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1.
Proc Biol Sci ; 290(2008): 20231514, 2023 Oct 11.
Article in English | MEDLINE | ID: mdl-37817602

ABSTRACT

There is an active debate concerning the association of handedness and spatial ability. Past studies used small sample sizes. Determining the effect of handedness on spatial ability requires a large, cross-cultural sample of participants and a navigation task with real-world validity. Here, we overcome these challenges via the mobile app Sea Hero Quest. We analysed the navigation performance from 422 772 participants from 41 countries and found no reliable evidence for any difference in spatial ability between left- and right-handers across all countries. A small but growing gap in performance appears for participants over 64 years old, with left-handers outperforming right-handers. Further analysis, however, suggests that this gap is most likely due to selection bias. Overall, our study clarifies the factors associated with spatial ability and shows that left-handedness is not associated with either a benefit or a deficit in spatial ability.


Subject(s)
Functional Laterality , Spatial Navigation , Humans , Middle Aged
2.
Sci Rep ; 13(1): 10844, 2023 07 05.
Article in English | MEDLINE | ID: mdl-37407585

ABSTRACT

Cognitive abilities can vary widely. Some people excel in certain skills, others struggle. However, not all those who describe themselves as gifted are. One possible influence on self-estimates is the surrounding culture. Some cultures may amplify self-assurance and others cultivate humility. Past research has shown that people in different countries can be grouped into a set of consistent cultural clusters with similar values and tendencies, such as attitudes to masculinity or individualism. Here we explored whether such cultural dimensions might relate to the extent to which populations in 46 countries overestimate or underestimate their cognitive abilities in the domain of spatial navigation. Using the Sea Hero Quest navigation test and a large sample (N = 383,187) we found cultural clusters of countries tend to be similar in how they self-rate ability relative to their actual performance. Across the world population sampled, higher self-ratings were associated with better performance. However, at the national level, higher self-ratings as a nation were not associated with better performance as a nation. Germanic and Near East countries were found to be most overconfident in their abilities and Nordic countries to be most under-confident in their abilities. Gender stereotypes may play a role in mediating this pattern, with larger national positive attitudes to male stereotyped roles (Hofstede's masculinity dimension) associated with a greater overconfidence in performance at the national level. We also replicate, with higher precision than prior studies, evidence that older men tend to overestimate their navigation skill more than other groups. These findings give insight into how culture and demographics may impact self-estimates of our abilities.


Subject(s)
Individuality , Spatial Navigation , Humans , Male , Aged , Masculinity , Cognition , Scandinavian and Nordic Countries
3.
Cognition ; 236: 105443, 2023 07.
Article in English | MEDLINE | ID: mdl-37003236

ABSTRACT

Despite extensive research on navigation, it remains unclear which features of an environment predict how difficult it will be to navigate. We analysed 478,170 trajectories from 10,626 participants who navigated 45 virtual environments in the research app-based game Sea Hero Quest. Virtual environments were designed to vary in a range of properties such as their layout, number of goals, visibility (varying fog) and map condition. We calculated 58 spatial measures grouped into four families: task-specific metrics, space syntax configurational metrics, space syntax geometric metrics, and general geometric metrics. We used Lasso, a variable selection method, to select the most predictive measures of navigation difficulty. Geometric features such as entropy, area of navigable space, number of rings and closeness centrality of path networks were among the most significant factors determining the navigational difficulty. By contrast a range of other measures did not predict difficulty, including measures of intelligibility. Unsurprisingly, other task-specific features (e.g. number of destinations) and fog also predicted navigation difficulty. These findings have implications for the study of spatial behaviour in ecological settings, as well as predicting human movements in different settings, such as complex buildings and transport networks and may aid the design of more navigable environments.


