOWRI; KOHNERT, KATHERINE; MEHOTCHEVA, TEODORA; OROZCO-FIGUEROA, ARACELI; TZENG, ANGELA; TZENG, OVID

2012-01-01

Timed picture naming was compared in seven languages that vary along dimensions known to affect lexical access. Analyses over items focused on factors that determine cross-language universals and cross-language disparities. With regard to universals, number of alternative names had large effects on reaction time within and across languages after target–name agreement was controlled, suggesting inhibitory effects from lexical competitors. For all the languages, word frequency and goodness of depiction had large effects, but objective picture complexity did not. Effects of word structure variables (length, syllable structure, compounding, and initial frication) varied markedly over languages. Strong cross-language correlations were found in naming latencies, frequency, and length. Other-language frequency effects were observed (e.g., Chinese frequencies predicting Spanish reaction times) even after within-language effects were controlled (e.g., Spanish frequencies predicting Spanish reaction times). These surprising cross-language correlations challenge widely held assumptions about the lexical locus of length and frequency effects, suggesting instead that they may (at least in part) reflect familiarity and accessibility at a conceptual level that is shared over languages. PMID:12921412

Parallel effects of memory set activation and search on timing and working memory capacity.

PubMed

Schweickert, Richard; Fortin, Claudette; Xi, Zhuangzhuang; Viau-Quesnel, Charles

2014-01-01

Accurately estimating a time interval is required in everyday activities such as driving or cooking. Estimating time is relatively easy, provided a person attends to it. But a brief shift of attention to another task usually interferes with timing. Most processes carried out concurrently with timing interfere with it. Curiously, some do not. Literature on a few processes suggests a general proposition, the Timing and Complex-Span Hypothesis: A process interferes with concurrent timing if and only if process performance is related to complex span. Complex-span is the number of items correctly recalled in order, when each item presented for study is followed by a brief activity. Literature on task switching, visual search, memory search, word generation and mental time travel supports the hypothesis. Previous work found that another process, activation of a memory set in long term memory, is not related to complex-span. If the Timing and Complex-Span Hypothesis is true, activation should not interfere with concurrent timing in dual-task conditions. We tested such activation in single-task memory search task conditions and in dual-task conditions where memory search was executed with concurrent timing. In Experiment 1, activating a memory set increased reaction time, with no significant effect on time production. In Experiment 2, set size and memory set activation were manipulated. Activation and set size had a puzzling interaction for time productions, perhaps due to difficult conditions, leading us to use a related but easier task in Experiment 3. In Experiment 3 increasing set size lengthened time production, but memory activation had no significant effect. Results here and in previous literature on the whole support the Timing and Complex-Span Hypotheses. Results also support a sequential organization of activation and search of memory. This organization predicts activation and set size have additive effects on reaction time and multiplicative effects on percent correct, which was found.

Effective Time Management in the Project Office. Executive Summary.

DTIC Science & Technology

1976-11-05

manager. It can be concluded from the study that project managers have difficulty in managing their time and that although neglected, time management should...be taught to project managers so as to preclude spending an inordinate amount of time to accomplish their job. An understanding and use of the time ... management principles delineated in the study should allow the manager to make much more effective use of his available time. (Author)

Reliability Analysis of Time to Complete the Obstacle Course Portion of the Load Effects Assessment Program (LEAP)

DTIC Science & Technology

2016-10-25

TIME TO COMPLETE THE OBSTACLE COURSE PORTION OF THE LOAD EFFECTS ASSESSMENT PROGRAM (LEAP) by K. Blake Mitchell Jessica M. Batty Megan E...Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for...2014 – June 2015 4. TITLE AND SUBTITLE RELIABILITY ANALYSIS OF TIME TO COMPLETE THE OBSTACLE COURSE PORTION OF THE LOAD EFFECTS ASSESSMENT PROGRAM

Effects of System Timing Parameters on Operator Performance in a Personnel Records Task

DTIC Science & Technology

1981-03-01

work sampling, embedded performance measures, and operator satisfaction ratings) are needed to provide a complete analysis of the effects of the four...HFL-8 l-l/NPRDC-8 1-1 March 1981 EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Robert C. Williges Beverly H...and Subtitle) S. TYPE OF REPORT & PERIOD COVERED EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Final

Processing of visually presented clock times.

PubMed

Goolkasian, P; Park, D C

1980-11-01

The encoding and representation of visually presented clock times was investigated in three experiments utilizing a comparative judgment task. Experiment 1 explored the effects of comparing times presented in different formats (clock face, digit, or word), and Experiment 2 examined angular distance effects created by varying positions of the hands on clock faces. In Experiment 3, encoding and processing differences between clock faces and digitally presented times were directly measured. Same/different reactions to digitally presented times were faster than to times presented on a clock face, and this format effect was found to be a result of differences in processing that occurred after encoding. Angular separation also had a limited effect on processing. The findings are interpreted within the framework of theories that refer to the importance of representational codes. The applicability to the data of Bank's semantic-coding theory, Paivio's dual-coding theory, and the levels-of-processing view of memory are discussed.

Is It Time Well Spent? The Relationship between Time Management Behaviours, Perceived Effectiveness and Work-Related Morale and Distress in a University Context

ERIC Educational Resources Information Center

Kearns, Hugh; Gardiner, Maria

2007-01-01

Despite the high "guru-factor" in time management, few claims have been subjected to empirical investigation. This study tests the claims that people who manage their time well perceive themselves to be more effective and feel less stressed. University staff and students were utilized to investigate the relationship between time management related…

17 CFR 260.7a-4 - Calculation of time.

Code of Federal Regulations, 2010 CFR

2010-04-01

... eastern daylight-saving time, whichever is in effect at the principal office of the Commission on the date... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Calculation of time. 260.7a-4... time. Saturdays, Sundays and holidays shall be counted in computing the effective date of applications...

Principal Time Management Skills: Explaining Patterns in Principals' Time Use, Job Stress, and Perceived Effectiveness

ERIC Educational Resources Information Center

Grissom, Jason A.; Loeb, Susanna; Mitani, Hajime

2015-01-01

Purpose: Time demands faced by school principals make principals' work increasingly difficult. Research outside education suggests that effective time management skills may help principals meet job demands, reduce job stress, and improve their performance. The purpose of this paper is to investigate these hypotheses. Design/methodology/approach:…

17 CFR 260.7a-4 - Calculation of time.

Code of Federal Regulations, 2014 CFR

2014-04-01

... eastern daylight-saving time, whichever is in effect at the principal office of the Commission on the date... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Calculation of time. 260.7a-4... time. Saturdays, Sundays and holidays shall be counted in computing the effective date of applications...

17 CFR 260.7a-4 - Calculation of time.

Code of Federal Regulations, 2013 CFR

2013-04-01

... eastern daylight-saving time, whichever is in effect at the principal office of the Commission on the date... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Calculation of time. 260.7a-4... time. Saturdays, Sundays and holidays shall be counted in computing the effective date of applications...

17 CFR 260.7a-4 - Calculation of time.

Code of Federal Regulations, 2011 CFR

2011-04-01

... eastern daylight-saving time, whichever is in effect at the principal office of the Commission on the date... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Calculation of time. 260.7a-4... time. Saturdays, Sundays and holidays shall be counted in computing the effective date of applications...

17 CFR 260.7a-4 - Calculation of time.

Code of Federal Regulations, 2012 CFR

2012-04-01

... eastern daylight-saving time, whichever is in effect at the principal office of the Commission on the date... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Calculation of time. 260.7a-4... time. Saturdays, Sundays and holidays shall be counted in computing the effective date of applications...

Effects of Time Management Instruction on Adolescents' Ability to Self-Manage Time in a Vocational Setting

ERIC Educational Resources Information Center

DiPipi-Hoy, Caroline; Jitendra, Asha K.; Kern, Lee

2009-01-01

This study investigated the effectiveness of a time self-management intervention in the work setting of four adolescents with developmental disabilities. A multiple baseline across participants design was used to examine the adolescents' ability to independently identify time and initiate work-related activities. Intervention was delivered by…

Application of the backward extrapolation method to pulsed neutron sources

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

Talamo, Alberto; Gohar, Yousry

We report particle detectors operated in pulse mode are subjected to the dead-time effect. When the average of the detector counts is constant over time, correcting for the dead-time effect is simple and can be accomplished by analytical formulas. However, when the average of the detector counts changes over time it is more difficult to take into account the dead-time effect. When a subcritical nuclear assembly is driven by a pulsed neutron source, simple analytical formulas cannot be applied to the measured detector counts to correct for the dead-time effect because of the sharp change of the detector counts overmore » time. This work addresses this issue by using the backward extrapolation method. The latter can be applied not only to a continuous (e.g. californium) external neutron source but also to a pulsed external neutron source (e.g. by a particle accelerator) driving a subcritical nuclear assembly. Finally, the backward extrapolation method allows to obtain from the measured detector counts both the dead-time value and the real detector counts.« less

Application of the backward extrapolation method to pulsed neutron sources

DOE PAGES

Talamo, Alberto; Gohar, Yousry

2017-09-23

We report particle detectors operated in pulse mode are subjected to the dead-time effect. When the average of the detector counts is constant over time, correcting for the dead-time effect is simple and can be accomplished by analytical formulas. However, when the average of the detector counts changes over time it is more difficult to take into account the dead-time effect. When a subcritical nuclear assembly is driven by a pulsed neutron source, simple analytical formulas cannot be applied to the measured detector counts to correct for the dead-time effect because of the sharp change of the detector counts overmore » time. This work addresses this issue by using the backward extrapolation method. The latter can be applied not only to a continuous (e.g. californium) external neutron source but also to a pulsed external neutron source (e.g. by a particle accelerator) driving a subcritical nuclear assembly. Finally, the backward extrapolation method allows to obtain from the measured detector counts both the dead-time value and the real detector counts.« less

Effects of shallow-layer reverberation on measurement of teleseismic P-wave travel times for ocean bottom seismograph data

NASA Astrophysics Data System (ADS)

Obayashi, Masayuki; Ishihara, Yasushi; Suetsugu, Daisuke

2017-03-01

We conducted synthetic experiments to evaluate the effects of shallow-layer reverberation in oceanic regions on P-wave travel times measured by waveform cross-correlation. Time shift due to waveform distortion by the reverberation was estimated as a function of period. Reverberations in the crystalline crust advance the P-waves by a frequency-independent time shift of about 0.3 s in oceans. Sediment does not affect the time shifts in the mid-ocean regions, but effects as large as -0.8 s or more occur where sediment thickness is greater than 600 m for periods longer than 15 s. The water layer causes time delays (+0.3 s) in the relatively shallow (<3500 m) water region for periods longer than 20 s. The time shift may influence mantle images obtained if the reverberation effects are not accounted for in seismic tomography. We propose a simple method to correct relative P-wave travel times at two sites for shallow-layer reverberation by the cross-convolution of the crustal responses at the two sites. [Figure not available: see fulltext. Caption: .

Seed after-ripening and dormancy determine adult life history independently of germination timing.

PubMed

de Casas, Rafael Rubio; Kovach, Katherine; Dittmar, Emily; Barua, Deepak; Barco, Brenden; Donohue, Kathleen

2012-05-01

• Seed dormancy can affect life history through its effects on germination time. Here, we investigate its influence on life history beyond the timing of germination. • We used the response of Arabidopsis thaliana to chilling at the germination and flowering stages to test the following: how seed dormancy affects germination responses to the environment; whether variation in dormancy affects adult phenology independently of germination time; and whether environmental cues experienced by dormant seeds have an effect on adult life history. • Dormancy conditioned the germination response to low temperatures, such that prolonged periods of chilling induced dormancy in nondormant seeds, but stimulated germination in dormant seeds. The alleviation of dormancy through after-ripening was associated with earlier flowering, independent of germination date. Experimental dormancy manipulations showed that prolonged chilling at the seed stage always induced earlier flowering, regardless of seed dormancy. Surprisingly, this effect of seed chilling on flowering time was observed even when low temperatures did not induce germination. • In summary, seed dormancy influences flowering time and hence life history independent of its effects on germination timing. We conclude that the seed stage has a pronounced effect on life history, the influence of which goes well beyond the timing of germination. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Effects of Time of Day on Classroom Behaviour in Children with ADHD

ERIC Educational Resources Information Center

Antrop, Inge; Roeyers, Herbert; De Baecke, Liesbet

2005-01-01

To examine the effects of time of day and playtime on hyperactive behaviour in children with ADHD, 14 boys with ADHD and 14 control children were observed and videotaped during a whole school day. Analyses reveal minor differential effects of time of day and playtime on the hyperactive behaviour of children with ADHD compared to control children…

Neurogenesis and the Spacing Effect: Learning over Time Enhances Memory and the Survival of New Neurons

ERIC Educational Resources Information Center

Sisti, Helene M.; Glass, Arnold L.; Shors, Tracey J.

2007-01-01

Information that is spaced over time is better remembered than the same amount of information massed together. This phenomenon, known as the spacing effect, was explored with respect to its effect on learning and neurogenesis in the adult dentate gyrus of the hippocampal formation. Because the cells are generated over time and because learning…

Time-Indexed Effect Size Metric for K-12 Reading and Math Education Evaluation

ERIC Educational Resources Information Center

Lee, Jaekyung; Finn, Jeremy; Liu, Xiaoyan

2011-01-01

Through a synthesis of test publisher norms and national longitudinal datasets, this study provides new national norms of academic growth in K-12 reading and math that can be used to reinterpret conventional effect sizes in time units. We propose d' a time-indexed effect size metric to estimate how long it would take for an "untreated"…

Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

PubMed Central

Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L. O.; Bigand, Emmanuel

2013-01-01

The present study used a temporal bisection task with short (<2 s) and long (>2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music. PMID:23882233

Evaluation of the UP4FUN Intervention: A Cluster Randomized Trial to Reduce and Break Up Sitting Time in European 10-12-Year-Old Children

PubMed Central

Vik, Frøydis N.; Lien, Nanna; Berntsen, Sveinung; De Bourdeaudhuij, Ilse; Grillenberger, Monika; Manios, Yannis; Kovacs, Eva; Chinapaw, Mai J. M.; Brug, Johannes; Bere, Elling

2015-01-01

Background The UP4FUN intervention is a family-involved school-based intervention aiming at reducing and breaking up sitting time at home (with special emphasis on screen time), and breaking up sitting time in school among 10–12 year olds in Europe. The purpose of the present paper was to evaluate its short term effects. Methodology/Principal Findings A total of 3147 pupils from Belgium, Germany, Greece, Hungary and Norway participated in a school-randomized controlled trial. The intervention included 1–2 school lessons per week for a period of six weeks, along with assignments for the children and their parents. Screen time and breaking up sitting time were registered by self-report and total sedentary time and breaking up sitting time by accelerometry. The effect of the intervention on these behaviors was evaluated by multilevel regression analyses. All analyses were adjusted for baseline values and gender. Significance level was p≤0.01. No significant intervention effects were observed, neither for self-reported TV/DVD or computer/game console time, nor for accelerometer-assessed total sedentary time and number of breaks in sitting time. The intervention group, however, reported more positive attitudes towards (β = 0.25 (95% CI 0.11, 0.38)) and preferences/liking for (β = 0.20 (95% CI 0.08, 0.32)) breaking up sitting time than the control group. Conclusions/Significance No significant intervention effect on self-reported screen time or accelerometer-assessed sedentary time or breaks in sitting time was observed, but positive effects on beliefs regarding breaking up sitting time were found in favor of the intervention group. Overall, these results do not warrant wider dissemination of the present UP4FUN intervention. Trial Registration International Standard Randomized Controlled Trial Number Registry ISRCTN34562078 PMID:25826704

Mask CD relationship to temperature at the time backscatter is received

NASA Astrophysics Data System (ADS)

Zable, Harold; Kronmiller, Tom; Pearman, Ryan; Guthrie, Bill; Shirali, Nagesh; Masuda, Yukihiro; Kamikubo, Takashi; Nakayamada, Noriaki; Fujimura, Aki

2017-07-01

Mask writers need to be able to write sub-50nm features accurately. Nano-imprint lithography (NIL) masters need to create sub-20nm line and space (L:S) patterns reliably. Increasingly slower resists are deployed, but mask write times need to remain reasonable. The leading edge EBM-9500 offers 1200A/cm2 current density to shoot variable shaped beam (VSB) to write the masks. Last year, thermal effect correction (TEC) was introduced by NuFlare in the EBM-95001. It is a GPU-accelerated inline correction for the effect that the temperature of the resist has on CD. For example, a 100nm CD may print at 102nm where that area was at a comparably high temperature at the time of the shot. Since thermal effect is a temporal effect, the simulated temperature of the surface of the mask is dynamically updated for the effect of each shot in order to accurately predict the cumulative effect that is the temperature at the location of the shot at the time of the shot and therefore its impact on CD. The shot dose is changed to reverse the effects of the temperature change. This paper for the first time reveals an enhancement to this thermal model and a simulator for it. It turns out that the temperature at the time each location receives backscatter from other shots also make a difference to the CD. The effect is secondary, but still measurable for some resists and substrates. Results of a test-chip study will be presented. The computation required for the backscatter effect is substantial. It has been demonstrated that this calculation can be performed fast enough to be inline with the EBM-9500 with a reasonable-sized computing platform. Run-time results and the computing architecture will be presented.

Time series trends of the safety effects of pavement resurfacing.

PubMed

Park, Juneyoung; Abdel-Aty, Mohamed; Wang, Jung-Han

2017-04-01

This study evaluated the safety performance of pavement resurfacing projects on urban arterials in Florida using the observational before and after approaches. The safety effects of pavement resurfacing were quantified in the crash modification factors (CMFs) and estimated based on different ranges of heavy vehicle traffic volume and time changes for different severity levels. In order to evaluate the variation of CMFs over time, crash modification functions (CMFunctions) were developed using nonlinear regression and time series models. The results showed that pavement resurfacing projects decrease crash frequency and are found to be more safety effective to reduce severe crashes in general. Moreover, the results of the general relationship between the safety effects and time changes indicated that the CMFs increase over time after the resurfacing treatment. It was also found that pavement resurfacing projects for the urban roadways with higher heavy vehicle volume rate are more safety effective than the roadways with lower heavy vehicle volume rate. Based on the exploration and comparison of the developed CMFucntions, the seasonal autoregressive integrated moving average (SARIMA) and exponential functional form of the nonlinear regression models can be utilized to identify the trend of CMFs over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of radiation protraction to escalate biologically effective dose to the treatment target

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

Kuperman, V. Y.; Spradlin, G. S.; Department of Mathematics, Embry-Riddle University, Daytona Beach, Florida 32114

2011-12-15

Purpose: The aim of this study is to evaluate how simultaneously increasing fraction time and dose per fraction affect biologically effective dose for the target (BED{sub tar}) while biologically effective dose for the normal tissue (BED{sub nt}) is fixed. Methods: In this investigation, BED{sub tar} and BED{sub nt} were studied by assuming mono-exponential repair of sublethal damage with tissue dependent repair half-time. Results: Our results demonstrate that under certain conditions simultaneously increasing fraction time and dose per fraction result in increased BED{sub tar} while BED{sub nt} is fixed. The dependence of biologically effective dose on fraction time is influenced bymore » the dose rate. In this investigation we analytically determined time-varying dose rate R-tilde which minimizes BED. Changes in BED with fraction time were compared for constant dose rate and for R-tilde. Conclusions: A number of recent experimental and theoretical studies have demonstrated that slow delivery of radiation (known as radiation protraction) leads to reduced therapeutic effect because of increased repair of sublethal damage. In contrast, our analysis shows that under certain conditions simultaneously increasing fraction time and dose per fraction are radiobiologically advantageous.« less

Research plan for establishing the effects of time varying noise exposures on community annoyance and acceptability

NASA Technical Reports Server (NTRS)

Borsky, P. N.

1980-01-01

The design of a community noise survey to determine the effects of time varying noise exposures in residential communities is presented. Complex physical and human variables involved in the health and welfare effects of environmental noise and the number-level tradeoffs and time of day penalties are among the factors considered. Emphasis is placed on community reactions where noise exposures are equal in day or evening but differ in the night time, and the effects of ambient noise on more intense aircraft noise exposures. Thirteen different times of day and types of operation situations with exposed populations up to 8-10 miles from the airport are identified. A detailed personal interview questionnaire as well as specific instructions to interviewers are included.

