Alternative Light Source Research Articles

Assessment of the proportion of households with burn victims, associated risk factors and knowledge of burn injury prevention strategies in South Western Uganda. A population based cross sectional survey

BackgroundBurn injuries are a major cause of morbidity and mortality within Low- and Middle-income countries (LMICs). Most of these burn injuries occur at home with children most at risk. The majority of burn related deaths and disability in LMICs have been described as preventable. Burns prevention requires adequate knowledge of the epidemiological characteristics and associated risk factors. The aim of this study was to assess the proportion of households with burn victims, the associated risk factors and knowledge of prevention strategies of burn injuries in Kakoba division, Mbarara city. MethodsWe did a population based cross sectional survey of households in Kakoba division. This is the most populous division in Mbarara city. Face-to-face interviews were conducted using a pretested structured questionnaire. Descriptive analysis was performed to establish prevalence and knowledge of preventive strategies for household burns. Univariate and multivariate logistic regression models were fitted to establish the factors influencing burn injuries at household level. ResultsOf the households in Kakoba Division, 41.2% had individuals who had previously sustained burn injuries within the household. Children were the most affected population with scald burns the most common type. The highest risk of burn injuries was associated with overcrowding in the households. Electricity as a light source was found to be protective. Candles and Kerosene lamps were the commonest alternative light sources. Majority 98% of the individuals in the households knew at least one burns prevention strategy with 93% practicing at least one. ConclusionBurns within the household are still high despite knowledge of risk factors with children being the most affected. Overcrowding still plays a significant role in household burn injuries. We therefore recommend closer supervision of children within the households. Cooking areas need to be properly designated and secured to limit access. Safer alternative light sources need to be explored such as solar lamps. Political leaders need to be involved in setting up and monitoring community-based fire safety practices to ensure compliance.

Medical evidence assisting non-fatal strangulation prosecution: a scoping review

ObjectivesNon-fatal strangulation (NFS) is a serious form of gendered violence that is fast becoming an offence in many jurisdictions worldwide. However, it often leaves little or no externally visible injuries...

A visible light-driven direct synthesis of industrially relevant glutaric acid diesters from aldehydes.

A straightforward and practical method has been developed to access α-substituted glutaric diesters from acrylates and aldehydes using visible light, with Eosin Y facilitating hydrogen atom transfer (HAT) and subsequent Giese-type addition. Also, sunlight has been successfully used as an alternative sustainable light source. The method has also been explored to access substituted 4,5-dihydro-2H-pyridazinones, which have potential biological and industrial applications. Comprehensive mechanistic investigations have been carried out.

Chrysanthemum: A Comprehensive Review on Recent Developments on In Vitro Regeneration.

Chrysanthemum is a flowering plant grown worldwide and is one of the most popular ornamental plants. Chrysanthemums are usually cultivated using root suckers and shoot cuttings. This conventional technique is relatively slow. In addition, as cuttings are gained regularly from mother plants, there is a chance of viral infection and degeneration, which raises the production cost. The hurdles mentioned above have been managed by applying in vitro propagation techniques, which can enhance reproduction rates through in vitro culture and use very small explants, which are impossible with the conventional approach. Usually, it is difficult to get true-to-type plants as the parents with good quality, but clonal propagation of a designated elite species makes it possible. Hence, this review highlights recent studies of the in vitro propagation of Chrysanthemum included; the appropriate explant sources, medium compositions, alternative disinfection of culture media, plant growth regulators (PGRs), different mutagenesis applications, acclimatization efficiency, and alternative light sources to overcome the shortcomings of conventional propagation techniques.

Uniform Illumination Using Single-Surface Lens through Wavefront Engineering

Recent advancements in high power light-emitting diode (LED) technology have presented greenhouse industry with a more efficient and flexible alternative light source for horticulture. However, the light distribution on the plant remains a challenge that has notable implications on the plant growth. A non-uniform light distribution on the canopy with hot spots is well-known to adversely affect the yield. Here, we present a technique to engineer the light wavefront of a solid-state source using a single-surface optics, which yields a highly uniform light distribution across the plant. This technique achieves over 90% illuminance uniformity, preserved at various distances from the source, for a cone of light with an up to 120° angular range. This work aids the paradigm shift towards LEDs as a competitive light source in horticulture.

