652 research outputs found

    Rich Nations, Poor Nations: How much can multiple equilibria explain?

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    The idea that income differences between rich and poor nations arise through multiple equilibria or 'poverty traps' is as intuitive as it is difficult to verify. In this paper, we explore the empirical relevance of such models. We calibrate a simple two sector model for 127 countries, and use the results to analyze the international prevalence of poverty traps and their consequences for productivity. We also examine the possible effects of multiplicity on the world distribution of income, and identify events in the data that may correspond to equilibrium switching.

    Rich nations, poor nations: how much can multiple equilibria explain?

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    This paper asks whether the income gap between rich and poor nations can be explained by multiple equilibria. We explore the quantitative implications of a simple two sector general equilibrium model that gives rise to multiplicity, and calibrate the model for a large number of countries. Under the assumptions of the model, around a quarter of the world’s economies are found to be in a low output equilibrium. The output gains associated with an equilibrium switch are sizeable, but well short of the vast income disparity observed in the data.poverty traps, multiple equilibria, TFP differences,calibration

    Galaxy And Mass Assembly: galaxy morphology in the green valley, prominent rings, and looser spiral arms

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    Galaxies broadly fall into two categories: star-forming (blue) galaxies and quiescent (red) galaxies. In between, one finds the less populated “green valley . Some of these galaxies are suspected to be in the process of ceasing their star-formation through a gradual exhaustion of gas supply or already dead and are experiencing a rejuvenation of star-formation through fuel injection. We use the Galaxy And Mass Assembly database and the Galaxy Zoo citizen science morphological estimates to compare the morphology of galaxies in the green valley against those in the red sequence and blue cloud. Our goal is to examine the structural differences within galaxies that fall in the green valley, and what brings them there. Previous results found disc features such as rings and lenses are more prominently represented in the green valley population. We revisit this with a similar sized data set of galaxies with morphology labels provided by the Galaxy Zoo for the GAMA fields based on new KiDS images. Our aim is to compare qualitatively the results from expert classification to that of citizen science. We observe that ring structures are indeed found more commonly in green valley galaxies compared to their red and blue counterparts. We suggest that ring structures are a consequence of disc galaxies in the green valley actively exhibiting characteristics of fading discs and evolving disc morphology of galaxies. We note that the progression from blue to red correlates with loosening spiral arm structure

    Identifying environmental and management factors that may be associated with the quality of life of kennelled dogs (Canis familiaris)

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    Abstract This paper describes the use of a validated quality of life assessment tool (described elsewhere) to identify environmental and management factors that may affect quality of life in dogs kennelled in rehoming centres. Dogs were allocated to one of four treatment groups, all of which had a positive (0.0 - 1.0) average quality of life score: long stay dogs with an enriched routine had a mean score of 0.477; long stay dogs with a standard routine had a mean score of 0.453; newly admitted dogs with an enriched routine had a mean score of 0.399; and newly admitted dogs with a standard routine had a mean score of 0.362. Only 2 of the dogs had a negative score (-1.0 - 0.0). Thirteen rehoming centre managers completed a questionnaire relating to the kennel environment and management practices of their rehoming centres. The environmental and management factorsâ�� associations with quality of life scores, collected from 202 dogs from the 13 rehoming centres using this scoring system, were analysed as fixed factors in a linear mixed-effect model, with rehoming centre fitted as a random factor, and a multiple linear regression model. There was a statistically significant association between quality of life scores and rehoming centre (H(12) = 54.153, p <0.001), however, the fitted linear mixed-effect model did not improve upon the null model and therefore cannot be used to explain the 29 variance in quality of life scores attributed to rehoming centre. The multiple linear regression model explained 42 of the variation in quality of life scores (F(10,131) = 9.318, p < 0.001): the provision of bunk beds increased quality of life scores by 0.3 (t = 3.476, p < 0.001); provision of 30 minutes or more of staff or volunteer interaction increased scores by 0.26 (t = -2.551, p = 0.012); grooming dogs decreased scores by 0.404 (t = 3.326, p = 0.001); exercising dogs more than once a day decreased scores by 0.173 (t = -3.644, p = <0.001), whereas exercising dogs for 30 minutes or more increased quality of life scores by 0.213 (t = -2.374, p = 0.019) and the provision of less common types of exercise increased scores by 0.504 (t = 5.120, p < 0.001); training dogs for 30 minutes or more every day increased scores by 0.688 (t = 3.040, p = 0.003) and training dogs less than daily decreased scores by 0.393 (t = -4.245, p < 0.001); feeding a diet of dry and wet food compared to dry food alone decreased scores by 0.08 (t = -2.331, p = 0.021); and a quiet environment increased scores by 0.275 (t = -3.459, p < 0.001). These results suggest that environmental design and kennel management have an impact on the quality of life of kennelled dogs and should be considered carefully in decision-making processes. However, further study may be required as grooming and exercising dogs more than once per day decreased quality of life scores, which are not obviously intuitive results