The effects of quantity and depth of processing on children's time perception.

PubMed

Arlin, M

1986-08-01

Two experiments were conducted to investigate the effects of quantity and depth of processing on children's time perception. These experiments tested the appropriateness of two adult time-perception models (attentional and storage size) for younger ages. Children were given stimulus sets of equal time which varied by level of processing (deep/shallow) and quantity (list length). In the first experiment, 28 children in Grade 6 reproduced presentation times of various quantities of pictures under deep (living/nonliving categorization) or shallow (repeating label) conditions. Students also compared pairs of durations. In the second experiment, 128 children in Grades K, 2, 4, and 6 reproduced presentation times under similar conditions with three or six pictures and with deep or shallow processing requirements. Deep processing led to decreased estimation of time. Higher quantity led to increased estimation of time. Comparative judgments were influenced by quantity. The interaction between age and depth of processing was significant. Older children were more affected by depth differences than were younger children. Results were interpreted as supporting different aspects of each adult model as explanations of children's time perception. The processing effect supported the attentional model and the quantity effect supported the storage size model.

The effects of achene type and germination time on plant performance in the heterocarpic Anacyclus clavatus (Asteraceae).

PubMed

Afonso, Ana; Castro, Sílvia; Loureiro, João; Mota, Lucie; Cerca de Oliveira, José; Torices, Rubén

2014-05-01

• In heterocarpy, fruits with different morphologies have been associated with alternative strategies of dispersal, germination, dormancy, and seedling competitive ability. In heterocarpic species, it is common to find fruits with competitive or dispersal syndromes. The competitive advantage of nondispersing fruits has been frequently attributed to their larger size, but recent studies have suggested that this could also be mediated by germination time. The main objective of our study was to investigate which factor, fruit type or germination time, most affects plant performance and, consequently, competitive ability, using the heterocarpic species Anacyclus clavatus• To explore the effects of achene type and germination time on plant performance, we followed an innovative experimental approach including two experiments: one allowing for differences in germination time, and the other evaluating the effect of achene type alone by synchronizing germination time.• A significant effect of germination time on several postdispersal life-history traits was observed: Achenes that germinated earlier produced plants with higher biomass and reproductive effort. When germination time was controlled, no significant differences were observed in any of the traits.• The competitive advantage of achenes with different morphologies was mainly mediated by germination time and not by differences in size or other intrinsic traits. The consequences of these results are discussed in light of the dispersal-competition trade-off. Our experimental approach (i.e., the synchronization of germination time) revealed the importance of manipulative experiments for testing the effects of germination time on plant survival and performance. © 2014 Botanical Society of America, Inc.

Time: a vital resource.

PubMed

Collins, Sandra K; Collins, Kevin S

2004-01-01

Resolving problems with time management requires an understanding of the concept of working smarter rather than harder. Therefore, managing time effectively is a vital responsibility of department managers. When developing a plan for more effectively managing time, it is important to carefully analyze where time is currently being used/lost. Keeping a daily log can be a time consuming effort. However, the log can provide information about ways that time may be saved and how to organize personal schedules to maximize time efficiency. The next step is to develop a strategy to decrease wasted time and create a more cohesive radiology department. The following list of time management strategies provides some suggestions for developing a plan. Get focused. Set goals and priorities. Get organized. Monitor individual motivation factors. Develop memory techniques. In healthcare, success means delivering the highest quality of care by getting organized, meeting deadlines, creating efficient schedules and appropriately budgeting resources. Effective time management focuses on knowing what needs to be done when. The managerial challenge is to shift the emphasis from doing everything all at once to orchestrating the departmental activities in order to maximize the time given in a normal workday.

Tests of general relativity using pulsars

NASA Technical Reports Server (NTRS)

Reichley, P. E.

1971-01-01

The arrival times of the pulses from each pulsar are measured by a cesium clock. The observations are all made at a frequency of 2388 MHz (12.5 cm wavelength) on a 26 m dish antenna. The effect of interstellar charged particles is a random one that increases the noise level on the arrival time measurements. The variation in clock rate is shown consisting of two effects: the time dilation effect of special relativity and the red shift effect of general relativity.

Short-term memory for pictures seen once or twice.

PubMed

Martini, Paolo; Maljkovic, Vera

2009-06-01

The present study is concerned with the effects of exposure time, repetition, spacing and lag on old/new recognition memory for generic visual scenes presented in a RSVP paradigm. Early memory studies with verbal material found that knowledge of total exposure time at study is sufficient to accurately predict memory performance at test (the Total Time Hypothesis), irrespective of number of repetitions, spacing or lag. However, other studies have disputed such simple dependence of memory strength on total study time, demonstrating super-additive facilitatory effects of spacing and lag, as well as inhibitory effects, such as the Ranschburg effect, Repetition Blindness and the Attentional Blink. In the experimental conditions of the present study we find no evidence of either facilitatory or inhibitory effects: recognition memory for pictures in RSVP supports the Total Time Hypothesis. The data are consistent with an Unequal-Variance Signal Detection Theory model of memory that assumes the average strength and the variance of the familiarity of pictures both increase with total study time. The main conclusion is that the growth of visual scene familiarity with temporal exposure and repetition is a stochastically independent process.

Missense Gamma-Aminobutyric Acid Receptor Polymorphisms Are Associated with Reaction Time, Motor Time, and Ethanol Effects in Vivo.

PubMed

García-Martín, Elena; Ramos, María I; Cornejo-García, José A; Galván, Segismundo; Perkins, James R; Rodríguez-Santos, Laura; Alonso-Navarro, Hortensia; Jiménez-Jiménez, Félix J; Agúndez, José A G

2018-01-01

Background: The Gamma-aminobutyric acid type A receptor (GABA-A receptor) is affected by ethanol concentrations equivalent to those reached during social drinking. At these concentrations, ethanol usually causes impairment in reaction and motor times in most, but not all, individuals. Objectives: To study the effect of GABA-A receptor variability in motor and reaction times, and the effect of low ethanol doses. Methods: Two hundred and fifty healthy subjects received one single dose of 0.5 g/Kg ethanol per os . Reaction and motor times were determined before ethanol challenge (basal), and when participants reached peak ethanol concentrations. We analyzed all common missense polymorphisms described in the 19 genes coding for the GABA-A receptor subunits by using TaqMan probes. Results: The GABRA6 rs4454083 T/C polymorphisms were related to motor times, with individuals carrying the C/C genotype having faster motor times, both, at basal and at peak ethanol concentrations. The GABRA4 rs2229940 T/T genotype was associated to faster reaction times and with lower ethanol effects, determined as the difference between basal reaction time and reaction time at peak concentrations. All these associations remained significant after correction for multiple comparisons. No significant associations were observed for the common missense SNPs GABRB3 rs12910925, GABRG2 rs211035, GABRE rs1139916, GABRP rs1063310, GABRQ rs3810651, GABRR1 rs12200969 or rs1186902, GABRR2 rs282129, and GABRR3 rs832032. Conclusions: This study provides novel information supporting a role of missense GABA-A receptor polymorphisms in reaction time, motor time and effects of low ethanol doses in vivo .

Sex differences in time perception during smoking abstinence.

PubMed

Ashare, Rebecca L; Kable, Joseph W

2015-04-01

Nicotine withdrawal leads to impulsive decision-making, which reflects a preference for smaller, immediate rewards and often prompts a relapse to smoking. The mechanism by which nicotine withdrawal leads to impulsive decision-making is not well known. An essential dimension of decision-making is time perception. Impulsive decisions reflect intolerance of temporal delays and the perception that time is passing more slowly. Sex may be an important factor in impulsive decision-making and time perception, but no studies have investigated whether sex moderates the effects of nicotine withdrawal on impulsive decision-making and time perception. Thirty-three (12 female) adult smokers completed 2 laboratory sessions: following 24-hr abstinence and once smoking-as-usual (order counterbalanced, abstinence biochemically verified). Participants completed 2 time perception tasks, a decision-making task, and self-report measures of craving, withdrawal, and mood. During time reproduction, males overestimated time during abstinence compared to smoking, whereas there was no session effect for females. On the time discrimination task, smokers were less accurate during abstinence, and this effect tended to be stronger among females. In general, males had higher discounting rates compared with females, but there was no effect of abstinence. The current data suggest that the effect of abstinence on time perception may be stronger in males and that males generally exhibit steeper delay discounting rates. Time perception may be an important mechanism in smoking abstinence. Our future work will investigate the role of time perception in smoking relapse and whether this is moderated by sex. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

How Changes in Psychosocial Job Characteristics Impact Burnout in Nurses: A Longitudinal Analysis.

PubMed

Pisanti, Renato; van der Doef, Margot; Maes, Stan; Meier, Laurenz Linus; Lazzari, David; Violani, Cristiano

2016-01-01

The main aim of this longitudinal study was to test the Job Demand-Control-Support (JDCS) model and to analyze whether changes in psychosocial job characteristics are related to (changes in) burnout. Previous studies on the effects of JDCS variables on burnout dimensions have indicated that the iso-strain hypothesis (i.e., high job demands, low control, and low support additively predict high stress reactions) and the buffer hypotheses (i.e., high job control and/or social support is expected to moderate the negative impact of high demands on stress reactions) have hardly been examined concurrently in a longitudinal design; and that the effects of changes of psychosocial job variables on burnout dimensions have hardly been analyzed. This two wave study was carried out over a period of 14 months in a sample of 217 Italian nurses. Hierarchical regression analyses were used to test the cross lagged main and interactive effects of JDCS variables, and to analyse the across-time effects of changes in JDCS dimensions on burnout variables. The Time 1 job characteristics explained 2-8% of the variance in the Time 2 burnout dimensions, but no support for the additive, or the buffer hypothesis of the JDCS model was found. Changes in job characteristics explained an additional 3-20% of variance in the Time 2 burnout dimensions. Specifically, high levels of emotional exhaustion at Time 2 were explained by high levels of social support at Time 1, and unfavorable changes in demands, control, and support over time; high depersonalization at Time 2 was explained by high social support at time 1 and by an increase in demands over time; and high personal accomplishment at Time 2 was predicted by high demands, high control, interactive effect demands × control × social support, at Time 1, and by a decrease in demands over time. No reversed effects of burnout on work characteristics have been found. Our findings suggest that the work environment is subject to changes: the majority of employees experienced considerable changes in all job conditions over time. These changes impacted employee burnout. Limitations and implications of the study are discussed.

How Changes in Psychosocial Job Characteristics Impact Burnout in Nurses: A Longitudinal Analysis

PubMed Central

Pisanti, Renato; van der Doef, Margot; Maes, Stan; Meier, Laurenz Linus; Lazzari, David; Violani, Cristiano

2016-01-01

Aims: The main aim of this longitudinal study was to test the Job Demand-Control-Support (JDCS) model and to analyze whether changes in psychosocial job characteristics are related to (changes in) burnout. Background: Previous studies on the effects of JDCS variables on burnout dimensions have indicated that the iso-strain hypothesis (i.e., high job demands, low control, and low support additively predict high stress reactions) and the buffer hypotheses (i.e., high job control and/or social support is expected to moderate the negative impact of high demands on stress reactions) have hardly been examined concurrently in a longitudinal design; and that the effects of changes of psychosocial job variables on burnout dimensions have hardly been analyzed. Design: This two wave study was carried out over a period of 14 months in a sample of 217 Italian nurses. Method: Hierarchical regression analyses were used to test the cross lagged main and interactive effects of JDCS variables, and to analyse the across-time effects of changes in JDCS dimensions on burnout variables. Results: The Time 1 job characteristics explained 2–8% of the variance in the Time 2 burnout dimensions, but no support for the additive, or the buffer hypothesis of the JDCS model was found. Changes in job characteristics explained an additional 3–20% of variance in the Time 2 burnout dimensions. Specifically, high levels of emotional exhaustion at Time 2 were explained by high levels of social support at Time 1, and unfavorable changes in demands, control, and support over time; high depersonalization at Time 2 was explained by high social support at time 1 and by an increase in demands over time; and high personal accomplishment at Time 2 was predicted by high demands, high control, interactive effect demands × control × social support, at Time 1, and by a decrease in demands over time. No reversed effects of burnout on work characteristics have been found. Conclusion: Our findings suggest that the work environment is subject to changes: the majority of employees experienced considerable changes in all job conditions over time. These changes impacted employee burnout. Limitations and implications of the study are discussed. PMID:27507952

Trauma Resuscitation Evaluation Times and Correlating Human Patient Simulation Training Differences-What is the Standard?

PubMed

Bonjour, Timothy J; Charny, Grigory; Thaxton, Robert E

2016-11-01

Rapid effective trauma resuscitations (TRs) decrease patient morbidity and mortality. Few studies have evaluated TR care times. Effective time goals and superior human patient simulator (HPS) training can improve patient survivability. The purpose of this study was to compare live TR to HPS resuscitation times to determine mean incremental resuscitation times and ascertain if simulation was educationally equivalent. The study was conducted at San Antonio Military Medical Center, Department of Defense Level I trauma center. This was a prospective observational study measuring incremental step times by trauma teams during trauma and simulation patient resuscitations. Trauma and simulation patient arms had 60 patients for statistical significance. Participants included Emergency Medicine residents and Physician Assistant residents as the trauma team leader. The trauma patient arm revealed a mean evaluation time of 10:33 and simulation arm 10:23. Comparable time characteristics in the airway, intravenous access, blood sample collection, and blood pressure data subsets were seen. TR mean times were similar to the HPS arm subsets demonstrating simulation as an effective educational tool. Effective stepwise approaches, incremental time goals, and superior HPS training can improve patient survivability and improved departmental productivity using TR teams. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Comparison of Statistical Approaches Dealing with Time-dependent Confounding in Drug Effectiveness Studies

PubMed Central

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W.; Tremlett, Helen

2017-01-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models (MSCMs) are frequently used to deal with such confounding. To avoid some of the problems of fitting MSCM, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as MSCM in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995 – 2008). PMID:27659168

Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies.

PubMed

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W; Tremlett, Helen

2018-06-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

Perfectionism, procrastination, and psychological distress.

PubMed

Rice, Kenneth G; Richardson, Clarissa M E; Clark, Dustin

2012-04-01

Using a cross-panel design and data from 2 successive cohorts of college students (N = 357), we examined the stability of maladaptive perfectionism, procrastination, and psychological distress across 3 time points within a college semester. Each construct was substantially stable over time, with procrastination being especially stable. We also tested, but failed to support, a mediational model with Time 2 (mid-semester) procrastination as a hypothesized mechanism through which Time 1 (early-semester) perfectionism would affect Time 3 (end-semester) psychological distress. An alternative model with Time 2 perfectionism as a mediator of the procrastination-distress association also was not supported. Within-time analyses revealed generally consistent strength of effects in the correlations between the 3 constructs over the course of the semester. A significant interaction effect also emerged. Time 1 procrastination had no effect on otherwise high levels of psychological distress at the end of the semester for highly perfectionistic students, but at low levels of Time 1 perfectionism, the most distressed students by the end of the term were those who were more likely to have procrastinated earlier in the semester. Implications of the stability of the constructs and their association over time, as well as the moderating effects of procrastination, are discussed in the context of maladaptive perfectionism and problematic procrastination.

Effect of cycle run time of backwash and relaxation on membrane fouling removal in submerged membrane bioreactor treating sewage at higher flux.

PubMed

Tabraiz, Shamas; Haydar, Sajjad; Sallis, Paul; Nasreen, Sadia; Mahmood, Qaisar; Awais, Muhammad; Acharya, Kishor

2017-08-01

Intermittent backwashing and relaxation are mandatory in the membrane bioreactor (MBR) for its effective operation. The objective of the current study was to evaluate the effects of run-relaxation and run-backwash cycle time on fouling rates. Furthermore, comparison of the effects of backwashing and relaxation on the fouling behavior of membrane in high rate submerged MBR. The study was carried out on a laboratory scale MBR at high flux (30 L/m 2 ·h), treating sewage. The MBR was operated at three relaxation operational scenarios by keeping the run time to relaxation time ratio constant. Similarly, the MBR was operated at three backwashing operational scenarios by keeping the run time to backwashing time ratio constant. The results revealed that the provision of relaxation or backwashing at small intervals prolonged the MBR operation by reducing fouling rates. The cake and pores fouling rates in backwashing scenarios were far less as compared to the relaxation scenarios, which proved backwashing a better option as compared to relaxation. The operation time of backwashing scenario (lowest cycle time) was 64.6% and 21.1% more as compared to continuous scenario and relaxation scenario (lowest cycle time), respectively. Increase in cycle time increased removal efficiencies insignificantly, in both scenarios of relaxation and backwashing.

Movement suppression time-out for undesirable behavior in psychotic and severely developmentally delayed children.

PubMed

Rolider, A; Van Houten, R

1985-01-01

The effects of a movement suppression time-out, which involved punishing any movement or verbalization while a client is in the time-out area, were evaluated in four experiments. The first experiment examined the effects of a DRO procedure and movement suppression plus DRO in suppressing self-injurious behavior in a psychotic child in three different situations. In Experiment 2, the results of the previous experiment were replicated with two dangerous behaviors in a second psychotic child. In a third experiment, movement suppression plus DRO was compared with contingent restraint in reducing inappropriate poking behavior in two settings. The movement suppression procedure eliminated poking whereas contingent restraint had little effect. In the final experiment, movement suppression time-out alone was compared with exclusionary time-out alone and simple corner time-out alone. Self-stimulation occurred at high levels during the exclusionary and simple corner time-out procedures. Self-stimulation was either suppressed or reduced during movement suppression time-out. The movement suppression time-out procedure produced a larger reduction in the target behavior in all three children. The effectiveness of the movement suppression procedure was explained in terms of the suppression of self-stimulation while the time-out procedure was being applied.

The effect of visual-motion time-delays on pilot performance in a simulated pursuit tracking task

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1977-01-01

An experimental study was made to determine the effect on pilot performance of time delays in the visual and motion feedback loops of a simulated pursuit tracking task. Three major interrelated factors were identified: task difficulty either in the form of airplane handling qualities or target frequency, the amount and type of motion cues, and time delay itself. In general, the greater the task difficulty, the smaller the time delay that could exist without degrading pilot performance. Conversely, the greater the motion fidelity, the greater the time delay that could be tolerated. The effect of motion was, however, pilot dependent.

Postural effects on the noninvasive baselines of ventricular performance

NASA Technical Reports Server (NTRS)

Lance, V. Q.; Spodick, D. H.

1977-01-01

The effects of posture on time-based noninvasive measurements were determined utilizing the sequence supine-sitting-standing in a formal protocol in which observer biases were eliminated by blinding the measurement and calculation phases. Compared to the supine posture, the sitting and standing postures produced significant increases in heart rate, isovolumic contraction time, pre-ejection period and pre-ejection period/left-ventricular ejection time and significant decreases in ejection time and ejection time index. The response patterns are consistent with the hemodynamic correlates cited in the literature which show increased adrenergic activity and decreased venous return in the sitting and standing postures, the effect on venous return being dominant.

Modelling and mitigating refractive propagation effects in precision pulsar timing observations

NASA Astrophysics Data System (ADS)

Shannon, R. M.; Cordes, J. M.

2017-01-01

To obtain the most accurate pulse arrival times from radio pulsars, it is necessary to correct or mitigate the effects of the propagation of radio waves through the warm and ionized interstellar medium. We examine both the strength of propagation effects associated with large-scale electron-density variations and the methodology used to estimate infinite frequency arrival times. Using simulations of two-dimensional phase-varying screens, we assess the strength and non-stationarity of timing perturbations associated with large-scale density variations. We identify additional contributions to arrival times that are stochastic in both radio frequency and time and therefore not amenable to correction solely using times of arrival. We attribute this to the frequency dependence of the trajectories of the propagating radio waves. We find that this limits the efficacy of low-frequency (metre-wavelength) observations. Incorporating low-frequency pulsar observations into precision timing campaigns is increasingly problematic for pulsars with larger dispersion measures.

Effects of Math Anxiety and Perfectionism on Timed versus Untimed Math Testing in Mathematically Gifted Sixth Graders

ERIC Educational Resources Information Center

Tsui, Joanne M.; Mazzocco, Michele M. M.

