Solution dyed fibers are synthetic fibers colored through the addition of insoluble pigmentation to the polymer prior to extrusion. This is in contrast to most textile fibers, which are traditionally ...colored via immersion in liquid dyebaths following extrusion. Solution dyed fibers are increasing in market share in numerous applications (e.g., apparel, carpet, upholstery), and thus, the microscopic characteristics and variety of pigments used to color them represent unexploited properties in forensic fiber comparisons. This paper presents the development of a microscopical process to first recognize a fiber as solution dyed and subsequently characterize the color and optical properties of each type of pigment found in a given fiber. To this end, a set of 76 fibers, representing polypropylene, nylon, polyester, and rayon, spanning all nominal colors and several consumer applications were analyzed longitudinally and in cross section using a combination of polarized light, fluorescence, and oil immersion microscopy. A given fiber contained between one and six different pigments, and a total of 260 pigments (not all unique) were recognized within this set of fibers. Pigment morphologies were categorized as angular, elongated, rounded, finely divided, or streaky, and about 40% of the pigments fluoresced. Ultimately, this body of data is intended to provide trace evidence examiners with a specific approach to recognize and begin to exploit pigmented fibers encountered in casework.
We report on a set of transmission experiments over seven different uncompensated fiber links carrying a 22-channel Nyquist-WDM signal comb based on polarization-multiplexed 16-quadrature amplitude ...modulation at RS=15.625 GBd(RB=125 Gb/s). The channel spacing was Δf=16 GHz. The experimental transmission performance was compared with analytical GN-model predictions showing a good agreement for all seven considered fiber types. Moreover, we used the experimental results for the validation of a fiber figure of merit based on the maximum reach, showing its effectiveness for approximate fiber performance prediction. Within the experimental tests, a maximum transmission distance of 3810 km at a bit error-rate of 1.5×10 -2 was achieved using a pure-silica-core fiber with 150 μm 2 effective area, at a net spectral-efficiency-distance product of 24700 (b·km)/(s· Hz), in a good agreement with the GN-model forecast.
In 2017 Cooktown resident Donna Steele was murdered and the case remained unsolved for more than a year. The forensic evidence from the investigation included two lengths of synthetic twine and a new ...protocol for the comparison of twine was developed to enhance the potential value of any evidence. The method was developed using 23 samples of similar twine collected across Australia. Traditional methods of physical and microscopic comparisons and polymer analysis by infrared spectroscopy were retained. Micro-spectrophotometry was used as an objective assessment of colour and was able to identify five groupings within the background samples. Measurements of hydrogen and carbon stable isotopic composition provided further delineation of the background samples. Combining traditional methods with micro-spectrophotometry and stable isotope measurements, the two case samples were found to be distinct from the background population and were indistinguishable when compared to each other.
A headspace solid-phase microextraction (HS-SPME) procedure based on five commercialised fibres (85
μm polyacrylate – PA, 100
μm polydimethylsiloxane – PDMS, 65
μm polydimethylsiloxane/divinylbenzene ...– PDMS/DVB, 70
μm carbowax/divinylbenzene – CW/DVB and 85
μm carboxen/polydimethylsiloxane – CAR/PDMS) is presented for the characterization of the volatile metabolite profile of four selected Madeira island fruit species, lemon (
Citrus limon), kiwi (
Actinidia deliciosa), papaya (
Carica papaya L.) and Chickasaw plum (
Prunus angustifolia). The isolation of metabolites was followed by thermal desorption gas chromatography–quadrupole mass spectrometry (GC–qMS) methodology. The performance of the target fibres was evaluated and compared. The SPME fibre coated with CW/DVB afforded the highest extraction efficiency in kiwi and papaya pulps, while in lemon and plum the same was achieved with PMDS/DVB fibre. This procedure allowed for the identification of 80 compounds, 41 in kiwi, 24 in plums, 23 in papaya and 20 in lemon. Considering the best extraction conditions, the most abundant volatiles identified in kiwi were the intense aldehydes and ethyl esters such as (E)-2-hexenal and ethyl butyrate, while in Chicasaw plum predominate 2-hexenal, 2-methyl-4-pentenal, hexanal, (Z)-3-hexenol and cyclohexylene oxide. The major compounds identified in the papaya pulp were benzyl isothiocyanate, linalool oxide, furfural, hydroxypropanone, linalool and acetic acid. Finally, lemon was shown to be the most divergent of the four fruits, being its aroma profile composed almost exclusively by terpens, namely limonene, γ-terpinene, o-cymene and α-terpinolene. Thirty two volatiles were identified for the first time in the fruit or close related species analysed and 14 volatiles are reported as novel volatile metabolites in fruits. This includes 5 new compounds in kiwi (2-cyclohexene-1,4-dione, furyl hydroxymethyl ketone, 4-hydroxydihydro-2(3H)-furanone, 5-acetoxymethyl-2-furaldehyde and ethanedioic acid), 4 in plum (4-hydroxydihydro-2(3H)-furanone, 5-methyl-2-pyrazinylmethanol, cyclohexylene oxide and 1-methylcyclohexene), 4 in papaya (octaethyleneglycol, 1,2-cyclopentanedione, 3-methyl-1,2-cyclopentanedione and 2-furyl methyl ketone) and 2 in lemon (geranyl farnesate and safranal). It is noteworthy that among the 15 volatile metabolites identified in papaya, 3-methyl-1,2-cyclopentanedione was previously described as a novel PPARγ (peroxisome proliferator-activated receptor γ) agonist, having a potential to minimize inflammation.
