229 research outputs found
Vicky Anticipates a Social Season
With the promise of the gayest social season in five years, Vicky is eagerly anticipating her holiday wardrobe. She\u27s finding new voluminous air about clothes this year, achieved with rounded shoulders, nipped-in waists and gathered skirts
Performance Characteristics of Airlift Pumps with Vortex Induced by Tangential Fluid Injection
The effect of the swirl component of air injection on the performance of an airlift pump was examined experimentally. An airlift pump is a device that pumps a liquid or slurry using only gas injection. In this study, the liquid used was water and the injected gas was air. The effect of the air swirl was determined by measuring the water discharge from an airlift pump with an air injection nozzle in which the air flow had both axial and tangential components and then repeating the tests with a nozzle with only axial injection. The induced water flow was measured using an orifice meter in the supply pipeline. Tests were run for air pressures ranging from 10 to 30 pounds per square inch, gauge (psig), at flow rates from 5 standard cubic feet per minute (scfm) up the maximum values attainable at the given pressure (usually in the range from 20 to 35 scfm). The nozzle with only axial injection produced a water flow rate that wasequivalent to or better than that induced by the nozzle with swirl. The swirl component of air injection was found to be detrimental to pump performance for all but the smallest air injection flow rate. Optimum efficiency was found for air injection pressures of 10 psig to 15 psig. In addition, the effect of using auxiliary tangential injection of water to create a swirl component in the riser before air injection on the overall capacity (i.e., flow rate) and efficiencyof the pump was examined. Auxiliary tangential water injection was found to have no beneficial effect on the pump capacity or performance in the present system
Grad Tests for Your Taste
Operation Pillsbury -this is the name Rosalie Riglin, home economics journalism graduate \u2746, gives her job as Pillsbury Mills\u27 Paris representative. Miss Riglin is working on Pillsbury\u27s European Recipe Service where she collects and tests European recipes which later appear in the Pillsbury advertisements for the benefit of American homemakers. The following is her personal letter about her work
POW\u27s Eat Foods of Their Dreams
Iowa State returned prisoners of war eat self-selected diets according to Rosalie Rigli
Exploring the relationship between depressive symptoms and attainment at school
Rates of depressive symptoms and disorder increase during adolescence and these are associated with a range of negative outcomes both in adolescence and adulthood. One possible pathway to poor outcomes is via low attainment at school. However the association between depressive symptoms and attainment is poorly understood. This thesis explored this association. First, a meta-analysis was conducted on associations between depressive symptoms and subsequent attainment (chapter 2). This found small but significant associations, as well as significant heterogeneity of effect sizes between studies. Second, the temporal direction of this association was investigated using a cross-lagged design (chapter 4). This found depressive symptoms to be associated with a decline in attainment over time. Third, possible mediators of this association were investigated in a 3-stage study design (chapter 5). Low school connectedness, concentration problems, and stressful life events were found to mediate associations between depressive symptoms at baseline and low attainment at follow-up. These studies identified gender, co-occurring conduct problems, and cognitive ability as sources of heterogeneity in the association between depressive symptoms and subsequent low attainment. These sources of heterogeneity were then further investigated. First, latent profile analysis was used to investigate depressive subgroups based on co-occurring conduct problems and symptom severity. Subgroups were identified and there was some evidence of differing associations with attainment and in aetiology. Second, higher cognitive ability was found to buffer the effects of stress on depressive symptoms and disorder in girls (chapter 7) as well as the effects of stress on attainment (chapter 5). Taken together, these findings advance understanding of the association between depressive symptoms and attainment at school. They also suggest specific groups with depressive symptoms that may merit special consideration (e.g. pupils with conduct problems or low cognitive ability) and pathways of importance (e.g. school connectedness)
The importance of a developmental perspective in Psychiatry: what do recent genetic epidemiological findings show?