2006-01-01

This study was designed to examine the effects of math anxiety and perfectionism on math performance, under timed testing conditions, among mathematically gifted sixth graders. We found that participants had worse math performance during timed versus untimed testing, but this difference was statistically significant only when the timed condition…

Effects of Access to a Stimulating Object on Infant Behavior during Tummy Time

ERIC Educational Resources Information Center

Kadey, Heather J.; Roane, Henry S.

2012-01-01

Placing infants in a prone position for "tummy time" often is recommended to ensure appropriate infant development and to combat the effects associated with infants spending extended periods of time in a supine position. However, tummy time may be associated with inappropriate infant behavior such as crying and noncompliance. We provided…

Timing Effects on Divorce: 20th Century Experience in the United States

ERIC Educational Resources Information Center

Schoen, Robert; Canudas-Romo, Vladimir

2006-01-01

Period divorce measures can misrepresent the underlying behavior of birth cohorts as changes in cohort timing produce changes in period probabilities of divorce. Building on methods used to adjust period fertility and marriage measures, we adjust U.S. period divorce rates for timing effects, calculating a timing index for every year between 1910…

Analysis of the tensile stress-strain behavior of elastomers at constant strain rates. I - Criteria for separability of the time and strain effects

NASA Technical Reports Server (NTRS)

Hong, S. D.; Fedors, R. F.; Schwarzl, F.; Moacanin, J.; Landel, R. F.

1981-01-01

A theoretical analysis of the tensile stress-strain relation of elastomers at constant strain rate is presented which shows that the time and the stress effect are separable if the experimental time scale coincides with a segment of the relaxation modulus that can be described by a single power law. It is also shown that time-strain separability is valid if the strain function is linearly proportional to the Cauchy strain, and that when time-strain separability holds, two strain-dependent quantities can be obtained experimentally. In the case where time and strain effect are not separable, superposition can be achieved only by using temperature and strain-dependent shift factors.

Effectiveness of different approaches to disseminating traveler information on travel time reliability.

DOT National Transportation Integrated Search

2014-01-01

The second Strategic Highway Research Program (SHRP 2) Reliability program aims to improve trip time reliability by reducing the frequency and effects of events that cause travel times to fluctuate unpredictably. Congestion caused by unreliable, or n...

Effect of Uniform Design on the Speed of Combat Tourniquet Application: A Simulation Study.

PubMed

Higgs, Andrew R; Maughon, Michael J; Ruland, Robert T; Reade, Michael C

2016-08-01

Tourniquets are issued to deployed members of both the United States (U.S. military and the Australian Defence Force (ADF). The ease of removing the tourniquet from the pocket of the combat uniform may influence its time to application. The ADF uniform uses buttons to secure the pocket, whereas the U.S. uniform uses a hook and loop fastener system. National differences in training may influence the time to and effectiveness of tourniquet application. To compare the time taken to retrieve and apply a tourniquet from the pocket of the Australian and the U.S. combat uniform and compare the effectiveness of tourniquet application. Twenty participants from both nations were randomly selected. Participants were timed on their ability to remove a tourniquet from their pockets and then apply it effectively. The U.S. personnel removed their tourniquets in shorter time (median 2.5 seconds) than Australians (median 5.72 seconds, p < 0.0001). ADF members (mean 41.36 seconds vs. 58.87 seconds, p < 0.037) applied the tourniquet more rapidly once removed from the pocket and trended to apply it more effectively (p = 0.1). The closure system of pockets on the combat uniform might influence the time taken to apply a tourniquet. Regular training might also reduce the time taken to apply a tourniquet effectively. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Effect of signals on two-route traffic system with real-time information

NASA Astrophysics Data System (ADS)

Tobita, Kazuhiro; Nagatani, Takashi

2012-12-01

We study the effect of signals on the vehicular traffic in the two-route system at the tour-time feedback strategy where the vehicles move ahead through a series of signals. The Nagel-Schreckenberg model is applied to the vehicular motion. The traffic signals are controlled by both cycle time and split. The tour times on two routes fluctuate periodically and alternately. The period increases with decreasing the split. Also, the tour time on each route varies with time by synchronizing with the density. The dependences of tour times and densities on both split and cycle time are clarified.

A Study on the Effectiveness of Lockup-Free Caches for a Reduced Instruction Set Computer (RISC) Processor

DTIC Science & Technology

1992-09-01

to acquire or develop effective simulation tools to observe the behavior of a RISC implementation as it executes different types of programs . We choose...Performance Computer performance is measured by the amount of the time required to execute a program . Performance encompasses two types of time, elapsed time...and CPU time. Elapsed time is the time required to execute a program from start to finish. It includes latency of input/output activities such as

Alleviation of harmful effect in stillage reflux in food waste ethanol fermentation based on metabolic and side-product accumulation regulation.

PubMed

Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Ma, Xiaoyu; Sonomoto, Kenji

2016-10-01

Stillage reflux fermentation in food waste ethanol fermentation could reduce sewage discharge but exert a harmful effect because of side-product accumulation. In this study, regulation methods based on metabolic regulation and side-product alleviation were conducted. Result demonstrated that controlling the proper oxidation-reduction potential value (-150mV to -250mV) could reduce the harmful effect, improve ethanol yield by 21%, and reduce fermentation time by 20%. The methods of adding calcium carbonate to adjust the accumulated lactic acid showed that ethanol yield increased by 17.3%, and fermentation time decreased by 20%. The accumulated glyceal also shows that these two methods can reduce the harmful effect. Fermentation time lasted for seven times without effect, and metabolic regulation had a better effect than side-product regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

NEIGHBORHOOD EFFECT HETEROGENEITY BY FAMILY INCOME AND DEVELOPMENTAL PERIOD: EVIDENCE FROM A COUNTERFACTUAL MODEL OF HIGH SCHOOL GRADUATION

PubMed Central

Wodtke, Geoffrey T.; Elwert, Felix; Harding, David J.

2016-01-01

Effects of disadvantaged neighborhoods on child educational outcomes likely depend on a family's economic resources and the timing of neighborhood exposures during the course of child development. This study investigates how timing of exposure to disadvantaged neighborhoods during childhood versus adolescence affects high school graduation and whether these effects vary across families with different income levels. It follows 6,137 children in the PSID from childhood through adolescence and overcomes methodological problems associated with the joint endogeneity of neighborhood context and family income by adapting novel counterfactual methods—a structural nested mean model estimated via two-stage regression-with-residuals—for time-varying treatments and time-varying effect moderators. Results indicate that exposure to disadvantaged neighborhoods, particularly during adolescence, has a strong negative effect on high school graduation, and that this negative effect is more severe for children from poor families. PMID:27017709

[Effects of sevoflurane and desflurane on pharmacodynamics of rocuronium in children].

PubMed

Kang, D X; Rao, Y Q; Ji, B; Li, J

2017-02-14

Objective: To observe the intraoperative influences on pharmacodynamics of rocuronium in children inhaling sevoflurane and desflurane for 40 min balance. Methods: Ninety children (ASAⅠ-Ⅱ) undergoing elective surgery with general anesthesia in Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University from July 2015 to May 2016 were randomly assigned into six groups ( n =15): Sevoflurane group (group S1 and S2), Desflurane group (group D1 and D2) and Propofol group (group P1 and P2). Children in group D1, S1 and P1 were allocated to research the dose-effect relationship of rocuronium, children in group D2, S2 and P2 were allocated to research the time-effect relationship of rocuronium. TOF-Watch SX monitor was used to exert a train-of-four stimulation (TOF) at ulnar nerve in wrist, then the adductor pollicis muscle appeared muscle twitch 4 times in turn which was recorded T(1, )T(2, )T(3) and T(4) respectively. After the success of the muscle relaxant calibration, 1.3 MAC sevoflurane and desflurane were inhaled and maintained for 40 min respectively in children in Sevoflurane group (group S1 and S2) and Desflurane group (group D1 and D2), Plasma target controlled infusion of 3.5-4.0 μg/ml propofol was always administered in Propofol group (group P1 and P2). 75 μg/kg rocuronium was injected each time in group S1, D1 and P1 respectively. Maximum inhibited effect of T(1) was recorded after every injection until inhibition of T(1) more than 95% eventually. The method of cumulative dose four times was used to calculate the efficiency curve of rocuronium[median effective dose (ED(50)), 90% effective dose (ED(90)) and 95% effective dose (ED(95))]. 0.6 mg/kg rocuronium was injected respectively through vein in group S2, D2 and P2. The recovery times of muscle relaxant were recorded which including time of T(1) disappeared (onset time), T(1) from 0% to 5% (peak effect time), T(1) from 0% to 25% (clinical effect time), T(1) from 25% to 75% (recovery index), T(1) from 0% to 70% (internal effect time), T(4)/T(1) (TOFr) from 0% to 70% and 90%. Results: ED(50, )ED(90) and ED(95) in group D1 were 128.73, 212.45 and 245.78 μg/kg respectively. ED(50, )ED(90) and ED(95) in group S1 were 132.46, 218.94 and 252.30 μg/kg respectively. ED(50, )ED(90) and ED(95) in group P1 were 230.56, 381.02 and 439.55 μg/kg respectively. ED(50, )ED(90) and ED(95) in group D1 and S1 were significantly lower than those in group P1 (all P <0.05), but there was no significant difference between D1 and S1 group ( P >0.05). Compared with group P2, the shorter onset time, the longer peak effect time and clinical effect time was observed in group D2 and S2, the longer recovery index, internal effect time and TOFr from 0% to 70% and 90% was observed in group S2 (all P <0.01). Conclusions: 1.3 MAC sevoflurane and desflurane inhaling for 40 min significantly reduces ED(50) and ED(95) of rocuronium, prolongs the onset time and action time of rocuronium in children. Sevoflurane can significantly prolong the recovery characteristics of rocuronium.

Recapturing time: a practical approach to time management for physicians.

PubMed

Gordon, Craig E; Borkan, Steven C

2014-05-01

Increasing pressures on physicians demand effective time management and jeopardise professional satisfaction. Effective time management potentially increases productivity, promotes advancement, limits burnout and improves both professional and personal satisfaction. However, strategies for improving time management are lacking in the current medical literature. Adapting time management techniques from the medical and non-medical literature may improve physician time management habits. These techniques can be divided into four categories: (1) setting short and long-term goals; (2) setting priorities among competing responsibilities; (3) planning and organising activities; and (4) minimising 'time wasters'. Efforts to improve time management can increase physician productivity and enhance career satisfaction.

More Learning in Less Time: A Guide to Effective Study for University Students.

ERIC Educational Resources Information Center

Kahn, Norma B.

A revision of "Effective and Efficient Study," a guide to effective study for university students, is presented. Topics include: self-evaluation using a checklist of factors involved in college reading and study problems; self-evaluation regarding test anxiety; organizing work and budgeting time; remembering effectively; improving…

Reducing pharmacy wait time to promote customer service: a follow-up study.

PubMed

Slowiak, Julie M; Huitema, Bradley E

2015-01-01

The present study had 3 objectives: (1) to evaluate the effects of 2 different interventions (feedback regarding customer satisfaction with wait time and combined feedback and goal setting) on wait time in a hospital outpatient pharmacy; (2) to assess the extent to which the previously applied interventions maintained their effects; and (3) to evaluate the differences between the effects of the original study and those of the present follow-up study. Participants were 10 employees (4 pharmacists and 6 technicians) of an outpatient pharmacy. Wait times and customer satisfaction ratings were collected for "waiting customers." An ABCB within-subjects design was used to assess the effects of the interventions on both wait time and customer satisfaction, where A was the baseline (no feedback and no goal setting); B was the customer satisfaction feedback; and C was the customer satisfaction feedback, the wait time feedback, and the goal setting for wait time reduction. Wait time decreased after baseline when the combined intervention was introduced, and wait time increased with the reintroduction of satisfaction feedback (alone). The results of the replication study confirm the pattern of the results of the original study and demonstrate high sensitivity of levels of customer satisfaction with wait time. The most impressive result of the replication is the nearly 2-year maintenance of lower wait time between the end of the original study and the beginning (baseline) of the replication.

Effects of self-blood on the molding process of polymethyl methacrylate bone cement.

PubMed

Guo, Ying-Jun; Nie, Lin; Zhang, Wen; Mu, Qing

2014-01-01

To evaluate whether the self-blood has influence on the molding process of polymethyl methacrylate (PMMA) bone cement, and to make sure whether it is valuable for the clinical practice. An in vitro study was performed to evaluate the prolonging-effect of self-blood on PMMA bone cement. The effect of prolonging was evaluated by the dough time (TD) and operable time (TO). Moreover, hardness test, squeezing value test and peak temperature test were also conducted to complete the evaluation of this program. The self-blood, especially the plasma, could greatly prolong the handling time of PMMA bone cement without affecting its basic characteristics including hardness, leakage level and peak temperature. On the other hand, we found that in some abnormal conditions, for example with hyperlipemia, self-blood though can also prolong the handling time, would cause some side-effects. We report a new effective way to prolong the handling time of PMMA bone cement by adding moderate amount of self-blood. But "individualized medicine" should be noticed because some abnormal conditions like hyperlipemia would cause undesired side-effects.

Analysis of Timing Control Mechanism of Utterance and Body Motion Using Dialogue between Human and Communication Robot

NASA Astrophysics Data System (ADS)

Takasugi, Shoji; Yamamoto, Tomohito; Muto, Yumiko; Abe, Hiroyuki; Miyake, Yoshihiro

The purpose of this study is to clarify the effects of timing control of utterance and body motion in human-robot interaction. Our previous study has already revealed the correlation of timing of utterance and body motion in human-human communication. Here we proposed a timing control model based on our previous research and estimated its influence to realize human-like communication using a questionnaire method. The results showed that the difference of effectiveness between the communication with the timing control model and that without it was observed. In addition, elderly people evaluated the communication with timing control much higher than younger people. These results show not only the importance of timing control of utterance and body motion in human communication but also its effectiveness for realizing human-like human-robot interaction.

Multiscale Analysis of Time Irreversibility Based on Phase-Space Reconstruction and Horizontal Visibility Graph Approach

NASA Astrophysics Data System (ADS)

Zhang, Yongping; Shang, Pengjian; Xiong, Hui; Xia, Jianan

Time irreversibility is an important property of nonequilibrium dynamic systems. A visibility graph approach was recently proposed, and this approach is generally effective to measure time irreversibility of time series. However, its result may be unreliable when dealing with high-dimensional systems. In this work, we consider the joint concept of time irreversibility and adopt the phase-space reconstruction technique to improve this visibility graph approach. Compared with the previous approach, the improved approach gives a more accurate estimate for the irreversibility of time series, and is more effective to distinguish irreversible and reversible stochastic processes. We also use this approach to extract the multiscale irreversibility to account for the multiple inherent dynamics of time series. Finally, we apply the approach to detect the multiscale irreversibility of financial time series, and succeed to distinguish the time of financial crisis and the plateau. In addition, Asian stock indexes away from other indexes are clearly visible in higher time scales. Simulations and real data support the effectiveness of the improved approach when detecting time irreversibility.

North-south asymmetric thermosphere response to geomagnetic storms caused by coronal mass ejections

NASA Astrophysics Data System (ADS)

Oliveira, D. M.; Zesta, E.; Schuck, P. W.; Sutton, E. K.

2017-12-01

We use CHAMP and GRACE density data in a statistical and superposed epoch analysis study to investigate the thermosphere global space and time response to CME-caused geomagnetic storms in the time period of September 2001 to September 2011. In order to account for solar cycle effects, we inter-calibrate both CHAMP and GRACE data against the Jacchia-Bowman 2008 (JB2008) empirical model under a regime of very low geomagnetic activity by fitting a polynomial fit with orthogonal expansion into the modeled density. We choose two different approaches related to physical effects of CME interactions with the magnetosphere. The zero epoch times are chosen as follows: in the first case, the instance of CME impact time associated with compression effects and, in the second case, the instance of time in which the IMF Bz turns suddenly southward, associated with the storm main phase onset. In general, in the second case, the thermosphere effects are more superposed in time in comparison to the effects of the first case. We find that, on average, large scale wave structures, presumably traveling atmospheric disturbances (TADs), propagate from auroral to equatorial regions in lag times as short as 3 hours. We also find that all local time regions, i.e., the global response, takes 2 more hours to occur. In addition, our findings show that there exists a strong north-south asymmetric heating, being most pronounced in the Southern Hemisphere in the moments preceding and following the zero epoch time. We attribute this effect to a combination of several factors that affect high latitude energy input into the upper atmosphere, such as seasons, IMF By component, and universal times, that is, the dipole longitude position during the developing of the storm main phase, the crucial time for energy input and subsequent thermosphere heating during geomagnetic storms.

Is leisure time availability associated with more or less severe daily stressors? An examination using eight-day diary data

PubMed Central

Qian, Xinyi Lisa; Yarnal, Careen M.; Almeida, David M.

2014-01-01

The stress suppressing model proposes that sufficient resources reduce stress. The stress exposure model suggests that certain factors expose individuals to more stress. The current study tested these two models by assessing the within-person lagging effect of leisure time on perceived severity of daily stressors. Analyzing eight-day diary data (N=2,022), we found that having more leisure time than usual on a day reduced perceived severity of daily stressors the next day and that the decrease in severity became larger with further increase in leisure time. Additionally, the effect is much stronger among busy individuals who usually had little leisure time. The findings demonstrated an accelerated suppressing effect that differed between-person, and the lagging effect affords stronger implication for causality than correlational analysis. PMID:24563564

Mixing of acrylic bone cement: effect of oxygen on setting properties.

PubMed

He, Shulin; Scott, Christopher; Higham, Paul

2003-12-01

The present study investigates the effect of different mixing methods on the setting properties of bone cement. It was found that vacuum mixing decreased the setting time of the bone cement by nearly 2 min (10%), compared to mixing in air. Two additional experiments, in which the bone cement powders were purged with argon or oxygen, and mixed with the methyl methacrylate monomer, revealed that oxygen concentrations in the bone cement had a great effect on the setting time. The setting time increases significantly as the oxygen concentration increases, which suggests that the decrease in the setting time by vacuum mixing may be attributed to the lower oxygen levels present in the mixer. No significant effect was observed on dough time or maximum exothermic temperature by varying oxygen concentrations in the bone cement mixer.

Time-dependent effects of cortisol on the contextualization of emotional memories.

PubMed

van Ast, Vanessa A; Cornelisse, Sandra; Meeter, Martijn; Joëls, Marian; Kindt, Merel

2013-12-01

The inability to store fearful memories into their original encoding context is considered to be an important vulnerability factor for the development of anxiety disorders like posttraumatic stress disorder. Altered memory contextualization most likely involves effects of the stress hormone cortisol, acting via receptors located in the memory neurocircuitry. Cortisol via these receptors induces rapid nongenomic effects followed by slower genomic effects, which are thought to modulate cognitive function in opposite, complementary ways. Here, we targeted these time-dependent effects of cortisol during memory encoding and tested subsequent contextualization of emotional and neutral memories. In a double-blind, placebo-controlled design, 64 men were randomly assigned to one of three groups: 1) received 10 mg hydrocortisone 30 minutes (rapid cortisol effects) before a memory encoding task; 2) received 10 mg hydrocortisone 210 minutes (slow cortisol) before a memory encoding task; or 3) received placebo at both times. During encoding, participants were presented with neutral and emotional words in unique background pictures. Approximately 24 hours later, context dependency of their memories was assessed. Recognition data revealed that cortisol's rapid effects impair emotional memory contextualization, while cortisol's slow effects enhance it. Neutral memory contextualization remained unaltered by cortisol, irrespective of the timing of the drug. This study shows distinct time-dependent effects of cortisol on the contextualization of specifically emotional memories. The results suggest that rapid effects of cortisol may lead to impaired emotional memory contextualization, while slow effects of cortisol may confer protection against emotional memory generalization. © 2013 Society of Biological Psychiatry.

[Effect of occupational stress on mental health].

