bluuebunny/crossref_metadata_2025 huggingface dataset:
Mediating effect of stress on the association between early trauma and psychological distress in Korean college students: a cross‐sectional observational study
Authors: Kim S. , Noh D. , Park S. I.
Published: August 2015

Accessible summary

What is known on the subject?

Despite the increase of studies into the predictors of psychological distress, few have attempted to address the mediation of stress in the relationship between early trauma and psychological distress.

What does this paper add to existing knowledge?

In this study, college students with trauma exposure before the age of 18 years reported high levels of college life stress and psychological distress. In addition, of the subcategories of early trauma, emotional abuse was most highly correlated with current stress and psychological distress.

This paper confirmed the partial mediating effect of stress between early trauma and psychological distress among Korean college students. In other words, this study found a direct effect of early trauma on current psychological distress and an indirect effect of early trauma on psychological distress mediated through life stress.

What are the implications for practice?

Early trauma and stress should be considered when developing interventions for college students' mental health, although individuals with trauma exposure have difficulties disclosing their traumatic event. Therefore, we suggest that stress management may be easier to apply and more effective in promoting college students' mental health than trauma‐focused interventions.

Introduction

Research has shown that early trauma and stress may affect current psychological distress. However, few studies have attempted to address the mediation of stress between early trauma and psychological distress.

Aim

This cross‐sectional observational study aimed to examine the mediating effects of stress on the association between early trauma and psychological distress in Korean college students.

Method

Participants included 216 college students (51.4% male) who completed self‐report questionnaires assessing early trauma, college life stress, and psychological distress.

Results

Early trauma, stress, and psychological distress were significantly correlated. Of the subcategories of early trauma, emotional abuse was most highly correlated with stress and psychological distress. The bootstrapping results indicate that stress is a partial mediator between early trauma and psychological distress after controlling for covariates including socioeconomic status, habitation status, and gender.

Discussion

The results imply that both early trauma and stress should be considered when developing interventions for college students' mental health. However, individuals with trauma exposure tend to have difficulties disclosing their traumatic event. Therefore, we suggest that stress management may be more feasible and effective in promoting college students' mental health than trauma‐focused interventions.
Exposure to war traumatic experiences, post‐traumatic stress disorder and post‐traumatic growth among nurses in Gaza
Authors: Shamia N. A. , Thabet A. A. M. , Vostanis P.
Published: August 2015

Accessible summary

What is known on the subject?

This study builds on existing research on war‐related factors that may affect health‐care staff by particularly focusing on trauma exposure in both professional and everyday life, as well as on correlates of later positive psychological changes.

What this paper adds to existing knowledge?

It shows that one in five nursing staff working in Gaza experienced post‐traumatic stress symptoms within the clinical range, 2 years after an incursion on Gaza and after being exposed to substantial trauma during this period.

Participants appeared to develop a variety of post‐traumatic growth responses following trauma exposure.

Although nurses experienced traumatic events both as civilians and in their health‐care capacity, personal exposure was strongly associated with PTSD symptoms.

What are the implications for practice?

Support to nursing and other health‐care professionals in war situations should entail different levels, remain available well after an acute conflict, and take into consideration both personal and practice‐related traumatic events. Mental health nursing practitioners can play a pivotal role in this.

Aim

To establish the association between war traumatic experiences, post‐traumatic stress disorder (PTSD) symptoms and post‐traumatic growth among nurses in the Gaza Strip, 2 years after an incursion on Gaza, and during a period of ongoing trauma exposure. This study builds on existing evidence by considering exposure to personal and work‐related traumatic events, and on factors associated with later positive psychological adaptation.

Methods

The sample consisted of 274 randomly selected nurses in Gaza who completed the Gaza Traumatic Events Checklist, PTSD Checklist, and Posttraumatic Growth Inventory.

Results

Of the nurses, 19.7% reported full PTSD. There was a significant relationship between traumatic events and PTSD scores; as well as between community‐related traumatic events and post‐traumatic growth. Participants reported a range of traumatic events, but PTSD and post‐traumatic growth scores were more strongly associated with community rather than work‐related traumas.

Discussion

Nursing professionals experienced high levels of distress 2 years following an acute period of conflict, both as civilians and in their health‐care capacity.

