1,939 research outputs found
The Light Growth Response of Phycomyces
With the help of an automated tracking system we have studied the characteristics of the transient light growth response of Phycomyces. The response shows a sharply defined latency. The Q10 of the reciprocal latency is 2.4. Response patterns at different peaks of the action spectrum are the same. The gradual variation of response magnitude over a wide range of adapted intensifies parallels that of phototropism. The responses to saturating stimuli exhibit a strong oscillation with a constant period of 1.6 min and variable damping. The growth responses to sinusoidally varying light intensities show a system bandwidth of 2.5 x 10-3 Hz. The linear dependence of phase shift on frequency is largely attributable to the latency observed with pulse stimuli. In the high intensity range a previously suspected increase of the steady-state growth rate with intensity has been confirmed. The light growth responses of mutants selected for diminished phototropism have been investigated. Many of these mutants have sizable but grossly distorted growth responses
Understanding suicide risk and eating disorders in college student populations: Results from a National Study
ObjectiveTo examine suicide risk by eating disorder severity and symptom presentation in a nationwide sample of college students.MethodThe Healthy Minds Study is the largest mental health survey of college populations in the United States. We analyzed the most recent available data (2015â2017) with 71,712 randomly selected students from 77 campuses. We estimated associations between two measures of suicidality (ideation and attempts) and three validated measures of eating disorder symptoms (the SCOFF, weight concerns scale, and the eating disorder examination questionnaire binge and purge items). Importantly, we also controlled for coâoccurring symptoms of depression and anxiety, based on validated screening tools. The large, diverse sample provided a unique opportunity to assess whether certain individual characteristics were associated with increased risk.ResultsEating disorder symptoms, even at subthreshold levels, were highly predictive of suicidality. Relative to students with no apparent eating disorder symptoms, students with the highest symptom levels (a SCOFF score of 5) had 11 times higher odds of attempting suicide, while those with subthreshold symptoms had two times higher odds. We also observed a strong association between suicide attempts and eating disorder presentations that included purging. Students from marginalized backgrounds, particularly gender and sexual minorities, were at increased risk for suicide and eating disorders.DiscussionIn the largest known study to date, findings suggest that eating disorders should be a priority within broader campus suicide prevention efforts, should be assessed along a continuum of severity and symptom presentation, and should focus on reaching vulnerable students.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154242/1/eat23188_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154242/2/eat23188.pd
Temporality, vulnerability, and energy justice in household low carbon innovations
Decarbonisation and innovation will change the affordability of different domestic energy services. This has the potential to alleviate vulnerability to fuel poverty, but it could create new injustices unless the risks are preempted and actively mitigated. In this paper, we ask: In what ways can emerging low-carbon innovations at the household scale complement, and complicate, achieving energy justice objectives? Drawing from four empirical case studies in the United Kingdom, the paper highlights different risks that come from different types of innovation required to tackle different decarbonisation challenges. More specifically, it assesses four particular household innovationsâenergy service contracts, electric vehicles, solar photovoltaic (PV) panels, and low carbon heatingâselected for their fit with a typology of incremental vs. radical technology and modest vs. substantial changes in user practices. It shows how in each case, such innovations come with a collection of opportunities but also threats. In doing so, the paper seeks to unveil the âpolitical economyâ of low-carbon innovations, identifying particular tensions alongside who wins and who loses, as well as the scope and temporality of those consequences
Ancient west Eurasian ancestry in southern and eastern Africa
The history of southern Africa involved interactions between indigenous
hunter-gatherers and a range of populations that moved into the region. Here we
use genome-wide genetic data to show that there are at least two admixture
events in the history of Khoisan populations (southern African hunter-gatherers
and pastoralists who speak non-Bantu languages with click consonants). One
involved populations related to Niger-Congo-speaking African populations, and
the other introduced ancestry most closely related to west Eurasian (European
or Middle Eastern) populations. We date this latter admixture event to
approximately 900-1,800 years ago, and show that it had the largest demographic
impact in Khoisan populations that speak Khoe-Kwadi languages. A similar signal
of west Eurasian ancestry is present throughout eastern Africa. In particular,
we also find evidence for two admixture events in the history of Kenyan,
Tanzanian, and Ethiopian populations, the earlier of which involved populations
related to west Eurasians and which we date to approximately 2,700 - 3,300
years ago. We reconstruct the allele frequencies of the putative west Eurasian
population in eastern Africa, and show that this population is a good proxy for
the west Eurasian ancestry in southern Africa. The most parsimonious
explanation for these findings is that west Eurasian ancestry entered southern
Africa indirectly through eastern Africa.Comment: Added additional simulations, some additional discussio
Collaborative Inquiry: Expanding the Boundaries of Knowledge Construction in Graduate Adult Education Research
The purpose of this roundtable session is to share ideas about collaborative inquiry as a research methodology. Facilitators include a faculty member from a doctoral program that encourages collaborative learning and collaborative inquiry, and two students, from the same doctoral program, who completed a fully collaborative doctoral research project
Observation of Macroscopic Structural Fluctuations in bcc Solid 4He
We report neutron diffraction studies of low density bcc and hcp solid 4He.
In the bcc phase, we observed a continuous dynamical behaviour involving
macroscopic structural changes of the solid. The dynamical behaviour takes
place in a cell full of solid, and therefore represents a solidsolid
transformation. The structural changes are consistent with a gradual rotation
of macroscopic grains separated by low angle grain boundaries. We suggest that
these changes are triggered by random momentary vibrations of the experimental
system. An analysis of Laue diffraction patterns indicates that in some cases
these structural changes, once initiated by a momentary impulse, seem to
proceed at a constant rate over times approaching an hour. The energy
associated with these macroscopic changes appears to be on the order of kT.
Under similar conditions (temperature and pressure), these effects were absent
in the hcp phase.Comment: 14 pages, 6 figure, accepted for PR
Translating Research Into Practice: Speeding the Adoption of Innovative Health Care Programs
Looks at case studies of four innovative clinical programs to determine key factors influencing the diffusion and adoption of innovations in health care
Increased emergency department use by adolescents and young adults with eating disorders
Objective: This study describes patterns of emergency department (ED) utilization by patients who screen positive for eating disorders. Method: ED patients aged 14â20 years ( n = 1,920) completed a computerized questionnaire. The analyses compared the rates of ED use between patients who screened positive for an eating disorder and those who did not and examined the reasons for ED use amongst patients with eating disorders. Results: ED patients who screened positive for eating disorders were significantly more likely to have previously visited the ED and, on average, utilized the ED at a rate 1.6 times higher than patients who screen negative for eating disorders. The most common chief complaints among patients who screen positive for eating disorders were abdominal pain and other gastrointestinalârelated problems. Discussion: Patients with eating disorders utilize the ED more frequently than those without and commonly present for complaints seemingly unrelated to their eating disorder. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2013)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97531/1/22070_ftp.pd
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