Working memory in wayfinding-a dual task experiment in a virtual city.

PubMed

Meilinger, Tobias; Knauff, Markus; Bülthoff, Heinrich H

2008-06-01

This study examines the working memory systems involved in human wayfinding. In the learning phase, 24 participants learned two routes in a novel photorealistic virtual environment displayed on a 220° screen while they were disrupted by a visual, a spatial, a verbal, or-in a control group-no secondary task. In the following wayfinding phase, the participants had to find and to "virtually walk" the two routes again. During this wayfinding phase, a number of dependent measures were recorded. This research shows that encoding wayfinding knowledge interfered with the verbal and with the spatial secondary task. These interferences were even stronger than the interference of wayfinding knowledge with the visual secondary task. These findings are consistent with a dual-coding approach of wayfinding knowledge. 2008 Cognitive Science Society, Inc.

Annual Report 1981. Part II.

DTIC Science & Technology

1982-01-01

Arkansas LRD AR 67 162.0 - 110 0 29 LD 1 Arkansas LRD AR 67 142.0 - 2 0 29 * Section 7 Flood Control Projects "Ilncludes dead storage. oonservation...m 0 ONO 0)00) ɜ Z -4N N Orin) 0.0 V ) 4, 0 aV) 0)-4 V m0 V 4e40 4P -0 1 000 m)0 0) 0 - 0 (. %V0) N 4-0 00 -0- 00 4 4 00 -~0 o0 NIr- N u -40 C) -N...4’ ) M0. 4r M V 000 I Lb J 0~ (14 N 0 -01 CIl U. U*C.V .X~ N N N %N 1 r N N N ui U)() ( 4P 0 0Mu D,0 10 V 2 W 0)0) NW- V0 l 21 N)4 N00. .0 W 0 10 NON

Alpha List of Prime Contract Awards. Oct 92-Sep 93. FY93. (Bt North America Inc. - Classified Location Domestic)

DTIC Science & Technology

1994-03-01

V4,(41, Or,.in cri nN c >1r- 0 10 f tao oinon0 40 M-4 -4 td n -w toce, of IC 𔃺 0 ca I1-&n UO0 - qtY(DC -04N I- . 30 C S-i Ur’L) . L-M4 U -4~ C...d 0o II Nca( 0 CI400W000 CD 10) Ny It 4. ev MNN.P.P rn If CIL I co00t I’l -4 co0 00000 -00 0 00C) 0 CV 4.4 Me V DCo tD H11 10 004D11 Nm Oin 000000...CO -4 0 11 -2c z .- Z 11 1 CO 0 fm 11 C z 2c z ed C z zx If I ca a 00 11 1- ed tv (d I td III 11 1 00000 11 00-t .- !`ý- W M It r- Ln Ln 0 tma N -4 -4

Moving solitons in the discrete nonlinear Schrödinger equation.

PubMed

Oxtoby, O F; Barashenkov, I V

2007-09-01

Using the method of asymptotics beyond all orders, we evaluate the amplitude of radiation from a moving small-amplitude soliton in the discrete nonlinear Schrödinger equation. When the nonlinearity is of the cubic type, this amplitude is shown to be nonzero for all velocities and therefore small-amplitude solitons moving without emitting radiation do not exist. In the case of a saturable nonlinearity, on the other hand, the radiation is found to be completely suppressed when the soliton moves at one of certain isolated "sliding velocities." We show that a discrete soliton moving at a general speed will experience radiative deceleration until it either stops and remains pinned to the lattice or--in the saturable case--locks, metastably, onto one of the sliding velocities. When the soliton's amplitude is small, however, this deceleration is extremely slow; hence, despite losing energy to radiation, the discrete soliton may spend an exponentially long time traveling with virtually unchanged amplitude and speed.

Autoantibodies to alfa-fodrin in patients with Hashimoto thyroiditis and Sjögren's syndrome: possible markers for a common secretory disorder.

PubMed

Szanto, Antonia; Csipo, Istvan; Horvath, Ildiko; Biro, Edit; Szodoray, Peter; Zeher, Margit

2008-09-01

Presence of autoantibodies to alfa-fodrin was investigated in patients with Sjögren's syndrome (n = 61), Hashimoto thyroiditis (n = 27), Sjögren's syndrome associated with Hashimoto thyroiditis (n = 31) and in healthy persons (n = 77). In each group, level of alfa-fodrin antibodies was higher than in the controls. There was no significant difference in their presence either between patients with Hashimoto thyroiditis with or without Sjögren's syndrome, or-in IgA isotype-between Sjögren's and Hashimoto thyroiditis patients. Correlation was found between the level of IgG alfa-fodrin and anti-thyroglobulin antibodies. Based on these findings, fodrin can be associated with both endocrine and exocrine glandular secretion. Antibodies to alfa-fodrin might have a role in the pathogenesis of Hashimoto thyroiditis concerning the "final common effectory pathway", secretion. Alfa-fodrin antibodies can be good markers of secretory disorders. Assessment of these autoantibodies might help the diagnosis and follow-up of patients with impaired secretory capability of not only autoimmune origin.

