Mobile spectroscopic instrumentation in archaeometry research

Mobile instrumentation is of growing importance to archaeometry research. Equipment is utilized in the field or at museums, thus avoiding transportation or risk of damage to valuable artifacts. Many spectroscopic techniques are nondestructive and micro-destructive in nature, which preserves the cultural heritage objects themselves. This review includes over 160 references pertaining to the use of mobile spectroscopy for archaeometry. Following a discussion of terminology related to mobile instrumental methods, results of a literature survey on their applications for cultural heritage objects is presented. Sections devoted to specific techniques are then provided: Raman spectroscopy, X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, laser-induced breakdown spectroscopy, and less frequently used techniques. The review closes with a discussion of combined instrumental approaches

New approaches to the study of sepsis

Models of sepsis have been instructive in understanding the sequence of events in animals and, to an extent, in humans with sepsis. Events developing early in sepsis suggest that a hyperinflammatory state exists, accompanied by a buildup of oxidants in tissues reflective of a redox imbalance. Development of immunosuppression and degraded innate and adaptive immune responses are well‐established complications of sepsis. In addition, there is robust activation of the complement system, which contributes to the harmful effects of sepsis. These events appear to be associated with development of multiorgan failure. The relevance of animal models of sepsis to human sepsis and the failure of human clinical trials are discussed, together with suggestions as to how clinical trial design might be improved. Currently there is no FDA‐approved drug for use in sepsis. This Review discusses the relevance of animal models to human sepsis and the failure of human clinical trials and provides suggestions as to how clinical trial design might be improved.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94452/1/1234_ftp.pd

Application of the operator product expansion to the short distance behavior of nuclear potentials

We investigate the short distance behavior of nucleon-nucleon (NN) potentials defined through Bethe-Salpeter wave functions, by perturbatively calculating anomalous dimensions of 6-quark operators in QCD. Thanks to the asymptotic freedom of QCD, 1-loop computations give certain exact results for the potentials in the zero distance limit. In particular the functional form of the S-state central NN potential at short distance $r$ is predicted to be a little weaker than $r^{-2}$. On the other hand, due to the intriguing character of the anomalous dimension spectrum, perturbative considerations alone can not determine whether this potential is repulsive or attractive at short distances. A crude estimation suggests that the force at short distance is repulsive, as found numerically in lattice QCD. A similar behavior is found for the tensor potential.Comment: 40 pages, no figure

Language learning interventions

The writers of this article set out to explore the effectiveness and efficiency of a number of language learning interventions with students who failed a Senate discretionary access module designed to address the articulation gap between schooling and university. The article discusses various reasons for student failure despite language interventions. The students discussed in the first part of the article all visited the lecturers in the English for Specific Purposes Unit on more than one occasion for personal consultations. At these contact sessions, students were encouraged to make use of a number of language, reading and writing interventions within the system. Their use was optional and most of the students in the study did not avail themselves of the opportunities presented. On reflection, the conclusion reached by the lecturers was that students did not understand the amount of time that they needed to invest in their language development to be successful and to overcome the combined effects of previous experience and fossilization. They therefore applied to the university Senate to change the module from a semester to a year model to enable them, through a compulsory assignment system, to force students to put in the hours necessary to succeed. The results for that intervention show that the hypothesis was correct and students need more time and structure if they are to improve their language competence sufficiently.Keywords: language learning interventions, English for specific purposes, language competence, fossilizationJournal for Language Teaching Vol. 39(1) 2005: 114-13

Ectoparasitic fauna of poultry species in Maiduguri, Borno State, Nigeria

Ectoparasitic fauna of 397 conveniently sampled domestic birds consisting of 213 chickens, 128 turkeys, 21 ducks, 19 guinea fowls, 8 pigeons and 8 geese were investigated in Maiduguri, Borno State. A total of one hundred and fifty-two 152 (38.29%) birds were infested with one ectoparasitic species or the other comprising of 115 (54.00%) chickens, 33 (25.78%) turkeys, 1 (5.26%) guinea fowl and 3 (37.50%) pigeons. No infestation was encountered among geese and ducks examined. The infestation rate differed significantly based on sex and age (p<0.05), but not the management system. Similarly, the occurrence varied significantly (p<0.05) based on locations of sampling (p<0.00001) and species of poultry examined (p<0.000049). Furthermore, 116 (29.21%) of the total birds examined had a single infestation with either louse, tick or mite species, while 36(9.06%) birds had mixed infestation with species from two or more of these ectoparasitic groups. Among the parasites encountered, lice present on 146 (36.77%) birds were the most prevalent, followed by mites 28(7.05%) and ticks 15(3.78%). Nine different species of ectoparasites belonging to the orders Mallophaga and Acarina were identified in the study. Menopon gallinae, Lipeurus caponis, Menacanthus stramineus, Goniodes gigas, Goniocotes gallinae and Columbicola columbae were the lice identified, while Cnemidocoptes mutans and Ornithonyssus bursa were the only species of mite identified. The poultry tick, Argas persicus was the only tick species found. Conclusively, the study revealed a high but variable burden of ectoparasitic infestation among poultry species examined, and that ectoparasites are common in minor poultry species as they do occur in chickens under different management systems in the study area. The need to investigate the diverse effects of ectoparasitism on the different poultry species is suggested here