Subject(s)
Space Perception , Spatial Navigation , Humans , Entropy , Spatial Behavior , Cognition , Movement
4.
Nat Commun ; 13(1): 7697, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36509747

ABSTRACT

Classically the human life-course is characterized by youth, middle age and old age. A wide range of biological, health and cognitive functions vary across this life-course. Here, using reported sleep duration from 730,187 participants across 63 countries, we find three distinct phases in the adult human life-course: early adulthood (19-33yrs), mid-adulthood (34-53yrs), and late adulthood (54+yrs). They appear stable across culture, gender, education and other demographics. During the third phase, where self-reported sleep duration increases with age, cognitive performance, as measured by spatial navigation, was found to have an inverted u-shape relationship with reported sleep duration: optimal performance peaks at 7 hours reported sleep. World-wide self-reported sleep duration patterns are geographically clustered, and are associated with economy, culture, and latitude.


Subject(s)
Sleep Duration , Sleep , Middle Aged , Adolescent , Adult , Humans , Time Factors , Self Report , Cognition
5.
Nature ; 604(7904): 104-110, 2022 04.
Article in English | MEDLINE | ID: mdl-35355009

ABSTRACT

The cultural and geographical properties of the environment have been shown to deeply influence cognition and mental health1-6. Living near green spaces has been found to be strongly beneficial7-11, and urban residence has been associated with a higher risk of some psychiatric disorders12-14-although some studies suggest that dense socioeconomic networks found in larger cities provide a buffer against depression15. However, how the environment in which one grew up affects later cognitive abilities remains poorly understood. Here we used a cognitive task embedded in a video game16 to measure non-verbal spatial navigation ability in 397,162 people from 38 countries across the world. Overall, we found that people who grew up outside cities were better at navigation. More specifically, people were better at navigating in environments that were topologically similar to where they grew up. Growing up in cities with a low street network entropy (for example, Chicago) led to better results at video game levels with a regular layout, whereas growing up outside cities or in cities with a higher street network entropy (for example, Prague) led to better results at more entropic video game levels. This provides evidence of the effect of the environment on human cognition on a global scale, and highlights the importance of urban design in human cognition and brain function.


Subject(s)
Built Environment , Cognition , Spatial Navigation , Video Games , Cities , Entropy , Humans
6.
AIDS Behav ; 26(2): 350-360, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34347198

ABSTRACT

The prevention effectiveness of oral preexposure prophylaxis (PrEP) is highly dependent on medication adherence but no validated longer term PrEP adherence measures are readily available for use by primary care clinicians caring for diverse populations. We compared two self-report measures (number of doses missed in past 7 days and day-by-day past week pill taking) to results of tenofovir concentrations in dried blood spot (DBS) samples at quarterly visits over the first 12 months of PrEP use. 1420 men and women in five US community health centers enrolled in a medication adherence substudy. For 3, 6, 9 and 12 months, the respective percentages of persons with self-report vs DBS levels consistent having taken all 7 doses in the week prior were 71% (51%), 70% (47%), 71% (46%) and 69% (44%). Conversely, the percentage of participants reporting taking 0-1 doses in the week prior by self-report vs DBS drug levels at 3, 6, 9 and 12 months consistent with this level of nonadherence of 6% (9%), 5% (10%), 8% (9%), and 9% (15%). The estimated risk of low adherence (estimated 0-1 doses in the week prior) was higher for participants of Black (RR 1.60, CI 1.09-2.34) or "Other" race (RR 1.62, CI 0.99-2.65) compared with participants of White race; being a transgender female (RR 2.31, CI 1.33-4.02) compared to men who have sex with men; or enrollment at a study site with less experience in the provision of PrEP. The estimated risk of low adherence by DBS was lower for participants with a higher number of sex partners in the past 3 months and those having a bachelor's degree or higher. More work is needed to provide clinicians with measures to assess medication adherence in diverse US populations being prescribed PrEP to support its effective use in reducing HIV acquisition in individuals and at the community level.