Comparison of different illumination systems for moisture prediction in cereal bars using hyperspectral imaging technology

Moisture content and its distribution is a critical parameter in the production of cereal bars. Inappropriate control of this quality parameter can lead to non-conforming products and excess waste on production lines. In the field of hyperspectral imaging, the search for alternative light sources to stabilised-halogen (cheaper and emitting less heat) is a growing need for the application of this technology in industry. This study compares three different illumination systems for moisture prediction in the visible-near infrared (vis-NIR) range (from 400 nm to 1000 nm). The hyperspectral images were acquired using three illumination systems including two halogen-based systems (stabilised-halogen and conventional-halogen) and an LED-based illumination system. The results showed that halogen-based illumination systems combined with a partial least squares model better predicted moisture in bars. Lower accuracies were obtained when the experiment was performed with an LED-based illumination system, which showed double the error of the halogen-based systems. It was concluded that this is a consequence of the information lost in bands appearing above 850 nm that may be revealing information about the moisture in bars since the second overtone of the water O–H is found at 970 nm. The results demonstrate that conventional halogen-based light systems in the vis-NIR range are a promising method for moisture prediction in cereal bars.

An alternative illumination source based on LEDs for PIV measurements on human swimmers—A feasibility study

Methods for flow visualization help to investigate the motion of fluids that are normally invisible. Especially, Particle Image Velocimetry (PIV) – with a laser as light source – has been established in the field of engineering and partly in biology. Since the standard measuring equipment applying a laser system is very sensitive with respect to transport, temperature, humidity as well as laser safety requirements have to be adhered, the observation and classification of flow pattern around human swimmers in swimming pools has been rarely applied. There is a need for a simple, powerful, affordable, robust, and portable illumination source which shall not harm the swimmer by exceeding the permitted maximum radiation for human skin and eyes. As a result, this technical note demonstrates an alternative light source system based on LEDs which enables PIV measurements around human swimmers similar to experiments with a (traditional) laser system. As an example, the flow fields of two different swimmers with a similar movement and phase are compared using both illumination methods laser and LED. Furthermore, a series of sequential velocity fields, produced by the motion of a monofin swimmer, generate a vortex pair with an inverse Karman vortex street which is typically seen in fish and marine mammal locomotion. Consequently, this LED illumination source is show to provide a sufficient suitable light intensity as well as light quality enabling the measurement of the flow field around swimmers.

Two-photon absorption cross-section investigation of visible-light photoinitiators under Q-switched Nd:YAG nanosecond pulse laser at 1064 nm

Two-photon polymerization (TPP) technologies commonly rely on femtosecond lasers such as Ti:sapphire which limits their accessibility due to high costs and complexities. Recently, multiple reports showed TPP under near-infrared irradiation which enables the use of alternative light sources such as Neodymium-doped lasers known to be affordable and efficient for a nanosecond and picosecond pulsed generation. 4,4′-Bis(dimethyl-amino) benzophenone or Michler’s ketone (MK), one of the photoinitiators commonly used for photopolymerization under UV irradiation, also shows an absorption band in the visible region which allows for two-photon polymerization at the fundamental wavelength of Neodymium-doped lasers at 1064 nm. In this report, we investigated the two-photon absorption (TPA) of MK in contrast with Irgacure-784 and Indane-1,3-dione, reported to also be promising photoinitiators for the same TPP process. Among them, MK showed a large TPA cross-section measured via the nonlinear transmission method and Z-scan technique with Q-switched Nd:YAG nanosecond pulse laser at 1064 nm, demonstrating MK as a promising photoinitiator for the low-cost two-photon polymerization.

Dermoscopy and skin imaging light sources: a comparison and review of spectral power distribution and color consistency.

.Significance: Dermoscopes incorporate light, polarizers, and optical magnification into a handheld tool that is commonly used by dermatologists to evaluate skin findings. Diagnostic accuracy is improved when dermoscopes are used, and some major artificial intelligence (AI) projects have been accomplished using dermocopic images. Color rendering consistency and fidelity are crucial for clinical diagnostics, AI, and image processing applications.Aim: With many devices available on the market, our objective was to measure the emission spectra of various dermoscopes, compare them with other light sources, and illustrate variations in reflected colors from images of a reference sample.Approach: A spectrometer measured the spectral power distribution (SPD) produced by four dermoscope models and three alternate light sources, illustrating differences in the emission spectra. Most dermoscopes use light-emitting diodes (LEDs), which are inconsistent when compared with one another. An LED was compared with halogen, xenon-arc, and daylight sources. Images of a micro ColorChecker were acquired from several sources, and three specific colors were selected to compare in CIELAB color space. Color consistency and color fidelity measured by color rendering index (CRI) and TM-30-18 graphical vectors show variation in saturation and chroma fidelity.Results: A marked degree of variation was observed in both the emission and reflected light coming from different dermoscopes and compared with other sources. The same chromophores appeared differently depending on the light source used.Conclusions: A lack of uniform illumination resulted in inconsistent image color and likely impacted metamerism and visibility of skin chromophores in real-world settings. Artificial light in skin examinations, especially LEDs, may present challenges for the visual separation of specific colors. Attention to LEDs SPD may be important, especially as the field increases dependency on machine/computer vision.

