Advances in solid phase microextraction for the analysis of volatile compounds in explosives, tire treatments, and entomological specimens

Solid phase microextraction is a powerful and versatile technique, well-suited to the analysis of numerous samples of forensic interest. The exceptional sensitivity of the SPME platform, combined with its adaptability to traditional GC-MS systems and its ability to extract samples with minimal work-up, make it appropriate to applications in forensic laboratories. In a series of research projects, solid phase microextraction was employed for the analysis of explosives, commercial tire treatments, and entomological specimens. In the first project, the volatile organic compounds emanating from two brands of pseudo-explosive training aids for use in detector dog imprinting were determined by SPME-GC-MS, and the efficacy of these training materials was tested in live canine trials. In the second project, the headspace above various plasticizers was analyzed comparative to that of Composition C-4 in order to draw conclusions about the odor compound, 2-ethyl-1-hexanol, with an eye toward the design of future training aids. In the third, automobile tires which had participated in professional race events were analyzed for the presence of illicit tire treatments, and in the fourth, a novel SPME-GC-MS method was developed for the analysis of blowfly (Diptera) liquid extracts. In the fifth and final project, the new method was put to the task of performing a chemotaxonomic analysis on pupa specimens, seeking to chemically characterize them according to their age, generation, and species

Irrigation-Yield Production Functions and Irrigation Water Use Effciency Response of Drought-Tolerant and Non-Drought-Tolerant Maize Hybrids under Different Irrigation Levels, Population Densities, and Environments

Irrigation-yield production functions (IYPFs), irrigation water use effciency (IWUE), and grain production per unit of applied irrigation of non-drought-tolerant (NDT) and drought-tolerant (DT) maize (Zea mays L.) hybrids were quantified in four locations with different climates in Nebraska [Concord (sub-humid), Clay Center (transition zone between sub-humid and semi-arid); North Platte (semi-arid); and, Scottsbluff (semi-arid)] during three growing seasons (2010, 2011, and 2012) at three irrigation levels (fully-irrigated treatment (FIT), early cut-off (ECOT), and rainfed (RFT)) under two plant population densities (PPDs) (low-PPD; 59,300 plants ha-1; and, high-PPD, 84,000 plants ha-1). Overall, DT hybrids’ performance was superior to NDT hybrid at RFT, ECT, and FIT conditions, as confirmed by the yield response, IYPF and IWUE when all locations, years, and PPDs were averaged. The yield response to water was greater with the high-PPD than the low-PPD in most cases. The magnitude of the highest yields for DT hybrids ranged from 7.3 (low-PPD) to 8.5% (high-PPD) under RFT, 3.7 (low-PPD) to 9.6% (high-PPD) under ECOT, and 3.9% (high-PPD) under FIT higher than NDT hybrid. Relatively, DT hybrids can resist drought-stress conditions longer than NDT hybrid with fewer penalties in yield reduction and maintain comparable or even higher yield production at non-stress-water conditions

T Cells Use Rafts for Survival

T cell homeostasis must be tightly controlled. In this issue of Immunity, Cho et al. (2010) describe results that begin to define the roles of the T cell receptor, self-peptide-MHC ligands, cytokines, and membrane rafts in this dynamic process

Benchmarking high fidelity single-shot readout of semiconductor qubits

Determination of qubit initialisation and measurement fidelity is important for the overall performance of a quantum computer. However, the method by which it is calculated in semiconductor qubits varies between experiments. In this paper we present a full theoretical analysis of electronic single-shot readout and describe critical parameters to achieve high fidelity readout. In particular, we derive a model for energy selective state readout based on a charge detector response and examine how to optimise the fidelity by choosing correct experimental parameters. Although we focus on single electron spin readout, the theory presented can be applied to other electronic readout techniques in semiconductors that use a reservoir.Comment: 19 pages, 8 figure

Fish Species, Some Uncommon, Collected From the Lower Minnesota River

Fish collections were made in the lower Minnesota River in the vicinity of the Black Dog Generating Plant and at the intake structure of the plant from April, 1976, to April, 1977 as part of a section 316(b) demonstration study. Composition of the fish community of the area is reported along with notes on several species whose occurrence was considered unusual . New information on the occurrence of river carpsucker (Carpiodes carpio Rafinesque) and river darter (Percina shumardi, Girard) to the Minnesota River is also presented

Skin TLR7 triggering promotes accumulation of respiratory dendritic cells and natural killer cells.

