Non-invasive Methodology Research Articles

Tear Film Dynamics between Low and High Contact Lens Dry Eye Disease Questionnaire (CLDEQ-8) Score with a Lehfilcon A Silicone Hydrogel Water Gradient Contact Lens: A Non-Invasive Methodology Approach

The purpose of this study is to evaluate the tear film dynamics between individuals with low and high Contact Lens Dry Eye Disease Questionnaire (CLDEQ-8) scores when wearing Lehfilcon A silicone hydrogel water gradient contact lenses. In this study, we implemented a longitudinal, single-location, self-comparison investigation. Variables measured included conjunctival redness, lipid layer thickness, tear meniscus height, first and mean non-invasive break-up time, CLDEQ-8, and standard patient evaluation of eye dryness (SPEED). In the second phase, participants were re-evaluated after 30 days of wearing the contact lenses to assess the tear film wearing the lenses. In a longitudinal comparison by group, we found that lipid layer thickness decreased 1.52 ± 1.38 (p < 0.01) and 0.70 ± 1.30 (p = 0.01) Guillon patterns degrees in the low and high CLDEQ-8 group, respectively. MNIBUT increased in 11.93 ± 17.93 (p < 0.01) and 7.06 ± 12.07 (p < 0.01) seconds. Finally, LOT increased in 22.19 ± 27.57 (p < 0.01) and 16.87 ± 25.09 (p < 0.01). In conclusion, this study demonstrates the effectiveness of Lehfilcon A silicone hydrogel water gradient contact lenses in improving tear film stability and reducing subjective dry eye symptoms in individuals with low and high CLDEQ-8 scores. However, it also led to an increase in conjunctival redness and a decrease in tear meniscus height.

Analysis of urine Raman spectra differences from patients with diabetes mellitus and renal pathologies.

Chronic kidney disease (CKD) poses a major public health burden. Diabetes mellitus (DM) is one of the major causes of CKD. In patients with DM, it can be difficult to differentiate diabetic kidney disease (DKD) from other causes of glomerular damage; it should not be assumed that all DM patients with decreased eGFR and/or proteinuria have DKD. Renal biopsy is the standard for definitive diagnosis, but other less invasive methods may provide clinical benefit. As previously reported, Raman spectroscopy of CKD patient urine with statistical and chemometric modeling may provide a novel, non-invasive methodology for discriminating between renal pathologies. Urine samples were collected from renal biopsied and non-biopsied patients presenting with CKD secondary to DM and non-diabetic kidney disease. Samples were analyzed by Raman spectroscopy, baselined with the ISREA algorithm, and subjected to chemometric modeling. Leave-one-out cross-validation was used to assess the predictive capabilities of the model. This proof-of-concept study consisted of 263 samples, including renal biopsied, non-biopsied diabetic and non-diabetic CKD patients, healthy volunteers, and the Surine™ urinalysis control. Urine samples of DKD patients and those with immune-mediated nephropathy (IMN) were distinguished from one another with 82% sensitivity, specificity, positive-predictive value (PPV), and negative-predictive value (NPV). Among urine samples from all biopsied CKD patients, renal neoplasia was identified in urine with 100% sensitivity, specificity, PPV, and NPV, and membranous nephropathy was identified with 66.7% sensitivity, 96.4% specificity, 80.0% PPV, and 93.1% NPV. Finally, DKD was identified among a population of 150 patient urine samples containing biopsy-confirmed DKD, other biopsy-confirmed glomerular pathologies, un-biopsied non-diabetic CKD patients (no DKD), healthy volunteers, and Surine™ with 36.4% sensitivity, 97.8% specificity, 57.1% PPV, and 95.1% NPV. The model was used to screen un-biopsied diabetic CKD patients and identified DKD in more than 8% of this population. IMN in diabetic patients was identified among a similarly sized and diverse population with 83.3% sensitivity, 97.7% specificity, 62.5% PPV, and 99.2% NPV. Finally, IMN in non-diabetic patients was identified with 50.0% sensitivity, 99.4% specificity, 75.0% PPV, and 98.3% NPV. Raman spectroscopy of urine with chemometric analysis may be able to differentiate between DKD, IMN, and other glomerular diseases. Future work will further characterize CKD stages and glomerular pathology, while assessing and controlling for differences in factors such as comorbidities, disease severity, and other lab parameters.