Optimization of light intensity and color temperature in the cultivation of Chlorella vulgaris culture using the Surface Response Method

Microalgae have an important role as a source of biomass in producing energy. One type of microalgae that has the potential to be developed is Chlorella vulgaris. Several factors that affect the growth and biomass production of Chlorella vulgaris microalgae are color temperature and light intensity because they play an important role in the photosynthesis process. This study aims to influence the effect of light and color temperature and optimize these parameters using Response Surface Methodology (RSM). Two independent variables were varied: light intensity 200, 400, 600, 800, 1000 lux and color temperature 3000, 4000, 5000, and 6000 K. The results showed that the average value of Chlorella vulgaris growth was higher along with higher light intensity. At a color temperature of 4000 K, the highest biomass yield and the most negligible biomass production were found at 6000 K. At a color temperature of 4000 K, it is feasible to apply it as an alternative lighting source in the production of Chlorella vulgaris. The combination of light intensity and color temperature shows that the specific growth rate and doubling time have opposite trends where high values produce low values and vice versa. Growth in dark conditions, the specific growth rate was 0.0026 day-1, and the optimal light intensity at 600 lux treatment. ANOVA evaluation showed that color temperature greatly affected growth. Based on the optimization, the optimal specific growth rate of 00751day-1 with the conditions of light intensity and color temperature of 556 lux and 4152 K, respectively.

Predicting alternate light absorption in areas of trauma based on degree of skin pigmentation: Not all wavelengths are equal

Detection and documentation of bruises on survivors of intimate partner violence (IPV) can provide valuable evidence to support investigation and subsequent prosecution of these crimes. Detection of bruises in persons with darker skin tones is often difficult, contributing to disparities in health and criminal justice responses to IPV. The purpose of this secondary data analysis was to determine whether use of an alternate light source (ALS) increased the predictive probability of successfully detecting bruises on diverse skin tones following a history of physical trauma. In this study, data were analyzed from a convenience sample of 157 subjects inclusive of six skin tones (very light, light, intermediate, tan, brown, dark) with induced bruises. Bruises were assessed under white light and an ALS 21 times over four weeks using 10 different ALS wavelength and goggle color combinations. Data analyzed included 31,841 skin observations obtained over 2897 participant assessments. Multilevel modeling was used to account for the correlation among the repeated measurements for each bruise. Across all categories of skin pigmentation, ALS wavelengths 415 nm and 450 nm viewed through a yellow filter had the most frequent detections of bruises (415 nm: n = 2777, 11.2%; 450 nm: n = 2747, 11.1%) and greater predictive probability of a positive finding (415 nm: 0.90–0.99; 450 nm: 0.85–0.99) than white light (n = 2487; 10%; 0.81–0.90). These two ALS wavelengths were the only combinations that provided greater probability of detection than white light on groups with darker skin (brown or dark), whereas additional ALS wavelengths/filters worked equally well on groups with lighter skin. Findings suggest use of an ALS in clinical assessments of patients of color who report IPV may help reduce health and criminal justice-related disparities.

Therapeutic dentistry in prehistoric Maryland—New analyses from the Hughes (18MO1) archeological site

Late Woodland period prehistoric human remains recovered from the Hughes site (18MO1) in the 1930s were only recently submitted for bioarcheological analysis. These remains represent 20 individuals exhibiting varying degrees of preservation and representation. Among the remains are several teeth suspected of undergoing antemortem dental modification. All of the examined dental cavitations were deep, and some show excavation all the way to the pulp. Dental remains representing three individuals (two adult females and a child) were examined to define etiology of altered occlusal cavitations in these teeth. The findings provide evidence of prehistoric, therapeutic dentistry in the Middle Atlantic region of the eastern United States. Two mandibles and a maxillary right dental quadrant representing three individuals were analyzed utilizing radiographs, visible and alternate light source macro photography, and scanning electron microscopy in three modes of detection. All three specimens showed signs of both radial and concentric tool marks to varying degrees in both enamel and dentin borders of carious lesions. The shape of the cavitations do not follow normal pathological patterns of undisturbed occlusal decay in teeth. Further, evidence is presented that the excavative tool motion changes from rotational drilling to radial scooping the further posterior the cavitation is located in the oral cavity. Lastly, it is proposed that the reason for these modifications was therapeutic dentistry.

