1,508 research outputs found
B627: The Relation of Tree and Stand Characteristics to Basal Area Growth of Red Spruce Trees in Partially Cut Stands in Eastern Maine
This bulletin reports on a study that evaluated the relationship of red spruce tree growth to various tree and stand conditions. Some of the tree characteristics selected for this study were initial dbh., live crown length, total height, total age at dbh, and the periodic basal area growth five years prior to partial cutting. Stand conditions that were considered included basal area per acre and the number of trees per acre, since both are relative measures of the competition between trees on any given area. The relationships between these factors would be useful in assessing the potential of any given tree or group of trees.https://digitalcommons.library.umaine.edu/aes_bulletin/1043/thumbnail.jp
B614: A Plan for the Recreational Development of the Machias Lakes Region in Washington County, Maine
The importance of forest land as the medium for wood fiber production has been recognized for some time. Recent developments and trends show that another function of this same forest land is that of providing a playground for millions of outdoor recreationists. This phenomenon has affected some areas to such an extent that certain forest lands are now considered to be more valuable as sources of outdoor recreation than as wood fiber production units. This bulletin presents a plan for landowners of a 90,000-acre tract of commercial forest land located midway between Bangor and Calais, Maine, in Washington County, to more completely utilize the recreational resource. In addition, it is proposed that the service provided would be such that an income could be expected in the form of a recreation use fee. It is not the intent of this report to advocate the allocation of 90,000 acres of commercial forest land for recreation pursuits alone. Rather, it is an attempt to illustrate the fact that the intensive recreational use of an area removes little land from timber production and increases the total satisfaction that may be realized from a specific tract of forest land.https://digitalcommons.library.umaine.edu/aes_bulletin/1059/thumbnail.jp
International Public Health Research Involving Interpreters: a Case Study from Bangladesh
Background: Cross-cultural and international research are important components of public health research, but the challenges of language barriers and working with interpreters are often overlooked, particularly in the case of qualitative research.
Methods: A case-study approach was used to explore experiences of working with an interpreter in Bangladesh as part of a research project investigating women's experiences of emergency obstetric care.
The case study: Data from the researcher's field notes provided evidence of experiences in working with an interpreter and show how the model of interviewing was adapted over time to give a more active role to the interpreter. The advantages of a more active role were increased rapport and "flow" in interviews. The disadvantages included reduced control from the researcher's perspective. Some tensions between the researcher and interpreter remained hard to overcome,
irrespective of the model used. Independent transcription and translation of the interviews also raised questions around accuracy in translation.
Conclusion: The issues examined in this case study have broader implications for public health research. Further work is needed in three areas: 1) developing effective relationships with interpreters; 2) the impact of the interpreter on the research process; and 3) the accuracy of the translation and level of analysis needed in any specific public health research. Finally, this paper highlights the importance to authors of reflecting on the potential impact of translation and interpretation on the research process when disseminating their research
Plasmonically Enhanced Reflectance of Heat Radiation from Low-Bandgap Semiconductor Microinclusions
Increased reflectance from the inclusion of highly scattering particles at
low volume fractions in an insulating dielectric offers a promising way to
reduce radiative thermal losses at high temperatures. Here, we investigate
plasmonic resonance driven enhanced scattering from microinclusions of
low-bandgap semiconductors (InP, Si, Ge, PbS, InAs and Te) in an insulating
composite to tailor its infrared reflectance for minimizing thermal losses from
radiative transfer. To this end, we compute the spectral properties of the
microcomposites using Monte Carlo modeling and compare them with results from
Fresnel equations. The role of particle size-dependent Mie scattering and
absorption efficiencies, and, scattering anisotropy are studied to identify the
optimal microinclusion size and material parameters for maximizing the
reflectance of the thermal radiation. For composites with Si and Ge
microinclusions we obtain reflectance efficiencies of 57 - 65% for the incident
blackbody radiation from sources at temperatures in the range 400 - 1600
{\deg}C. Furthermore, we observe a broadbanding of the reflectance spectra from
the plasmonic resonances due to charge carriers generated from defect states
within the semiconductor bandgap. Our results thus open up the possibility of
developing efficient high-temperature thermal insulators through use of the
low-bandgap semiconductor microinclusions in insulating dielectrics.Comment: Main article (8 Figures and 2 Tables) + Supporting Information (8
Figures
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SEIS: Insight's Seismic Experiment for Internal Structure of Mars.