Solvent field regulated superhalogen in pure and doped gold cluster anions

Condensed-phase synthesis of atomically precise clusters has become a vital branch of cluster science, where solvents are indispensable in the synthesis process. Herein, by employing the density functional theory (DFT) calculations and molecular dynamics (MD) simulations, we demonstrated that polar solvents not only provide an important environment to stabilize clusters, but they can also dramatically alter the electronic property of cluster anions forming novel superhalogen anions. Such a regulation effect was first verified in small model gas-phase pure and doped gold cluster anions, which was further evidenced in a real experimentally synthesized Au18 nanocluster. Different solvation models reveal that the solvent field, which is a noninvasive methodology different from conventional electron-counting rules, can be considered as a novel external field to remarkably increase the electron-binding capability of cluster anions while maintaining their geometrical and electronic structures. Considering the indispensability and convenient availability of the solvents, present findings may boost the potential applications of superatoms in constructing super oxidizers in the condensed phase.

The Proteome of Hand Eczema Assessed by Tape Stripping

Hand eczema (HE) is a prevalent skin disease. However, the classification of HE into different subtypes remains challenging. A limited number of previous studies have employed invasive biopsy-based strategies; yet, studies of the HE proteome using noninvasive tape-stripping methodology have not been reported. In this study, we wanted to assess whether global proteomic analysis of skin tape strip samples can be used for subclassification of patients with HE. Tape strips were collected from patients with HE and healthy skin. Liquid chromatography-mass spectrometry proteomics was performed, and the global protein expression was analyzed. We identified 2,919 proteins in stratum corneum-derived skin cells from tape strip samples. Compared with healthy skin, the lesional samples from patients with HE exhibited increased expression of immune-related markers and a decreased expression of structural barrier proteins. The difference between HE subtypes was restricted to the lesional skin areas and included an increased expression of skin barrier-related proteins independently of the concurrent AD. In conclusion, we found that the noninvasive tape strip method used in combination with liquid chromatography-mass spectrometry proteomics can be used for analysis of skin protein expression in patients with HE. Thus, the method shows potential for assessing the proteomic differences between subtypes of HE and biomarker discovery.

The Application of RGB, Multispectral, and Thermal Imagery to Document and Monitor Archaeological Sites in the Arctic: A Case Study from South Greenland

Over the past decades, climate change has accelerated the deterioration of heritage sites and archaeological resources in Arctic and subarctic landscapes. At the same time, increased tourism and growing numbers of site visitors contribute to the degradation and manipulation of archaeological sites. This situation has created an urgent need for new, quick, and non-invasive tools and methodologies that can help cultural heritage managers detect, monitor, and mitigate vulnerable sites. In this context, remote sensing and the applications of UAVs could play an important role. Here, we used a drone equipped with an RGB camera and a single multispectral/thermal camera to test different possible archeological applications at two well-known archaeological sites in the UNESCO World Heritage area of Kujataa in south Greenland. The data collected were used to test the potential of using the cameras for mapping (1) ruins and structures, (2) the impact of human activity, and (3) soil moisture variability. Our results showed that a combination of RGB and digital surface models offers very useful information to identify and map ruins and structures at the study sites. Furthermore, a combination of RGB and NDVI maps seems to be the best method to monitor wear and tear on the vegetation caused by visitors. Finally, we tried to estimate the surface soil moisture content based on temperature rise and the Temperature Vegetation Dryness Index (TVDI), but did not achieve any meaningful connection between TVDI and on-site soil moisture measurements. Ultimately, our results pointed to a limited archaeological applicability of the TVDI method in Arctic contexts.

Observational findings of transbronchial lung biopsy in patients with interstitial lung disease: a retrospective study in Aleppo University Hospital.