Implications for Practice

There is need for different levels of support for health‐care staff in war‐affected areas. Mental health nursing professionals have a central role in training, counselling and support to other health‐care colleagues.
The Basal Onaping Intrusion in the North Range: Roof rocks of the Sudbury Igneous Complex
Authors: Anders Denise , Osinski Gordon R. , Grieve Richard A. F. , Brillinger Derek T. M.
Published: August 2015

The 1.85 Ga Sudbury impact structure is one of the largest impact structures on Earth. Igneous bodies—the so‐called “Basal Onaping Intrusion”—occur at the contact between the Sudbury Igneous Complex (SIC) and the overlying Onaping Formation and occupy ~50% of this contact zone. The Basal Onaping Intrusion is presently considered part of the Onaping Formation, which is a complex series of breccias. Here, we present petrological and geochemical data from two drill cores and field data from the North Range of the Sudbury structure, which suggests that the Basal Onaping Intrusion is not part of the Onaping Formation. Our observations indicate that the Basal Onaping Intrusion crystallized from a melt and has a groundmass comprising a skeletal intergrowth of feldspar and quartz that points to simultaneous cooling of both components. Increasing grain size and decreasing amounts of clasts with increasing depth are general features of roof rocks of coherent impact melt rocks at other impact structures and the Basal Onaping Intrusion. Planar deformation features within quartz clasts of the Basal Onaping Intrusion are indicators for shock metamorphism and, together with the melt matrix, point to the Basal Onaping Intrusion as being an impact melt rock, by definition. Importantly, the contact between Granophyre of the SIC and Basal Onaping Intrusion is transitional and we suggest that the Basal Onaping Intrusion is what remains of the roof rocks of the SIC and, thus, is a unit of the SIC and not the Onaping Formation. We suggest henceforth that this unit be referred to as the “Upper Contact Unit” of the SIC.
Resveratrol in the treatment of pancreatic cancer
Authors: Xu Qinhong , Zong Liang , Chen Xin , Jiang Zhengdong , Nan Ligang , Li Jiahui , Duan Wanxing , Lei Jianjun , Zhang Lun , Ma Jiguang , Li Xuqi , Wang Zheng , Wu Zheng , Ma Qingyong , Ma Zhenhua
Published: August 2015

Pancreatic cancer (PCa), which is now the fourth most frequent cause of cancer‐related death, has a median survival of less than 6 months and a 5‐year survival rate of <6%. The hallmarks of this cancer include poor outcome, short survival duration, and resistance to therapy. The poor prognosis of PCa is related to its local recurrence, lymph node and liver metastases, and peritoneal dissemination. Recent studies have indicated that resveratrol has cancer‐chemopreventive and anticancer activities. In this short review we summarize the chemopreventive and treatment effects of resveratrol in PCa, as follows: resveratrol inhibits the proliferation of pancreatic cancer cells; induces apoptosis and cell cycle arrest; inhibits metastasis and invasion of PCa cells; inhibits the proliferation and viability of PCa stem cells; enhances the chemoradiosensitization of PCa cells; and can affect diabetes mellitus in addition to PCa. On the basis of these data, resveratrol may be considered a potential anticancer agent for the treatment of PCa.
Somatotrope GHRH/GH/IGF‐1 axis at the crossroads between immunosenescence and frailty
Authors: Bodart Gwennaelle , Goffinet Lindsay , Morrhaye Gabriel , Farhat Khalil , de Saint‐Hubert Marie , Debacq‐Chainiaux Florence , Swine Christian , Geenen Vincent , Martens Henri J.
Published: August 2015

Immunosenescence, characterized by complex modifications of immunity with age, could be related to frailty syndrome in elderly individuals, leading to an inadequate response to minimal aggression. Functional decline (i.e., the loss of ability to perform activities of daily living) is related to frailty and decreased physiological reserves and is a frequent outcome of hospitalization in older patients. Links between immunosenescence and frailty have been explored and 20 immunological parameters, including insulin‐like growth factor‐1 (IGF‐1), thymopoeisis, and telomere length, were shown to be affected in elderly patients with functional decline. A strong relationship between IGF‐1 and thymic ouput was evidenced. IGF‐1, a mediator of growth hormone (GH), was subsequently shown to induce interleukin‐7 secretion in cultured primary human thymic epithelial cells. We are exploring the stress hypothesis in which an acute stressor is used as the discriminator of frailty susceptibility. GH can counteract the deleterious immunosuppressive effects of stress‐induced steroids. Under nonstress conditions, the immunosenescent system preserves physiological responses, while under stress conditions, the combination of immunosenescence and a defect in the somatotrope axis might lead to functional decline.
Pulmonary arterial hypertension in a child with stage‐IV neuroblastoma after autologous hematopoietic stem cell transplantation and review of the literature
Authors: Özyörük Derya , Kibar Ayşe Esin , Sürücü Murat , Azak Emine , Emir Suna , Çetin İbrahim İlker , Tunç Bahattin , Özbek Namık Yaşar
Published: August 2015