Subject(s)
Anti-HIV Agents , HIV Infections , Pre-Exposure Prophylaxis , Sexual and Gender Minorities , Transgender Persons , Anti-HIV Agents/therapeutic use , Community Health Centers , Emtricitabine/therapeutic use , Female , HIV Infections/drug therapy , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Medication Adherence
7.
AJNR Am J Neuroradiol ; 42(2): 273-278, 2021 01.
Article in English | MEDLINE | ID: mdl-33361378

ABSTRACT

BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is an important event that is diagnosed on head NCCT. Increased NCCT utilization in busy hospitals may limit timely identification of ICH. RAPID ICH is an automated hybrid 2D-3D convolutional neural network application designed to detect ICH that may allow for expedited ICH diagnosis. We determined the accuracy of RAPID ICH for ICH detection and ICH volumetric quantification on NCCT. MATERIALS AND METHODS: NCCT scans were evaluated for ICH by RAPID ICH. Consensus detection of ICH by 3 neuroradiology experts was used as the criterion standard for RAPID ICH comparison. ICH volume was also automatically determined by RAPID ICH in patients with intraparenchymal or intraventricular hemorrhage and compared with manually segmented ICH volumes by a single neuroradiology expert. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID ICH were determined. RESULTS: We included 308 studies. RAPID ICH correctly identified 151/158 ICH cases and 143/150 ICH-negative cases, which resulted in high sensitivity (0.956, CI: 0.911-0.978), specificity (0.953, CI: 0.907-0.977), positive predictive value (0.956, CI: 0.911-0.978), and negative predictive value (0.953, CI: 0.907-0.977) for ICH detection. The positive likelihood ratio (20.479, CI 9.928-42.245) and negative likelihood ratio (0.046, CI 0.023-0.096) for ICH detection were similarly favorable. RAPID ICH volumetric quantification for intraparenchymal and intraventricular hemorrhages strongly correlated with expert manual segmentation (correlation coefficient r = 0.983); the median absolute error was 3 mL. CONCLUSIONS: RAPID ICH is highly accurate in the detection of ICH and in the volumetric quantification of intraparenchymal and intraventricular hemorrhages.


Subject(s)
Cerebral Hemorrhage/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Neural Networks, Computer , Neuroimaging/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies
8.
Am J Surg ; 219(6): 983-987, 2020 06.
Article in English | MEDLINE | ID: mdl-31590888

ABSTRACT

BACKGROUND: Postoperative urinary retention (POUR) and catheter-associated urinary tract infections (CAUTI) are associated with significantly longer hospital length-of-stay and increased costs.1 This study investigates the effect of early removal of urinary catheters on POUR and CAUTI in patients undergoing an ERP with a preoperative intrathecal injection. METHODS: Retrospective cohort study of a prospectively maintained database of patients who underwent elective colorectal surgery in an Enhanced Recovery pathway was compared to historical National Surgical Quality Improvement Program cohort of patients. Primary outcomes measured are 30-day POUR and postoperative CAUTI rates. RESULTS: The overall POUR rate of ERP patients compared to non-ERP patients was significantly less (8% vs. 13%, p < 0.05). CAUTI rates were not significantly different between pre-ERP and ERP patients (1.2 vs 2.3%, p = 0.19). CONCLUSIONS: For patients undergoing ERP with a preoperative intrathecal opioid injection, early removal of urinary catheter significantly decreased POUR and did not significantly affect CAUTI rates. SUMMARY: The effect of early removal of urinary catheters on postoperative urinary retention and catheter-associated UTI rates in patients undergoing an ERP with a single preoperative intrathecal opioid injection was studied. Early urinary catheter removal after intrathecal injection was associated with decreased rates of POUR and equivalent CAUTI rates.