Greenhouse evaluation of Bacillus subtilis AP-01 and Trichoderma harzianum AP-001 in controlling tobacco diseases.

PubMed

Maketon, Monchan; Apisitsantikul, Jirasak; Siriraweekul, Chatchai

2008-04-01

Two biological control agents, Bacillus subtilis AP-01 (Larminar(™)) and Trichoderma harzianum AP-001 (Trisan(™)) alone or/in combination were investigated in controlling three tobacco diseases, including bacterial wilt (Ralstonia solanacearum), damping-off (Pythium aphanidermatum), and frogeye leaf spot (Cercospora nicotiana). Tests were performed in greenhouse by soil sterilization prior to inoculation of the pathogens. Bacterial-wilt and damping off pathogens were drenched first and followed with the biological control agents and for comparison purposes, two chemical fungicides. But for frogeye leaf spot, which is an airborne fungus, a spraying procedure for every treatment including a chemical fungicide was applied instead of drenching. Results showed that neither B. subtilis AP-01 nor T harzianum AP-001 alone could control the bacterial wilt, but when combined, their controlling capabilities were as effective as a chemical treatment. These results were also similar for damping-off disease when used in combination. In addition, the combined B. subtilis AP-01 and T. harzianum AP-001 resulted in a good frogeye leaf spot control, which was not significantly different from the chemical treatment.

Improving data sharing in research with context-free encoded missing data.

PubMed

Hoevenaar-Blom, Marieke P; Guillemont, Juliette; Ngandu, Tiia; Beishuizen, Cathrien R L; Coley, Nicola; Moll van Charante, Eric P; Andrieu, Sandrine; Kivipelto, Miia; Soininen, Hilkka; Brayne, Carol; Meiller, Yannick; Richard, Edo

2017-01-01

Lack of attention to missing data in research may result in biased results, loss of power and reduced generalizability. Registering reasons for missing values at the time of data collection, or-in the case of sharing existing data-before making data available to other teams, can save time and efforts, improve scientific value and help to prevent erroneous assumptions and biased results. To ensure that encoding of missing data is sufficient to understand the reason why data are missing, it should ideally be context-free. Therefore, 11 context-free codes of missing data were carefully designed based on three completed randomized controlled clinical trials and tested in a new randomized controlled clinical trial by an international team consisting of clinical researchers and epidemiologists with extended experience in designing and conducting trials and an Information System expert. These codes can be divided into missing due to participant and/or participation characteristics (n = 6), missing by design (n = 4), and due to a procedural error (n = 1). Broad implementation of context-free missing data encoding may enhance the possibilities of data sharing and pooling, thus allowing more powerful analyses using existing data.

Dissecting the Structure-Function Relationship of a Fungicidal Peptide Derived from the Constant Region of Human Immunoglobulins.

PubMed

Ciociola, Tecla; Pertinhez, Thelma A; Giovati, Laura; Sperindè, Martina; Magliani, Walter; Ferrari, Elena; Gatti, Rita; D'Adda, Tiziana; Spisni, Alberto; Conti, Stefania; Polonelli, Luciano

2016-04-01

Synthetic peptides encompassing sequences related to the complementarity-determining regions of antibodies or derived from their constant region (Fc peptides) were proven to exert differential antimicrobial, antiviral, antitumor, and/or immunomodulatory activitiesin vitroand/orin vivo, regardless of the specificity and isotype of the parental antibody. Alanine substitution derivatives of these peptides exhibited unaltered, increased, or decreased candidacidal activitiesin vitro The bioactive IgG-derived Fc N10K peptide (NQVSLTCLVK) spontaneously self-assembles, a feature previously recognized as relevant for the therapeutic activity of another antibody-derived peptide. We evaluated the contribution of each residue to the peptide self-assembling capability by circular-dichroism spectroscopy. The interaction of the N10K peptide and its derivatives withCandida albicanscells was studied by confocal, transmission, and scanning electron microscopy. The apoptosis and autophagy induction profiles in yeast cells treated with the peptides were evaluated by flow cytometry, and the therapeutic efficacy against candidal infection was studied in aGalleria mellonellamodel. Overall, the results indicate a critical role for some residues in the self-assembly process and a correlation of that capability with the candidacidal activities of the peptidesin vitroand their therapeutic effectsin vivo. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Emergency Communications for NASA's Deep Space Missions

NASA Technical Reports Server (NTRS)

Shambayati, Shervin; Lee, Charles H.; Morabito, David D.; Cesarone, Robert J.; Abraham, Douglas S.