Pralidoxime in Acute Organophosphorus Insecticide Poisoning-A Randomised Controlled Trial

Background: Poisoning with organophosphorus (OP) insecticides is a major global public health problem, causing an estimated 200,000 deaths each year. Although the World Health Organization recommends use of pralidoxime, this antidote's effectiveness remains unclear. We aimed to determine whether the addition of pralidoxime chloride to atropine and supportive care offers benefit. Methods and Findings: We performed a double-blind randomised placebo-controlled trial of pralidoxime chloride (2 g loading dose over 20 min, followed by a constant infusion of 0.5 g/h for up to 7 d) versus saline in patients with organophosphorus insecticide self-poisoning. Mortality was the primary outcome; secondary outcomes included intubation, duration of intubation, and time to death. We measured baseline markers of exposure and pharmacodynamic markers of response to aid interpretation of clinical outcomes. Two hundred thirty-five patients were randomised to receive pralidoxime (121) or saline placebo (114). Pralidoxime produced substantial and moderate red cell acetylcholinesterase reactivation in patients poisoned by diethyl and dimethyl compounds, respectively. Mortality was nonsignificantly higher in patients receiving pralidoxime: 30/121 (24.8%) receiving pralidoxime died, compared with 18/114 (15.8%) receiving placebo (adjusted hazard ratio HR] 1.69, 95% confidence interval CI] 0.88-3.26, p = 0.12). Incorporating the baseline amount of acetylcholinesterase already aged and plasma OP concentration into the analysis increased the HR for patients receiving pralidoxime compared to placebo, further decreasing the likelihood that pralidoxime is beneficial. The need for intubation was similar in both groups (pralidoxime 26/121 21.5%], placebo 24/114 21.1%], adjusted HR 1.27 95% CI 0.71-2.29]). To reduce confounding due to ingestion of different insecticides, we further analysed patients with confirmed chlorpyrifos or dimethoate poisoning alone, finding no evidence of benefit. Conclusions: Despite clear reactivation of red cell acetylcholinesterase in diethyl organophosphorus pesticide poisoned patients, we found no evidence that this regimen improves survival or reduces need for intubation in patients with organophosphorus insecticide poisoning. The reason for this failure to benefit patients was not apparent. Further studies of different dose regimens or different oximes are required

Comprehensive characterization of molecular interactions based on nanomechanics

Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the structure of at least one binding partner is altered, mechanically transducing the binding into subsequent biological reactions. Here we present a nanomechanical micro-array technique for bio-medical research, which not only monitors the binding of effector molecules to their target but also the subsequent effect on a biological system in vitro. This label-free and real-time method directly and simultaneously tracks mass and nanomechanical changes at the sensor interface using micro-cantilever technology. To prove the concept we measured lipid vesicle (approximately 748*10(6) Da) adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da) to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions

A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells

Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many years because of their potential for large-scale manufacturing using roll-to-roll processing allied to their use of earth abundant raw materials. Two main challenges exist for DSC devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid electrolytes which can limit device lifetimes. To increase device efficiency requires optimized dye injection and regeneration, most likely from multiple dyes while replacement of liquid electrolytes requires solid charge transporters (most likely hole transport materials – HTMs). While theoretical and experimental work have both been widely applied to different aspects of DSC research, these approaches are most effective when working in tandem. In this context, this perspective paper considers the key parameters which influence electron transfer processes in DSC devices using one or more dye molecules and how modelling and experimental approaches can work together to optimize electron injection and dye regeneration. This paper provides a perspective that theory and experiment are best used in tandem to study DSC device

Changes in intracellular ion activities induced by adrenaline in human and rat skeletal muscle

To study the stimulating effect of adrenaline (ADR) on active Na+/K+ transport we used double-barrelled ion-sensitive micro-electrodes to measure the activities of extracellular K+ (aKe) and intracellular Na+ (aNai) in isolated preparations of rat soleus muscle, normal human intercostal muscle and one case of hyperkalemic periodic paralysis (h.p.p.). In these preparations bath-application of ADR (10−6 M) resulted in a membrane hyperpolarization and transient decreasesaKe andaNai which could be blocked by ouabain (3×10−4 M). In the h.p.p. muslce a continuous rise ofaNai induced by elevation ofaKe to 5.2 mM could be stopped by ADR. In addition, the intracellular K+ activity (aKi), the free intracellular Ca2+ concentration (pCai) and intracellular pH (pHi) were monitored in rat soleus muscle. During ADRaKi increased, pHi remained constant and intracellular Ca2+ apparently decreased. In conclusion, our data show that ADR primarily stimulates the Na+/K+ pump in mammalian skeletal muscle. This stimulating action is not impaired in the h.p.p. muscle