Subject(s)
Analgesics, Opioid/administration & dosage , Catheter-Related Infections/epidemiology , Device Removal , Enhanced Recovery After Surgery , Postoperative Complications/epidemiology , Urinary Catheters , Urinary Retention/epidemiology , Adult , Aged , Cohort Studies , Female , Humans , Injections, Spinal , Male , Middle Aged , Retrospective Studies , Time Factors
9.
J Pediatr Urol ; 12(6): 388.e1-388.e7, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27363329

ABSTRACT

INTRODUCTION: Increased case volumes and training are associated with better surgical outcomes. However, the impact of pediatric urology sub-specialization on perioperative complication rates is unknown. OBJECTIVES: To determine the presence and magnitude of difference in rates of common postoperative complications for elective pediatric urology procedures between specialization levels of urologic surgeons. The Nationwide Inpatient Sample (NIS), a nationally representative administrative database, was used. STUDY DESIGN: The NIS (1998-2009) was retrospectively reviewed for pediatric (≤18 years) admissions, using ICD-9-CM codes to identify urologic surgeries and National Surgical Quality Improvement Program (NSQIP) inpatient postoperative complications. Degree of pediatric sub-specialization was calculated using a Pediatric Proportion Index (PPI), defined as the ratio of children to total patients operated on by each provider. The providers were grouped into PPI quartiles: Q1, 0-25% specialization; Q2, 25-50%; Q3, 50-75%; Q4, 75-100%. Weighted multivariate analysis was performed to test for associations between PPI and surgical complications. RESULTS: A total of 71,479 weighted inpatient admissions were identified. Patient age decreased with increasing specialization: Q1, 7.9 vs Q2, 4.8 vs Q3, 4.8 vs Q4, 4.6 years, P < 0.01). Specialization was not associated with race (P > 0.20), gender (P > 0.50), or comorbidity scores (P = 0.10). Mortality (1.5% vs 0.2% vs 0.3% vs 0.4%, P < 0.01) and complication rates (15.5% vs 11.7% vs 9.6% vs 10.9%, P < 0.0001) both decreased with increasing specialization. Patients treated by more highly specialized surgeons incurred slightly higher costs (Q2, +4%; Q3, +1%; Q4 + 2%) but experienced shorter length of hospital stay (Q2, -5%; Q3, -10%; Q4, -3%) compared with the least specialized providers. A greater proportion of patients treated by Q1 and Q3 specialized urologists had CCS ≥2 than those seen by Q2 or Q4 urologists (12.5% and 12.2%, respectively vs 8.4% and 10.9%, respectively, P = 0.04). Adjusting for confounding effects, increased pediatric specialization was associated with decreased postoperative complications: Q2 OR 0.78, CI 0.58-1.05; Q3 OR 0.60, CI 0.44-0.84; Q4 OR 0.70, CI 0.58-0.84; P < 0.01. DISCUSSION: Providers with proportionally higher volumes of pediatric patients achieved better postoperative outcomes than their less sub-specialized counterparts. This may have arisen from increased exposure to pediatric anatomy and physiology, and greater familiarity with pediatric techniques. LIMITATION: The NIS admission-based retrospective design did not enable assessment of long-term outcomes, repeated admissions, or to track a particular patient across time. The study was similarly limited in evaluating the effect of pre-surgical referral patterns on patient distributions. CONCLUSIONS: Increased pediatric sub-specialization among urologists was associated with a decreased risk of mortality and surgical complications in children undergoing inpatient urologic procedures.


Subject(s)
Medicine , Pediatrics , Postoperative Complications/epidemiology , Urologic Surgical Procedures , Child , Child, Preschool , Female , Hospitalization , Humans , Male , Retrospective Studies
11.
West Indian Med J ; 62(1): 56-61, 2013 Jan.
Article in English | MEDLINE | ID: mdl-24171329