2011-01-01

The ability to communicate with spacecraft during emergencies is a vital service that NASA's Deep Space Network (DSN) provides to all deep space missions. Emergency communications is characterized by low data rates(typically is approximately10 bps) with the spacecraft using either a low-gain antenna (LGA, including omnidirectional antennas) or,in some cases, a medium-gain antenna (MGA). Because of the use of LGAs/MGAs for emergency communications, the transmitted power requirements both on the spacecraft andon the ground are substantially greater than those required for normal operations on the high-gain antenna (HGA) despite the lower data rates. In this paper, we look at currentand future emergency communications capabilities available to NASA's deep-space missions and discuss their limitations in the context of emergency mode operations requirements.These discussions include the use of the DSN 70-m diameter antennas, the use of the 34-m diameter antennas either alone or arrayed both for the uplink (Earth-to-spacecraft) and the downlink (spacecraft-to-Earth), upgrades to the ground transmitters, and spacecraft power requirements both with unitygain (0 dB) LGAs and with antennas with directivity (>0 dB gain, either LGA or MGA, depending on the gain). Also discussed are the requirements for forward-error-correctingcodes for both the uplink and the downlink. In additional, we introduce a methodology for proper selection of a directionalLGA/MGA for emergency communications.

Properties of a Purified Halophilic Malic Dehydrogenase

PubMed Central

Holmes, P. K.; Halvorson, H. Orin

1965-01-01

Holmes, P. K. (University of Illinois, Urbana), and H. Orin Halvorson. Properties of a purified halophilic malic dehydrogenase. J. Bacteriol. 90:316–326. 1965.—The malic dehydrogenase (MDH) from Halobacterium salinarium required high concentrations of monovalent ions for stability and activity. Studies of inactivation rates at different salt concentrations suggested that approximately 25% NaCl (w/v) is required to stabilize MDH. From 50 to 100% reactivation, depending on the salt concentration present during inactivation, could occur in 2.5 to 5 m NaCl or KCl. The optimal salt concentration for activity of MDH was a function of the pH, and ranged from 1 to 3 m NaCl or KCl. The effect of salt concentration on the pH-activity curves occurred chiefly below pH 7.0. Inactivation of MDH with heat or thiol reagents showed that the enzyme was more labile in the state induced by absence of salt. The activation of MDH by salts was attributed to a decreased rate of dissociation of MDH and reduced nicotinamide adenine dinucleotide (NADH2). The inactivation of the enzyme in the absence of salt could be largely prevented by the presence of NADH2. The S20.w of MDH decreased threefold at low salt concentrations. The enzyme was assumed to be in its native compact configuration only in the presence of a high concentration of salt. PMID:14329442

Prognostic model for psychological outcomes in ambulatory surgery patients: A prospective study using a structural equation modeling framework.

PubMed

Mijderwijk, Hendrik-Jan; Stolker, Robert Jan; Duivenvoorden, Hugo J; Klimek, Markus; Steyerberg, Ewout W

2018-01-01

Surgical procedures are increasingly carried out in a day-case setting. Along with this increase, psychological outcomes have become prominent. The objective was to evaluate prospectively the prognostic effects of sociodemographic, medical, and psychological variables assessed before day-case surgery on psychological outcomes after surgery. The study was carried out between October 2010 and September 2011. We analyzed 398 mixed patients, from a randomized controlled trial, undergoing day-case surgery at a university medical center. Structural equation modeling was used to jointly study presurgical prognostic variables relating to sociodemographics (age, sex, nationality, marital status, having children, religion, educational level, employment), medical status (BMI, heart rate), and psychological status associated with anxiety (State-Trait Anxiety Inventory (STAI), Hospital Anxiety and Depression Scale (HADS-A)), fatigue (Multidimensional Fatigue Inventory (MFI)), aggression (State-Trait Anger Scale (STAS)), depressive moods (HADS-D), self-esteem, and self-efficacy. We studied psychological outcomes on day 7 after surgery, including anxiety, fatigue, depressive moods, and aggression regulation. The final prognostic model comprised the following variables: anxiety (STAI, HADS-A), fatigue (MFI), depression (HADS-D), aggression (STAS), self-efficacy, sex, and having children. The corresponding psychological variables as assessed at baseline were prominent (i.e. standardized regression coefficients ≥ 0.20), with STAI-Trait score being the strongest predictor overall. STAI-State (adjusted R2 = 0.44), STAI-Trait (0.66), HADS-A (0.45) and STAS-Trait (0.54) were best predicted. We provide a prognostic model that adequately predicts multiple postoperative outcomes in day-case surgery. Consequently, this enables timely identification of vulnerable patients who may require additional medical or psychological preventive treatment or-in a worst-case scenario-could be unselected for day-case surgery.