PH is a rare condition with high mortality rate after pediatric HSCT. As clinical presentation is non‐specific and may mimic other conditions, a high degree of suspicion is required for diagnosis. Here, we present a patient with stage‐IV neuroblastoma who developed PAH after autologous HSCT. After exclusion of other causes of PH, we regarded that this condition was secondary to HSCT.
We All Need Help: “Big Data” and the Mismeasure of Public Administration
Authors: Lavertu Stéphane
Published: August 2015

Rapid advances in our ability to collect, analyze, and disseminate information are transforming public administration. This “big data” revolution presents opportunities for improving the management of public programs, but it also entails some risks. In addition to potentially magnifying well‐known problems with public sector performance management—particularly the problem of goal displacement—the widespread dissemination of administrative data and performance information increasingly enables external political actors to peer into and evaluate the administration of public programs. The latter trend is consequential because external actors may have little sense of the validity of performance metrics and little understanding of the policy priorities they capture. The author illustrates these potential problems using recent research on U.S. primary and secondary education and suggests that public administration scholars could help improve governance in the data‐rich future by informing the development and dissemination of organizational report cards that better capture the value that public agencies deliver.
Household Satellite Account for France
Authors: Poissonnier Aurélien , Roy Delphine
Published: August 2015

We estimate in a household satellite account (HHSA) the value of French domestic production in 2010 and 1998, using the input method and following Eurostat's recommendations. In line with previous studies, we find that extending the system of national accounts (SNA) frontier of production to domestic activities (house chores, cooking, care …) has a sizeable effect on key macroeconomic indicators (+33 percent GDP, −5 p.p. GDP growth, +50 percent disposable income, +58 percent consumption, and −10 p.p. of purchasing power growth). We conduct a sensitivity analysis to various methodological issues which have not yet been settled by an international benchmark. Quantitatively, the two most important issues are the boundary of household production—we favor a relatively narrow definition—and the use of a gross or a net wage—we prefer gross wage‐. However, estimates are much less sensitive to otherwise greatly debated issues such as which substitute wage to use.
Recovery of calf muscle endurance 3 months after anAchilles tendon rupture
Authors: Brorsson A. , Olsson N. , Nilsson‐Helander K. , Karlsson J. , Eriksson B. I. , Silbernagel K. G.
Published: August 2015

The purpose of this study was to evaluate calf muscle endurance in a seated position 3 months after anAchilles tendon rupture and to evaluate how the ability to perform standardized seated heel‐rises correlated to the single‐leg standing heel‐rise test and to patient‐reported symptoms evaluated with theAchilles tendonTotalRuptureScore (ATRS) 3 and 6 months after the injury. Ninety‐three patients were included from a cohort of 101 patients participating in a prospective, randomized controlled trial comparing surgical and nonsurgical treatment afterAchilles tendon rupture. Forty‐seven patients were treated surgically and 46 nonsurgically. Ninety‐one patients out of 93 (98%) could perform the standardized seated heel‐rises. At the 3‐month follow‐up, there was a significant difference (P < 0.001) between the injured and the healthy side performing standardized seated heel‐rises. There were also significant correlations (r = 0.29–0.37,P = < 0.05) between the standardized seated heel‐rises andATRS3 and 6 months after injury in the group who could not perform single‐leg standing heel‐rises. There were no significant differences between the surgical and nonsurgical treatment groups. The evaluation of standardized seated heel‐rises appears to be a useful tool to quantify progress and predict future functional performance and patient‐reported symptoms.
Health and economic burden of running‐related injuries in runners training for an event: A prospective cohort study
Authors: Hespanhol Junior L. C. , van Mechelen W. , Postuma E. , Verhagen E.
Published: August 2015

Prospective running‐related injury (RRI) data from runners training for an event are scarce, especially with regard to RRI‐associated costs. Therefore, the aim of this study was to investigate the prevalence and economic burden of RRIs in runners participating in an organized training program preparing them for an event. This was a prospective cohort study with 18 weeks of follow‐up. Individuals aged 18 or older and registered to participate in an organized running program were eligible. Follow‐up surveys were sent every 2 weeks to collect data about running exposure, RRIs, and costs. Of the 161 potential participants, 53 (32.9%) were included in this study. A total of 32 participants reported 41 RRIs. The mean prevalence during follow‐up was 30.8% [95% confidence interval (CI) 25.6–36.0%]. Overuse was the main mechanism of RRI (85.4%, n = 35). An RRI was estimated to have an economic burden of €57.97 (95% CI €26.17–94.00) due to healthcare utilization (direct costs) and €115.75 (95% CI €10.37–253.73) due to absenteeism from paid work (indirect costs). These results indicate that the health and economic burden of RRIs may be considered significant for public health. Therefore, prevention programs are needed for runners participating in organized training programs.
J‐Integral from Full Field Kinematic Data for Natural Rubber Compounds
Authors: Caimmi F. , Calabrò R. , Briatico‐Vangosa F. , Marano C. , Rink M.
Published: August 2015

