456 research outputs found

    A pilot study examining garment severance damage caused by a trained sharp-weapon user

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    The pilot study summarized in this paper aimed to raise awareness of a gap that exists in the forensic textile science literature about damage caused to clothing by trained sharp-weapon users. A male trained in the Filipino martial arts discipline of Eskrima performed attack techniques on a physical model of a male torso covered with a 97% cotton/3% elastane knitted T-shirt, that is, a garment commonly worn by males. Fabric severance appearance created by three different, but commonly available, knives was evaluated. High-speed video was used to capture each attack. After each attack the resulting damage to the garment was assessed. This pilot study highlighted differences in severances associated with weapon selection, that is, not all knives resulted in similar patterns of textile damage. In addition, a mixture of stab and slash severances were observed. The findings demonstrated the possible misinterpretation of textile damage under these circumstances compared to damage patterns reported in the existing forensic textile science literature for more commonly occurring knife attacks (i.e. stabbings)

    Victim’s posture and protective clothing changes the approach in an edged-weapon attack

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    Diverse groups of people use edged-weapons (i.e. knives, spears, swords) professionally. The training received affects how the edged-weapon is used and the area of the body targeted. There is a growing body of information available on the internet which is aimed at the training individuals in offensive knife attacks. This poster aims to raise awareness of this issue and highlight how a trained individual modifies an attack sequence depending on their victim’s posture and the protective clothing worn. A male trained in the Filipino martial arts discipline of Eskrima performed attack techniques on a static mannequin covered with a long sleeved upper body garment and leggings, a police custodian helmet and a HG1 + KR1 police body armour. In some simulated attacks the target was also dressed in a police high-visibility tactical vest on top of the body armour. High-speed video was used to capture each simulated attack and the impact location on the torso recorded using ultra-violet sensitive liquid applied to the weapon. Target posture was modified by adjusting the arm position of the mannequin. In a second series of experiments a PermaGel™ male target torso was used so that penetrating damage could be assessed. Data collected identified the change of attack due to victim’s posture and vulnerability of the neck, underarm area and groi

    A copper-catalyzed asymmetric oxime propargylation enables the synthesis of the gliovirin tetrahydro-1,2-oxazine core

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    The bicyclic tetrahydro-1,2-oxazine subunit of gliovirin is synthesized through a diastereoselective copper-catalyzed cyclization of an N-hydroxyamino ester. Oxidative elaboration to the fully functionalized bicycle was achieved through a series of mild transformations. Central to this approach was the development of the first catalytic, enantioselective propargylation of an oxime to furnish a key N-hydroyxamino ester intermediate

    Avian mycobacteriosis in chickens from a rural area of Argentina

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    An outbreak of avian tuberculosis was detected in chickens from a rural area of Chaco Province, northeastern Argentina. The hens were emaciated and presented granulomatous lesions of various sizes throughout the internal organs. The lesions observed in three necropsied birds consisted of granulomas containing alcohol/acid-fast bacilli. All the lesions found were diagnosed histopathologically as tuberculosis, Mycobacterium avium subsp. avium were isolated from the cultures and confirmed by polymerase chain reaction techniques

    Early spears as thrusting weapons: Isolating force and impact velocities in human performance trials

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    Human hunting has been a cornerstone of research in human evolutionary studies, and decades worth of research programmes into early weapon systems have improved our understanding of the subsistence behaviours of our genus. Thrusting spears are potentially one of the earliest hunting weapons to be manufactured and used by humans. However, a dearth of data on the mechanics of thrusting spear use has hampered experimental research. This paper presents a human performance trial using military personnel trained in bayonet use. Participants thrusted replicas of Middle Pleistocene wooden spears into PermaGelâ„¢. For each spear thrust, impact velocity was recorded with high-speed video equipment, and force profiles were recorded using a force transducer. The results demonstrate that training improves performance when compared with previous experimental results using untrained participants, and that the mechanics and biomechanics of spear thrusting are complex. The trial confirms that previous spear thrusting experiments firing spears as projectiles are failing to replicate the entire spear thrusting event, and that crossbows are too powerful to replicate the low velocities involved in spear thrusting. In order to better understand evidence of spear thrusting in the archaeological record, experimental protocols accurately replicating and recording the mechanics of spear thrusting in the past are proposed

    Azulene – Thiophene – Cyanoacrylic acid dyes with donor-π-acceptor structures. Synthesis, characterisation and evaluation in dye-sensitized solar cells

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    We report the synthesis of five new azulene containing dyes, having D-π-A type structures. These dyes are synthesised using a sulfonium salt cross-coupling reaction. The dyes have been evaluated spectroscopically, electrochemically, crystallographically, and as sensitizers in dye-sensitized solar cells. We propose a rationale for the dyes’ spectroscopic properties and performance in cells, based on conformational data derived from their crystal structures.</p

