2,122 research outputs found
An investigation into the enhancement of fingermarks in blood on fruit and vegetables
A number of studies have reported the successful enhancement of latent fingermarks on fruit and vegetables. A study was set up to identify the most effective technique for the enhancement of fingermarks in blood on various fruit and vegetables. The enhancement techniques targeted different components in blood and consisted of protein stains (e.g. acid black 1), peroxidase reagents (e.g. leuco crystal violet) and amino acid stains (e.g. ninhydrin). Different variables such as the ageing periods of the marks and a diminishing series were employed to assess the suitability and sensitivity of the enhancement techniques.Overall, the use of different protein stains appeared to be the most effective techniques for the enhancement of fingermarks in blood on fruit and vegetables. In addition, the aubergine and cucumber skins appeared to be the most responsive surface to the different chemical techniques during enhancement. On the contrary, little or no enhancement was achieved for fingermarks in blood on the nectarine fruit
An investigation into the detection of latent marks on the feathers and eggs of birds of prey
There are numerous enhancement techniques (physical and chemical) which have been developed for the successful visualisation of latent fingermarks. Nonetheless, problems arise when latent fingermarks require enhancement on difficult surfaces such as human skin, food stuffs, fabric and animals. The ability to develop latent fingermarks on the surface of bird of prey feathers and that of their eggs was investigated. Red and green magnetic fluorescent powders proved to be most suitable on the surface of bird of prey feathers whereas black magnetic powder was the most suitable technique on the eggs. These powders produced the highest quality of visible ridge-detailed developments over a controlled period of time
Characterisation of the transverse thermoelastic properties of natural fibres used in composites
To predict the properties of a composite, it is necessary to identify the properties of the constituent materials, especially those of the fibre. Mechanical properties of natural fibres (NF) are anisotropic and cannot be characterised in the same way as isotropic materials. Therefore further characterisation of the natural fibres is needed to determine their transverse thermo-mechanical behaviour. An understanding of the thermoelastic anisotropy of natural fibres is important for defining their performance in potential composite applications. In this study, thermoelastic properties of flax and sisal fibres where determined through a combination of experimental measurements and micromechanical modelling. Dynamic mechanical thermal analysis and thermal mechanical analysis techniques were employed to characterise model unidirectional NF-epoxy composites over a range off-axis loading angles. These results were input into a number of micromechanical and semi-empirical models to determine the transverse and longitudinal thermoelastic properties of the fibre. The results confirm the high degree of anisotropy in properties of the flax and sisal fibres
The Ethical and Methodological Dilemmas of a Not-SoNative Ethnographer
This presentation examines the ethical and methodological dilemmas I faced as a foreign doctoral student from a North American university doing research in my own Jamaican setting. Tensions re: Self-Location, political and ethical tensions re: Representation of Self, and tensions re: research design and reporting are explored as a means of constructing a critical understanding of such methodological and ethical dilemmas and their implications for the trustworthiness of qualitative research
Environmental effects on magnetic fluorescent powder development of fingermarks on bird of prey feathers
A comparison study of the effects of environmental conditions on the development of latent fingermarks on raptor feathers using green magnetic fluorescent powder was undertaken using both sebaceous loaded and natural fingermark deposits. Sparrowhawk feathers were stored in indoor conditions for 60 days (Study 1), and buzzard feathers were left exposed to two different environmental conditions (hidden and visible) for 21 days (Study 2), with developments made at regular ageing periods. In Study 1, latent fingermarks were successfully developed (Grade 1–4) on the indoor feathers up to 60 days after deposition – 98.6% of the loaded deposits and 85.3% for natural deposits. Under outdoor conditions in Study 2, both loaded and natural deposits were affected by environmental exposure. Latent fingermarks were successfully developed up to 14 days after deposition on the outdoor feathers, with some occasional recovery after 21 days. The visible feathers recorded 34.7% (loaded) and 16.4% (natural) successful developments (Grade 1–4), whereas the hidden feathers recorded 46.7% (loaded) and 22.2% (natural) successful developments, suggesting that protection from the environment helps to preserve latent fingermarks on the surface of a feather. Environmental exposure accelerated the deterioration of ridge detail and the number of successful developments
Optimal distribution and utilization of donated human breast milk: a novel approach
Background: The nutritional content of donated expressed breast milk (DEBM) is variable. Using DEBM to provide for the
energy requirements of neonates is challenging.