There is growing appreciation that a developmental perspective is helpful in Psychiatry. However, clinical practice and research, especially in an era of very large sample sizes, often ignore the developmental context. In this perspective piece, we discuss why a developmental view is important in Psychiatry and how recent genetic-epidemiological findings further highlight this. DSM-5 childhood neurodevelopmental disorders such as ADHD, typically onset in early childhood but can persist into adult life; the same ADHD genetic loading appears to contribute across the life course. However, recent longitudinal studies have observed that ADHD symptoms may emerge later during adolescence and adult life in some individuals although the etiology of this late-onset group is unclear. The epidemiology and genetics of depression do not appear to be the same in childhood, adolescence, and adult life. Recent genetic findings further highlight this. Autistic type problems and irritability also appear to show developmental variation in their genetic etiology. These findings raise the question of whether social communication and irritability have the same meaning at different ages. Schizophrenia typically onsets after adolescence. However, it is commonly preceded by childhood antecedents that do not resemble schizophrenia itself but do appear to index schizophrenia genetic liability. We conclude that there is a need for clinicians and scientists to adopt a developmental perspective in clinical practice and research by considering age-at-onset and changes over time as well as different developmental periods when interpreting clinical symptoms
Mendelian randomisation studies of Attention Deficit Hyperactivity Disorder
Background
Observational studies have found Attention Deficit Hyperactivity Disorder (ADHD) to be associated with an increased risk of adverse outcomes as well as with early risk factors; however it is not clear whether these associations reflect causal effects. Alternatives to traditional observational studies are needed to investigate causality: one such design is Mendelian randomization (MR), which uses genetic variants as instrumental variables for the exposure.
Methods
In this review we summarise findings from approximately 50 studies using MR to examine potentially causal associations with ADHD as either an exposure or outcome.
Results
To-date, few MR ADHD studies have investigated causal evidence with other neurodevelopmental, mental health and neurodegenerative conditions but those that have suggest a complex relationship with autism, some evidence of a causal effect on depression and limited evidence of a causal effect on neurodegenerative conditions. For substance use, MR studies provide evidence consistent with a causal effect of ADHD on smoking initiation, but findings for other smoking behaviours and cannabis use are less consistent. Studies of physical health suggest bidirectional causal effects with higher body mass index, with stronger effects for childhood obesity, as well as some evidence of causal effects on coronary artery disease and stroke in adults and limited evidence of causal effects on other physical health problems or sleep. Studies suggest bidirectional relationships between ADHD and socio-economic markers and provide some evidence that low birthweight may be a causal risk factor for ADHD, while bidirectional evidence has been found for some environmental factors. Finally, there is emerging evidence of bidirectional causal links between ADHD genetic liability and biological markers of human metabolism and inflammation.
Conclusions
While MR has advantages over traditional observational designs in addressing causality, we discuss limitations of current ADHD studies and future directions, including the need for larger genome-wide association studies (and using samples of different ancestries), and for triangulation with different methods
The impact of schizophrenia and mood disorder risk alleles on emotional problems: investigating change from childhood to middle age
Previous studies find that both schizophrenia and mood disorder risk alleles contribute to adult depression and anxiety. Emotional problems (depression or anxiety) begin in childhood and show strong continuities into adult life; this suggests that symptoms are the manifestation of the same underlying liability across different ages. However, other findings suggest that there are developmental differences in the etiology of emotional problems at different ages. To our knowledge, no study has prospectively examined the impact of psychiatric risk alleles on emotional problems at different ages in the same individuals. Data were analyzed using regression-based analyses in a prospective, population-based UK cohort (the National Child Development Study). Schizophrenia and major depressive disorder (MDD) polygenic risk scores (PRS) were derived from published Psychiatric Genomics Consortium genome-wide association studies. Emotional problems were assessed prospectively at six time points from age 7 to 42 years. Schizophrenia PRS were associated with emotional problems from childhood [age 7, OR 1.09 (1.03–1.15), p = 0.003] to mid-life [age 42, OR 1.10 (1.05–1.17), p < 0.001], while MDD PRS were associated with emotional problems only in adulthood [age 42, OR 1.06 (1.00–1.11), p = 0.034; age 7, OR 1.03 (0.98–1.09), p = 0.228]. Our prospective investigation suggests that early (childhood) emotional problems in the general population share genetic risk with schizophrenia, while later (adult) emotional problems also share genetic risk with MDD. The results suggest that the genetic architecture of depression/anxiety is not static across development
Assessment of age-at-onset criterion for adult attention-deficit hyperactivity disorder
To investigate the accuracy of the age-at-onset criterion in those who meet other DSM-5 ADHD criteria (N=138), using a prospective population cohort, we compared four different approaches to asking those at age 25 years when their symptoms started. Receiver Operating Characteristic curves showed variation between the approaches (χ((3)))=8.99, p=0.03); all four showed low discrimination against symptoms that had been assessed when they were children (area under the curve 0.57-0.68). Asking adults to recall specific symptoms may be preferable to recalling at what age symptoms started. However limitations to retrospective recall add to debate on the validity of ADHD age-at-onset assessment
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