Antimicrobial efficacy of chlorhexidine digluconate alone and in combination with eucalyptus oil, tea tree oil and thymol against planktonic and biofilm cultures of Staphylococcus epidermidis

Objectives Effective skin antisepsis and disinfection of medical devices are key factors in preventing many healthcare-acquired infections associated with skin microorganisms, particularly Staphylococcus epidermidis. The aim of this study was to investigate the antimicrobial efficacy of chlorhexidine digluconate (CHG), a widely used antiseptic in clinical practice, alone and in combination with tea tree oil (TTO), eucalyptus oil (EO) and thymol against planktonic and biofilm cultures of S. epidermidis. Methods Antimicrobial susceptibility assays against S. epidermidis in a suspension and in a biofilm mode of growth were performed with broth microdilution and ATP bioluminescence methods, respectively. Synergy of antimicrobial agents was evaluated with the chequerboard method. Results CHG exhibited antimicrobial activity against S. epidermidis in both suspension and biofilm (MIC 2–8 mg/L). Of the essential oils thymol exhibited the greatest antimicrobial efficacy (0.5–4 g/L) against S. epidermidis in suspension and biofilm followed by TTO (2–16 g/L) and EO (4–64 g/L). MICs of CHG and EO were reduced against S. epidermidis biofilm when in combination (MIC of 8 reduced to 0.25–1 mg/L and MIC of 32–64 reduced to 4 g/L for CHG and EO, respectively). Furthermore, the combination of EO with CHG demonstrated synergistic activity against S. epidermidis biofilm with a fractional inhibitory concentration index of <0.5. Conclusions The results from this study suggest that there may be a role for essential oils, in particular EO, for improved skin antisepsis when combined with CHG.

Antimicrobial efficacy of copper surfaces against spores and vegetative cells of Clostridium difficile: the germination theory

OBJECTIVES: Persistent contamination of surfaces by spores of Clostridium difficile is a major factor influencing the spread of C. difficile-associated diarrhoea (CDAD) in the clinical setting. In recent years, the antimicrobial efficacy of metal surfaces has been investigated against microorganisms including methicillin-resistant Staphylococcus aureus. This study compared the survival of C. difficile on stainless steel, a metal contact surface widely used in hospitals, and copper surfaces. METHODS: Antimicrobial efficacy was assessed using a carrier test method against dormant spores, germinating spores and vegetative cells of C. difficile (NCTC 11204 and ribotype 027) over a 3 h period in the presence and absence of organic matter. RESULTS: Copper metal eliminated all vegetative cells of C. difficile within 30 min, compared with stainless steel which demonstrated no antimicrobial activity (P < 0.05). Copper significantly reduced the viability of spores of C. difficile exposed to the germinant (sodium taurocholate) in aerobic conditions within 60 min (P < 0.05) while achieving a >or=2.5 log reduction (99.8% reduction) at 3 h. Organic material did not reduce the antimicrobial efficacy of the copper surface (P > 0.05).

"No one said girls could do engineering":a fresh look at an old problem

Previous work has drawn attention to what, in many respects, appears to be an insurmountable problem, the lack of women and girls in engineering. The debate about why young women are not attracted to engineering mostly focuses around issues of gender, with the profession stereotypically perceived as being more suitable for men. In seeking to investigate why this should be the case a participatory research approach was adopted in which two 17 year old female High School students were employed to interview their peers about their perceptions of engineering as a career. This paper presents some of the emergent findings of this research. In total twenty teenage girls from two city centre Schools were interviewed. The two teenage researchers developed the questions themselves, focusing on issues they identified as being important factors informing girls’ views of engineering. This approach provided a ‘new’ perspective – looking at the topic through the eyes of the target sample group. By drawing attention to some of the issues around gender and engineering, this paper contributes to current debates in this area – in doing so it provides a fresh look at an old problem and offers some workable solutions for ‘how to get more girls into engineering’.