Fully integrated electrically driven optical frequency comb at communication wavelength

Abstract To meet the high demand of data transmission capacity, optical communications systems have been developed. In order to increase the channel numbers for larger communication bandwidth, multi-mode lasers and laser arrays can be used. As an alternative coherent light source, optical frequency comb (OFC) contains multi-wavelength signal, and hence enables communication with data stream of tens of terabit/s. Fully integrated electrically driven OFCs are expected as a compact, robust, and low-cost light source for data communication. In this review article, the recent development progress on fully integrated electrically driven OFC generators are reviewed, with focus on the demonstrations in the past five years. Based on comb generation approaches, the works are categorized into two main types: one is OFC generators based on four-wave mixing in high-Q resonator, and the other is OFC generators based on mode-locked laser. At the end, a summary and future outlook are provided.

UV inactivation of Semliki Forest virus andE. colibacteria by alternative light sources

The quick spreading of the SARS-CoV-2 virus, initiating the global pandemic with a significant impact on economics and health, highlighted an urgent need for effective and sustainable restriction mechanisms of pathogenic microorganisms. UV-C radiation, causing inactivation of many viruses and bacteria, is one of the tools for disinfection of different surfaces, liquids, and air; however, mainly mercury 254 nm line is commonly used for it. In this paper, we report our results of the experiments with newly elaborated special type polychromatic non-mercury UV light sources, having spectral lines in the spectral region from 190 nm to 280 nm. Inactivation tests were performed with both Escherichia coli (E.coli) bacteria and Semliki Forest virus (SFV) as a representative of human enveloped RNA viruses. In addition, the effect of prepared lamps on virus samples in liquid and dry form (dried virus-containing solution) was tested. Reduction of 4 log10 of E.coli was obtained after 10 min of irradiation with both thallium-antimony and arsenic high-frequency electrodeless lamps. High reduction results for the arsenic light source demonstrated sensitivity of E. coli to wavelengths below 230 nm, including spectral lines around 200 nm. For the Semliki Forest virus, the thallium-antimony light source showed virus inactivation efficiency with a high virus reduction rate in the range of 3.10 to > 4.99 log10 within 5 min of exposure. Thus, the new thallium-antimony light source showed the most promising disinfection effect in bacteria and viruses, and arsenic light sources for bacteria inactivation, opening doors for many applications in disinfection systems, including for pathogenic human RNA viruses.

Improving the Forensic Documentation of Injuries Through Alternate Light: A Researcher-Practitioner Partnership.

An alternate light source (ALS) is a practitioner-driven technology that can potentially improve the documentation of injuries among victims of interpersonal violence. However, evidence-based guidelines are needed to incorporate and document an ALS skin assessment into a forensic medical examination that accurately reflects the science, context of forensic nursing practice, trauma-informed responses, and potential impact on criminal justice stakeholders. This article introduces the forensic nursing community to a current translation-into-practice project focused on developing and evaluating an ALS implementation program to improve the assessment and documentation of bruises among adult patients with a history of interpersonal violence. Our researcher-practitioner collaboration uses theory-based approaches that consider both the developed program's practice context and stakeholder impact. The goal is to provide evidentiary support for adult victims of violence and a more equitable forensic nursing practice that benefits diverse patient populations.

Alternate light source studies of simulated old bruises

Bruises are often challenging to detect in victims of assault, which may impact investigation and prosecution in cases of assault. Alternate light sources, such as ultraviolet and narrow band visible light, may be used to enhance the appearance of bruises. While violet light has been demonstrated to be the most effective alternate light source to visualise a recent bruise, an area that has not been explored is what is the most effective alternate light source to visualise an old bruise. To address this gap in the knowledge, old bruises were simulated by injecting pigskins with a reagent of blood, bilirubin, and ferritin.