This retrospective cohort research was done between 1 January 2020 and 18 April 2022 at the pulmonary department of Aleppo University Hospital, Syria, using patient records. In our study, 174 patients were examined. We included patients over the age of 18 who were referred or admitted to our department at Aleppo University Hospital after being diagnosed with diffuse parenchymal lung disease based on high-resolution computed tomography and clinical symptoms, while excluding other respiratory diseases such as tuberculosis and coronavirus disease 2019. Patients in the research were 53±7.1 years old on average. Cough and dyspnea were the most common clinical complaints among the patients, which accounted for 79.12 and 78.16%, respectively. A significant fraction of ground-glass opacity was detected on the high-resolution computed tomography, amounting to 102 (58.62%) and 74 (42.53%) for the reticular lesions, respectively. As a complication there were 40 patients with bleeding, of whom 24 had moderate bleeding, and 11 had major bleeding. We also had three patients with pneumothorax. The diagnostic yield of the TBLB in our ILD patients was 66.66%. An adequate diagnostic accuracy (66.66%) was detected in the TBLB in confirming the diagnosis of ILD; in addition, the bleeding was the most prevalent complication of this procedure. More interventional studies are needed to compare the diagnostic accuracy of this procedure with other invasive and noninvasive diagnostic methodologies of ILD.

Identification and characterization of a crucial guanine nucleotide exchange factor (GEF), p63RhoGEF in blood pressure regulation in zebrafish aiming for a novel high-throughput drug screening.

Smooth muscle contraction incorporates two pathways: the intracellular Ca2+ concentration-dependent and Ca2+ sensitization pathways. For years, the effector between the key players of the Ca2+ sensitization pathway, G protein-coupled receptors and a small GTPase, RhoA, was unknown until we identified a Guanine nucleotide Exchange Factor (GEF), p63RhoGEF. Unlike RhoA, ubiquitously expressed and thus irrelevant to a drug target with tissue specificity, p63RhoGEF expression is limited to smooth muscle. Our goal is to identify compounds that specifically inhibit p63RhoGEF, blood vessel constriction, and thus hypertension. We showed p63RhoGEF being activated upon microvasculature constriction in mice. However, using mice is not cost-efficient in large-scale inhibitory compound screening. Therefore, we moved our focus to zebrafish, one of the model animals of vertebrates, to invent a fast, easy-to-use, and non-invasive methodology of screening. We can directly observe the fin vascular network while the animal is alive, i.e., in physiologically ideal conditions. The bioinformatical analysis identified two pairs of potential p63RhoGEF isoforms in zebrafish. While reporting one Pfu amplified isoform, we identified some mutations in two other Taq amplified isoforms compared to those in the NCBI database and nailed the most relevant candidates through bioinformatical analysis. We report the process of analysis and the sequences of all amplicons. We constructed expression plasmids, over-expressed those p63RhoGEF candidates, and acquired preliminary observations. In the future, we will not only pursue functional analysis but also in situ hybridization to locate the expression of those isoforms to show that those newly identified isoforms are useful targets for drug screening. The system proposed here must set a solid foundation for screening p63RhoGEF inhibitors in physiologically ideal conditions and in a swift, cost-efficient manner.

Russian Icons, 17th–18th c. Non-Destructive, Non-Invasive Diagnostic Methodology for an Integrated Study of Micrographic Triptychs from the Benaki Museum Collection

The study aims to enhance our knowledge of the materials and techniques applied in the making of Russian, portable ecclesiastical paintings produced after the 16th century, and to evaluate a pilot, non-destructive, non-invasive, research methodology proposed for their examination. Based on research relating to the historical background of their production and distribution in the South, the availability of materials and the applied techniques, a non-destructive, non-invasive methodology is exploited to examine three triptychs and two polyptych side panels belonging to the collection of the Benaki Museum. As their small size and excellent state of preservation prohibit sampling, a study scheme based on visual examination, the implementation of a series of spectral imaging techniques (VIS, IRRFC, SWIR, UVL, RTI, X ray) and a non-invasive micro XRF analysis is tested. Fiber and wood-type identification are carried out microscopically. The collected information relates to the making of the frames and the supports, the design, the use of metal foils and pigments, the order of application of paint layers and the rendering techniques. Due to the non-destructive, non-invasive character of the procedure, organic constituents are not thoroughly examined. Use of an expected palette was confirmed, but the modelling proved rather sophisticated. Among the most interesting finds were the use of distinct pigment mixtures for the underpaints of the flesh parts and certain deviations from the expected rendering techniques. The methodology proved very effective in terms of its output, the global approach of the construction technique, the user-friendly application, the low cost and time consumption factors.

