Scaling theory of DNA confined in nanochannels and nanoslits

A scaling analysis is presented of the statistics of long DNA confined in nanochannels and nanoslits. It is argued that there are several regimes in between the de Gennes and Odijk limits introduced long ago. The DNA chain folds back on itself giving rise to a global persistence length which may be very large owing to entropic deflection. Moreover, there is an orientational excluded-volume effect between the DNA segments imposed solely by the nanoconfinement. These two effects cause the chain statistics to be intricate leading to nontrivial power laws for the chain extension in the intermediate regimes. It is stressed that DNA confinement within nanochannels differs from that in nanoslits because the respective orientational excluded-volume effects are not the same.Comment: 5 pages, 1 figure Several corrections, some minor changes in the text and replacement of one referenc

The Role of Common Agricultural Policy in the Landscape Evolution: the Case Study of Val d'Orcia (Siena, Italy)

In the last years there is growing debate between agricultural economists on the role of agriculture to product positive ad negative externalities. The externalities are defined as pubblic goods or no-commodity outputs (Marangon, 2006; Daugstad et al., 2006; OECD, 2001; Brunori et al., 2006) and they need of specific regulation. In rural areas landscape is a typical example of externality because it is the result of agricultural activity and it changes with the agricultural change. At same time, landscape in specific territorial contexts can assume historic, cultural, social and economic value, so that it could become a strategic resource for local development politics (Brunori et al, 2006). The decupling and cross-compliance introduced by the new Common Agricultural Policy (CAP) and the increasing demand of environmental goods by citizen/consumers are elements of novelty that will modify farms in next years. In particular, CAP reform could lead to farm externalisation of activity or suspension of business in many rural areas with important socio-economic and environmental impacts as, for example, on landscape. In Val d’Orcia, as in other Tuscany rural areas, landscape assumes the role of economic resource because it attracts tourists and is utilised to promote the territory (landscape as a “business card”). This is in connection with the rural configuration of the landscape and the high concentration of architectonic and artistic goods. To remember, for example, the UNESCO recognition in 2004 as “Val d’Orcia cultural landscape”. At same time, if this landscape is an important points of strength of the local economy, it shows also environmental fragility (biodiversity reduction, soli erosion, etc.) that they need specific actions. In agreement with art.1 of European Landscape Convention (European Council, 2000) where is affirmed that “Landscape means an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors”, this work shows the results of a survey developed in Val d’Orcia with this objectives: • to identify the driving forces that have leaded to the current landscape in Val d’Orcia to start to 1970th; • to try to define the possible landscape evolution in relationship with the novelty introduced by the CAP reform; • to suggest specific actions to drive the landscape evolution in the direction of a “sustainable rural landscape” where landscape is an element to strengthen the identity of local rural community, to promote local sustainable development and to safeguard environmental resources in their complex (European Council, 2000)

Workplace Bullying and Post-Traumatic Stress Disorder Symptomology: The Influence of Role Conflict and the Moderating Effects of Neuroticism and Managerial Competencies

Research has explored numerous consequences of workplace bullying, including a recent link to the exhibition of post-traumatic stress disorder (PTSD) symptomology. Role conflict as a workplace stressor may contribute to instances of bullying from a passive perspective, which may lead to PTSD symptomology in victims. What remains less explored is if role conflict has a direct relationship to PTSD symptomology and how personality traits such as neuroticism and workplace factors such as managerial competencies may moderate the stress brought on by role conflict. Hence the present study seeks to examine this gap in the literature. This study utilizes a between-subjects, cross-sectional design with 159 participants, 39.6% male and 60.4% female. Most participants (60%) were Italian workers of a large social cooperative organization. Confirmatory factor analysis indicated that the measurement model was valid and had an adequate model fit. Results from two separate moderated mediation analyses found a positive, full mediation between the independent variable of role conflict, the mediator of exposure to bullying, and the dependent variable of PTSD symptomology. Furthermore, in this study, neuroticism strengthened the indirect effect while managerial competencies weakened it. The results highlight the importance of training competent managers and providing resources for more vulnerable employees to moderate employee work stress and its negative outcomes

Rapid surfactant-free synthesis of Mg(OH)2 nanoplates and pseudomorphic dehydration to MgO

Magnesium hydroxide nanoplates ca. 50 nm in thickness can be prepared over minute timescales via hydrothermal synthesis in a multimode cavity (MMC) microwave reactor. This approach allows ca. 1 g of single-phase Mg(OH)2 to be synthesised in under 3 minutes without the requirement of surfactants or non-aqueous solvents. The hydroxide nanomaterial dehydrates at temperatures >200 K below that of the equivalent bulk material and can be utilised as a precursor for the pseudomorphic synthesis of nanoplates of MgO as investigated by TG-DTA-MS, XRD and SEM measurements. Equally, the pseudomorphic synthesis can be performed by irradiating the Mg(OH)2 nanomaterial with microwaves for 6 minutes to produce single phase MgO

A daily diary investigation on the job-related affective experiences fueled by work addiction