    Gadolinium and nephrogenic systemic fibrosis: time to tighten practice

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    Nephrogenic systemic fibrosis (NSF) is a relatively new entity, first described in 1997. Few cases have been reported, but the disease has high morbidity and mortality. To date it has been seen exclusively in patients with renal dysfunction. There is an emerging link with intravenous injection of gadolinium contrast agents, which has been suggested as a main triggering factor, with a lag time of days to weeks. Risk factors include the severity of renal impairment, major surgery, vascular events and other proinflammatory conditions. There is no reason to believe that children have an altered risk compared to the adult population. It is important that the paediatric radiologist acknowledges emerging information on NSF but at the same time considers the risk:benefit ratio prior to embarking on alternative investigations, as children with chronic kidney disease require high-quality diagnostic imaging

    Anormalidades morfológicas nucleares en hematíes del pez Prochilodus linneatus expuesto al clorpirifos

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    In recent years, the monitoring of xenobiotics (chemicals such as pesticides) in the environment has been very important, as the persistence of the biological activity of many of these compounds has been recognized. Chlorpyrifos is an organophosphorus insecticide of broad spectrum, used in agricultural and domestic activities. This pesticide as well as other chemicals may accidentally reach the aquatic ecosystem and the ictic fauna. Fish ingesting contaminated substances subsequently develop alterations due to bioaccumulation, becoming effective indicators of environmental pollution. The purpose of this study was to evaluate the genotoxicity of chlorpyrifos in P. linneatus (Pisces, Prochilodontidae) through the frequency of micronuclei (MN) and nuclear morphology alterations (AMN) in peripheral blood erythrocytes. After acclimatization the fish were divided into two control (C) and treated groups (T1 = 10 μg/l, T2 = 30 μg/l and T3 = 90 μg/l). Three replicates per group (C, T) were performed with a total of 3 animals per fishbowl. The animals remained in the aquariums for a period of 7 days. After this time they were sacrificed with an overdose of anaesthetic to extract blood from the caudal vein. Smears were stained with Giemsa. In the samples analyzed, the number of MN and AMN was determined after observation of 2000 cells per animal. Cells with intact cytoplasmic membrane were considered for the study. The analysis of blood smears in both groups revealed the presence of micronuclei and the following nuclear morphology alterations; notches, lobulated, evaginations, eigth shaped, segmentations and vacuolization nuclei. Individuals T3 showed significant variations in the frequency of MN and AMN with respect to the controls (p&lt;0.05), but not the T1 and T2 specimens. We conclude that chlorpyrifos at a dose of 90 μg/l could be harmful to the environment.Recientemente adquirió importancia el monitoreo de xenobióticos (como pesticidas) en el medio ambiente, debido a la persistencia de la actividad biológica de muchos de ellos. Clorpirifos es un insecticida organofosforado empleado a nivel agrícola y doméstico. Este plaguicida puede alcanzar accidentalmente el ecosistema acuático y la fauna íctica. Al ingerir sustancias contaminadas, los peces desarrollan alteraciones debidas a la bioacumulación, constituyéndose en eficaces indicadores de polución ambiental. El propósito del estudio fue evaluar la genotoxicidad del clorpirifos en P. linneatus (Pisces, Prochilodontidae) a través de la frecuencia de micronúcleos (MN) y de alteraciones de la morfología nuclear (AMN) en eritrocitos de sangre periférica. Los ensayos se realizaron con clorpirifos en su forma pura (Sigma Aldrich). Los peces se dividieron en grupos control (C) y tratados (T1 = 10 μg/l; T2 = 30 μg/l y T3 = 90 μg/l). Se realizaron tres replicas por grupo, con un total de 3 animales por pecera, los cuales permanecieron allí durante 7 días, tras lo cual fueron sacrificados con sobredosis de anestésico. Se extrajo sangre de la vena caudal, realizándose frotis que se colorearon con Giemsa, determinándose el número de MN y AMN luego de la observación de 2000 células por animal. Para el estudio se consideraron las células con sus membranas citoplasmáticas intactas. En ambos grupos, los frotis sanguíneos revelaron la presencia de micronúcleos, así como algunas de las siguientes alteraciones de la morfología nuclear: muesca, lobulación, evaginación, forma de ocho, segmentación y vacuolización nuclear. Los individuos del grupo T3 mostraron variaciones significativas en la frecuencia de MN y AMN respecto a los controles (p&lt;0,05), no así los ejemplares de los tratamientos T1 y T2. Por lo expuesto, surge que el clorpirifos a la dosis de 90 μg/l podría ser nocivo para el medio ambiente
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