Vitamin D and Death by Sunshine

Exposure to sunlight is the major cause of skin cancer. Ultraviolet radiation (UV) from the sun causes damage to DNA by direct absorption and can cause skin cell death. UV also causes production of reactive oxygen species that may interact with DNA to indirectly cause oxidative DNA damage. UV increases accumulation of p53 in skin cells, which upregulates repair genes but promotes death of irreparably damaged cells. A benefit of sunlight is vitamin D, which is formed following exposure of 7-dehydrocholesterol in skin cells to UV. The relatively inert vitamin D is metabolized to various biologically active compounds, including 1,25-dihydroxyvitamin D3. Therapeutic use of vitamin D compounds has proven beneficial in several cancer types, but more recently these compounds have been shown to prevent UV-induced cell death and DNA damage in human skin cells. Here, we discuss the effects of vitamin D compounds in skin cells that have been exposed to UV. Specifically, we examine the various signaling pathways involved in the vitamin D-induced protection of skin cells from UV.     

Hope and skepticism: Farmer and local community views on the socio-economic benefits of agricultural bioenergy

U.S. government policies and programs promoting agricultural bioenergy development have tended to prioritize national goals of energy security, economic growth and environmental improvement, while marginalizing the local experiences, views and concerns of farmers and rural communities that will produce the needed energy crops. Based on qualitative field interviews with 48 farming and non-farming participants in two switchgrass bioenergy projects (in southern Iowa and in northeastern Kentucky), this paper examines local perspectives on the potential opportunities, drawbacks, and tradeoffs of the emerging agricultural bioeconomy for rural people and places. Individual project participants expressed both positive and negative perceptions about the impacts of the agricultural bioeconomy, with local and regional revitalization being the benefit most desired and also least expected. Skepticism about the social impacts of the agricultural bioeconomy often stemmed from observations of corporate control in agriculture more generally. This research suggests that narrow instrumental views of farmers and rural communities as technical providers of energy feedstocks can be misleading, because they omit the local social and cultural context that complicates rural responses and receptivity to the development of the agricultural bioeconomy.     

Internalizing carbon costs in electricity markets: Using certificates in a load-based emissions trading scheme

Several western states have considered developing a regulatory approach to reduce greenhouse gas (GHG) emissions from the electric power industry, referred to as a load-based (LB) cap-and-trade scheme. A LB approach differs from the traditional source-based (SB) cap-and-trade approach in that the emission reduction obligation is placed upon Load Serving Entities (LSEs), rather than electric generators. The LB approach can potentially reduce the problem of emissions leakage, relative to a SB system. For any of these proposed LB schemes to be effective, they must be compatible with modern, and increasingly competitive, wholesale electricity markets. LSE's are unlikely to know the emissions associated with their power purchases. Therefore, a key challenge for a LB scheme is how to assign emissions to each LSE. This paper discusses the problems with one model for assigning emissions under a LB scheme and proposes an alternative, using unbundled Generation Emission Attribute Certificates. By providing a mechanism to internalize an emissions price signal at the generator dispatch level, the tradable certificate model addresses both these problems and provides incentives identical to a SB scheme.     

Quantitative analysis of mitoxantrone by surface-enhanced resonance Raman scattering

Mitoxantrone is an anticancer agent for which it is important to know the concentration in blood during therapy. Current methods of analysis are cumbersome, requiring a pretreatment stage. A method based on surface-enhanced resonance Raman scattering (SERRS) has been developed using a flow cell and silver colloid as the SERRS substrate. It is simple, sensitive, fast, and reliable. Both blood plasma and serum can be analyzed directly, but fresh serum is preferred here due to reduced fluorescence in the clinical samples available. Fluorescence is reduced further by the dilution of the serum in the flow cell and by quenching by the silver of surface-adsorbed material. The effectiveness of the latter process is dependent on the contact time between the serum and the silver. The linear range encompasses the range of concentrations detected previously in patient samples using HPLC methods. In a comparative study of a series of samples taken from a patient at different times, there is good agreement between the results obtained by HPLC and SERRS with no significant difference between them at the 95% limit. The limit of detection in serum using the final optimized procedure for SERRS was 4.0 x 10(-11) M (0.02 ng/mL) mitoxantrone. The ease with which the SERRS analysis can be carried out makes it the preferred choice of technique for mitoxantrone analysis.     

Loss of emotional experience after traumatic brain injury: Findings with the startle probe procedure.

The authors used affective modulation of the eyeblink startle response to examine the impact of traumatic brain injury (TBI) on emotional reactions to pictures. Participants were 13 individuals with severe TBI and 24 controls. Participants were presented with pictures that differed in affective valence (e.g., mutilated bodies, erotic couples, and household objects) while the eyeblink startle response to an acoustic probe was measured. Startle amplitude was used to assess valence of emotional response, and startle latency was used to index interest in the pictures. Subjective ratings of the affect and arousal elicited by the various pictures were also obtained. TBI impaired startle potentiation to unpleasant pictures but not startle attenuation to pleasant pictures. Further, subjective ratings indicated that TBI participants found unpleasant pictures less arousing than did controls. The results are consistent with recent evidence of differential impairment in negative versus positive emotions after TBI and are discussed in relation to 2 competing explanations of startle modulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towards evidence-based guidelines for wise use of computers by children

This paper argues for the systematic development and presentation of evidence-based guidelines for appropriate use of computers by children. The currently available guidelines are characterised and a proposed conceptual model presented. Five principles are presented as a foundation to the guidelines. The paper concludes with a framework for the guidelines, key evidence for and against guidelines, and gaps in the available evidence, with the aim of facilitating further discussion.