A non-invasive study of the effect of three commercial cleaning products on shellac-coated mahogany

The Royal Palace of Norway has a large 19th century wooden furniture collection and most of it is coated with shellac-based varnishes. Since these objects are part of the royal collections, they are still in daily use at the different residences and, therefore, need to be frequently cleaned. In this work, the effect of three cleaning commercial products (Baolin, Centurio, Fulgentin) used at the royal collections on shellac-coated mahogany is investigated for the first time. A non-invasive methodology (portable ER-FTIR spectroscopy and colorimetry) was applied to assess whether the chemical composition and the color of fresh and artificially aged mahogany wood mock-ups coated with shellac were affected by the above-mentioned cleaning products. This study shows that one of them causes changes in the varnished wood, thus potentially affecting the long-term conservation of this furniture collection.

Improved Tool for Predicting Skin Irritation on Reconstructed Human Epidermis Models Based on Electrochemical Impedance Spectroscopy

The rabbit skin irritation test has been the standard for evaluating the irritation potential of chemicals; however, alternative methods that do not use animal testing are actively encouraged. Reconstructed human epidermis (RhE) models mimic the biochemical and physiological properties of the human epidermis and can be used as an alternative method. On RhE methods, the metabolic activity of RhE models is used to predict skin irritation, with a reduction in metabolic activity indicating a reduced number of viable cells and linking cell death to skin irritation processes. However, new challenges have emerged as the use of RhE models increases, including the need for non-invasive and marker-free methodologies to assess cellular states. Electrochemical impedance spectroscopy (EIS) is one such methodology that can meet these requirements. In this study, our results showed that EIS can differentiate between irritant and non-irritant chemicals, with a significant increase in the capacitance values observed in the irritant samples. A ROC curve analysis showed that the prediction method based on EIS met OECD TG 439 requirements at all time points and had 95% within-laboratory reproducibility. Comparison with the MTT viability assay showed that prediction using EIS achieved higher sensitivity, specificity, and accuracy. These results suggest that EIS could potentially replace animal testing in the evaluation of irritation potential and could be a valuable addition to in vitro testing strategies.

Using a non-invasive multiple-method approach to characterize rock glaciers in the periglacial critical zone: An example from the San Juan Mountains, Colorado

Anthropogenic climate change threatens water storage and supply in the periglacial critical zone. Rock glaciers are widely distributed alpine aquifers with slower response to temperature increases, that provide the summer water flow of many alpine streams. Knowing the extent and makeup of rock glaciers is necessary to evaluate their potential for water supply. We used non-invasive methods, integrating geological, geomorphological, meteorological, and geophysical information to characterize the internal structure and hydrology of the Upper Camp Bird rock glacier (UCBRG) located on level 3 of Camp Bird Mine in Ouray, Colorado, and assessed the applicability of two electromagnetic induction systems in this highly heterogeneous landform with a history of anthropogenic activity. The time-domain (G-TEM™) system achieved deep subsurface penetration (~100 m) and realistic modeling of the internal structure of the UCBRG: a shell of volcanic rock fragments (<3 m thick; 1–100 Ohm-m), a meltwater component (102–103 Ohm-m), located between 50 and 100 m near the toe (subpermafrost flow), and 1–30 m in the soundings farthest from the toe (suprapermafrost flow within the active layer), and a frozen component (permafrost 50–80 m thick; 103–106 Ohm-m). The frequency-domain system, however, was highly susceptible to local environmental conditions, including anthropogenic objects (i.e., mine carts, lamp posts, tunnel tracks, etc.) and was unable to resolve UCBRG's internal makeup. The non-invasive methodology and general conceptual framework presented here can be used to characterize other alpine aquifers, contributing to the quantification of global water resources, and highlighting the importance of preserving rock glaciers as storage for critical water supply in the future.

