Quantum criticality in spin chains with non-ohmic dissipation

We investigate the critical behavior of a spin chain coupled to bosonic baths characterized by a spectral density proportional to $\omega^s$, with $s>1$. Varying $s$ changes the effective dimension $d_\text{eff} = d + z$ of the system, where $z$ is the dynamical critical exponent and the number of spatial dimensions $d$ is set to one. We consider two extreme cases of clock models, namely Ising-like and U(1)-symmetric ones, and find the critical exponents using Monte Carlo methods. The dynamical critical exponent and the anomalous scaling dimension $\eta$ are independent of the order parameter symmetry for all values of $s$. The dynamical critical exponent varies continuously from $z \approx 2$ for $s=1$ to $z=1$ for $s=2$, and the anomalous scaling dimension evolves correspondingly from $\eta \gtrsim 0$ to $\eta = 1/4$. The latter exponent values are readily understood from the effective dimensionality of the system being $d_\text{eff} \approx 3$ for $s=1$, while for $s=2$ the anomalous dimension takes the well-known exact value for the 2D Ising and XY models, since then $d_{\rm{eff}}=2$. A noteworthy feature is, however, that $z$ approaches unity and $\eta$ approaches 1/4 for values of $s < 2$, while naive scaling would predict the dissipation to become irrelevant for $s=2$. Instead, we find that $z=1,\eta=1/4$ for $s \approx 1.75$ for both Ising-like and U(1) order parameter symmetry. These results lead us to conjecture that for all site-dissipative $Z_q$ chains, these two exponents are related by the scaling relation $z = \text{max} {(2-\eta)/s, 1}$. We also connect our results to quantum criticality in nondissipative spin chains with long-range spatial interactions.Comment: 8 pages, 6 figure

Effect of green manure management on barley yields and N-recovery

Mulching of GM herbage can increase cereal yields compared to its removal. However, the same GM herbage removed for biogas production will provide biogas residue that can be used as spring fertilizer to cereals. This will improve N-recovery and reduce the risk for N pollution. Cooperation with existing biogas plants will be more efficient, as building small biogas plants are costly and challenging

Helping veterans achieve work: A Veterans Health Administration nationwide survey examining effective job development practices in the community.

Objective: Veterans Health Administration vocational services assist veterans with mental illness to acquire jobs; one major component of these services is job development. The purpose of this study was to characterize the nature of effective job development practices and to examine perceptions and intensity of job development services. Method: A national mixed-methods online survey of 233 Veterans Health Administration vocational providers collected data regarding frequency of employer contacts, perceptions of job development ease/difficulty, and effective job development practices when dealing with employers. Qualitative responses elucidating effective practices were analyzed using content analysis. Results: Vocational providers had a modest number of job development employer contacts across 2 weeks (M = 11.0, SD = 10.6) and fewer were face-to-face (M = 7.6, SD = 8.4). Over 70% of participants perceived job development to be difficult. Six major themes emerged regarding effective job development practices with employers: using an employer-focused approach; utilizing a targeted marketing strategy; engaging in preparation and follow-up; going about the employer interaction with genuineness, resilience, and a strong interpersonal orientation; serving as an advocate for veterans and educator of employers; utilizing specific employer-tailored strategies, such as arranging a one-on-one meeting with a decision maker and touring the business, individualizing a prescripted sales pitch, connecting on a personal level, and engaging in ongoing communication to solidify the working relationship. Conclusions and implications for practice: Respondents highlight several potentially effective job development strategies; tools and resources may be developed around these strategies to bolster job development implementation and allow opportunities for fruitful employer interactions

Label-free quantitative proteomic analysis of the oral bacteria Fusobacterium nucleatum and Porphyromonas gingivalis to identify protein features relevant in biofilm formation

Background The opportunistic pathogens Fusobacterium nucleatum and Porphyromonas gingivalis are Gram-negative bacteria associated with oral biofilm and periodontal disease. This study investigated interactions between F. nucleatum and P. gingivalis proteomes with the objective to identify proteins relevant in biofilm formation. Methods We applied liquid chromatography-tandem mass spectrometry to determine the expressed proteome of F. nucleatum and P. gingivalis cells grown in biofilm or planktonic culture, and as mono- and dual-species models. The detected proteins were classified into functional categories and their label-free quantitative (LFQ) intensities statistically compared. Results The proteomic analyses detected 1,322 F. nucleatum and 966 P. gingivalis proteins, including abundant virulence factors. Using univariate statistics, we identified significant changes between biofilm and planktonic culture (p-value ≤0.05) in 0,4% F. nucleatum, 7% P. gingivalis, and 14% of all proteins in the dual-species model. For both species, proteins involved in vitamin B2 (riboflavin) metabolism had significantly increased levels in biofilm. In both mono- and dual-species biofilms, P. gingivalis increased the production of proteins for translation, oxidation-reduction, and amino acid metabolism compared to planktonic cultures. However, when we compared LFQ intensities between mono- and dual-species, over 90% of the significantly changed P. gingivalis proteins had their levels reduced in biofilm and planktonic settings of the dual-species model. Conclusions The findings suggest that P. gingivalis reduces the production of multiple proteins because of the F. nucleatum presence. The results highlight the complex interactions of bacteria contributing to oral biofilms, which need to be considered in the design of prevention strategies.publishedVersio

Induced abortion on demand and birth rate in Sami-speaking municipalities and a control group in Finnmark, Norway

Objectives. The objective of this study was to analyze the birth and induced abortion on demand (IAD) rate among women in Sami-speaking communities and a control group in Finnmark County, Norway. Methods. The 6 northern municipalities included in the administration area of the Sami language law (study group) were matched with a control group of 9 municipalities. Population data (numbers, sex and age) were accessed from Statistics Norway. Data on birth rate and IAD during the time period 1999&#x2013;2009 were derived from the Medical Birth Registry (MBR) of Norway. Data on number of women in fertile age (15&#x2013;44 years) were obtained from Statistics Norway. Between 2001 and 2008, this age group was reduced by 12% (Sami) and 23% (controls), respectively. Results. Finnmark County has a high IAD rate and 1 in 4 pregnancies (spontaneous abortions excluded) ended in IAD in the study and control groups. The total fertility rate per woman was 1.94 and 1.87 births, respectively. There was no difference between groups with regard to the IAD/birth ratio (P=0.94) or general fertility rate GFR (P=0.82). Conclusions. Women in the Sami-majority area and a control group in Finnmark County experienced a similar frequency of IAD and fertility rate