Performance scanning electron microscopic investigations and elemental analysis of hair of the different animal species for forensic identification

Scanning electron microscopy and morphometric analysis of the hair in dromedaries with SEM-EDX in relation to age

BACKGROUND

Hair characterization is critical for determining animal individuality throughout life. This study aimed to assess the morphological features of dromedary camel hair in relation to age.

MATERIALS AND METHODS

Hair samples were obtained from the camel humps of 30 dromedary camels separated into three groups: G1 (n:10) aged one-year, G2 (n:10) aged 3-5 years, and G3 (n:10) at the age of 8-10 years. The hair was examined using light microscopy, SEM, and SEM-EDX.

RESULTS

The Maghrebi camel had varied medulla patterns and structures across the ages. In the G1 group 75% had continuous medulla patterns and amorphous medulla structures, compared to 70% in G2, and 90% in G3. The medulla index increased with age, rising from 0.3 to 0.77%. The shaft width grew in size from G1 to G2, then fell to approximately one-third of the G2 size at G3. The cortex and cuticle widths were also determined by age, and they increased in the G1 compared to G3 camels. The shape of the cuticle scales in G1 camels was wavy, like mountain tops with irregular edges, within G2 camels the scales were particularly long, oval-shaped scales with smooth, wavy borders. The scales of the older G3 camels were quite long and rectangular. SEM-EDX spectra recognized carbon, oxygen, nitrogen, sulfur, calcium, aluminum, silicon, and potassium at the medulla and cortex. Sulfur levels were highest in the G2 samples but lowest in the G1 samples.

CONCLUSION

The dromedary camel's hair structure and mineral content, particularly carbon and nitrogen, differed as camels aged.

Dynamic Drop Penetration of Horizontally Oriented Fiber Arrays

In this experimental study, we combine drop impact into porous media and onto a single fiber to study drop impact into fiber arrays inspired by mammalian fur coats. In our 3D-printed arrays, we vary the packing density, fiber alignment, strand cross-section, and wettability. Drops impact fibers fixed at both ends, penetrating over short periods of time by momentum and laterally spreading throughout the array. Using image analysis, we measure penetration depth and wetted width into the array. Impact Weber number and intrinsic porosity define penetration, retraction, and rebound regimes. On average, at an impact Weber number of ≈80, staggered fibers reduce penetration by 24% in hydrophilic fibers and 34% in hydrophobic fibers, and the penetration reduction percentage is expected to increase with increasing Weber number. Our results indicate that as density grows toward the density of mammalian pelts, penetration will reach a maximum value independent of drop impact velocity, thereby providing an effective rain barrier. Hydrophilicity at the densities we test, 50-150 strands/cm2, aids fiber array resistance to dynamic penetration by impacting drops through the promotion of lateral drop spreading and inhibition of drop fragmentation. Conversely, hydrophobic fibers best resist low-speed wicking. The fraction of a drop that infiltrates hydrophilic and hydrophobic fibers is nearly identical for a fixed Weber number because lateral spreading restricts the penetration depth into hydrophilic fibers but does not restrict mass infiltration. Above a critical Weber number, the entire drop mass penetrates fiber arrays regardless of strand wettability.

Biodegradation of Keratin Waste by Bacillus velezensis HFS_F2 through Optimized Keratinase Production Medium

Enormous aggregates of keratinous wastes are produced annually by the poultry and leather industries which cause environmental degradation globally. To combat this issue, microbially synthesized extracellular proteases known as keratinase are used widely which is effective in degrading keratin found in hair and feathers. In the present work, keratinolytic bacteria were isolated from poultry farm soil and feather waste, and various cultural conditions were optimized to provide the highest enzyme production for efficient keratin waste degradation. Based on the primary and secondary screening methods, the potent keratinolytic strain (HFS_F2T) with the highest enzyme activity 32.65 ± 0.16 U/mL was genotypically characterized by 16S rRNA sequencing and was confirmed as Bacillus velezensis HFS_F2T ON556508. Through one-variable-at-a-time approach (OVAT), the keratinase production medium was optimized with sucrose (carbon source), beef extract (nitrogen source) pH-7, inoculum size (5%), and incubation at 37 °C). The degree of degradation (%DD) of keratin wastes was evaluated after 35 days of degradation in the optimized keratinase production medium devoid of feather meal under submerged fermentation conditions. Further, the deteriorated keratin wastes were visually examined and the hydrolysed bovine hair with 77.32 ± 0.32% degradation was morphologically analysed through Field Emission Scanning Electron Microscopy (FESEM) to confirm the structural disintegration of the cuticle. Therefore, the current study would be a convincing strategy for reducing the detrimental impact of pollutants from the poultry and leather industries by efficient keratin waste degradation through the production of microbial keratinase.