Formant-Frequency Variation and Informational Masking of Speech by Extraneous Formants : Evidence Against Dynamic and Speech-Specific Acoustical Constraints

How speech is separated perceptually from other speech remains poorly understood. Recent research indicates that the ability of an extraneous formant to impair intelligibility depends on the variation of its frequency contour. This study explored the effects of manipulating the depth and pattern of that variation. Three formants (F1+F2+F3) constituting synthetic analogues of natural sentences were distributed across the 2 ears, together with a competitor for F2 (F2C) that listeners must reject to optimize recognition (left = F1+F2C; right = F2+F3). The frequency contours of F1 − F3 were each scaled to 50% of their natural depth, with little effect on intelligibility. Competitors were created either by inverting the frequency contour of F2 about its geometric mean (a plausibly speech-like pattern) or using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Adding a competitor typically reduced intelligibility; this reduction depended on the depth of F2C variation, being greatest for 100%-depth, intermediate for 50%-depth, and least for 0%-depth (constant) F2Cs. This suggests that competitor impact depends on overall depth of frequency variation, not depth relative to that for the target formants. The absence of tuning (i.e., no minimum in intelligibility for the 50% case) suggests that the ability to reject an extraneous formant does not depend on similarity in the depth of formant-frequency variation. Furthermore, triangle-wave competitors were as effective as their more speech-like counterparts, suggesting that the selection of formants from the ensemble also does not depend on speech-specific constraints.

Discourses of friendship between heterosexual women and gay men:mythical norms and an absence of desire

Gay men and heterosexual women may share some common interests in critiquing hetero-patriarchy. However feminism and gay liberationist politics do not always coincide and the role of individual subjectivities in recognising oppressive discourses of normativity remains debated. Interviews were conducted with seven friendship dyads of heterosexual women and gay men. Transcripts were subjected to discourse analysis, which suggested extensive management of heterosexist norms in the friends' accounts of friendship. The analysis highlighted ambiguity over the 'male' status of gay men, a concern with constructing the friendships as legitimately asexual, and the use of parody in the face of homophobia to disrupt normative assumptions. Although we primarily considered the role of heterosexist discourses, there is also evidence that other dimensions of non-normativity (for example, gender and ethnicity) are implicated in friendships constructed around shared otherness and mutual non-normativity. © 2010 SAGE.

Formant-frequency variation and informational masking of speech by extraneous formants:evidence against dynamic and speech-specific acoustical constraints

How speech is separated perceptually from other speech remains poorly understood. Recent research indicates that the ability of an extraneous formant to impair intelligibility depends on the variation of its frequency contour. This study explored the effects of manipulating the depth and pattern of that variation. Three formants (F1+F2+F3) constituting synthetic analogues of natural sentences were distributed across the 2 ears, together with a competitor for F2 (F2C) that listeners must reject to optimize recognition (left = F1+F2C; right = F2+F3). The frequency contours of F1 - F3 were each scaled to 50% of their natural depth, with little effect on intelligibility. Competitors were created either by inverting the frequency contour of F2 about its geometric mean (a plausibly speech-like pattern) or using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Adding a competitor typically reduced intelligibility; this reduction depended on the depth of F2C variation, being greatest for 100%-depth, intermediate for 50%-depth, and least for 0%-depth (constant) F2Cs. This suggests that competitor impact depends on overall depth of frequency variation, not depth relative to that for the target formants. The absence of tuning (i.e., no minimum in intelligibility for the 50% case) suggests that the ability to reject an extraneous formant does not depend on similarity in the depth of formant-frequency variation. Furthermore, triangle-wave competitors were as effective as their more speech-like counterparts, suggesting that the selection of formants from the ensemble also does not depend on speech-specific constraints. © 2014 The Author(s).

Anticancer effects of Curcuma C20-dialdehyde against colon and cervical cancer cell lines