In Vitro Growth Responses of Ornamental Bananas (Musa sp.) as Affected by Light Sources

Light-emitting diodes (LEDs) have become very popular for the production of horticultural crops. LEDs represent an alternative lighting source to regular fluorescent (FL) bulbs, increasing the quality of plants and minimizing production costs. LEDs also provide selective light intensity and quality, suitable for commercial micropropagation. The objective of this study was to evaluate the growth and development of in vitro ornamental bananas under different light sources. Two ornamental banana varieties were selected for this study: Musa ‘Little Prince’ and Musa ‘Truly Tiny’. Light quality and intensity of three different light sources were evaluated: LED-1 (116 μmol m−2 s−1), LED-2 (90 μmol m−2 s−1), and FL (100 μmol m−2 s−1). Length and biomass of plantlets were greater under LED-1 compared to FL but not significantly different from LED-2. The fresh and dry weight of shoots and roots, number of leaves, and number and length of roots were not significantly different between treatments. Chlorophyll content was greater under LEDs. Leaf number and stomata number and size were greater under FL. Our results indicate that shoot length and biomass could be improved by optimizing light quality and intensity. Different responses to light sources between the two banana varieties also indicated a genotype effect.

Forensic examination of semen sample using different tests: A review

A variety of bodily fluids can be found at crime scenes during investigations, which can play a crucial role for forensic investigator to link the suspect with the crime scene. Many techniques are primarily being used now days; specifically ALS (alternative light source) at different wavelengths to locate the evidences at crime scenes, Identifying semen in sex crime cases thus becomes very much useful because of the sensitivity of the cases. In this study, different techniques i.e. ALS, AP tests, Florence test, remain spectroscopy, DNA based methods for the identification of seminal fluid has been discussed.

Noninvasive, visual examination for the presence of gunshot residue on human skin.

When a firearm is discharged, the highest concentration of gunshot residue (GSR) is located on a shooter's hands, forearms, and clothing. Currently, collecting GSR from an individual's hands is accomplished with a carbon disk that is submitted for confirmatory analysis in a forensic laboratory. Presumptive chemical tests can be performed in the field, but these tests consume a portion of the GSR particles leaving a reduced amount of evidence available to be collected and sent to a forensic laboratory. An abundance of research exists for detecting GSR particles instantly on different fabrics using an alternate light source (ALS). This study expanded on that research and developed a noninvasive, visual examination to detect GSR on a suspected shooter's hands without destroying or removing any particles prior to collection. The hands of individuals who recently discharged a firearm were examined under a light source between 475 and 530nm and an infrared (IR) camera. The fluorescent particles observed on a shooter's hands under 520nm were similar in size and appearance to GSR particles observed on fabrics under an ALS. The fluorescent particles were collected and analyzed for GSR, and the results indicated that GSR particles were present. More testing needs to be conducted to determine if the fluorescent particles observed are inorganic or organic GSR particles. There is also potential to detect GSR under IR light; however, more research needs to be conducted to determine the composition of the particles observed after image enhancement.

Detection and visualization of human tears using alternate light sources for forensic purposes

The current scientific techniques for locating body fluids focus on quick and effective methodologies for easy and reliable identification. Efficient detection and identification of body fluids play a vital role in establishing the ‘corpus delecti’ of a crime. Non-destructive techniques such as the use of Alternate Light Sources (ALS) have been exploited for crime scene searches over large areas and detection of body fluids such as blood, semen, vaginal secretions, and saliva on a range of substrates. Tears are rarely found but can be considered as potential body fluid evidence due to their unique biochemical and molecular properties. Tears are secreted in response to physical or emotional stimuli. Due to the small volume of secretions, they are often overlooked in the crime scene. Tears may be found on surfaces such as clothing, bedding, tissue, handkerchief, or balaclava. The use of ALS to locate tears on tissue paper and fabric surfaces was tested which were not apparent to the naked eye. Tears stains were successfully detected on surfaces of forensic interest with varying sample ages up to three months with a broad excitation spectrum between 254 nm and 410 nm. Dried stains on tissue paper and fabric substrates were better detected with sharp margins, clear stain pattern visibility, and fluorescence intensity in comparison with moist and fresh stains. Tears stains can hence be detected with the use of ALS and suitable filter combinations under normal conditions and do not require any specific settings to locate them. These findings are suggestive for easy and quick identification of tears on large surfaces and as a presumptive test for forensic casework evidence examination.