Simple and field-adapted species identification of biological specimens combining multiplex multienzyme isothermal rapid amplification, lateral flow dipsticks, and universal primers for initial rapid screening without standard PCR laboratory

Species identification of biological specimens can provide the valuable clues and accelerate the speed of prosecution material processing for forensic investigation, especially when the case scene is inaccessible and the physical evidence is cumbersome. Thus, establishing a rapid, simple, and field-adapted species identification method is crucial for forensic scientists, particularly as first-line technology at the crime scene for initial rapid screening. In this study, we established a new field-adapted species identification method by combining multiplex multienzyme isothermal rapid amplification (MIRA), lateral flow dipstick (LFD) system, and universal primers. Universal primers targeting COX I and COX II genes were used in multiplex MIRA-LFD system for seven species identification, and a dedicated MIRA-LFD system primer targeting CYT B gene was used to detect the human material. DNA extraction was performed by collecting DNA directly from the centrifuged supernatant. Our study found that the entire amplification process took only 15 min at 37 °C and the results of LFDs could be visually observed after 10 min. The detection sensitivity of human material could reach 10 pg, which is equivalent to the detection of single cell. Different common animal samples mixed at the ratio of 1 ng:1 ng, 10 ng:1 ng, and 1 ng:10 ng could be detected successfully. Furthermore, the damaged and degraded samples could also be detected. Therefore, the convenient, feasible, and rapid approach for species identification is suitable for popularization as first-line technology at the crime scene for initial rapid screening and provides a great convenient for forensic application.

Histological and ultrastructural characterization of the dorso-ventral skin of the juvenile and the adult starry puffer fish (Arothron stellatus, Anonymous 1798)

BACKGROUND

The starry puffer fish (Arothron stellatus, Anonymous, 1798) is a poisonous tetradontidae fish inhabiting the Red sea. The skin constitutes an important defense against any external effects. The study aims to characterize the dorso-ventral skin of the juvenile and the adult starry puffer fish using light and scanning electron microscopies. Twenty specimens of juvenile and adult fresh fishes were used.

RESULTS

The scanning electron microarchitecture of the skin of the juvenile and adult fish showed delicate irregular-shaped protrusions, and well-defined bricks-like elevations on the dorsal side and interrupted folds as well as irregular-shaped protrusions on the ventral side. In adult fish, the patterned microridges of the superficial and deep epithelial cells (keratinocytes) were larger and well-defined in the dorsal skin than in the ventral side, the contrary was seen in the juvenile fish. The microridges were arranged in a fingerprint or honeycomb patterns. The openings of the mucous cells were more numerous in the dorsal skin in both age stages but more noticeable in adult. Furthermore, the sensory cells were more dominant in the juveniles than the adults. The odontic spines were only seen in adult. Histologically, few taste buds were observed in the epidermis of the dorsal skin surface of the adult fish. Both mucous and club cells were embedded in the epidermis of the juvenile and adult fish with different shapes and sizes. Melanophores were observed at the dorsal skin of both juvenile and adult fishes while fewer numbers were noticed at the ventral surfaces. Several dermal bony plates with different shapes and sizes were demonstrated in the skin of both adult and juvenile fishes.

CONCLUSION

The structural variations of skin of the juvenile and adult fishes may reflect the various environmental difficulties that they confront.