The application of the digital image correlation technique to the determination of the J‐integral at fracture initiation for carbon black‐filled natural rubber compounds is discussed. Three different compounds with varying carbon black content were tested, using two different test configurations: pure shear and biaxial tensile test. Digital image correlation was used to measure the displacement field around the crack tip in the tested specimens. From the displacement field, which was interpolated using a finite element scheme, the stresses were evaluated by using Ogden's hyperelastic model, and the J‐integral could be calculated. The results compare well with both theoretical and finite element results.
Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines
Authors: Vinnemeier C. D. , Brust P. , Owusu‐Dabo E. , Sarpong N. , Sarfo E. Y. , Bio Y. , Rolling T. , Dekker D. , Adu‐Sarkodie Y. , Eberhardt K. A. , May J. , Cramer J. P.
Published: August 2015

Objective

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new‐born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS‐related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials.

Methods

This double‐centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto‐vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS‐positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC).

Results

In total, 519 women were recruited at both study sites, recto‐vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively.

Discussion

Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study.
Inactivation of Zika virus in plasma with amotosalen and ultraviolet A illumination
Authors: Aubry Maite , Richard Vaea , Green Jennifer , Broult Julien , Musso Didier
Published: August 2015

BACKGROUND

Zika virus (ZIKV) is an arthropod‐borne virus (arbovirus) transmitted by mosquitoes. The potential for ZIKV transmission through blood transfusion was demonstrated during the ZIKV outbreak that occurred in French Polynesia from October 2013 to April 2014. Pathogen inactivation of blood products is a proactive strategy that provides the potential to reduce transfusion‐transmitted diseases. Inactivation of arboviruses by amotosalen and ultraviolet A (UVA) illumination was previously demonstrated for chikungunya, West Nile, and dengue viruses. We report here the efficiency of this process for ZIKV inactivation of human plasma.

STUDY DESIGN AND METHODS

Plasma units were spiked with ZIKV. Viral titers and RNA loads were measured in plasma before and after amotosalen and UVA photochemical treatment.

RESULTS

The mean ZIKV titers and RNA loads in plasma before inactivation were respectively 6.57 log TCID50/mL and 10.25 log copies/mL. After inactivation, the mean ZIKV RNA loads was 9.51 log copies/mL, but cell cultures inoculated with inactivated plasma did not result in infected cells and did not produce any replicative virus after one passage, nor detectable viral RNA from the second passage.

CONCLUSION

In this study we demonstrate that amotosalen combined with UVA light inactivates ZIKV in fresh‐frozen plasma. This inactivation process is of particular interest to prevent plasma transfusion‐transmitted ZIKV infections in areas such as French Polynesia, where several arboviruses are cocirculating.
Trade Openness and Income: A Tale of Two Regions
Authors: Camarero Mariam , Martínez‐Zarzoso Inmaculada , Nowak‐Lehmann Felicitas , Tamarit Cecilio
Published: August 2015

In this paper, we present evidence of the long‐run effect of trade openness on income per worker for two regions that have followed different liberalisation strategies, namely Asia and Latin America. A model that re‐examines these questions is estimated for two panels of Asian and Latin American countries over the 1980–2008 period using a novel empirical approach that accounts for endogeneity as well as for the time series properties of the variables involved. From an econometric point of view, we apply recent panel co‐integration techniques based on factor models that account for two additional elements usually neglected in previous empirical literature: cross‐dependence and structural breaks. The results point to a positive impact of trade openness in both Asia and Latin America although the size is smaller in the second region. We associate this finding with the degree to which trade was managed in both regions of the developing world.
Canine sterile nodular panniculitis: a retrospective study of 39 dogs
Authors: Contreary Caitlin L. , Outerbridge Catherine A. , Affolter Verena K. , Kass Philip H. , White Stephen D.
Published: August 2015

Background

Canine sterile nodular panniculitis (SNP) is an inflammatory disease of the panniculus that is typically managed with immunomodulatory or immunosuppressive treatments. It has been reported to be a cutaneous marker of an underlying systemic disease.

Hypothesis/Objectives

To assess the presence or absence of concurrent systemic diseases associated with canineSNPand to document breed predispositions.

Animals

Thirty nine dogs presented to a veterinary teaching hospital from 1990 to 2012 which met inclusion criteria.