PubMed

Yu, Shan-fa; Zhang, Rui; Ma, Liang-qing; Gu, Gui-zhen; Yang, Yan; Li, Kui-rong

2003-02-01

To study the effect of job psychological demands and job control on mental health and their interaction. 93 male freight train dispatchers were evaluated by using revised Job Demand-Control Scale and 7 strain scales. Stepwise regression analysis, Univariate ANOVA, Kruskal-Wallis H and Modian methods were used in statistic analysis. Kruskal-Wallis H and Modian methods analysis revealed the difference in mental health scores among groups of decision latitude (mean rank 55.57, 47.95, 48.42, 33.50, P < 0.05), the differences in scores of mental health (37.45, 40.01, 58.35), job satisfaction (53.18, 46.91, 32.43), daily life strains (33.00, 44.96, 56.12) and depression (36.45, 42.25, 53.61) among groups of job time demands (P < 0.05) were all statistically significant. ANOVA showed that job time demands and decision latitude had interaction effects on physical complains (R(2) = 0.24), state-anxiety (R(2) = 0.26), and daytime fatigue (R(2) = 0.28) (P < 0.05). Regression analysis revealed a significant job time demands and job decision latitude interaction effect as well as significant main effects of the some independent variables on different job strains (R(2) > 0.05). Job time demands and job decision latitude have direct and interactive effects on psychosomatic health, the more time demands, the more psychological strains, the effect of job time demands is greater than that of job decision latitude.

Anticipation of delayed action-effects: learning when an effect occurs, without knowing what this effect will be.

PubMed

Dignath, David; Janczyk, Markus

2017-09-01

According to the ideomotor principle, behavior is controlled via a retrieval of the sensory consequences that will follow from the respective movement ("action-effects"). These consequences include not only what will happen, but also when something will happen. In fact, recollecting the temporal duration between response and effect takes time and prolongs the initiation of the response. We investigated the associative structure of action-effect learning with delayed effects and asked whether participants acquire integrated action-time-effect episodes that comprise a compound of all three elements or whether they acquire separate traces that connect actions to the time until an effect occurs and actions to the effects that follow them. In three experiments, results showed that participants retrieve temporal intervals that follow from their actions even when the identity of the effect could not be learned. Furthermore, retrieval of temporal intervals in isolation was not inferior to retrieval of temporal intervals that were consistently followed by predictable action-effects. More specifically, when tested under extinction, retrieval of action-time and action-identity associations seems to compete against each other, similar to overshadowing effects reported for stimulus-response conditioning. Together, these results suggest that people anticipate when the consequences of their action will occur, independently from what the consequences will be.

Evaluation of Behavioral and Pharmacological Effects of Hydroalcoholic Extract of Valeriana prionophylla Standl. from Guatemala

PubMed Central

Holzmann, Iandra; Cechinel Filho, Valdir; Mora, Ticiana C.; Cáceres, Armando; Martínez, Jose Vicente; Cruz, Sully M.; de Souza, Márcia Maria

2011-01-01

There are few studies on the pharmacological properties of Valeriana prionophylla Standl. (VP), known as “Valeriana del monte”, and used in Mesoamerican folk medicine to treat sleep disorders. This study examines the pharmacological effects of the hydroalcoholic extract of the dry rhizome using the open field, rota rod, elevated plus-maze (EPM), forced swimming (FST), strychnine- and pentobarbital-induced sleeping time, PTZ-induced seizures, and the inhibitory avoidance tests. VP did not show any protective effect against PTZ-induced convulsions. In the EPM, exhibited an anxiolytic-like effect through the effective enhancement of the entries (38.5%) and time spent (44.7%) in the open arms, when compared with control group. Time spent and the numbers of entrances into the enclosed arms were decreased, similar to those effects observed with diazepam. In the FST, acute treatment with VP, produced a dose-dependent decrease in immobility time, similarly to imipramine. VP also produced a significant dose-dependent decrease in the latency of sleeping time, while producing an increase in total duration of sleep; influenced memory consolidation of the animals only at lower doses, unlike those that produced anti-depressant and anxiolytic effects. In summary, the results suggest that VP presents several psychopharmacological activities, including anxiolytic, antidepressant, and hypno-sedative effects. PMID:21754942

Consequences of Base Time for Redundant Signals Experiments

PubMed Central

Townsend, James T.; Honey, Christopher

2007-01-01

We report analytical and computational investigations into the effects of base time on the diagnosticity of two popular theoretical tools in the redundant signals literature: (1) the race model inequality and (2) the capacity coefficient. We show analytically and without distributional assumptions that the presence of base time decreases the sensitivity of both of these measures to model violations. We further use simulations to investigate the statistical power model selection tools based on the race model inequality, both with and without base time. Base time decreases statistical power, and biases the race model test toward conservatism. The magnitude of this biasing effect increases as we increase the proportion of total reaction time variance contributed by base time. We marshal empirical evidence to suggest that the proportion of reaction time variance contributed by base time is relatively small, and that the effects of base time on the diagnosticity of our model-selection tools are therefore likely to be minor. However, uncertainty remains concerning the magnitude and even the definition of base time. Experimentalists should continue to be alert to situations in which base time may contribute a large proportion of the total reaction time variance. PMID:18670591

On the time-dependent Aharonov-Bohm effect

NASA Astrophysics Data System (ADS)

Jing, Jian; Zhang, Yu-Fei; Wang, Kang; Long, Zheng-Wen; Dong, Shi-Hai

2017-11-01

The Aharonov-Bohm effect in the background of a time-dependent vector potential is re-examined for both non-relativistic and relativistic cases. Based on the solutions to the Schrodinger and Dirac equations which contain the time-dependent magnetic vector potential, we find that contrary to the conclusions in a recent paper (Singleton and Vagenas 2013 [4]), the interference pattern will be altered with respect to time because of the time-dependent vector potential.

Sex-dependent carry-over effects on timing of reproduction and fecundity of a migratory bird.

PubMed

Saino, Nicola; Ambrosini, Roberto; Caprioli, Manuela; Romano, Andrea; Romano, Maria; Rubolini, Diego; Scandolara, Chiara; Liechti, Felix

2017-03-01

Life of many organisms flows as a sequence of annual cycles. Timing of cyclical events is shaped by natural selection also via the domino effects that any life history stage has on the stages that follow. Such 'carry-over effects' have major consequences for evolutionary, ecological and demographic processes, but the causes that generate their individual-level variation, including the effect of sex, are poorly understood. We used light-level geolocators to study carry-over effects on the year-round life cycle of the long-distance migratory barn swallow (Hirundo rustica) and sex-dependent variation in their strength. Correlation analyses showed that timing of breeding influenced departure time for autumn migration in females but not in males. In addition, strong, time-mediated carry-over effects of timing of departure from the wintering areas in sub-Saharan Africa for spring migration on timing of arrival to the breeding grounds in Italy and Switzerland operated in both sexes. However, carry-over effects of spring migration phenology on breeding date and seasonal fecundity were observed among females but not among males. We used partial least squares path modelling to unveil the complex carry-over effects of phenology during the non-breeding season in combination with the ecological conditions experienced by individual swallows in the wintering area, as gauged by Normalized Difference Vegetation Index values (NDVI), on breeding performance. Phenology during the non-breeding season combined with NDVI during wintering accounted for as much as 65-70% of variation in subsequent seasonal fecundity in females, while such carry-over effects on breeding success of males were weaker. Intense, sex-specific carry-over effects can have impacted on evolutionary processes, including sexual selection, and affected phenological response to climate change, causing the large population decline observed in this species. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Dissociating effects of stimulus identity and load on working memory attentional guidance: lengthening encoding time eliminates the effect of load but not identity.

PubMed

Tsvetanov, Kamen A; Arvanitis, Theodoros N; Humphreys, Glyn W

2012-01-01

Effects of the identity and load of items in working memory (WM) on visual attention were examined. With a short interval between the WM item and a subsequent search task, there were effects of both load (slowed overall reaction times, RTs, in a WM condition relative to a mere repetition baseline) and identity (search RTs were affected by re-presentation of the item in WM in the search display). As the time to encode the initial display increased, the effects of load decreased while the effect of identity remained. The data indicate that the identity of stimuli in WM can affect the subsequent deployment of attention even when time is allowed for consolidation of the stimuli in WM, and that the WM effects are not causally related to the presence of cognitive load. The results are consistent with the identity of stimuli in WM modulating attention post the memory consolidation stage.

[Pharmacological study on hemostasis, analgesic and anti inflammation effects of the alcohol extract of Hibiscus tiliaceus].

PubMed

Qiu, Fen; Tian, Hui; Zhang, Zhi; Yuan, Xian-Ling; Tan, Yuan-Feng; Ning, Xiao-Qing

2013-10-01

To study the effects of hemostasis, analgesic and anti inflammation of the alcohol extract of Hibiscus tiliaceus and offer pharmacological and experimental basis for its safe and effective use in clinic. The effects of hemostasist were observed with tail breaking method, capillary tube method and slide method; Hot board and body distortion induced by acetic acid methods were applied in mice analgesia experiment, the mice model of acute auricle swelling induced by dmi ethylbenzene and capillary permeability induced by acetic acid were applied to observe the anti inflammatory effects. The alcohol extract of Hibiscus tiliaceus could significantly reduce the bleeding time and the clotting time, delay the plant reaction time and reduce the writhing times of the mice, and it also had effect on inhibiting swelling of mice ear and the permeability of the capillary. These results suggest that the alcohol extract of Hibiscus tiliaceus has the effects of hemostasis, analgesic and anti inflammation.

The Influence of Parental Education on Timing and Type of Union Formation: Changes Over the Life Course and Over Time in the Netherlands.

PubMed

Mooyaart, Jarl E; Liefbroer, Aart C

2016-08-01

Family background shapes young adults' decisions in their transition to adulthood, and the outcomes of these decisions lay the foundation for their subsequent life course. This study examines the influence of parental education on their children's union formation. We examine the timing of entry into a first union (a married or a cohabiting union), the choice between marriage and cohabitation, and the timing of first marriage. Data from eight nationally representative surveys conducted in the Netherlands are pooled (N = 39,777), with respondents being born between 1930 and 1990, to examine not only the effect of parental education on union formation but also whether this effect changes over birth cohorts, periods, and the life course, and varies by gender. Results from discrete-time hazard analyses show little change in the effect of parental education across cohorts and periods but strong life-course effects. Gender differences in the effect of parental education are relatively small.

Effect of intervention programs in schools to reduce screen time: a meta-analysis.

PubMed

Friedrich, Roberta Roggia; Polet, Jéssica Pinto; Schuch, Ilaine; Wagner, Mário Bernardes

2014-01-01

to evaluate the effects of intervention program strategies on the time spent on activities such as watching television, playing videogames, and using the computer among schoolchildren. a search for randomized controlled trials available in the literature was performed in the following electronic databases: PubMed, Lilacs, Embase, Scopus, Web of Science, and Cochrane Library using the following Keywords randomized controlled trial, intervention studies, sedentary lifestyle, screen time, and school. A summary measure based on the standardized mean difference was used with a 95% confidence interval. a total of 1,552 studies were identified, of which 16 were included in the meta-analysis. The interventions in the randomized controlled trials (n=8,785) showed a significant effect in reducing screen time, with a standardized mean difference (random effect) of: -0.25 (-0.37, -0.13), p<0.01. interventions have demonstrated the positive effects of the decrease of screen time among schoolchildren. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

1995 feels so close yet so far: the effect of event markers on subjective feelings of elapsed time.

PubMed

Zauberman, Gal; Levav, Jonathan; Diehl, Kristin; Bhargave, Rajesh

2010-01-01

Why does an event feel more or less distant than another event that occurred around the same time? Prior research suggests that characteristics of an event itself can affect the estimated date of its occurrence. Our work differs in that we focused on how characteristics of the time interval following an event affect people's feelings of elapsed time (i.e., their feelings of how distant an event seems). We argue that a time interval that is punctuated by a greater number of accessible intervening events related to the target event (event markers) will make the target event feel more distant, but that unrelated intervening events will not have this effect. In three studies, we found support for the systematic effect of event markers. The effect of markers was independent of other characteristics of the event, such as its memorability, emotionality, importance, and estimated date, a result suggesting that this effect is distinct from established dating biases.

The effects of heterogeneities on memory-dependent diffusion

NASA Astrophysics Data System (ADS)

Adib, Farhad; Neogi, P.

1993-07-01

Case II diffusion is often seen in glassy polymers, where the mass uptake in sorption is proportional to time t instead of sqrt{t}. A memory dependent diffusion is needed to explain such effects, where the relaxation function used to describe the memory effect has a characteristic time. The ratio of this time to the overall diffusion times is the diffusional Deborah number. Simple models show that case II results when the Deborah number is around one, that is, when the two time scales are comparable. Under investigation are the possible effects of the fact that the glassy polymers are heterogeneous over molecular scales. The averaging form given by DiMarzio and Sanchez has been used to obtain the averaged response. The calculated dynamics of sorption show that whereas case II is still observed, the long term tails change dramatically from the oscillatory to torpid, to chaotic, which are all observed in the experiments. The Deborah number defined here in a self-consistent manner collapses in those cases, but causes no other ill-effects.

Effects on gastrointestinal transit and antroduodenojejunal manometry after gut-directed hypnotherapy in irritable bowel syndrome (IBS).

PubMed

Lindfors, Perjohan; Törnblom, Hans; Sadik, Riadh; Björnsson, Einar S; Abrahamsson, Hasse; Simrén, Magnus

2012-12-01

Gut-directed hypnotherapy is an effective treatment in irritable bowel syndrome (IBS) but little is known about the mechanisms of action. In this study we aimed to investigate the effects on gastrointestinal motility when treating IBS with gut-directed hypnotherapy. We randomized 90 patients with IBS, refractory to standard management to receive gut-directed hypnotherapy 1 h/week for 12 weeks or supportive treatment for the same time period. Eighty-one subjects (40 hypnotherapy, 41 controls) could be evaluated by one or more of the following investigations, both before and after the intervention: gastric emptying time, small bowel transit time, colonic transit time, and antroduodenojejunal manometry. No significant differences in gastric emptying time, small bowel transit time, or colonic transit time was found when comparing the baseline and post-intervention measurements in the hypnotherapy group or in the control group. The same was true concerning the results of the antroduodenojejunal manometry. However, there was a numerical trend toward a higher number of migrating motor complexes at manometry and an accelerated gastric emptying time after hypnotherapy that did not reach statistical significance. In this study, we were not able to find evidence for long-standing effects on gastrointestinal motility as a mediator of the effects on IBS when treating the condition with gut-directed hypnotherapy. Further research to understand the mechanism of action is needed.

SYSTEMATIC CENTER-TO-LIMB VARIATION IN MEASURED HELIOSEISMIC TRAVEL TIMES AND ITS EFFECT ON INFERENCES OF SOLAR INTERIOR MERIDIONAL FLOWS

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

Zhao Junwei; Nagashima, Kaori; Bogart, R. S.

We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removingmore » the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s{sup -1} slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.« less

Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows

NASA Technical Reports Server (NTRS)

Zhao, Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, Alexander; Duvall, T. L., Jr.

2012-01-01

We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s-1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

Inhomogeneous diffusion and ergodicity breaking induced by global memory effects

NASA Astrophysics Data System (ADS)

Budini, Adrián A.

2016-11-01

We introduce a class of discrete random-walk model driven by global memory effects. At any time, the right-left transitions depend on the whole previous history of the walker, being defined by an urnlike memory mechanism. The characteristic function is calculated in an exact way, which allows us to demonstrate that the ensemble of realizations is ballistic. Asymptotically, each realization is equivalent to that of a biased Markovian diffusion process with transition rates that strongly differs from one trajectory to another. Using this "inhomogeneous diffusion" feature, the ergodic properties of the dynamics are analytically studied through the time-averaged moments. Even in the long-time regime, they remain random objects. While their average over realizations recovers the corresponding ensemble averages, departure between time and ensemble averages is explicitly shown through their probability densities. For the density of the second time-averaged moment, an ergodic limit and the limit of infinite lag times do not commutate. All these effects are induced by the memory effects. A generalized Einstein fluctuation-dissipation relation is also obtained for the time-averaged moments.

Time Pressure Increases Cooperation in Competitively Framed Social Dilemmas

PubMed Central

Cone, Jeremy; Rand, David G.

2014-01-01

What makes people willing to pay costs to benefit others? Does such cooperation require effortful self-control, or do automatic, intuitive processes favor cooperation? Time pressure has been shown to increase cooperative behavior in Public Goods Games, implying a predisposition towards cooperation. Consistent with the hypothesis that this predisposition results from the fact that cooperation is typically advantageous outside the lab, it has further been shown that the time pressure effect is undermined by prior experience playing lab games (where selfishness is the more advantageous strategy). Furthermore, a recent study found that time pressure increases cooperation even in a game framed as a competition, suggesting that the time pressure effect is not the result of social norm compliance. Here, we successfully replicate these findings, again observing a positive effect of time pressure on cooperation in a competitively framed game, but not when using the standard cooperative framing. These results suggest that participants' intuitions favor cooperation rather than norm compliance, and also that simply changing the framing of the Public Goods Game is enough to make it appear novel to participants and thus to restore the time pressure effect. PMID:25551386

Time pressure increases cooperation in competitively framed social dilemmas.

PubMed

Cone, Jeremy; Rand, David G

2014-01-01

What makes people willing to pay costs to benefit others? Does such cooperation require effortful self-control, or do automatic, intuitive processes favor cooperation? Time pressure has been shown to increase cooperative behavior in Public Goods Games, implying a predisposition towards cooperation. Consistent with the hypothesis that this predisposition results from the fact that cooperation is typically advantageous outside the lab, it has further been shown that the time pressure effect is undermined by prior experience playing lab games (where selfishness is the more advantageous strategy). Furthermore, a recent study found that time pressure increases cooperation even in a game framed as a competition, suggesting that the time pressure effect is not the result of social norm compliance. Here, we successfully replicate these findings, again observing a positive effect of time pressure on cooperation in a competitively framed game, but not when using the standard cooperative framing. These results suggest that participants' intuitions favor cooperation rather than norm compliance, and also that simply changing the framing of the Public Goods Game is enough to make it appear novel to participants and thus to restore the time pressure effect.

In vitro effects of recombinant activated factor VII on thrombin generation and coagulation following inhibition of platelet procoagulant activity by prasugrel.

PubMed

Mazzeffi, Michael; Szlam, Fania; Jakubowski, Joseph A; Tanaka, Kenichi A; Sugidachi, Atsuhiro; Levy, Jerrold H

2013-07-01

Prasugrel is a thienopyridyl P2Y12 antagonist with potent antiplatelet effects. At present, little is known about its effects on thrombin generation or what strategies may emergently reverse its anticoagulant effects. In the current study we evaluated whether recombinant activated factor VII may reverse prasugrel induced effects and increase thrombin generation in an in vitro model. The effect of prasugrel active metabolite, PAM (R-138727), was evaluated on platelet aggregation, thrombin generation, and rotational thromboelastometry parameters using blood from 20 healthy volunteers. Additionally, we evaluated the effects of adenosine diphosphate (ADP) and recombinant activated factor VII on restoring these parameters towards baseline values. PAM reduced maximum platelet aggregation and led to platelet disaggregation. It also decreased peak thrombin, increased lag time, and increased time to peak thrombin. Treatment with recombinant activated factor VII restored all three parameters of thrombin generation towards baseline. ADP decreased lag time and time to peak thrombin, but had no effect on peak thrombin. When recombinant activated factor VII and ADP were combined they had a greater effect on thrombin parameters than either drug alone. PAM also increased thromboelastometric clotting time and clot formation time, but had no effect on maximum clot firmness. Treatment with either recombinant activated factor VII or ADP restored these values towards baseline. Recombinant activated factor VII restores thrombin generation in the presence of PAM. In patients taking prasugrel with life-threatening refractory bleeding it has the potential to be a useful therapeutic approach. Additional clinical studies are needed to validate our findings. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cyber Power: Attack and Defense Lessons from Land, Sea, and Air Power

DTIC Science & Technology

2011-06-01

over defense for a long time to come. The logical conclusion is that effective electronic and cyber defense are impossible. However, in...air attack with sufficient accuracy and warning time to mount an effective defense. 3 The 1...considering the suddenness of the attack, it is unlikely that the enemy would have time enough to parry the blow effectively either in the air or from the

Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

ERIC Educational Resources Information Center

Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

2012-01-01

In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

Dynamic Quantum Allocation and Swap-Time Variability in Time-Sharing Operating Systems.

ERIC Educational Resources Information Center

Bhat, U. Narayan; Nance, Richard E.