An Innovative PEMFC Magnetic Field Emulator to Validate the Ability of a Magnetic Field Analyzer to Detect 3D Faults

An original non-invasive methodology of the fuel cell diagnosis is proposed to identify different positions of the faults in Proton Exchange Membrane Fuel Cell (PEMFC) stacks from external magnetic field measurements. The approach is based on computing the external magnetic field difference between normal and faulty PEMFC operating conditions. To evaluate the external magnetic field distribution, in this paper, we propose an improved design of the magnetic field analyzer. This analyzer amplifies the magnetic field around the cell to perform an accurate detection of the fault position. Moreover, the main contribution of this work is represented by conceiving and implementing a 3D multi-physical current distribution emulator of a proton exchange membrane fuel cell. The new concept of a proton exchange membrane fuel cell emulator has been specially designed to emulate the magnetic field of a real fuel cell stack. This emulator concept is also beneficial for a new model of the fuel cell, which implies a multi-physical coupling between electrochemical electric conduction and the generated magnetic field. Finally, finally, the numerical model and the emulator have been involved in the realization of numerical simulations and experimental analysis to prove the ability of the system to detect and localize 3D faults.

Identifying the midline thalamus in humans in vivo.

The midline thalamus is critical for flexible cognition, memory, and stress regulation in humans and its dysfunction is associated with several neurological and psychiatric disorders, including Alzheimer's disease, schizophrenia, and depression. Despite the pervasive role of the midline thalamus in cognition and disease, there is a limited understanding of its function in humans, likely due to the absence of a rigorous noninvasive neuroimaging methodology to identify its location. Here, we introduce a new method for identifying the midline thalamus in vivo using probabilistic tractography and k-means clustering with diffusion weighted imaging data. This approach clusters thalamic voxels based on data-driven cortical and subcortical connectivity profiles and then segments the midline thalamus according to anatomical connectivity tracer studies in rodents and macaques. Results from two different diffusion weighted imaging sets, including adult data (22-35years) from the Human Connectome Project (n = 127) and adolescent data (9-14years) collected at Florida International University (n = 34) showed that this approach reliably classifies midline thalamic clusters. As expected, these clusters were most evident along the dorsal/ventral extent of the third ventricle and were primarily connected to the agranular medial prefrontal cortex (e.g., anterior cingulate cortex), nucleus accumbens, and medial temporal lobe regions. The midline thalamus was then bisected based on a human brain atlas into a dorsal midline thalamic cluster (paraventricular and paratenial nuclei) and a ventral midline thalamic cluster (rhomboid and reuniens nuclei). This anatomical connectivity-based identification of the midline thalamus offers the opportunity for necessary investigation of this region in vivo in the human brain and how it relates to cognitive functions in humans, and to psychiatric and neurological disorders.

Glucocorticoid metabolites in an ex situ nocturnal bird, the tropical screech owl Megascops choliba: effects of sex, activity period and inter-individual variation

Glucocorticoids mediate physiological processes to obtain energy, presenting daily variation in basal levels that may be related to behavioural activity pattern. Identification of plasticity in the secretion of these hormones is essential to understand their effects on physiology and behaviour of wild birds and, therefore, their success in their natural or artificial environment. Serial endocrine evaluations are facilitated by implementing non-invasive methodologies that minimize possible effects of manipulation on the animal's physiological variables. However, non-invasive endocrine-behavioural studies in nocturnal birds, such as owls, are immature. The present work aimed to validate an enzyme immunoassay (EIA) to quantify glucocorticoid metabolites (MGC) in Megascops choliba as well as to evaluate differences in their production at the individual, sexual or daily level. We recorded the behaviour of nine owls during three continuous days to establish activity budget under captive conditions and aiming to correlate with daily MGC variation. The EIA proved to be effective in analytical assays and in pharmacological testing with synthetic ACTH, validating this immunoassay for the species. Additionally, individual differences in MGC production were confirmed in relation to the time of day, especially at 1700 and 2100, but not in relation to sex. During night hours, the owls showed greater behavioural activity, positively related to MGC values. Higher MGC concentrations were significantly related to greater expressions of active behaviours, such as maintenance, while lower MGC concentrations were recorded during moments of higher alertness and resting. The results presented show daily MGC variation to be inversed in this nocturnal species. Our findings can aid future theoretical studies of daily rhythm and evaluations of challenging and/or disturbing situations that result in changes in behaviour or hormonal cascades of these changes in ex situ populations of owls.