Methods

Inclusion in this retrospective study required a diagnosis ofSNPvia histopathological analysis and negative special stains for infectious organisms. Breed distributions of affected dogs were compared to all other dogs examined at this hospital during the study period. Correlations between the histological pattern of panniculitis and the histological presence of dermatitis, clinical presentation of lesions, dog breed and therapeutic outcomes were assessed.

Results

Australian shepherd dogs, Brittany spaniels, Dalmatians, Pomeranians and Chihuahuas were significantly over‐represented, but correlations between inflammatory patterns of panniculitis and other histological and clinical factors were not identified. Based on the information available in medical records, 32 dogs (82.1%) had no concurrent systemic diseases identified. Four dogs had concurrent polyarthritis, which may be related toSNPthrough unknown mechanisms.

Conclusions/Clinical Importance

This study identified several novel breed predilections forSNP; it failed to find any clear correlations with associated systemic diseases other than polyarthritis. The histological inflammatory pattern ofSNPdoes not predict therapeutic outcome.
Analysis of the Economic and Environmental Effects by the Offshore Wind Power Construction: In case of Kitakyushu City, Japan
Authors: Jung Woojong
Published: August 2015

The purpose of this study is to analyze the economic spillover effects and environmental impact of building offshore wind turbines on a local economy in Japan. Japan is facing a great turning point in its energy policy in the wake of the Great East Japan Earthquake, further increasing the importance of renewable energy. The offshore wind turbines experiment in Kitakyushu City is anticipated to showcase the potential of offshore wind power in Japan for the future and dynamize the local economy. As such, in this study, an economic and environmental impact assessment by Input–Output (I-O) analysis was conducted for the construction of the offshore wind turbines. The results show that building one hundred 3MW offshore wind turbine units will increase the induced production value by approximately 205.2 billion yen, equivalent to roughly 2.7% of Kitakyushu City’s total production value. Additionally, it is anticipated to create approximately 14 500 jobs. In terms of environmental impact, the increase in production is estimated to increase CO2 emissions by nearly 340 000 tonnes (an increase of approximately 2.1%). Accordingly, the environmental impact of building offshore wind turbines in Kitakyushu City is smaller than the economic impact, meaning that a sustainable between the economy and the environment can be found by the diffusion of renewable energy.
Compactifications of reductive groups as moduli stacks of bundles
Authors: Martens Johan , Thaddeus Michael
Published: August 2015

Let$G$be a split reductive group. We introduce the moduli problem ofbundle chainsparametrizing framed principal$G$-bundles on chains of lines. Any fan supported in a Weyl chamber determines a stability condition on bundle chains. Its moduli stack provides an equivariant toroidal compactification of$G$. All toric orbifolds may be thus obtained. Moreover, we get a canonical compactification of any semisimple$G$, which agrees with the wonderful compactification in the adjoint case, but which in other cases is an orbifold. Finally, we describe the connections with Losev–Manin’s spaces of weighted pointed curves and with Kausz’s compactification of$GL_{n}$.
GABAB receptor‐mediated feed‐forward circuit dysfunction in the mouse model of fragile X syndrome
Authors: Wahlstrom‐Helgren Sarah , Klyachko Vitaly A.
Published: August 2015

Key points

Cortico‐hippocampal feed‐forward circuits formed by the temporoammonic (TA) pathway exhibit a marked increase in excitation/inhibition ratio and abnormal spike modulation functions in Fmr1 knock‐out (KO) mice.

Inhibitory, but not excitatory, synapse dysfunction underlies cortico‐hippocampal feed‐forward circuit abnormalities in Fmr1 KO mice.

GABA release is reduced in TA‐associated inhibitory synapses of Fmr1 KO mice in a GABAB receptor‐dependent manner.

Inhibitory synapse and feed‐forward circuit defects are mediated predominately by presynaptic GABAB receptor signalling in the TA pathway of Fmr1 KO mice.

GABAB receptor‐mediated inhibitory synapse defects are circuit‐specific and are not observed in the Schaffer collateral pathway‐associated inhibitory synapses in stratum radiatum.