The effects of dynamic quantum allocation and swap-time variability on central processing unit (CPU) behavior are investigated using a model that allows both quantum length and swap-time to be state-dependent random variables. Effective CPU utilization is defined to be the proportion of a CPU busy period that is devoted to program processing, i.e.…

The Effectiveness of Time Management Strategies Instruction on Students' Academic Time Management and Academic Self Efficacy

ERIC Educational Resources Information Center

Kader, Fathi Abdul Hamid Abdul; Eissa, Mourad Ali

2015-01-01

This study investigated the effect of using time management strategies instruction on improving first year learning disabled students' academic time management and academic self efficacy. A total of 60 students identified with LD participated. The sample was divided into two groups; experimental (n = 30 boys) and control (n = 30 boys). ANCOVA and…

Two Effective Ways to Implement Wait Time. A Symposium on Wait Time.

ERIC Educational Resources Information Center

Swift, J. Nathan; And Others

The effects of instructional guides and a wait time feedback device (called a "Wait Timer") on the classroom interaction of middle school science teachers are examined. The Wait Timer, an unobtrusive indicator of wait time, is an automatic device that activates a light when a person speaks. The duration of the light at the end of a…

Effects of Full-Time and Part-Time High-Ability Programs on Developments in Students' Achievement Emotions

ERIC Educational Resources Information Center

Hornstra, Lisette; van der Veen, Ineke; Peetsma, Thea

2017-01-01

This study focused on effects of high-ability programs on students' achievement emotions, i.e. emotions that students experience that are associated with achievement activities. Participants were students in grade 4-6 of primary education: 218 students attended full-time high-ability programs, 245 attended part-time high-ability programs (i.e.…

Time-dependent effects of ultraviolet and nonthermal atmospheric pressure plasma on the biological activity of titanium

NASA Astrophysics Data System (ADS)

Choi, Sung-Hwan; Jeong, Won-Seok; Cha, Jung-Yul; Lee, Jae-Hoon; Yu, Hyung-Seog; Choi, Eun-Ha; Kim, Kwang-Mahn; Hwang, Chung-Ju

2016-09-01

Here, we evaluated time-dependent changes in the effects of ultraviolet (UV) and nonthermal atmospheric pressure plasma (NTAPPJ) on the biological activity of titanium compared with that of untreated titanium. Grade IV machined surface titanium discs (12-mm diameter) were used immediately and stored up to 28 days after 15-min UV or 10-min NTAPPJ treatment. Changes of surface characteristics over time were evaluated using scanning electron microscopy, surface profiling, contact angle analysis, X-ray photoelectron spectroscopy, and surface zeta-potential. Changes in biological activity over time were as determined by analysing bovine serum albumin adsorption, MC3T3-E1 early adhesion and morphometry, and alkaline phosphatase (ALP) activity between groups. We found no differences in the effects of treatment on titanium between UV or NTAPPJ over time; both treatments resulted in changes from negatively charged hydrophobic (bioinert) to positively charged hydrophilic (bioactive) surfaces, allowing enhancement of albumin adsorption, osteoblastic cell attachment, and cytoskeleton development. Although this effect may not be prolonged for promotion of cell adhesion until 4 weeks, the effects were sufficient to maintain ALP activity after 7 days of incubation. This positive effect of UV and NTAPPJ treatment can enhance the biological activity of titanium over time.

Quantifying effects of biodiversity on ecosystem functioning across times and places†

PubMed Central

Isbell, Forest; Cowles, Jane; Dee, Laura E.; Loreau, Michel; Reich, Peter B.; Gonzalez, Andrew; Hector, Andy; Schmid, Bernhard

2018-01-01

Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments. PMID:29493062

Double inverse-weighted estimation of cumulative treatment effects under nonproportional hazards and dependent censoring.

PubMed

Schaubel, Douglas E; Wei, Guanghui

2011-03-01

In medical studies of time-to-event data, nonproportional hazards and dependent censoring are very common issues when estimating the treatment effect. A traditional method for dealing with time-dependent treatment effects is to model the time-dependence parametrically. Limitations of this approach include the difficulty to verify the correctness of the specified functional form and the fact that, in the presence of a treatment effect that varies over time, investigators are usually interested in the cumulative as opposed to instantaneous treatment effect. In many applications, censoring time is not independent of event time. Therefore, we propose methods for estimating the cumulative treatment effect in the presence of nonproportional hazards and dependent censoring. Three measures are proposed, including the ratio of cumulative hazards, relative risk, and difference in restricted mean lifetime. For each measure, we propose a double inverse-weighted estimator, constructed by first using inverse probability of treatment weighting (IPTW) to balance the treatment-specific covariate distributions, then using inverse probability of censoring weighting (IPCW) to overcome the dependent censoring. The proposed estimators are shown to be consistent and asymptotically normal. We study their finite-sample properties through simulation. The proposed methods are used to compare kidney wait-list mortality by race. © 2010, The International Biometric Society.

Quantifying effects of biodiversity on ecosystem functioning across times and places.

PubMed

Isbell, Forest; Cowles, Jane; Dee, Laura E; Loreau, Michel; Reich, Peter B; Gonzalez, Andrew; Hector, Andy; Schmid, Bernhard

2018-06-01

Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments. © 2018 John Wiley & Sons Ltd/CNRS.

Clustering of time-course gene expression profiles using normal mixture models with autoregressive random effects

PubMed Central

2012-01-01

Background Time-course gene expression data such as yeast cell cycle data may be periodically expressed. To cluster such data, currently used Fourier series approximations of periodic gene expressions have been found not to be sufficiently adequate to model the complexity of the time-course data, partly due to their ignoring the dependence between the expression measurements over time and the correlation among gene expression profiles. We further investigate the advantages and limitations of available models in the literature and propose a new mixture model with autoregressive random effects of the first order for the clustering of time-course gene-expression profiles. Some simulations and real examples are given to demonstrate the usefulness of the proposed models. Results We illustrate the applicability of our new model using synthetic and real time-course datasets. We show that our model outperforms existing models to provide more reliable and robust clustering of time-course data. Our model provides superior results when genetic profiles are correlated. It also gives comparable results when the correlation between the gene profiles is weak. In the applications to real time-course data, relevant clusters of coregulated genes are obtained, which are supported by gene-function annotation databases. Conclusions Our new model under our extension of the EMMIX-WIRE procedure is more reliable and robust for clustering time-course data because it adopts a random effects model that allows for the correlation among observations at different time points. It postulates gene-specific random effects with an autocorrelation variance structure that models coregulation within the clusters. The developed R package is flexible in its specification of the random effects through user-input parameters that enables improved modelling and consequent clustering of time-course data. PMID:23151154

Exposure Time Optimization for Highly Dynamic Star Trackers

PubMed Central

Wei, Xinguo; Tan, Wei; Li, Jian; Zhang, Guangjun

2014-01-01

Under highly dynamic conditions, the star-spots on the image sensor of a star tracker move across many pixels during the exposure time, which will reduce star detection sensitivity and increase star location errors. However, this kind of effect can be compensated well by setting an appropriate exposure time. This paper focuses on how exposure time affects the star tracker under highly dynamic conditions and how to determine the most appropriate exposure time for this case. Firstly, the effect of exposure time on star detection sensitivity is analyzed by establishing the dynamic star-spot imaging model. Then the star location error is deduced based on the error analysis of the sub-pixel centroiding algorithm. Combining these analyses, the effect of exposure time on attitude accuracy is finally determined. Some simulations are carried out to validate these effects, and the results show that there are different optimal exposure times for different angular velocities of a star tracker with a given configuration. In addition, the results of night sky experiments using a real star tracker agree with the simulation results. The summarized regularities in this paper should prove helpful in the system design and dynamic performance evaluation of the highly dynamic star trackers. PMID:24618776

The effects of self-selected light-dark cycles and social constraints on human sleep and circadian timing: a modeling approach.

PubMed

Skeldon, Anne C; Phillips, Andrew J K; Dijk, Derk-Jan

2017-03-27

Why do we go to sleep late and struggle to wake up on time? Historically, light-dark cycles were dictated by the solar day, but now humans can extend light exposure by switching on artificial lights. We use a mathematical model incorporating effects of light, circadian rhythmicity and sleep homeostasis to provide a quantitative theoretical framework to understand effects of modern patterns of light consumption on the human circadian system. The model shows that without artificial light humans wakeup at dawn. Artificial light delays circadian rhythmicity and preferred sleep timing and compromises synchronisation to the solar day when wake-times are not enforced. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity ('social jet-lag'). The model implies that developmental changes in sleep homeostasis and circadian amplitude make adolescents particularly sensitive to effects of light consumption. The model predicts that ameliorating social jet-lag is more effectively achieved by reducing evening light consumption than by delaying social constraints, particularly in individuals with slow circadian clocks or when imposed wake-times occur after sunrise. These theory-informed predictions may aid design of interventions to prevent and treat circadian rhythm-sleep disorders and social jet-lag.

An comprehensive time-distance measurement of deep meridional flow and its temporal variation

NASA Astrophysics Data System (ADS)

Chen, Ruizhu; Zhao, Junwei

2016-10-01

We report our latest results on the Sun's deep solar meridional-flow measurements by time-distance helioseismology technique using 6 years of SDO/HMI Doppler-velocity data. Determination of the meridional flow by time-distance helioseismology depends on a precise measurement of the flow-induced travel-time shifts of acoustic waves traveling in the solar interior. To resolve the weak travel-time-shift signals due to deep meridional flow, we need a high signal-to-noise ratio and a robust removal of the center-to-limb (CtoL) effect, which dominates the travel-time shifts. Here we perform an ultimately comprehensive measurement that tracks acoustic waves between any two points on solar surface. The travel-time shifts are composed of CtoL effect, which is a function of disk-centric distances, and contribution from the flow component parallel to wave traveling direction, which is a function of latitude and orientation. Assuming these two effects are independent, we can derive the CtoL effect and meridional-flow contributions by solving a set of linear equations in a least-square sense. We show the solved CtoL effect and the inversion results for the solar meridional flow, and analyze the annual variation of meridional flow from May 2010 to Apr 2016.

Year-Round Daylight Saving Time Study : Volume 1. Interim Report on the Operation and Effects of Daylight Saving Time

DOT National Transportation Integrated Search

1975-06-01

The analyses of the effects of Year-Round Daylight Saving Time were not conslusive because they could not be reliablyseparated from other changes occuring simultaneously including fuel availability constraints, speed limit reductions, Sunday gasoline...

Later school start times for supporting the education, health, and well-being of high school students.

PubMed

Marx, Robert; Tanner-Smith, Emily E; Davison, Colleen M; Ufholz, Lee-Anne; Freeman, John; Shankar, Ravi; Newton, Lisa; Brown, Robert S; Parpia, Alyssa S; Cozma, Ioana; Hendrikx, Shawn

2017-07-03

A number of school systems worldwide have proposed and implemented later school start times as a means of avoiding the potentially negative impacts that early morning schedules can have on adolescent students. Even mild sleep deprivation has been associated with significant health and educational concerns: increased risk for accidents and injuries, impaired learning, aggression, memory loss, poor self-esteem, and changes in metabolism. Although researchers have begun to explore the effects of delayed school start time, no one has conducted a rigorous review of evidence to determine whether later school start times support adolescent health, education, and well-being. We aimed to assess the effects of a later school start time for supporting health, education, and well-being in high school students.Secondary objectives were to explore possible differential effects of later school start times in student subgroups and in different types of schools; to identify implementation practices, contextual factors, and delivery modes associated with positive and negative effects of later start times; and to assess the effects of later school start times on the broader community (high school faculty and staff, neighborhood, and families). We conducted the main search for this review on 28 October 2014 and updated it on 8 February 2016. We searched CENTRAL as well as 17 key electronic databases (including MEDLINE, Embase, ERIC, PsycINFO, and Sociological Abstracts), current editions of relevant journals and organizational websites, trial registries, and Google Scholar. We included any randomized controlled trials, controlled before-and-after studies, and interrupted time series studies with sufficient data points that pertained to students aged 13 to 19 years and that compared different school start times. Studies that reported either primary outcomes of interest (academic outcomes, amount or quality of sleep, mental health indicators, attendance, or alertness) or secondary outcomes (health behaviors, health and safety indicators, social outcomes, family outcomes, school outcomes, or community outcomes) were eligible. At least two review authors independently determined inclusion and exclusion decisions through screening titles, abstracts, and full-text reports. Two review authors independently extracted data for all eligible studies. We presented findings through a narrative synthesis across all studies. When two or more study samples provided sufficient information to permit effect size calculations, we conducted random-effects meta-analyses to synthesize effects across studies. Our search located 17 eligible records reporting on 11 unique studies with 297,994 participants; the studies examined academic outcomes, amount and quality of sleep, mental health indicators, attendance, and student alertness. Overall, the quality of the body of evidence was very low, as we rated most studies as being at high or unclear risk of bias with respect to allocation, attrition, absence of randomization, and the collection of baseline data. Therefore, we cannot be confident about the effects of later school start times.Preliminary evidence from the included studies indicated a potential association between later school start times and academic and psychosocial outcomes, but quality and comparability of these data were low and often precluded quantitative synthesis. Four studies examined the association between later school start times and academic outcomes, reporting mixed results. Six studies examined effects on total amount of sleep and reported significant, positive relationships between later school start times and amount of sleep. One study provided information concerning mental health outcomes, reporting an association between decreased depressive symptoms and later school start times. There were mixed results for the association between later school start times and absenteeism. Three studies reported mixed results concerning the association between later school start times and student alertness. There was limited indication of potential adverse effects on logistics, as the qualitative portions of one study reported less interaction between parents and children, and another reported staffing and scheduling difficulties. Because of the insufficient evidence, we cannot draw firm conclusions concerning adverse effects at this time.It is important to note the limitations of this evidence, especially as randomized controlled trials and high-quality primary studies are difficult to conduct; school systems are often unwilling or unable to allow researchers the necessary control over scheduling and data collection. Moreover, this evidence does not speak to the process of implementing later school starts, as the included studies focused on reporting the effects rather than exploring the process. This systematic review on later school start times suggests several potential benefits for this intervention and points to the need for higher quality primary studies. However, as a result of the limited evidence base, we could not determine the effects of later school start times with any confidence.

Does displayed enthusiasm favour recall, intrinsic motivation and time estimation?

PubMed

Moè, Angelica

2016-11-01

Displayed enthusiasm has been shown to relate to intrinsic motivation, vitality, and positive affect, but its effects on recall performance and time estimation have not yet been explored. This research aimed at studying the effects of a delivery style characterised by High Enthusiasm (HE) on recall, time estimation, and intrinsic motivation. In line with previous studies, effects on intrinsic motivation were expected. In addition, higher recall and lower time estimations were hypothesised. In two experiments, participants assigned to a HE condition or to a normal reading control condition listened to a narrative and to a descriptive passage. Then, they were asked to rate perceived time, enthusiasm, pleasure, interest, enjoyment and curiosity, before writing a free recall. Experiment 1 showed that in the HE condition, participants recalled more, were more intrinsically motivated, and expressed lower time estimations compared to the control condition. Experiment 2 confirmed the positive effects of HE reading compared to normal reading, using different passages and a larger sample.

Effects of particle size and heating time on thiobarbituric acid (TBA) test of soybean powder.

PubMed

Lee, Youn-Ju; Yoon, Won-Byong

2013-06-01

Effects of particle size and heating time during TBA test on the thiobarbituric acid reactive substance (TBARS) of soybean (Glycine Max) powder were studied. Effects of processing variables involved in the pulverization of soybean, such as the temperature of soybean powder, the oxygen level in the vessel, and the pulverisation time, were investigated. The temperature of the soybean powder and the oxygen level had no significant influence on the TBARS (p<0.05). The pulverization time and the heating time during TBA test significantly affected the TBARS. Change of TBARS during heating was well described by the fractional conversion first order kinetics model. A diffusion model was introduced to quantify the effect of particle size on TBARS. The major finding of this study was that the TBA test to estimate the level of the lipid oxidation directly from powders should consider the heating time and the mean particle sizes of the sample. Copyright © 2012 Elsevier Ltd. All rights reserved.

Smoking Education for Low-Educated Adolescents: Comparing Print and Audiovisual Messages.

PubMed

de Graaf, Anneke; van den Putte, Bas; Zebregs, Simon; Lammers, Jeroen; Neijens, Peter

2016-11-01

This study aims to provide insight into which modality is most effective for educating low-educated adolescents about smoking. It compares the persuasive effects of print and audiovisual smoking education materials. We conducted a field experiment with two conditions (print vs. video) and three measurement times (Time 1, Time 2, and Time 3). A total of 221 high school students in the second year of the lowest levels of education in the Netherlands participated at all three time points of the study. Results showed that participants in both conditions had more negative beliefs about smoking after being exposed to the smoking education than before, but there were no differences between the print and video version in this effect. However, the video version did make the attitude toward smoking more negative at Time 3 compared to baseline, whereas the text version did not, which suggests that the video version was more effective for educating low-educated adolescents about smoking. © 2016 Society for Public Health Education.

Effects of time delay and pitch control sensitivity in the flared landing

NASA Technical Reports Server (NTRS)

Berthe, C. J.; Chalk, C. R.; Wingarten, N. C.; Grantham, W.

1986-01-01

Between December 1985 and January 1986, a flared landing program was conducted, using the USAF Total In-Flight simulator airplane, to examine time delay effects in a formal manner. Results show that as pitch sensitivity is increased, tolerance to time delay decreases. With the proper selection of pitch sensitivity, Level I performance was maintained with time delays ranging from 150 milliseconds to greater than 300 milliseconds. With higher sensitivity, configurations with Level I performance at 150 milliseconds degraded to level 2 at 200 milliseconds. When metrics of time delay and pitch sensitivity effects are applied to enhance previously developed predictive criteria, the result is an improved prediction technique which accounts for significant closed loop items.

Scattering characteristics of electromagnetic waves in time and space inhomogeneous weakly ionized dusty plasma sheath

NASA Astrophysics Data System (ADS)

Guo, Li-xin; Chen, Wei; Li, Jiang-ting; Ren, Yi; Liu, Song-hua

2018-05-01

The dielectric coefficient of a weakly ionised dusty plasma is used to establish a three-dimensional time and space inhomogeneous dusty plasma sheath. The effects of scattering on electromagnetic (EM) waves in this dusty plasma sheath are investigated using the auxiliary differential equation finite-difference time-domain method. Backward radar cross-sectional values of various parameters, including the dust particle radius, charging frequency of dust particles, dust particle concentration, effective collision frequency, rate of the electron density variation with time, angle of EM wave incidence, and plasma frequency, are analysed within the time and space inhomogeneous plasma sheath. The results show the noticeable effects of dusty plasma parameters on EM waves.

Aerosol speckle effects on atmospheric pulsed lidar backscattered signals

NASA Technical Reports Server (NTRS)

Murty, S. R.

1989-01-01

For coherently pulsed lidar systems, the effects of refractive turbulence along the path on the aerosol speckle field propagation and on the decorrelation time are investigated. For a coherence bandwidth of 4.1 x 10 to the 11th rad/s and a time delay of 1.65 x 10 to the -14th s, the effect of pulse broadening is found to be negligible. It is suggested that pulse broadening effects need to be taken into account when the correlation time due to aerosol dephasing approaches the nanosecond range.

Examining the Time Course of Indexical Specificity Effects in Spoken Word Recognition

ERIC Educational Resources Information Center

McLennan, Conor T.; Luce, Paul A.

2005-01-01

Variability in talker identity and speaking rate, commonly referred to as indexical variation, has demonstrable effects on the speed and accuracy of spoken word recognition. The present study examines the time course of indexical specificity effects to evaluate the hypothesis that such effects occur relatively late in the perceptual processing of…

An investigation of time course of category and semantic priming.

PubMed

Ray, Suchismita

2008-04-01

Low semantically similar exemplars in a category demonstrate the category-priming effect through priming of the category (i.e., exemplar-category-exemplar), whereas high semantically similar exemplars in the same category demonstrate the semantic-priming effect (i.e., direct activation of one high semantically similar exemplar by another). The author asked whether the category- and semantic-priming effects are based on a common memory process. She examined this question by testing the time courses of category- and semantic-priming effects. She tested participants on either category- or semantic-priming paradigm at 2 different time intervals (6 min and 42 min) by using a lexical decision task using exemplars from categories. Results showed that the time course of category priming was different from that of semantic priming. The author concludes that these 2 priming effects are based on 2 separate memory processes.