Resolution Enhancement in PET Reconstruction Using Collimation

NASA Astrophysics Data System (ADS)

Metzler, Scott D.; Matej, Samuel; Karp, Joel S.

2013-02-01

Collimation can improve both the spatial resolution and sampling properties compared to the same scanner without collimation. Spatial resolution improves because each original crystal can be conceptually split into two (i.e., doubling the number of in-plane crystals) by masking half the crystal with a high-density attenuator (e.g., tungsten); this reduces coincidence efficiency by 4× since both crystals comprising the line of response (LOR) are masked, but yields 4× as many resolution-enhanced (RE) LORs. All the new RE LORs can be measured by scanning with the collimator in different configurations.In this simulation study, the collimator was assumed to be ideal, neither allowing gamma penetration nor truncating the field of view. Comparisons were made in 2D between an uncollimated small-animal system with 2-mm crystals that were assumed to be perfectly absorbing and the same system with collimation that narrowed the effective crystal size to 1 mm. Digital phantoms included a hot-rod and a single-hot-spot, both in a uniform background with activity ratio of 4:1. In addition to the collimated and uncollimated configurations, angular and spatial wobbling acquisitions of the 2-mm case were also simulated. Similarly, configurations with different combinations of the RE LORs were considered including (i) all LORs, (ii) only those parallel to the 2-mm LORs; and (iii) only cross pairs that are not parallel to the 2-mm LORs. Lastly, quantitative studies were conducted for collimated and uncollimated data using contrast recovery coefficient and mean-squared error (MSE) as metrics. The reconstructions show that for most noise levels there is a substantial improvement in image quality (i.e., visual quality, resolution, and a reduction in artifacts) by using collimation even when there are 4 fewer counts or-in some cases-comparing with the noiseless uncollimated reconstruction. By comparing various configurations of sampling, the results show that it is the matched combination of both improved spatial resolution of each LOR and the increase in the number of LORs that yields improved reconstructions. Further, the quantitative studies show that for low-count scans, the collimated data give better MSE for small lesions and the uncollimated data give better MSE for larger lesions; for highcount studies, the collimated data yield better quantitative values for the entire range of lesion sizes that were evaluated.

Organ Preservation in Rectal Adenocarcinoma: a phase II randomized controlled trial evaluating 3-year disease-free survival in patients with locally advanced rectal cancer treated with chemoradiation plus induction or consolidation chemotherapy, and total mesorectal excision or nonoperative management.

PubMed

Smith, J Joshua; Chow, Oliver S; Gollub, Marc J; Nash, Garrett M; Temple, Larissa K; Weiser, Martin R; Guillem, José G; Paty, Philip B; Avila, Karin; Garcia-Aguilar, Julio

2015-10-23

Treatment of patients with non-metastatic, locally advanced rectal cancer (LARC) includes pre-operative chemoradiation, total mesorectal excision (TME) and post-operative adjuvant chemotherapy. This trimodality treatment provides local tumor control in most patients; but almost one-third ultimately die from distant metastasis. Most survivors experience significant impairment in quality of life (QoL), due primarily to removal of the rectum. A current challenge lies in identifying patients who could safely undergo rectal preservation without sacrificing survival benefit and QoL. This multi-institutional, phase II study investigates the efficacy of total neoadjuvant therapy (TNT) and selective non-operative management (NOM) in LARC. Patients with MRI-staged Stage II or III rectal cancer amenable to TME will be randomized to receive FOLFOX/CAPEOX: a) before induction neoadjuvant chemotherapy (INCT); or b) after consolidation neoadjuvant chemotherapy (CNCT), with 5-FU or capecitabine-based chemoradiation. Patients in both arms will be re-staged after completing all neoadjuvant therapy. Those with residual tumor at the primary site will undergo TME. Patients with clinical complete response (cCR) will receive non-operative management (NOM). NOM patients will be followed every 3 months for 2 years, and every 6 months thereafter. TME patients will be followed according to NCCN guidelines. All will be followed for at least 5 years from the date of surgery or--in patients treated with NOM--the last day of treatment. The studies published thus far on the safety of NOM in LARC have compared survival between select groups of patients with a cCR after NOM, to patients with a pathologic complete response (pCR) after TME. The current study compares 3-year disease-free survival (DFS) in an entire population of patients with LARC, including those with cCR and those with pCR. We will compare the two arms of the study with respect to organ preservation at 3 years, treatment compliance, adverse events and surgical complications. We will measure QoL in both groups. We will analyze molecular indications that may lead to more individually tailored treatments in the future. This will be the first NOM trial utilizing a regression schema for response assessment in a prospective fashion. NCT02008656.