    Demonstration of all-or-none loss of imprinting in mRNA expression in single cells

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    Loss of imprinting (LOI) is the reactivation of the silenced allele of an imprinted gene, leading to perturbation of monoallelic expression. We tested the hypothesis that LOI of PLAGL1, a representative maternally imprinted gene, occurs through an all-or-none process leading to a mixture of fully imprinted and nonimprinted cells. Herein using a quantitative RT-PCR-based experimental approach, we measured LOI at the single cell level in human trophoblasts and demonstrated a broad distribution of LOI among cells exhibiting LOI, with the mean centered at ∼100% LOI. There was a significant (P < 0.01) increase in expression after 2 days of 5-aza-2′-deoxycytidine (AZA) treatment and a significant (P < 0.01) increase in LOI after both 1 and 2 days of AZA treatment, while the distribution remained broad and centered at ∼100% LOI. We propose a transcriptional pulsing model to show that the broadness of the distribution reflects the stochastic nature of expression between the two alleles in each cell. The mean of the distribution of LOI in the cells is consistent with our hypothesis that LOI occurs by an all-or-none process. All-or-none LOI could lead to a second distinct cell population that may have a selective advantage, leading to variation of LOI in normal tissues, such as the placenta, or in neoplastic cells

    The effects of partial sleep restriction and altered sleep timing on appetite and food reward.

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    We examined the effects of partial sleep restriction (PSR) with an advanced wake-time or delayed bedtime on measures of appetite, food reward and subsequent energy intake (EI). Twelve men and 6 women (age: 23 ± 4 years, body fat: 18.8 ± 10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-time), 50% PSR with an advanced wake-time and 50% PSR with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), ad libitum EI (validated food menu), appetite sensations (visual analogue scales), the satiety quotient (SQ; mm/100 kcal) and food reward (Leeds Food Preference Questionnaire and the relative-reinforcing value (RRV) of preferred food task). Increased fasting and post-standard breakfast appetite ratings were noted following PSR with an advanced wake-time compared to the control and PSR with a delayed bedtime sessions (Fasting hunger ratings: 77 ± 16 vs. 65 ± 18 and 64 ± 16; P = 0.01; Post-meal hunger AUC: 5982 ± 1781 vs. 4508 ± 2136 and 5198 ± 2201; P = 0.03). Increased explicit wanting and liking for high-relative to low-fat foods were also noted during the advanced wake-time vs. control session (Explicit wanting: -3.5 ± 12.5 vs. -9.3 ± 8.9, P = 0.01; Explicit liking: -1.6 ± 8.5 vs. -7.8 ± 9.6, P = 0.002). No differences in the RRV of preferred food, the SQ and ad libitum lunch intake were noted between sessions. These findings suggest that appetite sensations and food reward are increased following PSR with an advanced wake-time, rather than delayed bedtime, vs. CONTROL: However, this did not translate into increased EI during a test meal. Given the increasing prevalence of shift workers and incidences of sleep disorders, additional studies are needed to evaluate the prolonged effects of voluntary sleep restriction with altered sleep timing on appetite and EI measurements

    Auditory dysfunction in type 2 Stickler Syndrome.