Development of a non-invasive method for testicular toxicity evaluation using a novel compact magnetic resonance imaging system.

In non-clinical animal studies for drug discovery, histopathological evaluation is the most powerful tool to assess testicular toxicity. However, histological analysis is extremely invasive; many experimental animals are needed to evaluate changes in the pathology and anatomy of the testes over time. As an alternative, small animal magnetic resonance imaging (MRI) offers a non-invasive methodology to examine testicular toxicity without radiation. The present study demonstrated the suitability of a new, ready-to-use compact MRI platform using a high-field permanent magnet to assist with the evaluation of testicular toxicity. To validate the utility of the MRI platform, male mice were treated with busulfan (40 mg/kg, intraperitoneal injection). Twenty-eight days after treatment, both testes in busulfan-treated and control mice (n = 6/group) were non-invasively scanned in situ by MRI at 1 tesla. On a T1-weighted 3D gradient-echo MRI sequences (voxel size: 0.23 × 0.23 × 0.50 mm), the total testicular volume in busulfan-treated mice was significantly smaller than in controls. On T1-weighted images, the signal intensity of the testes was significantly higher in busulfan-treated mice than in controls. The mice were sacrificed, and the testes were isolated for histopathological analysis. The weight of the testes in busulfan-treated mice significantly decreased, similar to the results of the non-invasive analysis. Additionally, periodic acid-Schiff stain-positive effusions were observed in the interstitium of the busulfan-treated mouse testes, potentially explaining T1 shortening due to a high concentration of glycoproteinaceous content. The present data demonstrated a rapid evaluation of testicular toxicity in vivo by compact MRI.

Biomarkers of reproductive health in wildlife and techniques for their assessment

Historically, reproductive health in wildlife species has been evaluated primarily via immunoassay detection of fecal and urinary steroid hormone metabolites. This combination of sample type, biomarker category, and assay has been preferred for decades due to the ease of assessing reproductive health through the evaluation of stable compounds in easily collected biological samples using a cost-effective method. Increasingly, beginning with high performance liquid chromatography (HPLC) and more recently with convergence chromatography and ultra HPLC coupled with mass spectrometry (MS), wildlife studies are incorporating more sensitive and specific high-throughput technologies for the assessment of not only steroid hormone metabolites but proteins as well. Of note, a comprehensive health evaluation requires the measurement of biological readouts that modulate reproduction such as: glucocorticoids, leptin, insulin, thyroid hormones, melatonin, the microbiome, and markers of inflammation. Emerging modulatory biomarkers of reproductive health include acute phase proteins, microRNAs, and reactive oxygen species. Several of these biomarkers require application of newer technologies such as LC-MS/MS and sequencing, which demonstrates the need for the field of wildlife reproductive biology to diversify from its reliance on immunoassays. Importantly, endocrine disrupting chemicals adversely affect many aspects of reproductive function and evaluation of these compounds requires high throughput technology such as LC-MS/MS. The application of sequencing, particularly Next Generation Sequencing of bulk RNA (RNA-Seq) and single cell RNA-Seq, is uncommon in studies of wildlife reproductive health. However, as the cost of these methods decreases and consortiums of wildlife researchers band together to raise funds in support of studies using these technologies, their use will become more routine. Future research should focus on integration of known biomarkers of related systems into comprehensive reproductive assessments and the development of new biomarkers which are sensitive, precise, and employ non-invasive methodologies for the assessment of reproductive health of wildlife species.