ABSTRACT

OBJECTIVES: Although common worldwide, intravaginal cleansing is associated with poor health outcomes. We sought to describe intravaginal cleansing among women attending a sexually transmitted infection (STI) clinic in Jamaica. METHODS: We examined intravaginal cleansing ("washing up inside the vagina", douching, and products or materials used) among 293 participants in a randomized trial of counselling messages at an STI clinic in Kingston. We focussed on information on intravaginal cleansing performed in the 30 days and three days preceding their baseline study visit. We describe reported cleansing behaviours and used logistic regression to identify correlates of intravaginal cleansing. RESULTS: Fifty-eight per cent of participants reported intravaginal cleansing in the previous 30 days, and 46% did so in the three days before baseline. Among those who cleansed in the previous 30 days, 88% reported doing so for hygiene unrelated to sex, and three-fourths reported generally doing so more than once per day. Soap (usually with water) and water alone were the most common products used for washing; commercial douches or detergents were reported infrequently. Intravaginal cleansing in the three days before the baseline visit was positively associated with having more than one sex partner in the previous three months (adjusted odds ratio [AOR], 1.9; 95% CI, 1.1, 3.2), and negatively associated with experiencing itching in the genital area at baseline (AOR, 0.6; 95% CI, 0.4, 1.0). CONCLUSIONS: A large proportion of women attending STI clinics in Jamaica engage in frequent intravaginal cleansing, indicating a need for clinicians to discuss this topic with them accordingly.


Subject(s)
Health Behavior , Sexual Behavior , Sexually Transmitted Diseases/prevention & control , Vaginal Douching , Adult , Ambulatory Care Facilities/statistics & numerical data , Female , Humans , Jamaica , Logistic Models , Sexual Partners , Sexually Transmitted Diseases/physiopathology , Sexually Transmitted Diseases/psychology , Soaps/therapeutic use , Time Factors , Treatment Outcome , Vaginal Douching/instrumentation , Vaginal Douching/methods
12.
West Indian med. j ; 62(1): 56-61, Jan. 2013. tab
Article in English | LILACS | ID: biblio-1045588

ABSTRACT

OBJECTIVES: Although common worldwide, intravaginal cleansing is associated with poor health outcomes. We sought to describe intravaginal cleansing among women attending a sexually transmitted infection (STI) clinic in Jamaica. METHODS: We examined intravaginal cleansing ("washing up inside the vagina", douching, and products or materials used) among 293 participants in a randomized trial of counselling messages at an STI clinic in Kingston. We focussed on information on intravaginal cleansing performed in the 30 days and three days preceding their baseline study visit. We describe reported cleansing behaviours and used logistic regression to identify correlates of intravaginal cleansing RESULTS: Fifty-eight per cent of participants reported intravaginal cleansing in the previous 30 days, and 46% did so in the three days before baseline. Among those who cleansed in the previous 30 days, 88% reported doing so for hygiene unrelated to sex, and three-fourths reported generally doing so more than once per day. Soap (usually with water) and water alone were the most common products used for washing; commercial douches or detergents were reported infrequently. Intravaginal cleansing in the three days before the baseline visit was positively associated with having more than one sex partner in the previous three months (adjusted odds ratio [AOR], 1.9; 95% CI, 1.1, 3.2), and negatively associated with experiencing itching in the genital area at baseline (AOR, 0.6; 95% CI, 0.4, 1.0). CONCLUSIONS: A large proportion of women attending STI clinics in Jamaica engage in frequent intravaginal cleansing, indicating a need for clinicians to discuss this topic with them accordingly.