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    PURPOSE: To present the extent and site of lesion of auditory dysfunction in a large cohort of individuals with type 2 Stickler Syndrome. Type 2 Stickler Syndrome results from a mutation in the gene coding for α-1 type XI pro-collagen, which has been identified in the human vitreous, cartilage and the cochlea of the mouse. The condition is characterised by classic ocular abnormalities, auditory dysfunction, osteoarthropathy and oro-facial dysplasia. METHODS: This is a population study which used a combination of audiometric, tympanometric, and self-report measures on a series of 65 individuals (mean age 29.2 years, range 3-70, female 63.1%) with genetically confirmed type 2 Stickler Syndrome. RESULTS: Hearing impairment was identified in at least one ear for 69% of individuals. Analysis against age-matched normative data showed that reduced hearing sensitivity was present across all test frequencies. Sensorineural hearing loss was most common (77% of ears), with conductive (3%), mixed (7%) and no hearing loss (13%), respectively. The proportion of hypermobile tympanic membranes (24%) was less than previously documented in type 1 Stickler Syndrome. When present, this appears to arise as a direct result of collagen abnormalities in the middle ear. Self-report measures of speech and spatial hearing in sound were comparable to a non-syndromic cohort with similar audiometric thresholds. CONCLUSIONS: Auditory impairment in type 2 Stickler Syndrome is predominantly associated with cochlear hearing loss of varying severities across affected individuals. The impact on hearing thresholds can be seen across the frequency range, suggesting a contribution of defective collagen throughout the cochlea. Self-report questionnaires showed that difficulties understanding speech, and spatial information in sound (such as that used for localisation), were worse than a young, normal-hearing population but comparable to a non-syndromic cohort with similar audiometric thresholds. Therefore, it is likely that hearing loss in type 2 Stickler Syndrome arises in the auditory periphery, without significant central processing deficits

    Complexity in decision making: Determining university library opening hours

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    Making decisions on academic library opening hours is complex with many pressures on managers. This research surveys senior academic library managers from the UK, using a questionnaire to reveal views on library opening hours, the decision making process, and the pressures which influenced their decisions. A variety of factors were found, in particular satisfying undergraduate demands. The research also revealed the sources of information important in making decisions on opening hours and the influence of ‘political’ issues in the decision making process. Some institutions remove complexity by utilising 24/7 opening, though this is not an option for many

    Closed-Loop Insulin Delivery during Pregnancy in Women with Type 1 Diabetes.

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    BACKGROUND: In patients with type 1 diabetes who are not pregnant, closed-loop (automated) insulin delivery can provide better glycemic control than sensor-augmented pump therapy, but data are lacking on the efficacy, safety, and feasibility of closed-loop therapy during pregnancy. METHODS: We performed an open-label, randomized, crossover study comparing overnight closed-loop therapy with sensor-augmented pump therapy, followed by a continuation phase in which the closed-loop system was used day and night. Sixteen pregnant women with type 1 diabetes completed 4 weeks of closed-loop pump therapy (intervention) and sensor-augmented pump therapy (control) in random order. During the continuation phase, 14 of the participants used the closed-loop system day and night until delivery. The primary outcome was the percentage of time that overnight glucose levels were within the target range (63 to 140 mg per deciliter [3.5 to 7.8 mmol per liter]). RESULTS: The percentage of time that overnight glucose levels were in the target range was higher during closed-loop therapy than during control therapy (74.7% vs. 59.5%; absolute difference, 15.2 percentage points; 95% confidence interval, 6.1 to 24.2; P=0.002). The overnight mean glucose level was lower during closed-loop therapy than during control therapy (119 vs. 133 mg per deciliter [6.6 vs. 7.4 mmol per liter], P=0.009). There were no significant differences between closed-loop and control therapy in the percentage of time in which glucose levels were below the target range (1.3% and 1.9%, respectively; P=0.28), in insulin doses, or in adverse-event rates. During the continuation phase (up to 14.6 additional weeks, including antenatal hospitalizations, labor, and delivery), glucose levels were in the target range 68.7% of the time; the mean glucose level was 126 mg per deciliter (7.0 mmol per liter). No episodes of severe hypoglycemia requiring third-party assistance occurred during either phase. CONCLUSIONS: Overnight closed-loop therapy resulted in better glucose control than sensor-augmented pump therapy in pregnant women with type 1 diabetes. Women receiving day-and-night closed-loop therapy maintained glycemic control during a high proportion of the time in a period that encompassed antenatal hospital admission, labor, and delivery. (Funded by the National Institute for Health Research and others; Current Controlled Trials number, ISRCTN71510001.)