Background: Recent attention on chemotherapeutic intervention against cancer has been focused on discovering and developing phytochemicals as anticancer agents with improved efficacy, low drug resistance and toxicity, low cost and limited adverse side effects. In this study, we investigated the effects of Curcuma C20-dialdehyde on growth, apoptosis and cell cycle arrest in colon and cervical cancer cell lines. Materials and Methods: Antiproliferative, apoptosis induction, and cell cycle arrest activities of Curcuma C20-dialdehyde were determined by WST cell proliferation assay, flow cytometric Alexa fluor 488-annexin V/propidium iodide (PI) staining and PI staining, respectively. Results: Curcuma C20 dialdehyde suppressed the proliferation of HCT116, HT29 and HeLa cells, with IC50 values of 65.4±1.74 μg/ml, 58.4±5.20 μg/ml and 72.0±0.03 μg/ml, respectively, with 72 h exposure. Flow cytometric analysis revealed that percentages of early apoptotic cells increased in a dose-dependent manner upon exposure to Curcuma C20-dialdehyde. Furthermore, exposure to lower concentrations of this compound significantly induced cell cycle arrest at G1 phase for both HCT116 and HT29 cells, while higher concentrations increased sub-G1 populations. However, the concentrations used in this study could not induce cell cycle arrest but rather induced apoptotic cell death in HeLa cells. Conclusions: Our findings suggest that the phytochemical Curcuma C20-dialdehyde may be a potential antineoplastic agent for colon and cervical cancer chemotherapy and/or chemoprevention. Further studies are needed to characterize the drug target or mode of action of the Curcuma C20-dialdehyde as an anticancer agent.

Concurrent codes:a holographic-type encoding robust against noise and loss

Concurrent coding is an encoding scheme with 'holographic' type properties that are shown here to be robust against a significant amount of noise and signal loss. This single encoding scheme is able to correct for random errors and burst errors simultaneously, but does not rely on cyclic codes. A simple and practical scheme has been tested that displays perfect decoding when the signal to noise ratio is of order -18dB. The same scheme also displays perfect reconstruction when a contiguous block of 40% of the transmission is missing. In addition this scheme is 50% more efficient in terms of transmitted power requirements than equivalent cyclic codes. A simple model is presented that describes the process of decoding and can determine the computational load that would be expected, as well as describing the critical levels of noise and missing data at which false messages begin to be generated.

Through the prisms of gender and power: Agency in international courtship between Colombian women and American men

Since 1999 Colombia has experienced dramatic increases in emigration, particularly the emigration of women towards the U.S. as fiancées of U.S. citizens or residents. Parallel to this trend is the increased number of websites facilitating these Colombian-American matches. This dissertation investigates the agency of Colombian women and American men who pursue romantic courtship through the services of International Marriage Brokers (IMBs) from the “Gendered Geographies of Power” (GGP) framework of analysis. It examines how both groups’ social locations, their positioning in multiple axes of differentiation including gender, nationality and social class, affects how and why they exert their agency across and within different geographic scales. Most importantly, it investigates the role the imagination plays (imagination work) in both men and women’s agency, an aspect of the GGP framework that has been under-researched and theorized to date. The research also finds that this imagination work is promoted and cultivated in deeply gendered ways by IMBs seeking to profit off this transnational courtship. ^ Employing data collected via interviews and content analysis of IMBs’ websites, the dissertation analyzes comparatively the expectations each group (women, men and IMBs) bring to their imagination work and experiences of the courtship marketplace. A central question posed and answered in the dissertation is “What do women and men courting each other in cyberspace seek and do they find it?” The dissertation finds that the men seek “traditional” women and the women seek “liberated” less “macho” men. Ironically, the men find Colombian women who are among the most “liberated” women in their homeland but who downplay this aspect of themselves in order to strategically find a more modern man and migrate abroad where they expect to find greater personal and professional opportunities.^

Women and development in Senegal: Microcredit and household well being

The challenging living conditions of many Senegalese families, and the absence of a providing spouse, have led women to covet new economic opportunities, such as microcredit loans. These loans offer Senegalese women the possibility to financially support their households and become active participants in their economies by starting or sustaining their micro businesses. The study takes place in Grand-Yoff, an overpopulated peri-urban area of the Senegalese capital city Dakar, where most people face daily survival issues. This research examines the impact of microcredit activities in the household of Senegalese female loan recipients in Grand-Yoff by examining socioeconomic indicators, in particular outcomes of health, education and nutrition.^ The research total sample is constituted of 166 female participants who engage in microcredit activities. The research combines both qualitative and quantitative methods. Data for the study were gathered through interviews, surveys, participant observation, focus-groups with the study participants and some of their household members, and document analysis.^ While some women in the study make steady profits from their business activities, others struggle to make ends meet from their businesses’ meager or unreliable profits. Some study participants who are impoverished have no choice but to invest their loans directly into their households’ dire needs, hence missing their business prerogative. Many women in the study end up in a vicious cycle of debt by defaulting on their loans or making late payments because they do not have the required household and socioeconomic conditions to take advantage of these loans. Therefore, microcredit does not make a significant impact in the households of the poorest female participants. The study finds that microcredit improves the household well-being - especially nutrition, health and education - of the participants who have acquired significant social capital such as a providing spouse, formal education, training, business experience, and belonging to business or social networks.^ The study finds that microcredit’s household impact is intimately tied to the female borrowers’ household conditions and social capital. It is recommended that microcredit services and programs offer their female clients assistance and additional basic services, financial guidance, lower interest rates, and flexible repayment schedules. ^

