Structural stability of interaction networks against negative external fields

We explore structural stability of weighted and unweighted networks of positively interacting agents against a negative external field. We study how the agents support the activity of each other to confront the negative field, which suppresses the activity of agents and can lead to collapse of the whole network. The competition between the interactions and the field shape the structure of stable states of the system. In unweighted networks (uniform interactions) the stable states have the structure of k-cores of the interaction network. The interplay between the topology and the distribution of weights (heterogeneous interactions) impacts strongly the structural stability against a negative field, especially in the case of fat-tailed distributions of weights. We show that apart from critical slowing down there is also a critical change in the system structure that precedes the network collapse. The change can serve as an early warning of the critical transition. To characterize changes of network structure we develop a method based on statistical analysis of the k-core organization and so-called "corona" clusters belonging to the k-cores.

Astrocytic water channel aquaporin-4 modulates brain plasticity in both mice and humans: a potential gliogenetic mechanism underlying language-associated learning

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.

Community health needs assessment: a nurses' global health project in Vietnam

BACKGROUND

Global health has been directed to providing solutions to various health issues cross-nations, and nurses have received wide recognition as a key health workforce to reduce health disparities globally. Nurses involved in global health research are required to implement evidence-based global nursing practices based on the assessments of local health needs.

AIM

To assess health needs and to suggest future interventions in rural communities of Vietnam.

METHODS

A multifaceted rapid participatory appraisal with information pyramid was used applying mixed methods from six sources: existing record review, surveys of community residents, surveys of healthcare providers, focus group discussions with community leaders, informal discussions with governmental health administrators and observations of community health station (CHS) facilities.

RESULTS

The majority used the CHSs as primary health facilities with high satisfaction for services currently provided. However, there were needs for the stations to provide more comprehensive services including chronic diseases, and for healthcare providers to improve their competences. Community leaders showed high interest in health information for chronic diseases and strong commitment to involvement in the activities for health of their communities. The findings suggest future interventions in the areas of the enhancement of CHS' functions, human resources and the self-care capacity of community residents.

CONCLUSION AND POLICY IMPLICATIONS

The rapid participatory appraisal approach emphasizing community participation and partnership was a useful tool to compile accurate information about the current needs of the community on health, the preparedness of healthcare services to meet community's demands and about community capacity. This process is fundamental to nurses, who initiate global health projects in resource-limited international countries, to generate evidences regarding practice, research and policy for taking responsibilities in promoting the sustainable development goals.

Randomised trial comparing forced-air warming to the upper or lower body to prevent hypothermia during thoracoscopic surgery in the lateral decubitus position

BACKGROUND

In the supine position, forced-air warming is more effective on the lower body than on the upper body to prevent intraoperative hypothermia. However, it is unknown in the lateral decubitus position. We thus compared forced-air warming on the upper and lower bodies in the lateral position.

METHODS

Patients (n=123) were randomised to receive forced-air warming on the upper body or lower body during thoracoscopic surgery in the lateral position. We measured the nasopharyngeal temperature at 0, 30, 60, 90, and 120 min after lateral positioning during surgery and the infrared tympanic membrane temperature at 0, 30, 60, 90, and 120 min after surgery. Patients received both upper and lower body warming at a temperature of <35.5°C. The primary outcome was the incidence of intraoperative hypothermia with a temperature of <36.0°C.

RESULTS

Intraoperative hypothermia was less frequent with the upper body warming than with the lower body warming {21/62 vs 35/61, risk ratio [95% confidence interval (CI)] 0.6 (0.4-0.9), P=0.011}. The intraoperative temperature was higher with the upper body warming than with the lower body warming at 30 (P=0.002), 60 (P<0.001), and 90 (P<0.001) min after lateral positioning, and the postoperative temperature was higher at 0 (P<0.001) and 30 (P=0.001) min after surgery. Fewer patients received both upper and lower body warming in the upper body warming group than in the lower body warming group during surgery (1 vs 7, P=0.032).

CONCLUSIONS

Forced-air warming was more effective on the upper body than on the lower body to prevent hypothermia during thoracoscopic surgery in the lateral decubitus position.

CLINICAL TRIAL REGISTRATION

NCT02993666.

Underage drinking, group identity and access to alcohol: a qualitative study of Chinese youths

Despite substantial research into underage youth's source of alcohol, few studies have examined how they go about obtaining alcohol through various means. This study explored the nature of alcohol access by Chinese adolescents and how their own perceptions around alcohol availability influence them to source alcohol in particular ways. This research involved focus groups with 111 young people aged 14-17 in Hong Kong, China. A grounded theory analysis was conducted using NVivo 10. While participants perceived ease of obtaining alcohol from retail outlets, proxy purchasing through friendship group members was reported as routine experience primarily to avoid potential embarrassment of being turned away. Convincing vendors that they were of legal drinking age was the convention used most commonly by Chinese teen drinkers. Participants expressed resentment toward adults who were willing to supply minors with alcohol. Nevertheless, this feeling of disappointment did not alter the ways they sourced alcohol. Access activities embodied a symbol of group identity in the collectivist Chinese culture. Results suggest that greater consideration should be given to understanding the complex interplay between alcohol access and community experience within peers. The perceived importance of face saving in Chinese culture may provide avenues for preventing youth access to alcohol.