Effect of liquid gate bias rising time in pH sensors based on Si nanowire ion sensitive field effect transistors

NASA Astrophysics Data System (ADS)

Jang, Jungkyu; Choi, Sungju; Kim, Jungmok; Park, Tae Jung; Park, Byung-Gook; Kim, Dong Myong; Choi, Sung-Jin; Lee, Seung Min; Kim, Dae Hwan; Mo, Hyun-Sun

2018-02-01

In this study, we investigate the effect of rising time (TR) of liquid gate bias (VLG) on transient responses in pH sensors based on Si nanowire ion-sensitive field-effect transistors (ISFETs). As TR becomes shorter and pH values decrease, the ISFET current takes a longer time to saturate to the pH-dependent steady-state value. By correlating VLG with the internal gate-to-source voltage of the ISFET, we found that this effect occurs when the drift/diffusion of mobile ions in analytes in response to VLG is delayed. This gives us useful insight on the design of ISFET-based point-of-care circuits and systems, particularly with respect to determining an appropriate rising time for the liquid gate bias.

Effect of Local TOF Kernel Miscalibrations on Contrast-Noise in TOF PET

NASA Astrophysics Data System (ADS)

Clementel, Enrico; Mollet, Pieter; Vandenberghe, Stefaan

2013-06-01

TOF PET imaging requires specific calibrations: accurate characterization of the system timing resolution and timing offset is required to achieve the full potential image quality. Current system models used in image reconstruction assume a spatially uniform timing resolution kernel. Furthermore, although the timing offset errors are often pre-corrected, this correction becomes less accurate with the time since, especially in older scanners, the timing offsets are often calibrated only during the installation, as the procedure is time-consuming. In this study, we investigate and compare the effects of local mismatch of timing resolution when a uniform kernel is applied to systems with local variations in timing resolution and the effects of uncorrected time offset errors on image quality. A ring-like phantom was acquired on a Philips Gemini TF scanner and timing histograms were obtained from coincidence events to measure timing resolution along all sets of LORs crossing the scanner center. In addition, multiple acquisitions of a cylindrical phantom, 20 cm in diameter with spherical inserts, and a point source were simulated. A location-dependent timing resolution was simulated, with a median value of 500 ps and increasingly large local variations, and timing offset errors ranging from 0 to 350 ps were also simulated. Images were reconstructed with TOF MLEM with a uniform kernel corresponding to the effective timing resolution of the data, as well as with purposefully mismatched kernels. To CRC vs noise curves were measured over the simulated cylinder realizations, while the simulated point source was processed to generate timing histograms of the data. Results show that timing resolution is not uniform over the FOV of the considered scanner. The simulated phantom data indicate that CRC is moderately reduced in data sets with locally varying timing resolution reconstructed with a uniform kernel, while still performing better than non-TOF reconstruction. On the other hand, uncorrected offset errors in our setup have a larger potential for decreasing image quality and can lead to a reduction of CRC of up to 15% and an increase in the measured timing resolution kernel up to 40%. However, in realistic conditions in frequently calibrated systems, using a larger effective timing kernel in image reconstruction can compensate uncorrected offset errors.

Geographically distributed real-time digital simulations using linear prediction

DOE PAGES

Liu, Ren; Mohanpurkar, Manish; Panwar, Mayank; ...

2016-07-04

Real time simulation is a powerful tool for analyzing, planning, and operating modern power systems. For analyzing the ever evolving power systems and understanding complex dynamic and transient interactions larger real time computation capabilities are essential. These facilities are interspersed all over the globe and to leverage unique facilities geographically-distributed real-time co-simulation in analyzing the power systems is pursued and presented. However, the communication latency between different simulator locations may lead to inaccuracy in geographically distributed real-time co-simulations. In this paper, the effect of communication latency on geographically distributed real-time co-simulation is introduced and discussed. In order to reduce themore » effect of the communication latency, a real-time data predictor, based on linear curve fitting is developed and integrated into the distributed real-time co-simulation. Two digital real time simulators are used to perform dynamic and transient co-simulations with communication latency and predictor. Results demonstrate the effect of the communication latency and the performance of the real-time data predictor to compensate it.« less

Geographically distributed real-time digital simulations using linear prediction

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

Liu, Ren; Mohanpurkar, Manish; Panwar, Mayank

Real time simulation is a powerful tool for analyzing, planning, and operating modern power systems. For analyzing the ever evolving power systems and understanding complex dynamic and transient interactions larger real time computation capabilities are essential. These facilities are interspersed all over the globe and to leverage unique facilities geographically-distributed real-time co-simulation in analyzing the power systems is pursued and presented. However, the communication latency between different simulator locations may lead to inaccuracy in geographically distributed real-time co-simulations. In this paper, the effect of communication latency on geographically distributed real-time co-simulation is introduced and discussed. In order to reduce themore » effect of the communication latency, a real-time data predictor, based on linear curve fitting is developed and integrated into the distributed real-time co-simulation. Two digital real time simulators are used to perform dynamic and transient co-simulations with communication latency and predictor. Results demonstrate the effect of the communication latency and the performance of the real-time data predictor to compensate it.« less

Analytical model of coincidence resolving time in TOF-PET

NASA Astrophysics Data System (ADS)

Wieczorek, H.; Thon, A.; Dey, T.; Khanin, V.; Rodnyi, P.

2016-06-01

The coincidence resolving time (CRT) of scintillation detectors is the parameter determining noise reduction in time-of-flight PET. We derive an analytical CRT model based on the statistical distribution of photons for two different prototype scintillators. For the first one, characterized by single exponential decay, CRT is proportional to the decay time and inversely proportional to the number of photons, with a square root dependence on the trigger level. For the second scintillator prototype, characterized by exponential rise and decay, CRT is proportional to the square root of the product of rise time and decay time divided by the doubled number of photons, and it is nearly independent of the trigger level. This theory is verified by measurements of scintillation time constants, light yield and CRT on scintillator sticks. Trapping effects are taken into account by defining an effective decay time. We show that in terms of signal-to-noise ratio, CRT is as important as patient dose, imaging time or PET system sensitivity. The noise reduction effect of better timing resolution is verified and visualized by Monte Carlo simulation of a NEMA image quality phantom.

41 CFR 302-2.10 - Does the 2-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

Code of Federal Regulations, 2010 CFR

2010-07-01

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41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or from...

41 CFR 302-2.10 - Does the 2-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false Does the 2-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or from...

41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or from...

41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or from...

Combined Effects of Time Spent in Physical Activity, Sedentary Behaviors and Sleep on Obesity and Cardio-Metabolic Health Markers: A Novel Compositional Data Analysis Approach

PubMed Central

Chastin, Sebastien F. M.; Palarea-Albaladejo, Javier; Dontje, Manon L.; Skelton, Dawn A.

2015-01-01

The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity. PMID:26461112

A mathematical approach for evaluating Markov models in continuous time without discrete-event simulation.

PubMed

van Rosmalen, Joost; Toy, Mehlika; O'Mahony, James F

2013-08-01

Markov models are a simple and powerful tool for analyzing the health and economic effects of health care interventions. These models are usually evaluated in discrete time using cohort analysis. The use of discrete time assumes that changes in health states occur only at the end of a cycle period. Discrete-time Markov models only approximate the process of disease progression, as clinical events typically occur in continuous time. The approximation can yield biased cost-effectiveness estimates for Markov models with long cycle periods and if no half-cycle correction is made. The purpose of this article is to present an overview of methods for evaluating Markov models in continuous time. These methods use mathematical results from stochastic process theory and control theory. The methods are illustrated using an applied example on the cost-effectiveness of antiviral therapy for chronic hepatitis B. The main result is a mathematical solution for the expected time spent in each state in a continuous-time Markov model. It is shown how this solution can account for age-dependent transition rates and discounting of costs and health effects, and how the concept of tunnel states can be used to account for transition rates that depend on the time spent in a state. The applied example shows that the continuous-time model yields more accurate results than the discrete-time model but does not require much computation time and is easily implemented. In conclusion, continuous-time Markov models are a feasible alternative to cohort analysis and can offer several theoretical and practical advantages.

Full Bayes Poisson gamma, Poisson lognormal, and zero inflated random effects models: Comparing the precision of crash frequency estimates.

PubMed

Aguero-Valverde, Jonathan

2013-01-01

In recent years, complex statistical modeling approaches have being proposed to handle the unobserved heterogeneity and the excess of zeros frequently found in crash data, including random effects and zero inflated models. This research compares random effects, zero inflated, and zero inflated random effects models using a full Bayes hierarchical approach. The models are compared not just in terms of goodness-of-fit measures but also in terms of precision of posterior crash frequency estimates since the precision of these estimates is vital for ranking of sites for engineering improvement. Fixed-over-time random effects models are also compared to independent-over-time random effects models. For the crash dataset being analyzed, it was found that once the random effects are included in the zero inflated models, the probability of being in the zero state is drastically reduced, and the zero inflated models degenerate to their non zero inflated counterparts. Also by fixing the random effects over time the fit of the models and the precision of the crash frequency estimates are significantly increased. It was found that the rankings of the fixed-over-time random effects models are very consistent among them. In addition, the results show that by fixing the random effects over time, the standard errors of the crash frequency estimates are significantly reduced for the majority of the segments on the top of the ranking. Copyright © 2012 Elsevier Ltd. All rights reserved.

Theoretical investigation of polarization effects in solution: Importance of solvent collective motions

NASA Astrophysics Data System (ADS)

Ishida, Tateki

2015-01-01

Recent theoretical studies on interesting topics related to polarization effects in solutions are presented. As one of interesting topics, ionic liquids (ILs) solvents are focused on. The collective dynamics of electronic polarizability through interionic dynamics and the effect of polarization in ILs, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]), are studied with molecular dynamics simulation. Also, the time-dependent polarization effect on the probe betaine dye molecule, pyridinium N-phenoxide, in water is investigated by a time-dependent reference interaction site model self-consistent field (time-dependent RISM-SCF) approach. The importance of considering polarization effects on solution systems related to solvent collective motions is shown.

Analysis of conditional genetic effects and variance components in developmental genetics.

PubMed

Zhu, J

1995-12-01

A genetic model with additive-dominance effects and genotype x environment interactions is presented for quantitative traits with time-dependent measures. The genetic model for phenotypic means at time t conditional on phenotypic means measured at previous time (t-1) is defined. Statistical methods are proposed for analyzing conditional genetic effects and conditional genetic variance components. Conditional variances can be estimated by minimum norm quadratic unbiased estimation (MINQUE) method. An adjusted unbiased prediction (AUP) procedure is suggested for predicting conditional genetic effects. A worked example from cotton fruiting data is given for comparison of unconditional and conditional genetic variances and additive effects.

Analysis of Conditional Genetic Effects and Variance Components in Developmental Genetics

PubMed Central

Zhu, J.

1995-01-01

A genetic model with additive-dominance effects and genotype X environment interactions is presented for quantitative traits with time-dependent measures. The genetic model for phenotypic means at time t conditional on phenotypic means measured at previous time (t - 1) is defined. Statistical methods are proposed for analyzing conditional genetic effects and conditional genetic variance components. Conditional variances can be estimated by minimum norm quadratic unbiased estimation (MINQUE) method. An adjusted unbiased prediction (AUP) procedure is suggested for predicting conditional genetic effects. A worked example from cotton fruiting data is given for comparison of unconditional and conditional genetic variances and additive effects. PMID:8601500

Effect of "group spell" upon Shotokan black-belt performance of Heian kata.

PubMed

Layton, C; Moran, P

1999-10-01

11 experienced black-belt subjects were individually timed on each of the five Heian kata and then timed again when performing as part of a group. The pull of the group had a significant effect upon timing on two of the kata.

Project Lateday : The Level of Accidents Under the Effect of Daylight Saving All Year

DOT National Transportation Integrated Search

1975-10-01

Year-round daylight saving time (YRDST) has recently been observed in the United States. The observance of double daylight saving time (DDST) is under some consideration. One of the principal expected effects of the adoption of these time systems is ...

Age at Menarche and Time Spent in Education: A Mendelian Randomization Study.

PubMed

Gill, D; Del Greco M, F; Rawson, T M; Sivakumaran, P; Brown, A; Sheehan, N A; Minelli, C

2017-09-01

Menarche signifies the primary event in female puberty and is associated with changes in self-identity. It is not clear whether earlier puberty causes girls to spend less time in education. Observational studies on this topic are likely to be affected by confounding environmental factors. The Mendelian randomization (MR) approach addresses these issues by using genetic variants (such as single nucleotide polymorphisms, SNPs) as proxies for the risk factor of interest. We use this technique to explore whether there is a causal effect of age at menarche on time spent in education. Instruments and SNP-age at menarche estimates are identified from a Genome Wide Association Study (GWAS) meta-analysis of 182,416 women of European descent. The effects of instruments on time spent in education are estimated using a GWAS meta-analysis of 118,443 women performed by the Social Science Genetic Association Consortium (SSGAC). In our main analysis, we demonstrate a small but statistically significant causal effect of age at menarche on time spent in education: a 1 year increase in age at menarche is associated with 0.14 years (53 days) increase in time spent in education (95% CI 0.10-0.21 years, p = 3.5 × 10 -8 ). The causal effect is confirmed in sensitivity analyses. In identifying this positive causal effect of age at menarche on time spent in education, we offer further insight into the social effects of puberty in girls.

The integration of stimulus dimensions in the perception of music.

PubMed

Prince, Jon B

2011-11-01

A central aim of cognitive psychology is to explain how we integrate stimulus dimensions into a unified percept, but how the dimensions of pitch and time combine in the perception of music remains a largely unresolved issue. The goal of this study was to test the effect of varying the degree of conformity to dimensional structure in pitch and time (specifically, tonality and metre) on goodness ratings and classifications of melodies. The pitches and durations of melodies were either presented in their original order, as a reordered sequence, or replaced with random elements. Musically trained and untrained participants (24 each) rated melodic goodness, attending selectively to the dimensions of pitch, time, or both. Also, 24 trained participants classified whether or not the melodies were tonal, metric, or both. Pitch and temporal manipulations always influenced responses, but participants successfully emphasized either dimension in accordance with instructions. Effects of pitch and time were mostly independent for selective attention conditions, but more interactive when evaluating both dimensions. When interactions occurred, the effect of either dimension increased as the other dimension conformed more to its original structure. Relative main effect sizes (| pitch η(2) - time η(2) |) predicted the strength of pitch-time interactions (pitch × time η(2)); interactions were stronger when main effect sizes were more evenly matched. These results have implications for dimensional integration in several domains. Relative main effect size could serve as an indicator of dimensional salience, such that interactions are more likely when dimensions are equally salient.

Mediation analysis with time varying exposures and mediators

PubMed Central

VanderWeele, Tyler J.; Tchetgen Tchetgen, Eric J.

2016-01-01

Summary In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the “mediational g-formula.” When there is no mediation, the mediational g-formula reduces to Robins’ regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl’s mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators. PMID:28824285

Mediation analysis with time varying exposures and mediators.

PubMed

VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

Aging dynamics of quantum spin glasses of rotors

NASA Astrophysics Data System (ADS)

Kennett, Malcolm P.; Chamon, Claudio; Ye, Jinwu

2001-12-01

We study the long time dynamics of quantum spin glasses of rotors using the nonequilibrium Schwinger-Keldysh formalism. These models are known to have a quantum phase transition from a paramagnetic to a spin-glass phase, which we approach by looking at the divergence of the spin-relaxation rate at the transition point. In the aging regime, we determine the dynamical equations governing the time evolution of the spin response and correlation functions, and show that all terms in the equations that arise solely from quantum effects are irrelevant at long times under time reparametrization group (RPG) transformations. At long times, quantum effects enter only through the renormalization of the parameters in the dynamical equations for the classical counterpart of the rotor model. Consequently, quantum effects only modify the out-of-equilibrium fluctuation-dissipation relation (OEFDR), i.e. the ratio X between the temperature and the effective temperature, but not the form of the classical OEFDR.

Study of the effect of solar flares on the VLF signal during D layer disappearance time

NASA Astrophysics Data System (ADS)

Palit, Sourav; Chakrabarti, Sandip Kumar; Ray, Suman

We have modeled the effect of solar flare on the VLF signal during D layer disappearance time of the lower ionosphere by using the Monte Carlo simulation and a simple chemical scheme We have calculated the electron density profile during the flare using GEANT4 and the chemical model and put it as input to the LWPC to find the VLF amplitude variation due to the flare during the time when the D-layer is disappearing. We have compared the effect on the observed VLF signals with this model. We found that the long decay phase of a solar flare specially during the D-layer disappearance time causes the shifting of the sunset terminator times of VLF signals towards the nighttime. For observation we have taken the data for NWC-IERC propagation path. We have investigated the effect for different classes of flares.

Sporicidal Effects of Iodine-oxide Thermite Reaction Products

NASA Astrophysics Data System (ADS)

Russell, Rod; Bless, Stephan; Blinkova, Alexandra; Chen, Tiffany; InstituteAdvanced Tehnology Collaboration; Dept of Molecular Genetics; Microbiology-UT Austin Collaboration; Chemistry; Biochemistry-UT Austin Collaboration

2011-06-01

Iodine pentoxide-aluminum thermite reactions have been driven by impacts at 1000 m/s on steel plates 3 mm or thicker. The activation energy of this material reaction is 197 J/g. The reactivity is increased by reducing grain size. This reaction releases iodine gas that is known to be a sporicide. In order to test the impact reactions for sporicidal effects, reactions took place in closed chambers containing dried Bacillus subtilis spores. The reduction in colony-forming units was dependent on the exposure time; long exposure times resulted in a 105 decrease in germination rate. This was shown to be due to the gas exposure and not the heat or turbulence. Sporicidal effectiveness was increased by adding neodymium and saran resin. The sporicidal effect is very dependent on exposure time, ranging from about 90% kill for times on the order of a second to 99.99% for one-hour times.

Research and development program for the development of advanced time-temperature dependent constitutive relationships. Volume 1: Theoretical discussion

NASA Technical Reports Server (NTRS)

Cassenti, B. N.

1983-01-01

The results of a 10-month research and development program for the development of advanced time-temperature constitutive relationships are presented. The program included (1) the effect of rate of change of temperature, (2) the development of a term to include time independent effects, and (3) improvements in computational efficiency. It was shown that rate of change of temperature could have a substantial effect on the predicted material response. A modification to include time-independent effects, applicable to many viscoplastic constitutive theories, was shown to reduce to classical plasticity. The computation time can be reduced by a factor of two if self-adaptive integration is used when compared to an integration using ordinary forward differences. During the course of the investigation, it was demonstrated that the most important single factor affecting the theoretical accuracy was the choice of material parameters.

Choosing the Most Effective Pattern Classification Model under Learning-Time Constraint.

PubMed

Saito, Priscila T M; Nakamura, Rodrigo Y M; Amorim, Willian P; Papa, João P; de Rezende, Pedro J; Falcão, Alexandre X

2015-01-01

Nowadays, large datasets are common and demand faster and more effective pattern analysis techniques. However, methodologies to compare classifiers usually do not take into account the learning-time constraints required by applications. This work presents a methodology to compare classifiers with respect to their ability to learn from classification errors on a large learning set, within a given time limit. Faster techniques may acquire more training samples, but only when they are more effective will they achieve higher performance on unseen testing sets. We demonstrate this result using several techniques, multiple datasets, and typical learning-time limits required by applications.

Effects of Arm Ergometry Exercise on the Reaction, Movement and Response Times of the Lower Extremities.

ERIC Educational Resources Information Center

Israel, Richard G.

A study determined the effects of fatigue produced in the upper extremities on the reaction time, movement time, and response time of the lower extremities in 30 male subjects, 19-25 years old. Each subject participated in a 10 trial practice session one day prior to the experiment and immediately preceding the pre-test. The pre-test consisted of…

Nuclear spin dependence of time reversal invariance violating effects in neutron scattering

NASA Astrophysics Data System (ADS)

Gudkov, Vladimir; Shimizu, Hirohiko M.