A study of the perceived effectiveness of existing recruitment and general institution -wide practices used to enhance women and minority full -time faculty representation at Florida's public universities

As a federal contractor, the State University System of Florida (SUSF) has instituted a wide range of affirmative action practices to hire and promote women and minorities. Should affirmative action be abolished, universities valuing a diverse faculty will have to rely on voluntary practices to attract members of these groups. I explored the present use and perceived effectiveness of recruitment and institution-wide practices used to promote a diverse workforce and identified those practices considered very effective by informed respondents at the nine participating universities. ^ Two questionnaires were used for data collection. Selected recruitment and general institution-wide best practices found in previous studies were used as benchmarks for comparison with existing practices. The questionnaires also included an open-ended question to identify indigenous practices. A follow-up semi-structured interview was conducted to gather information regarding the background of identified practices. ^ Two overall themes emerged from the study. The first was the perception among respondents that women have made substantial gains in faculty representation. This perception is substantiated by actual percentage of women tenure-earning faculty. The second theme was that many of the practices considered very effective are affirmative action-driven, providing women and minorities considerations not afforded White males. These practices, because they single out members of one group over another based on gender and race/ethnicity may become illegal should affirmative action mandates be abolished. ^ Analysis of the data revealed that universities with the highest percentage of practices considered effective and universities located in the most urban areas of the state were the universities with the highest percentage of minority tenure-earning faculty. There appears to be no similar relationship between universities in urban areas and those with the highest percentage of practices considered effective and women tenure-earning faculty representation. The most frequently identified recruitment practice was the development of a receptive institutional image for women and minorities. The most frequently identified practice in promoting a receptive institutional climate was the use of conflict resolution processes and grievance procedures. Five themes also emerged from the 22 barriers in recruiting women and minority full-time faculty identified by the respondents. The most commonly identified barriers were related to a lack of financial resources to support effective practices. ^

Through the Prisms of Gender and Power: Agency in International Courtship between Colombian Women and American Men

Since 1999 Colombia has experienced dramatic increases in emigration, particularly the emigration of women towards the U.S. as fiancées of U.S. citizens or residents. Parallel to this trend is the increased number of websites facilitating these Colombian-American matches. This dissertation investigates the agency of Colombian women and American men who pursue romantic courtship through the services of International Marriage Brokers (IMBs) from the “Gendered Geographies of Power” (GGP) framework of analysis. It examines how both groups’ social locations, their positioning in multiple axes of differentiation including gender, nationality and social class, affects how and why they exert their agency across and within different geographic scales. Most importantly, it investigates the role the imagination plays (imagination work) in both men and women’s agency, an aspect of the GGP framework that has been under-researched and theorized to date. The research also finds that this imagination work is promoted and cultivated in deeply gendered ways by IMBs seeking to profit off this transnational courtship. Employing data collected via interviews and content analysis of IMBs’ websites, the dissertation analyzes comparatively the expectations each group (women, men and IMBs) bring to their imagination work and experiences of the courtship marketplace. A central question posed and answered in the dissertation is “What do women and men courting each other in cyberspace seek and do they find it?” The dissertation finds that the men seek “traditional” women and the women seek “liberated” less “macho” men. Ironically, the men find Colombian women who are among the most “liberated” women in their homeland but who downplay this aspect of themselves in order to strategically find a more modern man and migrate abroad where they expect to find greater personal and professional opportunities.