175 research outputs found
Research Notes: Determinate-Dt2 Effects on Soybean Characteristics.
Bernard (1972) studied a gene, Dt2, which hastened the termination of apical stem growth and decreased both plant height and number of nodes per plant. In a \u27Harosoy\u27 background, a Dt2 isoline had a 15% reduction in height and was three days earlier maturing but was similar in yield to Harosoy . There was some reduction in weight per seed associated with the Dt2 effect
Research Notes: Soybean Gene Resources Recently Received from China
Forty soybean cultivars were received from the Peoples Republic of China in a number of exchanges between June 1973 and June 1974. The first eight cultivars that we received were grown in row tests at Harrow, Woodslee and Ridgetown in 1975, along with \u27Harlen,\u27 \u27Harosoy 63,\u27 and \u27Harcar.\u27 These eight, plus the next seven that we received, had been tested in hill plots at Harrow in 1974, along with Hardome, Harlen, Harosoy 63, and \u27Harwood.\u27 The highest and lowest cultivar values are given for each of a number of characteristics within each group of cultivars as an indication of the potential value of the new germplasm
Visual impairment, eye diseases and dementia risk: A systematic review and meta-analysis
This is the author accepted manuscript. The final version is available from IOS Press via the DOI in this recordBackground: Visual impairment and eye diseases have been associated with dementia,
though with mixed findings and often in cross-sectional studies.
Objective: To identify prospective studies investigating associations between visual
impairment or common eye diseases and risk of all-cause dementia or key dementia subtypes.
Methods: We searched Medline, PsycINFO, and Embase from inception to January 2020. We
also conducted backward and forward citation searches of included studies and set up alerts to
identify studies published after the search date. Random-effects meta-analysis was used to
combine adjusted estimates across studies.
Results: Thirty studies met our eligibility criteria. For visual impairment, pooled estimates
indicated an increased risk of all-cause dementia (37,705 participants, 3,415 cases, risk ratio
[RR] = 1.38, 95% confidence interval [CI]: 1.19-1.59, I2 = 28.6%). Pooled estimates also
suggested an increased dementia risk associated with cataract (6,659 participants, 1,312 cases,
hazard ratio [HR] = 1.17, 95% CI 1.00-1.38, I2= 0.0%) and diabetic retinopathy (43,658
participants, 7,060 cases, HR= 1.34, 95% CI 1.11-1.61, I2= 63.9%), respectively. There was
no evidence of an association between glaucoma (175,357 participants, 44,144 cases, HR=
0.97, 95% CI 0.90-1.04, I2= 51.5%) or age-related macular degeneration (7,800,692
participants, >2,559 cases, HR= 1.15, 95% CI 0.88-1.50, I2= 91.0%) and risk of dementia,
respectively.
Conclusion: As visual impairment, cataract and diabetic retinopathy are associated with an
increased likelihood of developing dementia, early diagnosis may help identify those at risk of
dementia. Given most causes of visual impairment are treatable or preventable, the potential
for dementia prevention warrants further investigation.Nicolaus and Margrit Langbehn FoundationMoorfields Eye CharityUKRIAlzheimerâs Research UKNational Health and Medical Research Council (NHMRC)JP Moulton FoundationNational Institute on AgingNational Institutes of Health (NIH)Alan Turing InstituteEngineering and Physical Sciences Research Council (EPSRC)Federal Ministry of Education and Research (BMBF)Federal Joint Committee (G-BA) Innovation Fun
\u27Vitamin D and cognition in older adults\u27: updated international recommendations.
BACKGROUND: Hypovitaminosis D, a condition that is highly prevalent in older adults aged 65 years and above, is associated with brain changes and dementia. Given the rapidly accumulating and complex contribution of the literature in the field of vitamin D and cognition, clear guidance is needed for researchers and clinicians.
METHODS: International experts met at an invitational summit on \u27Vitamin D and Cognition in Older Adults\u27. Based on previous reports and expert opinion, the task force focused on key questions relating to the role of vitamin D in Alzheimer\u27s disease and related disorders. Each question was discussed and voted using a Delphi-like approach.
RESULTS: The experts reached an agreement that hypovitaminosis D increases the risk of cognitive decline and dementia in older adults and may alter the clinical presentation as a consequence of related comorbidities; however, at present, vitamin D level should not be used as a diagnostic or prognostic biomarker of Alzheimer\u27s disease due to lack of specificity and insufficient evidence. This population should be screened for hypovitaminosis D because of its high prevalence and should receive supplementation, if necessary; but this advice was not specific to cognition. During the debate, the possibility of \u27critical periods\u27 during which vitamin D may have its greatest impact on the brain was addressed; whether hypovitaminosis D influences cognition actively through deleterious effects and/or passively by loss of neuroprotection was also considered.