2018-06-01

The spin structure of parity violating and time reversal invariance violating effects in neutron scattering is discussed. The explicit relations between these effects are presented in terms of functions nuclear spins and neutron partial widths of p -wave resonances.

Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

NASA Astrophysics Data System (ADS)

Figuerola, Jordi; Charalambidou, Iris; Santamaria, Luis; Green, Andy J.

2010-06-01

Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser’s gut (i.e. the retention time, survival and germination of ingested seeds). A combination of experiments with captive waterbirds and aquatic plant seeds was used to analyse the following: (a) the effects of inter- and intra-specific variation in seed size and duck species on seed retention time in the gut and (b) the relationship between retention time and the percent germination and germination rates of seeds. Among the three Scirpus species used, those with smaller seeds showed higher survival after ingestion by birds and longer retention times inside their guts than those with larger seeds. For Potamogeton pectinatus, only seeds from the smaller size class (<8 mg) survived ingestion. Retention time affected the percent germination and germination rate of Scirpus seeds but in a manner that varied for the different plant and bird species studied. We recorded both linear and non-linear effects of retention time on percent germination. In addition, germination rate was positively correlated with retention time in Scirpus litoralis but negatively correlated in Scirpus lacustris. Small seed size can favour dispersal over larger distances. However, the effects of retention time on percent germination can modify the seed shadows produced by birds due to higher percent germination of seeds retained for short or intermediate periods. The changes in dispersal quality associated with dispersal distance (which is expected to be positively related to retention time) will affect the probability of seedling establishment over longer distances and, thus, the spatial characteristics of the effective seed shadow.

Three-factor models versus time series models: quantifying time-dependencies of interactions between stimuli in cell biology and psychobiology for short longitudinal data.

PubMed

Frank, Till D; Kiyatkin, Anatoly; Cheong, Alex; Kholodenko, Boris N

2017-06-01

Signal integration determines cell fate on the cellular level, affects cognitive processes and affective responses on the behavioural level, and is likely to be involved in psychoneurobiological processes underlying mood disorders. Interactions between stimuli may subjected to time effects. Time-dependencies of interactions between stimuli typically lead to complex cell responses and complex responses on the behavioural level. We show that both three-factor models and time series models can be used to uncover such time-dependencies. However, we argue that for short longitudinal data the three factor modelling approach is more suitable. In order to illustrate both approaches, we re-analysed previously published short longitudinal data sets. We found that in human embryonic kidney 293 cells cells the interaction effect in the regulation of extracellular signal-regulated kinase (ERK) 1 signalling activation by insulin and epidermal growth factor is subjected to a time effect and dramatically decays at peak values of ERK activation. In contrast, we found that the interaction effect induced by hypoxia and tumour necrosis factor-alpha for the transcriptional activity of the human cyclo-oxygenase-2 promoter in HEK293 cells is time invariant at least in the first 12-h time window after stimulation. Furthermore, we applied the three-factor model to previously reported animal studies. In these studies, memory storage was found to be subjected to an interaction effect of the beta-adrenoceptor agonist clenbuterol and certain antagonists acting on the alpha-1-adrenoceptor / glucocorticoid-receptor system. Our model-based analysis suggests that only if the antagonist drug is administer in a critical time window, then the interaction effect is relevant. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.

PubMed

Schilling, Keith E; Wolter, Calvin F; Isenhart, Thomas M; Schultz, Richard C

2015-11-01

Strategies to reduce nitrate-nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443-ha Bear Creek watershed in north-central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m (7.6 mi) to 0.04 m (62 mi), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile-drained watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Tracking the Time Course of Word-Frequency Effects in Auditory Word Recognition with Event-Related Potentials

ERIC Educational Resources Information Center

Dufour, Sophie; Brunelliere, Angele; Frauenfelder, Ulrich H.

2013-01-01

Although the word-frequency effect is one of the most established findings in spoken-word recognition, the precise processing locus of this effect is still a topic of debate. In this study, we used event-related potentials (ERPs) to track the time course of the word-frequency effect. In addition, the neighborhood density effect, which is known to…

Improved Flux Formulations for Unsteady Low Mach Number Flows

DTIC Science & Technology

2012-06-01

it requires the resolution of disparate time scales. Unsteady effects may arise from a combination of hydrodynamic effects in which pressure...including rotorcraft flows, jets and shear layers include a combination of both acoustic and hydrodynamic effects. Furthermore these effects may be...preconditioning parameter used for time scaling also affects the dissipation for the spatial flux, hydrodynamic unsteady effects (such as vortex propagation

Demand characteristics, pre-test attitudes and time-on-task trends in the effects of chewing gum on attention and reported mood in healthy volunteers.

PubMed

Allen, A P; Smith, A P

2012-10-01

Previous research has indicated that chewing gum enhances reported alertness, but has variable effects on attention. Demand characteristics may explain these effects. The current study investigated the effects of gum and demand characteristics on attention and reported mood over time. Participants completed measures of mood and attention, with and without chewing gum. To manipulate demand characteristics, they were told that the hypothesised effect of gum was either positive or negative, or no hypothesis was mentioned. Attitudes towards gum were assessed pre- and post-manipulation. Gum increased reported alertness; this effect was only significant for positive and neutral demand characteristics. Vigilance accuracy was reduced for chewing gum, but only in the fourth minute of the task, and gum reduced focussed attention accuracy, but only for the first 64 trials. Demand characteristics did not moderate time-on-task effects. Gum improved selective attention. A positive effect on response organisation was observed; this was significant when demand characteristics and pre-test attitudes to gum were both negative. The results suggest that demand characteristics moderate effects on self-reported alertness and response organisation, but cannot explain time-on-task effects or variable main effects on other aspects of attention. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effects of physical activity on sleep: a meta-analytic review.

PubMed

Kredlow, M Alexandra; Capozzoli, Michelle C; Hearon, Bridget A; Calkins, Amanda W; Otto, Michael W

2015-06-01

A significant body of research has investigated the effects of physical activity on sleep, yet this research has not been systematically aggregated in over a decade. As a result, the magnitude and moderators of these effects are unclear. This meta-analytical review examines the effects of acute and regular exercise on sleep, incorporating a range of outcome and moderator variables. PubMed and PsycINFO were used to identify 66 studies for inclusion in the analysis that were published through May 2013. Analyses reveal that acute exercise has small beneficial effects on total sleep time, sleep onset latency, sleep efficiency, stage 1 sleep, and slow wave sleep, a moderate beneficial effect on wake time after sleep onset, and a small effect on rapid eye movement sleep. Regular exercise has small beneficial effects on total sleep time and sleep efficiency, small-to-medium beneficial effects on sleep onset latency, and moderate beneficial effects on sleep quality. Effects were moderated by sex, age, baseline physical activity level of participants, as well as exercise type, time of day, duration, and adherence. Significant moderation was not found for exercise intensity, aerobic/anaerobic classification, or publication date. Results were discussed with regards to future avenues of research and clinical application to the treatment of insomnia.

Study protocol to examine the effects of spaceflight and a spaceflight analog on neurocognitive performance: extent, longevity, and neural bases.

PubMed

Koppelmans, Vincent; Erdeniz, Burak; De Dios, Yiri E; Wood, Scott J; Reuter-Lorenz, Patricia A; Kofman, Igor; Bloomberg, Jacob J; Mulavara, Ajitkumar P; Seidler, Rachael D

2013-12-18

Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether spaceflight also affects other central nervous system functions such as cognition is yet largely unknown, but of importance in consideration of the health and performance of crewmembers both in- and post-flight. We are therefore conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor and cognitive performance changes. Here we present the protocol of our study. This study includes three groups (astronauts, bed rest subjects, ground-based control subjects) for which each the design is single group with repeated measures. The effects of spaceflight on the brain will be investigated in astronauts who will be assessed at two time points pre-, at three time points during-, and at four time points following a spaceflight mission of six months. To parse out the effect of microgravity from the overall effects of spaceflight, we investigate the effects of seventy days head-down tilted bed rest. Bed rest subjects will be assessed at two time points before-, two time points during-, and three time points post-bed rest. A third group of ground based controls will be measured at four time points to assess reliability of our measures over time. For all participants and at all time points, except in flight, measures of neurocognitive performance, fine motor control, gait, balance, structural MRI (T1, DTI), task fMRI, and functional connectivity MRI will be obtained. In flight, astronauts will complete some of the tasks that they complete pre- and post flight, including tasks measuring spatial working memory, sensorimotor adaptation, and fine motor performance. Potential changes over time and associations between cognition, motor-behavior, and brain structure and function will be analyzed. This study explores how spaceflight induced brain changes impact functional performance. This understanding could aid in the design of targeted countermeasures to mitigate the negative effects of long-duration spaceflight.

The immediate effects of therapeutic keyboard music playing for finger training in adults undergoing hand rehabilitation.

PubMed

Zhang, Xiaoying; Liu, Songhuai; Yang, Degang; Du, Liangjie; Wang, Ziyuan

2016-08-01

[Purpose] The purpose of this study was to examine the immediate effects of therapeutic keyboard music playing on the finger function of subjects' hands through measurements of the joint position error test, surface electromyography, probe reaction time, and writing time. [Subjects and Methods] Ten subjects were divided randomly into experimental and control groups. The experimental group used therapeutic keyboard music playing and the control group used grip training. All subjects were assessed and evaluated by the joint position error test, surface electromyography, probe reaction time, and writing time. [Results] After accomplishing therapeutic keyboard music playing and grip training, surface electromyography of the two groups showed no significant change, but joint position error test, probe reaction time, and writing time obviously improved. [Conclusion] These results suggest that therapeutic keyboard music playing is an effective and novel treatment for improving joint position error test scores, probe reaction time, and writing time, and it should be promoted widely in clinics.

The use of propensity score methods with survival or time-to-event outcomes: reporting measures of effect similar to those used in randomized experiments.

PubMed

Austin, Peter C

2014-03-30

Propensity score methods are increasingly being used to estimate causal treatment effects in observational studies. In medical and epidemiological studies, outcomes are frequently time-to-event in nature. Propensity-score methods are often applied incorrectly when estimating the effect of treatment on time-to-event outcomes. This article describes how two different propensity score methods (matching and inverse probability of treatment weighting) can be used to estimate the measures of effect that are frequently reported in randomized controlled trials: (i) marginal survival curves, which describe survival in the population if all subjects were treated or if all subjects were untreated; and (ii) marginal hazard ratios. The use of these propensity score methods allows one to replicate the measures of effect that are commonly reported in randomized controlled trials with time-to-event outcomes: both absolute and relative reductions in the probability of an event occurring can be determined. We also provide guidance on variable selection for the propensity score model, highlight methods for assessing the balance of baseline covariates between treated and untreated subjects, and describe the implementation of a sensitivity analysis to assess the effect of unmeasured confounding variables on the estimated treatment effect when outcomes are time-to-event in nature. The methods in the paper are illustrated by estimating the effect of discharge statin prescribing on the risk of death in a sample of patients hospitalized with acute myocardial infarction. In this tutorial article, we describe and illustrate all the steps necessary to conduct a comprehensive analysis of the effect of treatment on time-to-event outcomes. © 2013 The authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Planning and Time Management: Keys to Effective Educational Leadership.

ERIC Educational Resources Information Center

Sergiovanni, Thomas J.

1980-01-01

Educational administrators' concern with planning and time management results from the fragmentation of their daily activities, which research has documented, and their consequent search for order and control. Time is important because its scarcity affects productivity and its use has social-psychological effects on staffs' perceptions of…

The Effects of Extended Time on Writing Performance

ERIC Educational Resources Information Center

Goegan, Lauren D.; Harrison, Gina L.

2017-01-01

The effects of extended time on the writing performance of university students with learning disabilities (LD) was examined. Thirty-eight students (19 LD; 19 non-LD) completed a collection of cognitive, linguistic, and literacy measures, and wrote essays under regular and extended time conditions. Limited evidence was found to support the…

An Effective Time and Management Strategy in Quality Circles.

ERIC Educational Resources Information Center

Halverson, Don E.

Contending that participation in quality circles enhances effective time management by school administrators and teachers, this guide provides both a theoretical briefing and practical recommendations for better time management. A pre- posttest prefaces a review of basic concepts of quality circles with reference to the work of Abraham Maslow,…

Time Perception and Depressive Realism: Judgment Type, Psychophysical Functions and Bias

PubMed Central

Kornbrot, Diana E.; Msetfi, Rachel M.; Grimwood, Melvyn J.

2013-01-01

The effect of mild depression on time estimation and production was investigated. Participants made both magnitude estimation and magnitude production judgments for five time intervals (specified in seconds) from 3 sec to 65 sec. The parameters of the best fitting psychophysical function (power law exponent, intercept, and threshold) were determined individually for each participant in every condition. There were no significant effects of mood (high BDI, low BDI) or judgment (estimation, production) on the mean exponent, n = .98, 95% confidence interval (.96–1.04) or on the threshold. However, the intercept showed a ‘depressive realism’ effect, where high BDI participants had a smaller deviation from accuracy and a smaller difference between estimation and judgment than low BDI participants. Accuracy bias was assessed using three measures of accuracy: difference, defined as psychological time minus physical time, ratio, defined as psychological time divided by physical time, and a new logarithmic accuracy measure defined as ln (ratio). The ln (ratio) measure was shown to have approximately normal residuals when subjected to a mixed ANOVA with mood as a between groups explanatory factor and judgment and time category as repeated measures explanatory factors. The residuals of the other two accuracy measures flagrantly violated normality. The mixed ANOVAs of accuracy also showed a strong depressive realism effect, just like the intercepts of the psychophysical functions. There was also a strong negative correlation between estimation and production judgments. Taken together these findings support a clock model of time estimation, combined with additional cognitive mechanisms to account for the depressive realism effect. The findings also suggest strong methodological recommendations. PMID:23990960

Impact of real-time notification of Clostridium difficile test results and early initiation of effective antimicrobial therapy.

PubMed

Polen, Christian B; Judd, William R; Ratliff, Patrick D; King, Gregory S

2018-05-01

Clostridium difficile is a prominent nosocomial pathogen and is the most common causative organism of health care-associated diarrhea. To our knowledge, no studies have investigated the impact of real-time notification of culture results with rapid antimicrobial stewardship program (ASP) intervention in the setting of C difficile infection (CDI). The purpose of this study was to assess the impact of real-time notification of detection of toxigenic C difficile by DNA amplification results in patients with confirmed CDI. This is a single-center, retrospective cohort study at a 433-bed tertiary medical center in central Kentucky. The study consisted of 2 arms: patients treated for CDI prior to implementation of real-time provider notification and patients postimplementation. The primary outcome was time to initiation of effective antimicrobial therapy. The median time to initiation of effective antimicrobial therapy decreased from 5.75 hours in the preimplementation cohort to 2.05 hours in the postimplementation cohort (P = .001). ASP intervention also resulted in a shorter time from detection of CDI to order entry of effective antimicrobial therapy in the patient's electronic medical record (3.0 vs 0.6 hours; P = .001). The implementation of a real-time notification system to alert a pharmacist-led ASP of toxigenic CDI resulted in statistically significant shorter times to order entry and subsequent initiation of effective antimicrobial therapy and contact precautions. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Effects of quantity, quality, and contact time of dissolved organic matter on bioconcentration of benzo[a]pyrene in the nematode Caenorhabditis elegans

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

Haitzer, M.; Hoess, S.; Burnison, B.K.

1999-03-01

Quantity and quality of dissolved organic matter (DOM) and the time allowed for DOM to interact with organic contaminants can influence their bioavailability. The authors studied the effect of natural aquatic DOM that had been in contact with benzo[a]pyrene (B[a]P) for 1 to 12 d on the bioconcentration of B[a]P in the nematode Caenorhabditis elegans. Dissolved organic matter quality and quantity was varied by using DOM from three different sources, each in three different concentrations. A model, based on the assumption that only freely dissolved B[a]P is bioavailable, was employed to estimate biologically determined partition coefficients [K{sub p}(biol.)]. Expressing themore » data for each combination of DOM source and contact time in a single K{sub p} (biol.) value allowed a direct comparison of the effects of different DOM qualities and contact times. The results show that the effect of DOM from a specific source was dependent on DOM quantity, but they also observed a distinct effect of DOM quality (represented by different sampling locations) on the bioconcentration of B[a]P. Contact time had no significant influence for the effects of two DOM sources on the bioconcentration of B[a]P. However, the third DOM source was significantly more effective with increased contact time, leading to lower B[a]P bioconcentration in the nematodes.« less

Deja Vu All Over Again: Effects of Reenactment on Toddlers' Event Memory.

ERIC Educational Resources Information Center

Sheffield, Ellyn G.; Hudson, Judith A.

1998-01-01

Four experiments examined the effects of reenactment on 18-month-olds' event memory. Results indicated that reenacting novel activities in a laboratory playroom improved event memory. Reenactment was more effective after a time delay, and the effects of timing of reenactment were more pronounced after a six-month delay. Reenacting half of the…

50 CFR 660.360 - Recreational fishery-management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... authorized for recreational fishing are hook-and-line and spear. Spears may be propelled by hand or by... when the closure is in effect. The closure is not in effect at this time. This closure may be imposed... when the closure is in effect. The closure is not in effect at this time. This closure may be imposed...

50 CFR 660.360 - Recreational fishery-management measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... authorized for recreational fishing are hook-and-line and spear. Spears may be propelled by hand or by... when the closure is in effect. The closure is not in effect at this time. This closure may be imposed... when the closure is in effect. The closure is not in effect at this time. This closure may be imposed...

Dyakonov-Perel Effect on Spin Dephasing in n-Type GaAs

NASA Technical Reports Server (NTRS)

Ning, C. Z.; Wu, M. W.

2003-01-01

A paper presents a study of the contribution of the Dyakonov-Perel (DP) effect to spin dephasing in electron-donor-doped bulk GaAs in the presence of an applied steady, moderate magnetic field perpendicular to the growth axis of the GaAs crystal. (The DP effect is an electron-wave-vector-dependent spin-state splitting of the conduction band, caused by a spin/orbit interaction in a crystal without an inversion center.) The applicable Bloch equations of kinetics were constructed to include terms accounting for longitudinal optical and acoustic phonon scattering as well as impurity scattering. The contributions of the aforementioned scattering mechanisms to spin-dephasing time in the presence of DP effect were examined by solving the equations numerically. Spin-dephasing time was obtained from the temporal evolution of the incoherently summed spin coherence. Effects of temperature, impurity level, magnetic field, and electron density on spin-dephasing time were investigated. Spin-dephasing time was found to increase with increasing magnetic field. Contrary to predictions of previous simplified treatments of the DP effect, spin-dephasing time was found to increase with temperature in the presence of impurity scattering. These results were found to agree qualitatively with results of recent experiments.

When does time matter? maternal employment, children's time with parents, and child development.

PubMed

Hsin, Amy; Felfe, Christina

2014-10-01

This study tests the two assumptions underlying popularly held notions that maternal employment negatively affects children because it reduces time spent with parents: (1) that maternal employment reduces children's time with parents, and (2) that time with parents affects child outcomes. We analyze children's time-diary data from the Child Development Supplement of the Panel Study of Income Dynamics and use child fixed-effects and IV estimations to account for unobserved heterogeneity. We find that working mothers trade quantity of time for better "quality" of time. On average, maternal work has no effect on time in activities that positively influence children's development, but it reduces time in types of activities that may be detrimental to children's development. Stratification by mothers' education reveals that although all children, regardless of mother's education, benefit from spending educational and structured time with their mothers, mothers who are high school graduates have the greatest difficulty balancing work and child care. We find some evidence that fathers compensate for maternal employment by increasing types of activities that can foster child development as well as types of activities that may be detrimental. Overall, we find that the effects of maternal employment are ambiguous because (1) employment does not necessarily reduce children's time with parents, and (2) not all types of parental time benefit child development.

Use of the landmark method to address immortal person-time bias in comparative effectiveness research: a simulation study.