OBJETIVOS: Aunque común mundialmente, la limpieza intravaginal se halla asociada con pobres resultados de salud. Buscamos describir la limpieza intravaginal entre mujeres que asisten a una clínica de infecciones de transmisión sexual (ITS) en Jamaica. MÉTODOS: Examinamos la limpieza intravaginal ("lavado del interior de la vagina", ducha, y productos o materiales usados) entre 293 participantes en una prueba aleatoria de mensajes de counseling en una clínica de ITS en Kingston. Las participantes proporcionaron la información sobre la limpieza intravaginal realizada en los 30 y tres días que precedieron a su visita para el estudio inicial. Describimos las conductas de limpieza reportadas y la regresión logística usada para identificar los correlatos de la limpieza intravaginal. RESULTADOS: Cincuenta y ocho por ciento de las participantes reportaron la limpieza intravaginal en los 30 días anteriores, y el 46% lo hicieron en los tres días antes del inicio del estudio. Entre aquéllas que realizaron la limpieza en los 30 días anteriores, el 88% reportó haberlo hecho por razones de higiene independientes de la vida sexual, y tres cuartos reportaron hacerlo de manera general más de una vez al día. Jabón (normalmente con agua) y agua solamente fueron los productos más comunes usados para el lavado. Las duchas comerciales o detergentes no fueron reportadas muy frecuentemente. La limpieza intravaginal en los tres días antes de la visita del estudio inicial estuvo positivamente asociada con tener más de una pareja sexual en los tres meses anteriores (odds ratio ajustado [AOR], 1.9; 95% CI, 1.1, 3.2), y negativamente asociado con experimentar comezón en el área genital al inicio del estudio (AOR, 0.6; 95% CI, 0.4, 1.0). CONCLUSIONES: Un gran número de mujeres que asisten a las clínicas de ITS en Jamaica practican frecuentemente la limpieza intravaginal, lo cual indica la necesidad de que los médicos clínicos discutan este asunto con ellas.


Subject(s)
Humans , Female , Adult , Sexual Behavior , Health Behavior , Sexually Transmitted Diseases/prevention & control , Vaginal Douching , Soaps/therapeutic use , Time Factors , Sexual Partners , Logistic Models , Treatment Outcome , Ambulatory Care Facilities , Jamaica
13.
Pharmacogenomics J ; 10(6): 524-36, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20195289

ABSTRACT

Treatment of latent tuberculosis infection (LTBI) generally includes isoniazid (INH), a drug that can cause serious hepatotoxicity. Carboxylesterases (CES) are important in the metabolism of a variety of substrates, including xenobiotics. We hypothesized that genetic variation in CES genes expressed in the liver could affect INH-induced hepatotoxicity. Three CES genes are known to be expressed in human liver: CES1, CES2 and CES4. Our aim was to systematically characterize genetic variation in these novel candidate genes and test whether it is associated with this adverse drug reaction. As part of a pilot study, 170 subjects with LTBI who received only INH were recruited, including 23 cases with hepatotoxicity and 147 controls. All exons and the promoters of CES1, CES2 and CES4 were bidirectionally sequenced. A large polymorphic deletion was found to encompass exons 2 to 6 of CES4. No significant association was found. Eleven single-nucleotide polymorphisms (SNPs) in CES1 were in high linkage disequilibrium with each other. One of these SNPs, C(-2)G, alters the translation initiation sequence of CES1 and represents a candidate functional polymorphism. Replication of this possible association in a larger sample set and functional studies will be necessary to determine if this CES1 variant has a role in INH-induced hepatotoxicity.


Subject(s)
Carboxylic Ester Hydrolases/genetics , Chemical and Drug Induced Liver Injury/genetics , Isoniazid/adverse effects , Adult , Aged , Carboxylesterase/genetics , Case-Control Studies , Female , Gene Deletion , Humans , Latent Tuberculosis/drug therapy , Linkage Disequilibrium , Liver/enzymology , Male , Middle Aged , Polymorphism, Genetic , Polymorphism, Single Nucleotide
14.
J Perinatol ; 30(4): 281-5, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19812586

ABSTRACT

OBJECTIVE: Our aim was to determine the incidence of anatomical abnormalities after a urinary tract infection (UTI) in infants <2 months of age hospitalized in the neonatal intensive care unit (NICU). STUDY DESIGN: This was a retrospective, single-center cohort study of infants <2 months of age in the NICU with a UTI and documented renal imaging. RESULT: We identified 141 infants with UTIs. The mean gestational age and birth weight were 28 weeks and 1254 g, respectively. The most commonly identified pathogen was coagulase-negative Staphylococcus (28%, 44 of 156). A major abnormality was found on at least one imaging study for 4% (5 of 118) of infants. Major abnormalities were noted on 4% (5 of 114) of renal ultrasounds and 2% (2 of 82) of voiding cystourethrography examinations. CONCLUSION: Among infants in the NICU <2 months of age at the time of a UTI, the prevalence of major anatomical abnormalities is <5%.