Development of a methodology for the characterisation and assessment of biodeteriogens on archaeological surfaces by use of a portable LED-induced fluorescence instrument

The present study focuses on the development of a fast, non-invasive methodology, appropriate for the detection and characterization of biodeterioration present on the surface of archaeological/historical stone objects and monuments, by exploiting the characteristic fluorescence emission of biological deposits. Fluorescence spectra were collected by use of a portable LED (Light Emitting Diode)-Induced Fluorescence (LED-IF) instrument. Three limestone fragments and one mortar fragment, from different monuments in Greece, presenting various types of biodeterioration on their surface, have been investigated in the laboratory. First, fluorescence emission spectra were acquired with a benchtop laboratory spectrofluorometer in order to select the optimum excitation wavelengths for the fluorophores present in the biological crust. An evaluation of the portable LED-IF instrument was conducted by assessing the performance of its optical components and different LED excitation sources, while an investigation of several experimental parameters on the fluorescence signal was also performed. Furthermore, issues related to the efficiency of detection and identification of biological growth have been studied, such as the effect of sample surface wetting on the fluorescence signal. The results of the present study demonstrate that the LED-IF instrument can be used for a fast and reliable assessment of the presence of biodeterioration on monuments.

The Colors of the Butterfly Wings: Non-Invasive Microanalytical Studies of Hand-Coloring Materials in 19th-Century Daguerreotypes

The public expected color from the early photographic images, yet, daguerreotypes—the first commercially available photographic process—failed to register the natural colors. Daguerreotypists developed several coloring methods to solve this inconvenience after 1840. Scientific analyses of the hand-colored daguerreotypes are limited, and the primary information sources available are manuals and patents. This study aims to contribute to the knowledge of hand-coloring techniques, which impacts conservation practices, mainly the cleaning procedures and complements technical art history investigations. We studied nine colored daguerreotypes with a non-invasive methodology based on three spectroscopic techniques: X-ray fluorescence (XRF), micro-Raman spectroscopy (μ-Raman), and micro-Fourier-transform infrared spectroscopy in reflection mode (μ-rFTIR). The results revealed the different colorants and some of their mixtures employed by the colorist. It also adds information regarding the photographic production of three studios: Désiré François Millet, active in Paris between 1840 and 1868; Antoine Claudet (1797–1867), active in London; and the James E. McClees and Washington Lafayette Germon studio, operative between 1846 and 1855 in Philadelphia, USA. These technical details constitute a helpful comparison to future studies on Daguerreian studios and colored daguerreotypes.

Autofluorescence Imaging to Evaluate Retinal Disease Progression in Rodent.

Fundus autofluorescence (FAF) imaging is a noninvasive retinal imaging methodology that allows mapping of lipofuscin distribution in the retinal pigment epithelium cell (RPE). Excessive accumulation of lipofuscin granules in the lysosomal compartment of RPE cells represents a common downstream pathogenetic pathway in various hereditary and complex retinal diseases, including age-related macular degeneration. The clinical applications of FAF coupled with its ease of use, and the noninvasive nature of characterizing retinal diseases, are increasingly valuable to the field of ophthalmology and in assessing the progression of retinitis pigmentosa (RP). Quantitative AF (qAF) enhances the understanding of retinal disease processes, serves as a diagnostic aid, and allows for the monitoring of the effects of therapeutic interventions. This chapter introduces basic principles of FAF and general protocols of FAF evaluating retinal disease progression in rodents.

Determining sex in golden eagle (Aquila chrysaetos) nestlings

Incorporating sex ratios of nestlings into population viability studies increases knowledge of overall health of endangered populations. Currently, a reliable non-invasive method to identify the sex of golden eagle nestlings is not available; however, claims are commonly made based on morphology. Ten biometric measurements from 43 Scottish golden eagles aged 2–7.5 weeks were assessed to see if sex could actually be determined using this non-invasive methodology. Sex was confirmed via molecular analysis of blood samples. Discrete and principal component analyses of the different biometrics could not correctly determine individual nestling sex. Therefore, despite being more invasive, molecular sexing remains the recommended tool of choice for accurate sex identification of Scottish golden eagle nestlings younger than 7.5 weeks of age. This has important implications for golden eagle field studies where empirical morphological measurements are frequently and typically taken, but we have shown are not reliable in determining the sex of such young nestlings.