Objective: The authors hypothesized that a system of DEBM energy content categorization and distribution would improve
energy intake from DEBM.
Methods: We compared infants’ actual cumulative energy intake with projected energy intake, had they been fed using our
proposed system. Eighty-five milk samples were ranked by energy content. The bottom, middle, and top tertiles were classified
as red, amber, and green energy content categories, respectively. Data on 378 feeding days from 20 babies who received this
milk were analyzed. Total daily intake of DEBM was calculated in mL/kg/day and similarly ranked. Infants received red energy
content milk, with DEBM intake in the bottom daily volume intake tertile; amber energy content milk, with intake in the middle
daily volume intake tertile; and green energy content milk when intake reached the top daily volume intake tertile.
Results: Actual median cumulative energy intake from DEBM was 1612 (range, 15-11 182) kcal. Using DEBM with the
minimum energy content from the 3 DEBM energy content categories, median projected cumulative intake was 1670 (range
13-11 077) kcal, which was not statistically significant (P = .418). Statistical significance was achieved using DEBM with the
median and maximum energy content from each energy content category, giving median projected cumulative intakes of 1859
kcal (P = .0006) and 2280 kcal (P = .0001), respectively.
Conclusion: Cumulative energy intake from DEBM can be improved by categorizing and distributing milk according to
energy content
Sampling in Qualitative Research: Insights from an Overview of the Methods Literature
The methods literature regarding sampling in qualitative research is characterized by important inconsistencies and ambiguities, which can be problematic for students and researchers seeking a clear and coherent understanding. In this article we present insights about sampling in qualitative research derived from a systematic methods overview we conducted of the literature from three research traditions: grounded theory, phenomenology, and case study. We identified and selected influential methods literature from each tradition using a purposeful and transparent procedure, abstracted textual data using structured abstraction forms, and used a multistep approach for deriving conclusions from the data. We organize the findings from this review into eight topic sections corresponding to the major domains of sampling identified in the review process: definitions of sampling, usage of the term sampling strategy, purposeful sampling, theoretical sampling, sampling units, saturation, sample size, and the timing of sampling decisions. Within each section we summarize how the topic is characterized in the corresponding literature, present our comparative analysis of important differences among research traditions, and offer analytic comments on the findings for that topic. We identify several specific issues with the available guidance on certain topics, representing opportunities for future methods authors to improve our collective understanding
Resistance training volume load with and without exercise displacement
Monitoring the resistance training volume load (VL) (sets × reps × load) is essential to managing resistance training and the recovery⁻adaptation process. Eight trained weightlifters, seven of which were at national level, participated in the study. VL was measured both with (VLwD) and without (VL) the inclusion of barbell displacement, across twenty weeks of training, in order to allow for comparisons to be made of these VL calculating methods. This consisted of recording the load, repetition count, and barbell displacement for every set executed. Comparisons were made between VL and VLwD for individual blocks of training, select training weeks, and select training days. Strong, statistically significant correlations (r ≥ 0.78, < 0.001) were observed between VL and VLwD between all training periods analyzed. -tests revealed statistically significant ( ≤ 0.018) differences between VL and VLwD in four of the seven training periods analyzed. The very strong relationship between VL and VLwD suggest that a coach with time constraints and a large number of athletes can potentially spare the addition of displacement. However, differences in percent change indicate that coaches with ample time should include displacement in VL calculations, in an effort to acquire more precise workload totals
Critical Approach to Reflexivity in Grounded Theory
A problem with the popular desire to legitimate one’s research through the inclusion of reflexivity is its increasingly uncritical adoption and practice, with most researchers failing to define their understandings, specific positions, and approaches. Considering the relative recentness with which reflexivity has been explicitly described in the context of grounded theory, guidance for incorporating it within this research approach is currently in the early stages. In this article, we illustrate a three-stage approach used in a grounded theory study of how parents of children with autism navigate intervention. Within this approach, different understandings of reflexivity are first explored and mapped, a methodologically consistent position that includes the aspects of reflexivity one will address is specified, and reflexivity-related observations are generated and ultimately reported. According to the position specified, we reflexively account for multiple researcher influences, including on methodological decisions, participant interactions and data collection, analysis, writing, and influence of the research on the researcher. We hope this illustrated approach may serve both as a potential model for how researchers can critically design and implement their own context-specific approach to reflexivity, and as a stimulus for further methodological discussion of how to incorporate reflexivity into grounded theory research
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