The amino acid sequence of the adenovirus type 31 (subgenus A) fibre polypeptide was deduced from the nucleotide sequence of the fibre gene. The analysed peptide sequence showed an organization ...consistent with the structural domains described for other adenoviruses: an amino-terminal tail region, an intervening shaft region and a carboxy-terminal knob. The AV31 fibre shaft displayed 20 repeats of the 15-amino-acid segments in the shaft domain, which agreed with the reported length of the fibre. The predicted AV31 fibre polypeptide sequence was compared to fibre polypeptides of serotypes representing subgenera A to F. As expected, AV31 and AV12, both belonging to subgenus A, showed the highest overall homology (75.4%). When comparing the AV31 fibre to the fibre polypeptides of subgenera B to F, AV31 and AV41 (subgenus F) shared the highest overall homology (35.3%), followed by AV40 (34.8%). The lowest overall homology (20.3%) was found for the AV31 and AV3 fibres (subgenus B). From the data presented, it could be suggested that AV31 is more closely related to the enteric viruses of subgenus F than to the other adenoviruses analysed. Comparing the fibre polypeptides of 14 adenovirus serotypes, 10 conserved amino acid sequences were detected, 5 of which were in the knob region. Since the fibre knob interacts with the host cell during infection, these conserved amino acids might be important for virus attachment. The gastroenteritis-causing adenoviruses AV40 and AV41 shared 3 additional conserved amino acid residues with AV31 and AV12 in the knob region.
La séquence en acides aminés du polypeptide de la fibre de l'adénovirus 31 (AV31, sous-genre A) a été déduite de la séquence nucléotidique du gène de la fibre. L'analyse de cette séquence montre une organisation qui correspond aux domaines structuraux déjà décrits pour les autres adénovirus: une région dite “queue” en position N-terminale, une région “tige” intermédiaire, et un renflement distal C-terminal. La tige de la fibre de l'AV31 est composée de 20 répétitions du motif de 15 acides aminés, ce qui est en bonne concordance avec la longueur de la protéine fibre reportée précédemment. La séquence prédite pour la fibre de l'AV31 a été comparée à celle de sérotypes représentant les sous-genres A à F. Comme prévu, l'AV31 et l'AV12, tous deux appartenant au sousgenre A, montrent la plus forte homologie de séquence (75.4%). La comparaison avec les fibres des sous-genres B à F révèle que l'AV31 et l'AV41 (sous-genre F) possèdent la plus forte homologie globale (35.3%), suivi de l'AV40 (34.8%). Le plus faible degré d'homologie (20.3%) a été observé entre l'AV31 et l'AV3 (sous-genre B). L'ensemble de ces résultats suggèrent que l'AV31 est plus proche des virus entériques du sous-genre F que des autres adénovirus caractérisés jusqu'ici. L'analyse comparative de la séquence de la fibre de 14 sérotypes différents a montré que l'on pouvait individualiser 10 séquences conservées, dont 5 situées dans le renflement distal. Puisque c'est cette région de la fibre qui interagit avec la cellule hôte durant la phase initiale de l'infection, ces acides aminés conservés doivent jouer un rôle important dans l'attachement du virus. Les adénovirus qui sont les agents étiologiques de gastroentérites, AV40 et AV41, possèdent 3 résidus d'acides aminés supplémentaires en commun avec les sérotypes AV31 et AV12, dans la région du renflement distal.
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