Preen gland of the laughing dove (Streptopelia senegalensis aegyptiaca): Light and electron microscopic analysis

This work reviews the microscopic anatomy of the preen gland in laughing dove (Streptopelia senegalensis aegyptiaca) using light, scanning, and transmission electron microscopes. The gland possessed two large pea-shaped lobes. The glandular lobules of each lobe were huddled in elliptical, triangle, round shapes, connected with each other by strands of connective tissue septae. The lobule was composed of glandular follicles, each follicle folded and enclosed by a sheath of connective tissue connected with the neighboring ones by interfollicular septae. The gland's parenchyma was coated with a dense connective tissue capsule composed of collagen, elastic, and reticular fibers. The secretory tubules were divided into peripheral tubules and central tubules. The central ones were located close to the major cavity and lined with thin epithelium, whereas the peripheral tubules were adjacent to the capsule and characterized by taller epithelium. The central secretory tubules were lined with four cell layers: flattened basal, large-sized polyhedral intermediate, and secretory cell layers, as well as a degenerative cells layer that formed of small cells with pale cytoplasm and pyknotic nuclei. Variable sizes and shapes of Herbst corpuscles were detected alongside the papillary duct and near the glandular lobe. Transmission electron microscopy view revealed that the cytoplasm of the intermediate cells contained a dense population of mitochondria, while the secretory and degenerative cells contained fewer mitochondria. In conclusion, these structures will be beneficial for understanding the habitat differences of laughing doves. RESEARCH HIGHLIGHTS: Grossly, the preen gland (PG) of the laughing dove formed of two large pea-shaped lobes. The glandular lobule was composed of glandular follicles, each follicle was folded and enclosed by a sheath of connective tissue connected with the neighboring ones by interfollicular septae. The central secretory tubules were lined with four cell layers: basal, intermediate, secretory, and degenerative cell layers. Variable sizes and shapes of Herbst corpuscles were detected alongside the papillary duct and near the glandular lobe of the PG. In transmission electron microscopic analysis, the cytoplasm of the intermediate cells contained a dense population of mitochondria, while the secretory and degenerative cells contained fewer mitochondria.

Multidimensional Profiling of Human Body Hairs Using Qualitative and Semi-Quantitative Approaches with SR-XRF, ATR-FTIR, DSC, and SEM-EDX

This study aimed to assess the potential of a multidimensional approach to differentiate body hairs based on their physico-chemical properties and whether body hairs can replace the use of scalp hair in studies linked to forensic and systemic intoxication. This is the first case report controlling for confounding variables to explore the utility of multidimensional profiling of body hair using synchrotron synchrotron microbeam X-ray fluorescence (SR-XRF) for longitudinal and hair morphological region mapping) and benchtop methods, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) (complemented with chemometrics analysis), energy dispersive X-ray analysis (EDX) (complemented with heatmap analysis), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analysis (complemented by descriptive statistics) to profile different body hairs in terms of their elemental, biochemical, thermal, and cuticle properties. This multidimensional approach provided supportive information to emphasize the intricate and rather complex interplay between the organization and levels of elements and biomolecules within the crystalline and amorphous matrix of different body hairs responsible for the differences in physico-chemical properties between body hairs that are predominantly affected by the growth rate, follicle or apocrine gland activity, and external factors such as cosmetic use and exposure to environmental xenobiotics. The data from this study may have important implications for forensic science, toxicology and systemic intoxication, or other studies involving hair as a research matrix.

Histomorphology and ultrastructure of the proventriculus of the broad breasted white turkey (Meleagris gallopavo, Linnaeus 1758)

This study aims to examine the functional morphology of the proventriculus of the broad breasted white turkey (BBWT) (Meleagris gallopavo, Linnaeus 1758) using gross anatomy, light microscopy, gross/histomorphometric analysis, and scanning and transmission electron microscopy. The proventriculus was characterized internally by many elevated papillae with a mound, leafy flower, and lotus flower-shapes. Each papilla was enclosed by concentrically organized mucosal folds with distinct or indistinct proventricular gland openings on its top. Longitudinal folds and grooves at the junction of the proventriculus with the esophagus exhibited various sized and shaped openings of esophageal glands with irregular outlines. Histologically, the surface epithelium of the proventriculus was covered by a thin layer of cuticle, particularly evident at its junction with the gizzard. The lamina epithelialis and propria, and secretory units of proventricular lobules were infiltrated by aggregations of lymphocytes and lymphoid follicles (nodules). Variably shaped glandular lobules of proventricular glands occupied the submucosa, surrounded by thin strands of smooth muscle fibers derived from muscularis mucosa. Triangular, cuboidal, or columnar-shaped secretory oxyntico-peptic cells lined the secretory units. Many telocytes (pyramidal or fusiform-shaped cell bodies with lengthy telopodes) were observed in interstitial tissue. Further, two types of argyrophilic endocrine cells were identified within the glandular epithelium. The morphology of the M. gallopavo proventriculus reflects its dietary habits and behavior.