Background and aims: We studied the quality of the job-related emotional experiences associated with work addiction. We hypothesized that work addiction would fuel both a higher level of daily job-related negative affect and a lower level of daily job-related positive affect and that such affective experiences would mediate the relationship between work addiction and emotional exhaustion reported at the end of the working day. Additionally, in light of typical behaviors and cognitions associated with work addiction, we also hypothesized that work addiction would modify the relationships between day workload and same day emotional strain reactions (i.e., job-related negative affect and job-related positive affect). Methods: Participants were 213 workers (42.5% female), most of whom holding a high-profile job position, who were followed for 10 consecutive working days in the context of a daily diary study. Results: Multilevel analyses controlling for neuroticism revealed that work addiction was uniquely and positively related to daily job-related negative affect and that the latter mediated the relationship between work addiction and daily emotional exhaustion. On the other hand, work addiction was not negatively related to daily job-related positive affect; this relationship emerged only when removing neuroticism from the model. Additionally, work addiction strengthened the relationship between day workload and day job-related negative affect. Discussion: Results indicate that work addicted are characterized by the experience of a negatively connotated affect during work, and that this kind of affect may be a mechanism explaining the work addiction-burnout relationship

ANTIMICROBIAL PEPTIDES ARE TARGETS FOR BACTERIAL ADP-RIBOSYLTRANSFERASE ENZYMES

Background: Human α-defensins (HNPs 1-3) are small cationic, amphipatic peptides with microbicidal activities. HNP-1 is the physiological target of ART1, an arginine (Arg) specific eucaryotic ribosyltransferase enzyme1. Mono ADP-ribosylation of Arg14 of HNP-1 modulates its biological activities2. Bacterial exotoxins like Cholera Toxin (CT) by Vibrio cholerae, Heat Labile Enterotoxin (LT1) by Escherichia coli and Exoenzyme S (ExoS) by Pseudomonas aeruginosa are arginine ADP-ribosyltransferase enzymes that alter cell functions by modifying protein targets. Objectives: 1. Evaluate the ADP ribosylation of HNP-1 by CT, LT1 and ExoS. 2. Purify modified peptides and identify the ADP-ribosylated Arg. Methods: ADP-ribosylation of HNP-1 will be evaluated with biotinilated NAD by western blot. Purification of modified peptides will be performed by reverse phase HPLC. Identification of modification will be performed by Maldi-Toff analysis. Results: 1. CT and LT1 are effective in ADP-ribosylating HNP-1 as equal as the well known activity of ART1. On the other hand ExoS does not recognize HNP-1 as substrate. 2. Ongoing experiments are purifications and characterization of modified peptides by reverse-phase HPLC and Maldi-Toff analysis. Conclusions: 1. The different ADP-ribosylating activities displayed by CT, LT1 and ExoS on HNP-1 might be explained with differences in microbial pathogenesis, as the toxins released by V. cholerae and E. coli are involved in the early stages of infections, during the interactions with surface epithelial cells, while ExoS by P. aeruginosa is active during blood dissemination, when the pathogen has already overcome epithelial barrier. References: 1 Balducci et al., 1999, Am J Respir Cell Mol Biol, 21, 337-46 2 Paone et al., 2006, J Biol Chem, 281, 17054-6

Workaholism, intensive smartphone use, and the sleep-wake cycle: A multiple mediation analysis

Recent contributions have reported sleep disorders as one of the health impairment outcomes of workaholism. A possible factor affecting the sleep-wake cycle might be the intensive use of smartphones. The current study aimed to explore the role of intensive smartphone use in the relationship between workaholism and the sleep-wake cycle. Two serial multiple mediation models were tested on a sample of 418 employees, who filled self-report questionnaires measuring workaholism, use of smartphones, sleep quality and daytime sleepiness, using conditional process analysis for testing direct and indirect effects. Results supported our hypotheses regarding two serial multiple mediation models-that intensive smartphone use and poor sleep quality mediated the relationship between workaholism and daytime sleepiness, and that smartphone use and daytime sleepiness mediated the relationship between workaholism and poor quality of sleep. Although the use of a cross-sectional design and the snowball technique for collecting data can be considered as possible limitations, the current study is one of the first to document the potential detrimental role of the intensive smartphone use on the workaholism-sleep disorders relationship

BMI can influence adult males' and females' airway hyperresponsiveness differently

BACKGROUND: Epidemiological data indicate that obesity is a risk factor for asthma, but scientific literature is still debating the association between changes in body mass index (BMI) and airway hyperresponsiveness (AHR). METHODS: This study aimed at evaluating the influence of BMI on AHR, in outpatients with symptoms suggestive of asthma. 4,217 consecutive adult subjects (2,439 M; mean age: 38.2±14.9 yrs; median FEV(1) % predicted: 100 [IQR:91.88-107.97] and FEV(1)/FVC % predicted: 85.77% [IQR:81.1-90.05]), performed a methacholine challenge test for suspected asthma. Subjects with PD(20) < 200 or 200 < PD(20) < 800 or PD(20) > 800 were considered affected by severe, moderate or mild AHR, respectively. RESULTS: A total of 2,520 subjects (60% of all cases) had a PD(20) < 3,200 μg, with a median PD(20) of 366 μg [IQR:168–1010.5]; 759, 997 and 764 patients were affected by mild, moderate and severe AHR, respectively. BMI was not associated with increasing AHR in males. On the contrary, obese females were at risk for AHR only when those with moderate AHR were considered (OR: 1.772 [1.250-2.512], p = 0.001). A significant reduction of FEV(1)/FVC for unit of BMI increase was found in moderate AHR, both in males (β = −0.255; p =0.023) and in females (β = −0.451; p =0.017). CONCLUSIONS: Our findings indicate that obesity influences AHR only in females with a moderate AHR level. This influence may be mediated by obesity-associated changes in baseline lung function