Relevance to industry

The current generation of children in affluent countries will typically have over 10 years of computer experience before they enter the workforce. Consequently, the primary prevention of computer-related health disorders and the development of good productivity skills for the next generation of workers needs to occur during childhood.     

Interleukin-12 is required for control of the growth of attenuated aromatic-compound-dependent salmonellae in BALB/c mice: role of gamma interferon and macrophage activation

The attenuated S. typhimurium SL3261 (aroA) strain causes mild infections in BALB/c mice. We were able to exacerbate the disease by administering anti-interleukin-12 (IL-12) antibodies, resulting in bacterial counts in the spleens and livers of anti-IL-12-treated mice that were 10- to 100-fold higher than the ones normally observed in premortem mice; yet the animals showed only mild signs of illness. Nevertheless, they eventually died of a slow, progressive disease. Mice infected with salmonellae become hypersusceptible to endotoxin. We found that IL-12 neutralization prevented the death of infected mice following subcutaneous injection of lipopolysaccharide. Granulomatous lesions developed in the spleens and livers of control animals, as opposed to a widespread infiltration of mononuclear cells seen in the organs of anti-IL-12-treated mice. In the latter (heavily infected), salmonellae were seen within mononuclear cells, indicating an impairment of the bactericidal or bacteriostatic ability of the phagocytes in the absence of biologically active IL-12. Gamma interferon (IFN-gamma) levels were reduced in the sera and tissue homogenates from anti-IL-12-treated mice compared to those in control animals. Furthermore, fluorescence-activated cell sorter analysis on spleen cells showed that IL-12 neutralization impaired the upregulation of I-Ad/I-Ed antigens on macrophages from infected mice. Inducible nitric oxide synthase and IFN-gamma mRNA production was down-regulated in anti-IL-12-treated mice, which also showed an increased production of IL-10 mRNA and a decrease in nitric oxide synthase activity in the tissues. Administration of recombinant IFN-gamma to anti-IL-12-treated mice was able to restore host resistance, granuloma formation, and expression of major histocompatibility complex class II antigens in F4/80(+) and CD11b+ spleen cells.     

Linguistic and location effects in compliance with pesticide warning labels for amateur and professional users

Three studies explored amateur and professional users' compliance with pesticide warning labels. Professionals were classified as people working in a profession in which the use of pesticides is a necessary part of their job. Amateurs used pesticides only in their leisure time. The first study showed that the wording used affected perception of the appropriateness of hazard statements, one of the most effective variations being the use of the personal pronoun (statements beginning "You should..."). The location of warning information was also found to affect actual compliance: Compliance increased when warning information was presented in the directions for use section. A supplemental directive increased compliance only for professional users. In a final study, "best-case" and "worst-case" linguistic variations were combined with best-case and worst-case locations for safety information. Instruction statements using the personal pronoun and presented in the directions for use section resulted in the highest levels of compliance. The differences in compliance between amateur and professional users are interpreted within the framework of Rasmussen's (1986) distinction among skill-, rule-, and knowledge-based behavior. Actual or potential applications of this research include the design of warning labels and safety information.     

Phase retrieval from subdivision of the focal plane with a lenslet array

A phase retrieval algorithm derived from subdivision of the complex field at the focal plane is proposed. This subdivision is achieved with a lenslet array at the focal plane in a manner similar to the pyramid wave-front sensor. The phase retrieval algorithm significantly improves the wave-front estimate that can be attained as a linear combination of the aperture images. This phase retrieval algorithm also avoids the twin-image stagnation problem inherent in phase retrieval and phase retrieval in conjunction with the Shack-Hartmann sensor.     

Resonance Raman spectroscopy of photolabile transition metal carbonyls: controlled photoalteration with continuous wave lasers to record spectra of reactants or transient species

A method has been developed that enables resonance Raman spectra of photolabile species in solution to be recorded under conditions where the level of photoalteration is controlled: a low level enables reactant spectra to be recorded, whereas a high level enables the spectra of short-lived transient species to be recorded in real time using continuous-wave (CW) lasers and standard Raman detection equipment. The design includes a sealed flow system, enabling air-sensitive species to be studied under an inert atmosphere. A simple theoretical model has been developed to aid the interpretation of experimental results, and its applicability is demonstrated. Controlled photoalteration and its theory are demonstrated with 413.1-nm excitation of carbonmonoxymyoglobin (MbCO), which generates deoxymyoglobin (deoxy-Mb) on photolysis, and for which the spectra of both species are well established. The methods have also been applied to two air-sensitive, photolabile transition metal carbonyls using 514.5-nm wavelength excitation: for Cp2Mo2(CO)6 (Cp = eta5-C5H5), increasing levels of photoalteration result only in a decrease in the parent band intensities, relative to the solvent bands; for Cp2Fe2(CO)4, increasing levels of photoalteration result in the appearance of additional bands that are assigned to the transient species CpFe(mu-CO)3FeCp, formed following the loss of a CO ligand.