Circuit hyperexcitability has been implicated in neuropathology of fragile X syndrome, the most common inheritable cause of intellectual disability. Yet, how canonical unitary circuits are affected in this disorder remains poorly understood. Here, we examined this question in the context of the canonical feed‐forward inhibitory circuit formed by the temporoammonic (TA) branch of the perforant path, the major cortical input to the hippocampus. TA feed‐forward circuits exhibited a marked increase in excitation/inhibition ratio and major functional defects in spike modulation tasks in Fmr1 knock‐out (KO) mice, a fragile X mouse model. Changes in feed‐forward circuits were caused specifically by inhibitory, but not excitatory, synapse defects. TA‐associated inhibitory synapses exhibited increase in paired‐pulse ratio and in the coefficient of variation of IPSPs, consistent with decreased GABA release probability. TA‐associated inhibitory synaptic transmission in Fmr1 KO mice was also more sensitive to inhibition of GABAB receptors, suggesting an increase in presynaptic GABAB receptor (GABABR) signalling. Indeed, the differences in inhibitory synaptic transmission between Fmr1 KO and wild‐type (WT) mice were eliminated by a GABABR antagonist. Inhibition of GABABRs or selective activation of presynaptic GABABRs also abolished the differences in the TA feed‐forward circuit properties between Fmr1 KO and WT mice. These GABABR‐mediated defects were circuit‐specific and were not observed in the Schaffer collateral pathway‐associated inhibitory synapses. Our results suggest that the inhibitory synapse dysfunction in the cortico‐hippocampal pathway of Fmr1 KO mice causes hyperexcitability and feed‐forward circuit defects, which are mediated in part by a presynaptic GABABR‐dependent reduction in GABA release.
Joint estimation of tissue types and linear attenuation coefficients for photon counting CT
Authors: Nakada Kento , Taguchi Katsuyuki , Fung George S. K. , Amaya Kenji
Published: August 2015

Purpose:

Newly developed spectral computed tomography (CT) such as photon counting detector CT enables more accurate tissue‐type identification through material decomposition technique. Many iterative reconstruction methods, including those developed for spectral CT, however, employ a regularization term whose penalty transition is designed using pixel value of CT image itself. Similarly, the tissue‐type identification methods are then applied after reconstruction; thus, it is impossible to take into account probability distribution obtained from projection likelihood. The purpose of this work is to develop comprehensive image reconstruction and tissue‐type identification algorithm which improves quality of both reconstructed image and tissue‐type map.

Methods:

The authors propose a new framework to jointly perform image reconstruction, material decomposition, and tissue‐type identification for photon counting detector CT by applying maximum a posteriori estimation with voxel‐based latent variables for the tissue types. The latent variables are treated using a voxel‐based coupled Markov random field to describe the continuity and discontinuity of human organs and a set of Gaussian distributions to incorporate the statistical relation between the tissue types and their attenuation characteristics. The performance of the proposed method is quantitatively compared to that of filtered backprojection and a quadratic penalized likelihood method by 100 noise realization.

Results:

Results showed a superior trade‐off between image noise and resolution to current reconstruction methods. The standard deviation (SD) and bias of reconstructed image were improved from quadratic penalized likelihood method: bias, −0.9 vs −0.1 Hounsfield unit (HU); SD, 46.8 vs 27.4 HU. The accuracy of tissue‐type identification was also improved from quadratic penalized likelihood method: 80.1% vs 86.9%.

Conclusions:

The proposed method makes it possible not only to identify tissue types more accurately but also to reconstruct CT images with decreased noise and enhanced sharpness owing to the information about the tissue types.
High resolution functional photoacoustic tomography of breast cancer
Authors: Li Xiaoqi , Heldermon Coy D. , Yao Lei , Xi Lei , Jiang Huabei
Published: August 2015

Purpose:

To evaluate the feasibility of functional photoacoustic tomography (fPAT) for high resolution detection and characterization of breast cancer and to demonstrate for the first time quantitative hemoglobin concentration and oxygen saturation images of breasts that were formed with model‐based reconstruction of tomographic photoacoustic data.

Methods:

The study was HIPAA compliant and was approved by the university institutional review board. Written informed consents were obtained from all the participants. Ten cases, including six cancer and four healthy (mean age = 50 yr; age range = 41–66 yr), were examined. Functional images of breast tissue including absolute total hemoglobin concentration (HbT) and oxygen saturation (StO2%) were obtained by fPAT and cross validated with magnetic resonance imaging (MRI) readings and/or histopathology.

Results:

HbT and StO2% maps from all six pathology‐confirmed cancer cases (60%) show clear detection of tumor, while MR images indicate clear detection of tumor for five of six cancer cases; one small tumor was read as near‐complete‐resolution by MRI. The average HbT and StO2% value of suspicious lesion area for the cancer cases was 61.6 ± 18.9 μM/l and 67.5% ± 5.2% compared to 25.6 ± 7.4 μM/l and 65.2% ± 3.8% for background normal tissue.