PubMed

Mi, Xiaojuan; Hammill, Bradley G; Curtis, Lesley H; Lai, Edward Chia-Cheng; Setoguchi, Soko

2016-11-20

Observational comparative effectiveness and safety studies are often subject to immortal person-time, a period of follow-up during which outcomes cannot occur because of the treatment definition. Common approaches, like excluding immortal time from the analysis or naïvely including immortal time in the analysis, are known to result in biased estimates of treatment effect. Other approaches, such as the Mantel-Byar and landmark methods, have been proposed to handle immortal time. Little is known about the performance of the landmark method in different scenarios. We conducted extensive Monte Carlo simulations to assess the performance of the landmark method compared with other methods in settings that reflect realistic scenarios. We considered four landmark times for the landmark method. We found that the Mantel-Byar method provided unbiased estimates in all scenarios, whereas the exclusion and naïve methods resulted in substantial bias when the hazard of the event was constant or decreased over time. The landmark method performed well in correcting immortal person-time bias in all scenarios when the treatment effect was small, and provided unbiased estimates when there was no treatment effect. The bias associated with the landmark method tended to be small when the treatment rate was higher in the early follow-up period than it was later. These findings were confirmed in a case study of chronic obstructive pulmonary disease. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The effect of loading time on flexible pavement dynamic response: a finite element analysis

NASA Astrophysics Data System (ADS)

Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley

2007-12-01

Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

Recurrence time statistics for finite size intervals

NASA Astrophysics Data System (ADS)

Altmann, Eduardo G.; da Silva, Elton C.; Caldas, Iberê L.

2004-12-01

We investigate the statistics of recurrences to finite size intervals for chaotic dynamical systems. We find that the typical distribution presents an exponential decay for almost all recurrence times except for a few short times affected by a kind of memory effect. We interpret this effect as being related to the unstable periodic orbits inside the interval. Although it is restricted to a few short times it changes the whole distribution of recurrences. We show that for systems with strong mixing properties the exponential decay converges to the Poissonian statistics when the width of the interval goes to zero. However, we alert that special attention to the size of the interval is required in order to guarantee that the short time memory effect is negligible when one is interested in numerically or experimentally calculated Poincaré recurrence time statistics.

Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

NASA Astrophysics Data System (ADS)

Qi, Huimin; Li, Daxin; Zhang, Jingjing; Liu, Li; Zhang, Quanbin

2008-05-01

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg·d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

Effect of noise on the power spectrum of passively mode-locked lasers

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

Eliyahu, D.; Salvatore, R.A.; Yariv, A.

1997-01-01

We analyze the effects of noise on the power spectrum of pulse trains generated by a continuously operating passively mode-locked laser. The shape of the different harmonics of the power spectrum is calculated in the presence of correlated timing fluctuations between neighboring pulses and in the presence of amplitude fluctuations. The spectra at the different harmonics are influenced mainly by the nonstationary timing-jitter fluctuations; amplitude fluctuations slightly modify the spectral tails. Estimation of the coupling term between the longitudinal cavity modes or the effective saturable absorber coefficient is made from the timing-jitter correlation time. Experimental results from an external cavitymore » two-section semiconductor laser are given. The results show timing-jitter fluctuations having a relaxation time much longer than the repetition period. {copyright} 1997 Optical Society of America.« less

Handling time in economic evaluation studies.

PubMed

Permsuwan, Unchalee; Guntawongwan, Kansinee; Buddhawongsa, Piyaluk

2014-05-01

The discount rates and time horizons used in a health technology assessment (HTA) can have a significant impact on the results, and thus the prioritization of technologies. Therefore, it is important that clear guidance be provided on the appropriate discount rates for cost and health effect and appropriate time horizons. In this paper we conduct a review of relevant case studies and guidelines and provide guidance for all researchers conducting economic evaluations of health technologies in the Thai context. A uniform discount rate of 3% is recommended for both costs and health effects in base case analyses. A sensitivity analysis should also be conducted, with a discount range of 0-6%. For technologies where the effects are likely to sustain for at least 30y ears, a rate of 4% for costs and 2% for health effects is recommended. The time horizon should be long enough to capture the full costs and effects of the programs.

The effect of papaine on the time course of the end-plate current.

PubMed

Humar, M; Kordas, M; Melik, Z

1980-07-01

Papaine is known to detach cholinesterases from the synaptic cleft. It could be expected that this would result in an increase of the amplitude and half-time of the end-plate current. Thus, the effect of papaine on the end-plate current. Thus, the effect of papaine on the end-plate current should be similar to the effect of anticholinesterase methanesulfonylfluoride. The end-plate current was recorded in frog skeletal muscle at various levels of membrane potential, before and after papaine was added to the bath. The effect of papaine was an increase of the half-time of the end-plate current, similarly as after treatment of the muscle by methanesulfonylfluoride. It seems that both papaine and methanesulfonylfluoride have a similar mechanism of action. In either experimental condition hydrolysis of transmitter is decreased or abolished, which results in an increase of the half-time of the end-plate current.

[Effects of subliminal mere exposure to group members on intergroup evaluation: category evaluation measured in the Implicit Association Test (IAT)].

PubMed

Kawakami, Naoaki; Yoshida, Fujio

2010-10-01

This study investigated the effects of subliminal mere exposure to ingroup or outgroup members on intergroup evaluation as measured in the Implicit Association Test (IAT). Participants first memorized the members of two groups. Then, they were assigned to either group by lot, and completed the IAT for intergroup evaluation (Time 1). In the next phase, half the participants were subliminally exposed to ingroup members and half to outgroup members. Upon completion of the exposure, the same IAT was administered at Time 2. The results showed that participants who were exposed to ingroup members evaluated the ingroup more positively at Time 2 than at Time 1. Participants who were exposed to outgroup members did not show an effect toward the outgroup. The finding that the mere exposure effect occurred only for the ingroup exposure condition suggests that unconscious awareness of the ingroup enhances the mere exposure effect.

Immediate Effects of Clock-Turn Strategy on the Pattern and Performance of Narrow Turning in Persons With Parkinson Disease.

PubMed

Yang, Wen-Chieh; Hsu, Wei-Li; Wu, Ruey-Meei; Lin, Kwan-Hwa

2016-10-01

Turning difficulty is common in people with Parkinson disease (PD). The clock-turn strategy is a cognitive movement strategy to improve turning performance in people with PD despite its effects are unverified. Therefore, this study aimed to investigate the effects of the clock-turn strategy on the pattern of turning steps, turning performance, and freezing of gait during a narrow turning, and how these effects were influenced by concurrent performance of a cognitive task (dual task). Twenty-five people with PD were randomly assigned to the clock-turn or usual-turn group. Participants performed the Timed Up and Go test with and without concurrent cognitive task during the medication OFF period. The clock-turn group performed the Timed Up and Go test using the clock-turn strategy, whereas participants in the usual-turn group performed in their usual manner. Measurements were taken during the 180° turn of the Timed Up and Go test. The pattern of turning steps was evaluated by step time variability and step time asymmetry. Turning performance was evaluated by turning time and number of turning steps. The number and duration of freezing of gait were calculated by video review. The clock-turn group had lower step time variability and step time asymmetry than the usual-turn group. Furthermore, the clock-turn group turned faster with fewer freezing of gait episodes than the usual-turn group. Dual task increased the step time variability and step time asymmetry in both groups but did not affect turning performance and freezing severity. The clock-turn strategy reduces turning time and freezing of gait during turning, probably by lowering step time variability and asymmetry. Dual task compromises the effects of the clock-turn strategy, suggesting a competition for attentional resources.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A141).

Impact of Patient Navigation Interventions on Timely Diagnostic Follow Up for Abnormal Cervical Screening.

PubMed

Paskett, Electra D; Dudley, Donald; Young, Gregory S; Bernardo, Brittany M; Wells, Kristen J; Calhoun, Elizabeth A; Fiscella, Kevin; Patierno, Steven R; Warren-Mears, Victoria; Battaglia, Tracy A

2016-01-01

As part of the Patient Navigation Research Program, we examined the effect of patient navigation versus usual care on timely diagnostic follow-up, defined as clinical management for women with cervical abnormalities within accepted time frames. Participants from four Patient Navigation Research Program centers were divided into low- and high-risk abnormality groups and analyzed separately. Low-risk participants (n = 2088) were those who enrolled with an initial Pap test finding of atypical squamous cells of undetermined significance (ASCUS) with a positive high-risk human papillomavirus (HPV) serotype, atypical glandular cells, or low-grade squamous intraepithelial lesion (LGSIL). High-risk participants were those with an initial finding of high-grade squamous intraepithelial lesion (HGSIL) (n = 229). A dichotomous outcome of timely diagnostic follow-up within 180 days was used for the low-risk abnormality group and timely diagnostic follow-up within 60 days for the high-risk group, consistent with treatment guidelines. A logistic mixed-effects regression model was used to evaluate the intervention effect using a random effect for study arm within an institution. A backward selection process was used for multivariable model building, considering the impact of each predictor on the intervention effect. Low-risk women in the patient navigation arm showed an improvement in the odds of timely diagnostic follow-up across all racial groups, but statistically significant effects were only observed in non-English-speaking Hispanics (OR 5.88, 95% CI 2.81-12.29). No effect was observed among high-risk women. These results suggest that patient navigation can improve timely diagnostic follow-up among women with low-risk cervical abnormalities, particularly in non-English-speaking Hispanic women.

Why Is 10 Past 10 the Default Setting for Clocks and Watches in Advertisements? A Psychological Experiment.

PubMed

Karim, Ahmed A; Lützenkirchen, Britta; Khedr, Eman; Khalil, Radwa

2017-01-01

Have you ever noticed that in watch advertisements the time is usually set at 10:10? The reasons and psychological effects of this default time setting are elusive. In Experiment 1, we hypothesized that watches showing a time setting resembling a smiling face (10:10) would enhance emotional valence and intention to buy compared to a neutral time setting (11:30), whereas a time setting resembling a sad face (8:20) would have the opposite effect. Moreover, we investigated a possible interaction effect with the gender of the participants. In Experiment 2, we directly tested the hypotheses that watches set at 10:10 resemble a smiling face, whereas watches set at 8:20 resemble a sad face. The data of the first experiment reveal that watches set at 10:10 showed a significant positive effect on the emotion of the observer and the intention to buy. However, watches set at 8:20 did not show any effect on the emotion or the intention to buy. Moreover, watches set at 10:10 induced in women significantly stronger ratings of pleasure than in men. The data of the second experiment show that participants consistently perceive high resemblance between watches set at 10:10 and a smiling face as well as high resemblance between watches set at 8:20 and a sad face. This study provides for the first time empirical evidence for the notion that using watches with a time setting resembling a smiling face (like 10:10) can positively affect the emotional response of the observers and their evaluation of a seen watch, even though they are not aware of the fact that the shown time setting is inducing this effect. Practical implications of the observed findings and alternative explanations are discussed.

Long-term follow-up effects of the HomeStyles randomized controlled trial in families with preschool children on social cognitive theory constructs associated with physical activity cognitions and behaviors.

PubMed

Quick, Virginia; Martin-Biggers, Jennifer; Povis, Gayle Alleman; Worobey, John; Hongu, Nobuko; Byrd-Bredbenner, Carol

2018-05-01

This study examined long-term follow-up effects of participation in the HomeStyles RCT, using Social Cognitive Theory constructs, on physical activity cognitions, home environment, and lifestyle behavioral practices of families with preschool children (ages 2 to 5 years). Parents were systematically randomized to experimental or attention control group at baseline. Those completing all surveys that comprised of valid, reliable measures were the analytic sample (n = 61 experimental, n = 63 control; mean age 32.8 ± 5.9SD years). Repeated measures ANCOVA, controlling for prognostic variables (e.g., parent sex) revealed that variables assessing modeling of physical activity for children increased significantly (P ≤ .01) in both groups with no significant time by group effects. Paired t-tests indicated the experimental group's self-efficacy for keeping children's weight healthy and performing health promoting behaviors increased significantly over time whereas the control group did not but with no significant time by group effects. Self-regulation paired t-test findings indicated that total screentime the experimental group allowed children decreased significantly over time with no significant time by group effect. The value parents placed on physical activity for children increased over time in both groups with a significant time effect. The experimental group over time had significantly greater increases in the availability of physical activity space and supports inside the home than the control group. Improvements noted have the potential to help protect children and parents from excess weight gain, yet findings indicate considerable opportunity for continued improvement as well as elucidation of factors affecting concomitant changes in both study groups. Copyright © 2018 Elsevier Inc. All rights reserved.

Increasing Recovery Time Between Injuries Improves Cognitive Outcome After Repetitive Mild Concussive Brain Injuries in Mice

PubMed Central

Zhang, Jimmy; Mannix, Rebekah; Whalen, Michael J.

2012-01-01

Abstract BACKGROUND: Although previous evidence suggests that the cognitive effects of concussions are cumulative, the effect of time interval between repeat concussions is largely unknown. OBJECTIVE: To determine the effect of time interval between repeat concussions on the cognitive function of mice. METHODS: We used a weight-drop model of concussion to subject anesthetized mice to 1, 3, 5, or 10 concussions, each a day apart. Additional mice were subjected to 5 concussions at varying time intervals: daily, weekly, and monthly. Morris water maze performance was measured 24 hours, 1 month, and 1 year after final injury. RESULTS: After 1 concussion, injured and sham-injured mice performed similarly in the Morris water maze. As the number of concussions increased, injured mice performed worse than sham-injured mice. Mice sustaining 5 concussions either 1 day or 1 week apart performed worse than sham-injured mice. When 5 concussions were delivered at 1-month time intervals, no difference in Morris water maze performance was observed between injured and sham-injured mice. After a 1-month recovery period, mice that sustained 5 concussions at daily and weekly time intervals continued to perform worse than sham-injured mice. One year after the final injury, mice sustaining 5 concussions at a daily time interval still performed worse than sham-injured mice. CONCLUSION: When delivered within a period of vulnerability, the cognitive effects of multiple concussions are cumulative, persistent, and may be permanent. Increasing the time interval between concussions attenuates the effects on cognition. When multiple concussions are sustained by mice daily, the effects on cognition are long term. PMID:22743360

Effects of different storage time on hatching results and some egg quality characteristics of rock partridge (A. graeca) (management and production).

PubMed

Günhan, S; Kirikçi, K

2017-06-01

In this research, partridge eggs were stored during zero to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 and 36 to 42 d, respectively. The effect of different egg storage periods on egg protein and moisture rates, mineral contents, and some egg quality and hatching characteristics were investigated. The extension of egg storage times didn't affect the external quality features like shell weight, shell thickness, and albumen rate, but it affected the yolk weight, yolk index, albumen index, and Haugh unit (P < 0.05). Yolk weight was increased and yolk index, albumen index, and Haugh unit values were decreased with the extension of storage time. Different storage times of partridge eggs did not have important effects on the protein rates. Protein and humidity rate of the eggs were 14.21 and 67.64%, respectively. There were some elements such as S, P, Na, K, and Ca, but Al, Cd, Co, Mo, and Pb could not be found in the partridge eggs. There is no effect of the storage time on the mineral content of the egg. Storage time had negative effect on fertility and hatchability after 21 d of storage d, but no effect on hatchability of fertile eggs. As this study showed, partridge eggs are resistant to long storage times, as partridge egg proteins can resist degradation in the optimum storage times. To determine egg degradation, the study should be focused on partridge eggshell features, which are responsible for degradation. As a result of this research, partridge eggs can be stored for 21 d under optimum storage conditions without any negative hatchability results. © 2017 Poultry Science Association Inc.

Why Is 10 Past 10 the Default Setting for Clocks and Watches in Advertisements? A Psychological Experiment

PubMed Central

Karim, Ahmed A.; Lützenkirchen, Britta; Khedr, Eman; Khalil, Radwa

2017-01-01

Have you ever noticed that in watch advertisements the time is usually set at 10:10? The reasons and psychological effects of this default time setting are elusive. In Experiment 1, we hypothesized that watches showing a time setting resembling a smiling face (10:10) would enhance emotional valence and intention to buy compared to a neutral time setting (11:30), whereas a time setting resembling a sad face (8:20) would have the opposite effect. Moreover, we investigated a possible interaction effect with the gender of the participants. In Experiment 2, we directly tested the hypotheses that watches set at 10:10 resemble a smiling face, whereas watches set at 8:20 resemble a sad face. The data of the first experiment reveal that watches set at 10:10 showed a significant positive effect on the emotion of the observer and the intention to buy. However, watches set at 8:20 did not show any effect on the emotion or the intention to buy. Moreover, watches set at 10:10 induced in women significantly stronger ratings of pleasure than in men. The data of the second experiment show that participants consistently perceive high resemblance between watches set at 10:10 and a smiling face as well as high resemblance between watches set at 8:20 and a sad face. This study provides for the first time empirical evidence for the notion that using watches with a time setting resembling a smiling face (like 10:10) can positively affect the emotional response of the observers and their evaluation of a seen watch, even though they are not aware of the fact that the shown time setting is inducing this effect. Practical implications of the observed findings and alternative explanations are discussed. PMID:28878709

Effects of intra-aortic balloon pump timing on baroreflex activities in a closed-loop cardiovascular hybrid model.

PubMed

Fresiello, Libera; Khir, Ashraf William; Di Molfetta, Arianna; Kozarski, Maciej; Ferrari, Gianfranco

2013-03-01

Despite 50 years of research to assess the intra-aortic balloon pump (IABP) effects on patients' hemodynamics, some issues related to the effects of this therapy are still not fully understood. One of these issues is the effect of IABP, its inflation timing and duration on peripheral circulation autonomic controls. This work provides a systematic analysis of IABP effects on baroreflex using a cardiovascular hybrid model, which consists of computational and hydraulic submodels. The work also included a baroreflex computational model that was connected to a hydraulic model with a 40-cm(3) balloon. The IABP was operated at different inflation trigger timings (-0.14 to 0.31 s) and inflation durations (0.05-0.45 s), with time of the dicrotic notch being taken as t = 0. Baroreflex-dependent parameters-afferent and efferent pathway activity, heart rate, peripheral resistance, and venous tone-were evaluated at each of the inflation trigger times and durations considered. Balloon early inflation (0.09 s before the dicrotic notch) with inflation duration of 0.25 s generated a maximum net increment of afferent pathway activity of 10%, thus leading to a decrement of efferent sympathetic activity by 15.3% compared with baseline values. These times also resulted in a reduction in peripheral resistance and heart rate by 4 and 4.3% compared with baseline value. We conclude that optimum IABP triggering time results in positive effects on peripheral circulation autonomic controls. Conversely, if the balloon is not properly timed, peripheral resistance and heart rate may even increase, which could lead to detrimental outcomes. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Effects of steam treatment on bending properties and chemical composition of moso bamboo (Phyllostachys pubescens)

Treesearch

R. J. Zhao; Z. H. Jiang; C. Hse; T. Shupe

2010-01-01

Effects of temperature (25, 160 and 200 °C) and time (15 and 30 min) of steam treatment on the mechanical and chemical characteristics of moso bamboo were studied. The modulus of rupture (MOR) and modulus of elasticity (MOE) of the outer culm were at least 2.4 and 2.2 times respectively greater than those of the inner culm. Temperature and time had no effect on bending...

Can We Predict Cognitive Performance Decrements Due to Sleep Loss and the Recuperative Effects of Caffeine

DTIC Science & Technology

2015-10-14

such as timely short naps and caffeine, are often used to mitigate the effects of sleep loss on performance. However, the timing, duration, and dosage...loss and the restorative effects of different dosages of caffeine on a specific individual’s performance. When used as a decision-aid tool, this model...provides the means to maximize Warfighter cognitive performance, resulting in peak alertness and prolonged alertness at the desired times

The effect of hubs and shortcuts on fixation time in evolutionary graphs

NASA Astrophysics Data System (ADS)

Askari, Marziyeh; Moradi Miraghaei, Zeinab; Aghababaei Samani, Keivan

2017-07-01

How can a new species (like a gene, an idea, or a strategy) take over the whole of a population? This process, which is called fixation, is considerably affected by the structure of the population. There are two key quantities to quantify the fixation process, namely fixation probability and fixation time. Fixation probability has been vastly studied in recent years, but fixation time has not been completely explored, yet. This is because the discovery of a relationship between fixation time and network structure is quite challenging. In this paper we investigate this relationship for a number of well-known complex networks. We show that the existence of a few high-degree nodes (hubs) in the network results in a longer fixation time, while the existence of a few short-cuts decreases the fixation time. Furthermore we investigate the effect of network parameters, such as connection probability, on fixation time. We show that by increasing the density of edges, fixation time decreases for all types of studied networks. Finally, we survey the effect of rewiring probability in a Watts-Strogatz network on fixation time.