By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.Electronic supplementary materialThe online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users
Exploring implications of context specificity and cognitive load in residents
Introduction: Context specificity (CS) refers to the variability in clinical reasoning across different presentations of the same diagnosis. Cognitive load (CL) refers to limitations in working memory that may impact clinicians’ clinical reasoning. CL might be one of the factors that lead to CS. Although CL during clinical reasoning would be expected to be higher in internal medicine residents, CL’s effect on CS in residents has not been studied. Methods: Internal medicine residents watched a series of three cases portrayed on videos. Following each case, participants filled out a post-encounter form and completed a validated measure of CL. Results: Fourteen residents completed all three cases. Across cases, self-reported CL was relatively high and there were small to moderate correlations between CL and performance in clinical reasoning (r’s = .43, -.33, -.23). In terms of changing CL across cases, the correlations between change in CL and change in total performance were statistically significantly only in moving from case 1 to case 2 (r = -.54, p =.05). Discussion and Conclusion: Residents self-reported measurements of CL were relatively high across cases. However, higher CL was not consistently associated with poorer performance. We did observe the expected associations when looking at case-to-case change in CL. This relationship warrants further study
Antiferromagnetic-ferromagnetic phase domain development in nanopatterned FeRh islands
The antiferromagnetic-to-ferromagnetic phase transition in B2-ordered FeRh is imaged in laterally confined nanopatterned islands using photoemission electron microscopy with x-ray magnetic circular dichroism contrast. The resulting magnetic images directly detail the progression in the shape and size of the FM phase domains during heating and cooling through the transition. In 5-μm-square islands this domain development during heating is shown to proceed in three distinct modes—nucleation, growth, and merging—each with subsequently greater energy costs. In 0.5-μm islands, which are smaller than the typical final domain size, the growth mode is stunted and the transition temperature is found to be reduced by 20 K. The modification to the transition temperature is found by high-resolution scanning transmission electron microscopy to be due to a 100-nm chemically disordered edge grain present as a result of ion implantation damage during the patterning. FeRh has unique possibilities for magnetic memory applications; the inevitable changes to its magnetic properties due to subtractive nanofabrication will need to be addressed in future work in order to progress from sheet films to suitable patterned devices
Contextual factors and clinical reasoning: differences in diagnostic and therapeutic reasoning in board certified versus resident physicians
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background
The impact of context on the complex process of clinical reasoning is not well understood. Using situated cognition as the theoretical framework and videos to provide the same contextual “stimulus” to all participants, we examined the relationship between specific contextual factors on diagnostic and therapeutic reasoning accuracy in board certified internists versus resident physicians.
Methods
Each participant viewed three videotaped clinical encounters portraying common diagnoses in internal medicine. We explicitly modified the context to assess its impact on performance (patient and physician contextual factors). Patient contextual factors, including English as a second language and emotional volatility, were portrayed in the videos. Physician participant contextual factors were self-rated sleepiness and burnout.. The accuracy of diagnostic and therapeutic reasoning was compared with covariates using Fisher Exact, Mann-Whitney U tests and Spearman Rho’s correlations as appropriate.
Results
Fifteen board certified internists and 10 resident physicians participated from 2013 to 2014. Accuracy of diagnostic and therapeutic reasoning did not differ between groups despite residents reporting significantly higher rates of sleepiness (mean rank 20.45 vs 8.03, U = 0.5, p < .001) and burnout (mean rank 20.50 vs 8.00, U = 0.0, p < .001). Accuracy of diagnosis and treatment were uncorrelated (r = 0.17, p = .65). In both groups, the proportion scoring correct responses for treatment was higher than the proportion scoring correct responses for diagnosis.
Conclusions
This study underscores that specific contextual factors appear to impact clinical reasoning performance. Further, the processes of diagnostic and therapeutic reasoning, although related, may not be interchangeable. This raises important questions about the impact that contextual factors have on clinical reasoning and provides insight into how clinical reasoning processes in more authentic settings may be explained by situated cognition theory
Young HIV-Infected Children and Their Adult Caregivers Prefer Tablets to Syrup Antiretroviral Medications in Africa
Background: Provision of anti-retroviral therapy (ART) for HIV-infected children is complicated using syrup formulations, which are costlier than tablets, harder to transport and store and difficult for health-workers to prescribe and caregivers to administer. Dispersible/crushable tablets may be more appropriate. We studied the acceptability of syrups and scored tablets among young children who used both in the AntiRetroviral Research fOr Watoto (ARROW) trial. Methods: ARROW is an ongoing randomized trial of paediatric ART monitoring and treatment strategies in 1206 children in Uganda and Zimbabwe. 405 children initially received syrups of combination ART including Nevirapine, Zidovudine, Abacavir and Lamivudine before changing, when reaching the 12-,15 kg weightband, to scored adult-dose tablets prescribed according to WHO weightband tables. Caregiver expectations and experiences were collected in questionnaires at their last visit on syrups and after 8 and 24 weeks on tablets. Results: Questionnaires were completed by caregivers of 267 children (median age 2.9 years (IQR 2.5, 3.4)). At last visit on syrups, 79 % caregivers reported problems with syrups, mostly related to number, weight, transportation and conspicuousness of bottles. Difficulties taking tablets were expected by 127(48%) caregivers; however, after 8 and 24 weeks, only 26 % and 18 % reported their children had problems with tablets and no problems were reported with transportation/conspicuousness. Taste, swallowing or vomiting were reported as problems ‘sometimes/often ’ for 14%, 9%
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
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