The TLR7 agonist imiquimod has been used successfully as adjuvant for skin treatment of virus-associated warts and basal cell carcinoma. The effects of skin TLR7 triggering on respiratory leukocyte populations are unknown. In a placebo-controlled experimental animal study we have used multicolour flow cytometry to systematically analyze the modulation of respiratory leukocyte subsets after skin administration of imiquimod. Compared to placebo, skin administration of imiquimod significantly increased respiratory dendritic cells (DC) and natural killer cells, whereas total respiratory leukocyte, alveolar macrophages, classical CD4+ T helper and CD8+ T killer cell numbers were not or only moderately affected. DC subpopulation analyses revealed that elevation of respiratory DC was caused by an increase of respiratory monocytic DC and CD11b(hi) DC subsets. Lymphocyte subpopulation analyses indicated a marked elevation of respiratory natural killer cells and a significant reduction of B lymphocytes. Analysis of cytokine responses of respiratory leukocytes after stimulation with Klebsiella pneumonia indicated reduced IFN-γ and TNF-α expression and increased IL-10 and IL-12p70 production after 7 day low dose skin TLR7 triggering. Additionally, respiratory NK cytotoxic activity was increased after 7d skin TLR7 triggering. In contrast, lung histology and bronchoalveolar cell counts were not affected suggesting that skin TLR7 stimulation modulated respiratory leukocyte composition without inducing overt pulmonary inflammation. These data suggest the possibility to modulate respiratory leukocyte composition and respiratory cytokine responses against pathogens like Klebsiella pneumonia through skin administration of a clinically approved TLR7 ligand. Skin administration of synthetic TLR7 ligands may represent a novel, noninvasive means to modulate respiratory immunity

AGA practitioner challenges: A mixed‐methods pilot survey

Background Androgenetic alopecia (AGA) practitioner care may be hampered by commercial biases and hair loss' omission from most medical curricula. Aim and Method Between November 2020 and September 2021, 34 AGA professionals (86% British; 62% trichologists), participated in a pilot, mixed-methods, survey. Practitioner views on: 1a–1j) AGA's commercial influences (e.g., participants were quantitatively assessed on their understanding of a popular, commercially-funded, AGA study) and 2a–2h) constraints on evidenced-based AGA responding (e.g., ethical dilemmas) were assessed. Quantitative responses are reported descriptively whilst qualitative responses are categorized alongside illustrative quotes. Results On average, (1a–1d) 42% of participants were misled by the popular AGA study and (1e) participants underestimated the extent of commercial biases in AGA research as 25%; (2a–2e). Participants also indicated that AGA treatment limitations and misinformation ethically challenged them (e.g., “[It's difficult to know when] to treat or not without being able to confirm the outcome”). (2c) Most (77%) indicated society played a powerful role in exacerbating AGA distress (e.g., “Society is hyper critical of appearance”) and 30% indicated greater “treatment” accessibility was needed: (e.g., “hair loss product [should] give clear indication of what the active ingredients are and how effective they are”). Conclusions Despite the limited sample size, these finding cohere with previous identified challenges of the AGA practitioner role. Evidence based guidance and research scrutiny tools would help practitioners overcome such challenges

EC00-2540 Field Records for Restricted Use Pesticide Applications and Integrated Crop Management by Private Applicators

Private applicators must record their restricted use pesticide (RUP) applications, as required by the Food, Agriculture, Conservation and Trade (FACT) Act of 1990. The USDA Agricultural Marketing Service administers this activity. In Nebraska, RUP application records must be maintained for three years from the date of application. The certified pesticide applicator should retain these RUP records, but must be able to make them accessible for copying by authorized representatives. This booklet is a suggested guide for preliminary or final RUP application records