Conclusions:

fPAT has the potential to be a significant add‐on in breast cancer detection and characterization as it provides submillimeter resolution functional images of breast lesions.
The effects of physiological adjustments on the perceptual and acoustical characteristics of simulated laryngeal vocal tremor
Authors: Lester Rosemary A. , Story Brad H.
Published: August 2015

The purpose of this study was to determine if adjustments to the voice source [i.e., fundamental frequency (F0), degree of vocal fold adduction] or vocal tract filter (i.e., vocal tract shape for vowels) reduce the perception of simulated laryngeal vocal tremor and to determine if listener perception could be explained by characteristics of the acoustical modulations. This research was carried out using a computational model of speech production that allowed for precise control and manipulation of the glottal and vocal tract configurations. Forty-two healthy adults participated in a perceptual study involving pair-comparisons of the magnitude of “shakiness” with simulated samples of laryngeal vocal tremor. Results revealed that listeners perceived a higher magnitude of voice modulation when simulated samples had a higher mean F0, greater degree of vocal fold adduction, and vocal tract shape for /i/ vs /ɑ/. However, the effect of F0 was significant only when glottal noise was not present in the acoustic signal. Acoustical analyses were performed with the simulated samples to determine the features that affected listeners' judgments. Based on regression analyses, listeners' judgments were predicted to some extent by modulation information present in both low and high frequency bands.
New Team, New Fans: A Longitudinal Examination of Team Identification as a Driver of University Identification
Authors: Katz Matthew , Heere Bob
Published: August 2015

The authors examined the longitudinal development of team identification among stakeholders of a newly formed intercollegiate football team to empirically measure the impact of a new football team on university identification. Using a multidimensional approach to identification, data were collected over a 3-year period and analyzed using growth curve analysis to determine the changes and trajectories of the individual dimensions of identification related to both the new football team and the larger university. Conditional growth models were used to determine the percentage of change in university identification explained by changes in team identification—to test whether new team identification drives identification with the larger university. The presented findings allow for an improved understanding of the psychological impact of a new football team for the university community by using growth curve analysis, which provides a more detailed and accurate empirical examination of identification, rather than traditional two-wave cross-lagged designs. Implications of the longitudinal nature of identification and the psychological value of a new football team for the university are discussed.
Intravascular pressure enhances the abundance of functional K
v
1.5 channels at the surface of arterial smooth muscle cells
Authors: Kidd Michael W. , Leo M. Dennis , Bannister John P. , Jaggar Jonathan H.
Published: August 2015

Intravascular pressure limits vasoconstriction by increasing the surface abundance of K
v
1.5 on arterial myocytes.
Characterization of the Global Stabilizing Substitution A77V and Its Role in the Evolution of CTX-M β-Lactamases
Authors: Patel Meha P. , Fryszczyn Bartlomiej G. , Palzkill Timothy
Published: August 2015

The widespread use of oxyimino-cephalosporin antibiotics drives the evolution of the CTX-M family of β-lactamases that hydrolyze these drugs and confer antibiotic resistance. Clinically isolated CTX-M enzymes carrying the P167S or D240G active site-associated adaptive mutation have a broadened substrate profile that includes the oxyimino-cephalosporin antibiotic ceftazidime. The D240G substitution is known to reduce the stability of CTX-M-14 β-lactamase, and the P167S substitution is shown here to also destabilize the enzyme. Proteins are marginally stable entities, and second-site mutations that stabilize the enzyme can offset a loss in stability caused by mutations that enhance enzyme activity. Therefore, the evolution of antibiotic resistance enzymes can be dependent on the acquisition of stabilizing mutations. The A77V substitution is present in CTX-M extended-spectrum β-lactamases (ESBLs) from a number of clinical isolates, suggesting that it may be important in the evolution of antibiotic resistance in this family of β-lactamases. In this study, the effects of the A77V substitution in the CTX-M-14 model enzyme were characterized with regard to the kinetic parameters for antibiotic hydrolysis as well as enzyme expression levelsin vivoand protein stabilityin vitro. The A77V substitution has little effect on the kinetics of oxyimino-cephalosporin hydrolysis, but it stabilizes the CTX-M enzyme and compensates for the loss of stability resulting from the P167S and D240G mutations. The acquisition of global stabilizing mutations, such as A77V, is an important feature in β-lactamase evolution and a common mechanism in protein evolution.
Loss of Hypermucoviscosity and Increased Fitness Cost in Colistin-Resistant Klebsiella pneumoniae Sequence Type 23 Strains
Authors: Choi Myung-Jin , Ko Kwan Soo
Published: August 2015