CONCLUSIONS: The international task force agreed on five overarching principles related to vitamin D and cognition in older adults. Several areas of uncertainty remain, and it will be necessary to revise the proposed recommendations as new findings become available
The central engine of GRB 130831A and the energy breakdown of a relativistic explosion
Gamma-ray bursts (GRBs) are the most luminous explosions in the universe, yet
the nature and physical properties of their energy sources are far from
understood. Very important clues, however, can be inferred by studying the
afterglows of these events. We present optical and X-ray observations of GRB
130831A obtained by Swift, Chandra, Skynet, RATIR, Maidanak, ISON, NOT, LT and
GTC. This burst shows a steep drop in the X-ray light-curve at s
after the trigger, with a power-law decay index of . Such a rare
behaviour cannot be explained by the standard forward shock (FS) model and
indicates that the emission, up to the fast decay at s, must be of
"internal origin", produced by a dissipation process within an
ultrarelativistic outflow. We propose that the source of such an outflow, which
must produce the X-ray flux for day in the cosmological rest frame,
is a newly born magnetar or black hole. After the drop, the faint X-ray
afterglow continues with a much shallower decay. The optical emission, on the
other hand, shows no break across the X-ray steep decrease, and the late-time
decays of both the X-ray and optical are consistent. Using both the X-ray and
optical data, we show that the emission after s can be explained
well by the FS model. We model our data to derive the kinetic energy of the
ejecta and thus measure the efficiency of the central engine of a GRB with
emission of internal origin visible for a long time. Furthermore, we break down
the energy budget of this GRB into the prompt emission, the late internal
dissipation, the kinetic energy of the relativistic ejecta, and compare it with
the energy of the associated supernova, SN 2013fu.Comment: Accepted for publication by MNRAS. 21 pages, 3 figures, 8 tables.
Extra table with magnitudes in the sourc
Public participation in decision-making on the coverage of new antivirals for hepatitis C.
Purpose - New hepatitis C medicines such as sofosbuvir underline the need to balance considerations of innovation, clinical evidence, budget impact and equity in health priority-setting. The purpose of this paper is to examine the role of public participation in addressing these considerations. Design/methodology/approach - The paper employs a comparative case study approach. It explores the experience of four countries - Brazil, England, South Korea and the USA - in making coverage decisions about the antiviral sofosbuvir and involving the public and patients in these decision-making processes. Findings - Issues emerging from public participation ac tivities include the role of the universal right to health in Brazil, the balance between innovation and budget impact in England, the effect of unethical medical practices on public perception in South Korea and the legitimacy of priority-setting processes in the USA. Providing policymakers are receptive to these issues, public participation activities may be re-conceptualized as processes that illuminate policy problems relevant to a particular context, thereby promoting an agenda-setting role for the public. Originality/value - The paper offers an empirical analysis of public involvement in the case of sofosbuvir, where the relevant considerations that bear on priority-setting decisions have been particularly stark. The perspectives that emerge suggest that public participation contributes to raising attention to issues that need to be addressed by policymakers. Public participation activities can thus contribute to setting policy agendas, even if that is not their explicit purpose. However, the actualization of this contribution is contingent on the receptiveness of policymakers.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Emerald
The origin of the early time optical emission of Swift GRB 080310
We present broadband multi-wavelength observations of GRB 080310 at redshift
z = 2.43. This burst was bright and long-lived, and unusual in having extensive
optical and near IR follow-up during the prompt phase. Using these data we
attempt to simultaneously model the gamma-ray, X-ray, optical and IR emission
using a series of prompt pulses and an afterglow component. Initial attempts to
extrapolate the high energy model directly to lower energies for each pulse
reveal that a spectral break is required between the optical regime and 0.3 keV
to avoid over predicting the optical flux. We demonstrate that afterglow
emission alone is insufficient to describe all morphology seen in the optical
and IR data. Allowing the prompt component to dominate the early-time optical
and IR and permitting each pulse to have an independent low energy spectral
indices we produce an alternative scenario which better describes the optical
light curve. This, however, does not describe the spectral shape of GRB 080310
at early times. The fit statistics for the prompt and afterglow dominated
models are nearly identical making it difficult to favour either. However one
enduring result is that both models require a low energy spectral index
consistent with self absorption for at least some of the pulses identified in
the high energy emission model.Comment: 24 pages, 12 figures, 12 tables. Accepted to MNRA
Patterns of public participation: opportunity structures and mobilization from a cross-national perspective
Purpose: The paper summarizes data from twelve countries, chosen to exhibit wide variation, on the role and place of public participation in the setting of priorities. It seeks to exhibit cross-national patterns in respect of public participation, linking those differences to institutional features of the countries concerned. Design/methodology/approach: The approach is an example of case-orientated qualitative assessment of participation practices. It derives its data from the presentation of country case studies by experts on each system. The country cases are located within the historical development of democracy in each country. Findings: Patterns of participation are widely variable. Participation that is effective through routinized institutional processes appears to be inversely related to contestatory participation that uses political mobilization to challenge the legitimacy of the priority setting process. No system has resolved the conceptual ambiguities that are implicit in the idea of public participation. Originality/value: The paper draws on a unique collection of country case studies in participatory practice in prioritization, supplementing existing published sources. In showing that contestatory participation plays an important role in a sub-set of these countries it makes an important contribution to the field because it broadens the debate about public participation in priority setting beyond the use of minipublics and the observation of public representatives on decision-making bodies
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