Subject(s)
Hydronephrosis/complications , Hydronephrosis/epidemiology , Urinary Tract Infections/complications , Urogenital Abnormalities/complications , Urogenital Abnormalities/epidemiology , Academic Medical Centers/statistics & numerical data , Female , Humans , Hydronephrosis/diagnostic imaging , Infant , Infant, Newborn , Intensive Care Units, Neonatal/statistics & numerical data , Male , North Carolina/epidemiology , Prevalence , Ultrasonography , Urogenital Abnormalities/diagnostic imaging
15.
Psychol Res ; 73(5): 644-58, 2009 Sep.
Article in English | MEDLINE | ID: mdl-18998160

ABSTRACT

For large numbers of targets, path planning is a complex and computationally expensive task. Humans, however, usually solve such tasks quickly and efficiently. We present experiments studying human path planning performance and the cognitive processes and heuristics involved. Twenty-five places were arranged on a regular grid in a large room. Participants were repeatedly asked to solve traveling salesman problems (TSP), i.e., to find the shortest closed loop connecting a start location with multiple target locations. In Experiment 1, we tested whether humans employed the nearest neighbor (NN) strategy when solving the TSP. Results showed that subjects outperform the NN-strategy, suggesting that it is not sufficient to explain human route planning behavior. As a second possible strategy we tested a hierarchical planning heuristic in Experiment 2, demonstrating that participants first plan a coarse route on the region level that is refined during navigation. To test for the relevance of spatial working memory (SWM) and spatial long-term memory (LTM) for planning performance and the planning heuristics applied, we varied the memory demands between conditions in Experiment 2. In one condition the target locations were directly marked, such that no memory was required; a second condition required participants to memorize the target locations during path planning (SWM); in a third condition, additionally, the locations of targets had to retrieved from LTM (SWM and LTM). Results showed that navigation performance decreased with increasing memory demands while the dependence on the hierarchical planning heuristic increased.


Subject(s)
Memory , Problem Solving , Space Perception , Adult , Female , Humans , Male , Mental Processes , Motivation
16.
Obstet Gynecol ; 110(2 Pt 2): 485-6, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17666637

ABSTRACT

BACKGROUND: Cold hemagglutinin disease is an acquired autoimmune hemolytic anemia caused by an immunoglobulin M autoantibody directed against the polysaccharide antigens on the red blood cell surface. This case presents the challenges surrounding the management of cold hemagglutinin disease in pregnancy. CASE: A pregnant woman in her thirties with type-2 diabetes, reporting shortness of breath and productive cough, was found to have anemia, reticulocytosis, bilirubinemia, positive direct Coombs test result, positive cold agglutinin antibody, and raised lactate dehydrogenase levels. As the infection screen and autoimmune serology results were negative, she was diagnosed as having idiopathic cold hemagglutinin disease. The management included keeping the patient warm and hydrated and treating the anemia with warm packed red blood cell transfusion. CONCLUSION: Cold hemagglutinin disease is a rare condition. Investigations to rule out infections help determine the diagnosis of cold hemagglutinin disease of unknown origin.


Subject(s)
Anemia, Hemolytic, Autoimmune/therapy , Erythrocyte Transfusion/methods , Erythrocytes/immunology , Pregnancy Complications, Hematologic/therapy , Adult , Anemia, Hemolytic, Autoimmune/diagnosis , Autoantibodies/analysis , Autoantibodies/blood , Cold Temperature , Coombs Test , Cryoglobulins/analysis , Cryoglobulins/immunology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/therapy , Female , Humans , Immunoglobulin M/analysis , Immunoglobulin M/blood , Pregnancy , Pregnancy Complications, Hematologic/diagnosis , Pregnancy Outcome , Pregnancy in Diabetics/therapy
17.
Environ Sci Technol ; 40(20): 6261-8, 2006 Oct 15.
Article in English | MEDLINE | ID: mdl-17120551