Relationship between serum testosterone and nocturia in men without benign prostate enlargement

Recent studies have focused on the relationship between nocturia and serum testosterone because testosterone is thought to be an important factor of prostate growth. However, it remains unclear whether altered serum concentrations of testosterone is associated with an increased risk of nocturia because patients who were taking diuretics or who had a large prostate, which may precipitate nocturia, were not excluded from most previous studies. We analyzed the clinical records of 596 non-benign prostatic enlargement (BPE) male patients to explore the relationship between serum total testosterone and nocturia. All patients were evaluated using a serum prostate-specific antigen (PSA) assay, measurement of serum total testosterone, transrectal ultrasonography, uroflowmetry, and a compilation of the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) questionnaires. Nocturia was defined as ≥2 nocturnal voiding episodes. The number of nocturia episodes was assessed using IPSS question 7. To evaluate the effect of serum testosterone on nocturia, multivariate regression analysis was performed including the covariates of age, IPSS, IIEF score, body mass index, PSA, prostate volume, and maximal urine flow rate. Based on multivariate linear analysis, serum testosterone level was not significantly associated with the severity of nocturia. However, with regard to the relationship between prevalence of nocturia and serum testosterone, prevalence of nocturia was significantly positively associated with age (OR = 1.048, p = 0.005), total IPSS (OR = 1.217, p < 0.001), and testosterone level (OR = 1.150, p = 0.041). Therefore, in men without an enlarged prostate, testosterone may play an opposing role in the etiology of nocturia.

Control of parasitic infection with ivermectin long-acting injection (IVOMEC® GOLD) and production benefit in first-season grazing cattle facing a high-level larval challenge in Germany

Gastrointestinal and pulmonary nematode infections are affecting the health and productivity of grazing cattle worldwide. To evaluate the effects of a single treatment with ivermectin long-acting injection (IVM LAI; IVOMEC® GOLD, Merial; 3.15 % ivermectin w/v) in first-grazing season cattle, two studies were conducted under continued stocking conditions for 84 or 100 days in Bavaria, Germany. Each study involved 68 naturally infected, approximately 4- to 6-month-old Brown Swiss bull calves. Animals were blocked based on pretreatment body weights. Within each block of four animals, animals were randomly assigned to treatments: one to saline (control) and three to IVM LAI. Treatments were injected at 1 mL/50 kg body weight subcutaneously in front of the shoulder. Animals in both studies were managed as one herd each grazing together. Cattle were weighed and fecal samples were collected pretreatment and at intervals thereafter for determination of weight gain and treatment efficacy, respectively. Fecal examination including composite fecal culture indicated the presence of nematodes of the genera Cooperia (dominating), Haemonchus, Nematodirus, Ostertagia, Strongyloides, Trichostrongylus, Trichuris, and Dictyocaulus, and Moniezia cestodes in the cattle. Following treatment, IVM LAI-treated cattle did not shed any Dictyocaulus larvae for 84 days while controls continued to pass larvae. Compared to the controls, IVM LAI-treated cattle had significantly (p < 0.01) lower strongylid egg counts at each occasion. Percentage reductions were ≥94 % up to 70 days after treatment and were ≥83.9 and 58.9 % at 84 and 100 days. Over the 84- or 100-day study periods, IVM LAI-treated cattle gained significantly more weight than the controls: 22.7 and 12.4 kg, respectively. The two studies demonstrated a high efficacy of IVM LAI against gastrointestinal and pulmonary nematode infections under field conditions in Germany which was associated with significant benefit as to weight gain.

Schottky barrier-gated high performance photodetectors using a water-borne polymeric colloid

Here, we demonstrate the synergetic application of a cationic surfactant (CTAB) for the fabrication of a fast response organic photoconductor via an environmentally benign fabrication process. A water-borne colloid of the semiconducting polymer PBTTT was fabricated via a mini-emulsion process with CTAB as the surfactant, and deposited onto a Au-patterned substrate to complete the photoconductor device geometry. Due to the preferential adsorption of the ammonium cation of the CTAB molecules onto the Au surface, a dipole layer was created and thus the work function of Au was significantly reduced, as confirmed by ultraviolet photoelectron spectroscopic studies. We show that the resulting Schottky barrier between Au-CTAB and PBTTT can be used as an artificial 'gate' for a trap-limited photoconductive mechanism, leading to a fast temporal response of the photoconductor without sacrificing the efficient photoconductive gain-generating mechanism. As a result, a high detectivity of 4.92 × 10(10) Jones, as well as a high gain of 107, can be realized from the PBTTT-based organic photoconductor. This result opens the possibility of fabricating high performance and simple structured organic photodetectors via a nontoxic fabrication process.

Synchronization in the random-field Kuramoto model on complex networks

We study the impact of random pinning fields on the emergence of synchrony in the Kuramoto model on complete graphs and uncorrelated random complex networks. We consider random fields with uniformly distributed directions and homogeneous and heterogeneous (Gaussian) field magnitude distribution. In our analysis, we apply the Ott-Antonsen method and the annealed-network approximation to find the critical behavior of the order parameter. In the case of homogeneous fields, we find a tricritical point above which a second-order phase transition gives place to a first-order phase transition when the network is either fully connected or scale-free with the degree exponent γ>5. Interestingly, for scale-free networks with 2<γ≤5, the phase transition is of second-order at any field magnitude, except for degree distributions with γ=3 when the transition is of infinite order at K_{c}=0 independent of the random fields. Contrary to the Ising model, even strong Gaussian random fields do not suppress the second-order phase transition in both complete graphs and scale-free networks, although the fields increase the critical coupling for γ>3. Our simulations support these analytical results.