    Diabetes and pregnancy:national trends over a 15 year period

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    Aims/hypothesis: We aimed to examine time trends in national perinatal outcomes in pregnancies complicated by pre-existing type 1 or type 2 diabetes. Methods: We analysed episode-level data on all obstetric inpatient delivery events (live or stillbirth) between 1 April 1998 and 31 March 2013 (n = 813,921) using the Scottish Morbidity Record (SMR02). Pregnancies to mothers with type 1 (n = 3229) and type 2 (n = 1452) diabetes were identified from the national diabetes database (Scottish Care Information-Diabetes), and perinatal outcomes were compared among women with type 1 diabetes, type 2 diabetes and those without diabetes. Results: The number of pregnancies complicated by diabetes increased significantly, by 44% in type 1 diabetes and 90% in type 2 diabetes, across the 15 years examined, to rates of 1 in 210 and 1 in 504 deliveries, respectively. Compared with women without diabetes, delivery occurred 2.6 weeks earlier (type 1 diabetes 36.7 ± 2.3 weeks) and 2 weeks earlier (type 2 diabetes 37.3 ± 2.4 weeks), respectively, showing significant reductions for both type 1 (from 36.7 weeks to 36.4 weeks, p = 0.03) and type 2 (from 38.0 weeks to 37.2 weeks, p &lt; 0.001) diabetes across the time period. The proportions of preterm delivery were markedly increased in women with diabetes (35.3% type 1 diabetes, 21.8% type 2 diabetes, 6.1% without diabetes; p &lt; 0.0001), and these proportions increased with time for both groups (p &lt; 0.005). Proportions of elective Caesarean sections (29.4% type 1 diabetes, 30.5% type 2 diabetes, 9.6% without diabetes) and emergency Caesarean sections (38.3% type 1 diabetes, 29.1% type 2 diabetes, 14.6% without diabetes) were greatly increased in women with diabetes and increased over time except for stable rates of emergency Caesarean section in type 1 diabetes. Gestational age-, sex- and parity-adjusted z score for birthweight (1.33 ± 1.34; p &lt; 0.001) were higher in type 1 diabetes and increased over time from 1.22 to 1.47 (p &lt; 0.001). Birthweight was also increased in type 2 diabetes (0.94 ± 1.34; p &lt; 0.001) but did not alter with time. There were 65 perinatal deaths in offspring of mothers with type 1 diabetes and 39 to mothers with type 2 diabetes, representing perinatal mortality rates of 20.1 (95% CI 14.7, 24.3) and 26.9 (16.7, 32.9) per 1000 births, respectively, and rates 3.1 and 4.2 times, respectively, those observed in the non-diabetic population (p &lt; 0.001). Stillbirth rates in type 1 and type 2 diabetes were 4.0-fold and 5.1-fold that in the non-diabetic population (p &lt; 0.001). Perinatal mortality and stillbirth rates showed no significant fall over time despite small falls in the rates for the non-diabetic population. Conclusions/interpretation: Women with diabetes are receiving increased intervention in pregnancy (earlier delivery, increased Caesarean section rates), but despite this, higher birthweights are being recorded. Improvements in rates of stillbirth seen in the general population are not being reflected in changes in stillbirth or perinatal mortality in our population with diabetes
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