ABSTRACT

Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercuryto interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination of lacustrine food webs. Geologic sources of mercury were small, based on analyses of underlying bedrock and C-horizon soils, and nearly all mercury in the 0- and A-horizon soils was derived from atmospheric deposition. Analyses of dated sediment cores from five lakes showed that most (63% +/- 13%) of the mercury accumulated in lake sediments during the 1900s was from anthropogenic sources. Contamination of food webs was assessed by analysis of whole, 1-year-old yellow perch (Perca flavescens), a regionally important prey fish. The concentrations of total mercury in yellow perch and of methylmercury in lake water varied substantially among lakes, reflecting the influence of ecosystem processes and variables that affect the microbial production and abundance of methylmercury. Models developed with the information-theoretic approach (Akaike Information Criteria) identified lake water pH, dissolved sulfate, and total organic carbon (an indicator of wetland influence) as factors influencing methylmercury concentrations in lake water and fish. We conclude that nearly all of the mercury in fish in this seemingly pristine


Subject(s)
Fishes/metabolism , Fresh Water/analysis , Mercury/analysis , Soil/analysis , Air Pollutants/analysis , Animals , Conservation of Natural Resources/methods , Ecosystem , Environmental Pollutants/analysis , Methylmercury Compounds/analysis , Minnesota , Models, Theoretical , Water Pollutants, Chemical/analysis
18.
J Obstet Gynaecol ; 25(7): 666-8, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16263540

ABSTRACT

The National Sentinel Audit found that one in five births in England and Wales was by caesarean section. The reasons for the increase in caesarean section rates are multi-factorial. Anecdotally, it is suggested that obstetric intervention rates and caesarean section rates vary among obstetricians without a difference in fetal and maternal outcomes. The aim of this prospective observational study of 817 deliveries was to assess the effect of experience on the caesarean section rates for different obstetricians. Obstetricians with greater than 3 years of 2nd on-call labour ward experience had a statistically significant lower caesarean rate than less experienced obstetricians 10.25% vs 25.49%, respectively (p < 0.05). Differences in instrument deliveries was also studied.


Subject(s)
Cesarean Section/statistics & numerical data , Clinical Competence , Internship and Residency , Medical Audit , Medical Staff, Hospital , Obstetrics/standards , Practice Patterns, Physicians'/statistics & numerical data , Adult , Cesarean Section/methods , Emergencies , Female , Hospitals, Maternity , Humans , Incidence , Internship and Residency/standards , Maternal Age , Medical Staff, Hospital/standards , Pregnancy , Pregnancy Outcome , Probability , Prospective Studies , Statistics, Nonparametric , United Kingdom
19.
J Obstet Gynaecol ; 25(5): 432-4, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16183574

ABSTRACT

A survey was carried out of 145 pregnant women in the third trimester in pregnancy to assess motivators to stop tobacco smoking and assess women's knowledge of fetal and maternal risk of smoking. In addition, the survey was to assess the acceptability of nicotine replacement products use in pregnancy. The findings of this survey show that pregnant women tend to know about the maternal risks of smoking but their knowledge is deficient about fetal risks. The knowledge of the association of cot death risk and tobacco smoking appears to be the greatest motivator to stop smoking. Overall, 74% wished to stop smoking in pregnancy and 68% would accept a nicotine replacement product.


Subject(s)
Health Knowledge, Attitudes, Practice , Maternal Exposure/adverse effects , Nicotine/therapeutic use , Nicotinic Agonists/therapeutic use , Smoking Cessation/methods , Smoking/adverse effects , Adolescent , Adult , Female , Health Surveys , Humans , Patient Acceptance of Health Care , Pregnancy , Pregnancy Trimester, Third , Prenatal Care
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