In this study, we investigated the effects of colistin resistance on virulence and fitness in hypermucoviscous (HV)
Klebsiella pneumoniae
sequence type 23 (ST23) strains. Colistin-resistant mutants were developed from three colistin-susceptible HV
K. pneumoniae
ST23 strains. The lipid A structures of strains were analyzed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. Changes in HV were investigated using the string test, and extracellular polysaccharide production was quantified. The expression levels of the
phoQ
,
pmrD
,
pmrB
,
pbgP
,
magA
, and p-
rmpA2
genes, serum resistance, and biofilm-forming activity were determined. The fitness of colistin-resistant mutants compared to that of the parental strains was examined by determining the competitive index (CI). The colistin-resistant mutants exhibited reduced HV, which was accompanied by decreased formation of capsular polysaccharides (CPS) and reduced expression of genes (
magA
and p-
rmpA2
). While there was enhanced expression of
pmrD
and
pbgP
in all colistin-resistant derivatives, there were differences in the expression levels of
phoQ
and
pmrB
between strains. MALDI-TOF analysis detected the addition of aminoarabinose or palmitate to the lipid A moiety of lipopolysaccharide in the colistin-resistant derivatives. In addition, survival rates in the presence of normal human serum were decreased in the mutant strains, and CI values (0.01 to 0.19) indicated significant fitness defects in the colistin-resistant derivatives compared to the respective parental strains. In hypervirulent HV
K. pneumoniae
strains, the acquisition of colistin resistance was accompanied by reduced CPS production, impaired virulence, and a significant fitness cost.
Optimizing the Initial Amikacin Dosage in Adults
Authors: White Bryan P. , Lomaestro Ben , Pai Manjunath P.
Published: August 2015

We report on the pharmacokinetics (PK) and pharmacodynamics (PD) of high-dose (>15 mg/kg of body weight per day) amikacin. A mean (standard deviation [SD]) maximum drug concentration in the serum (
C
max
) and 24-h area under the concentration-time curve (AUC
24
) of 101 (49.4) mg/liter and 600 (387) mg · h/liter, respectively, were observed (
n
= 73) with 28.0 (8.47) mg/kg/day doses. An initial amikacin dose of 2,500 mg in adults weighing 40 kg to 200 kg with therapeutic drug monitoring to adjust the maintenance dose will optimize its PK and PD.
Effects of Selection Pressure and Genetic Association on the Relationship between Antibiotic Resistance and Virulence in Escherichia coli
Authors: Zhang Lixin , Levy Karen , Trueba Gabriel , Cevallos William , Trostle James , Foxman Betsy , Marrs Carl F. , Eisenberg Joseph N. S.
Published: August 2015

Antibiotic selection pressure and genetic associations may lead to the cooccurrence of resistance and virulence in individual pathogens. However, there is a lack of rigorous epidemiological evidence that demonstrates the cooccurrence of resistance and virulence at the population level. Using samples from a population-based case-control study in 25 villages in rural Ecuador, we characterized resistance to 12 antibiotics among pathogenic (
n
= 86) and commensal (
n
= 761)
Escherichia coli
isolates, classified by the presence or absence of known diarrheagenic virulence factor genes. The prevalences of resistance to single and multiple antibiotics were significantly higher for pathogenic isolates than for commensal isolates. Using a generalized estimating equation, antibiotic resistance was independently associated with virulence factor carriage, case status, and antibiotic use (for these respective factors: odds ratio [OR] = 3.0, with a 95% confidence interval [CI] of 1.7 to 5.1; OR = 2.0, with a 95% CI of 1.3 to 3.0; and OR = 1.5, with a 95% CI of 0.9 to 2.5). Virulence factor carriage was more strongly related to antibiotic resistance than antibiotic use for all antibiotics examined, with the exception of fluoroquinolones, gentamicin, and cefotaxime. This study provides epidemiological evidence that antibiotic resistance and virulence factor carriage are linked in
E. coli
populations in a community setting. Further, these data suggest that while the cooccurrence of resistance and virulence in
E. coli
is partially due to antibiotic selection pressure, it is also genetically determined. These findings should be considered in developing strategies for treating infections and controlling for antibiotic resistance.
Hepatitis C Virus Genotype 4 Resistance and Subtype Demographic Characterization of Patients Treated with Ombitasvir plus Paritaprevir/Ritonavir
Authors: Schnell Gretja , Tripathi Rakesh , Beyer Jill , Reisch Thomas , Krishnan Preethi , Lu Liangjun , Dekhtyar Tatyana , Hall Coleen , Vilchez Regis A. , Pilot-Matias Tami , Collins Christine
Published: August 2015

Hepatitis C virus (HCV) genotype 4 (GT4) is genetically diverse, with 17 confirmed subtypes, and comprises approximately 13% of infections worldwide. In this study, we identified GT4 subtypes by phylogenetic analysis, assessed differences in patient demographics across GT4 subtypes, examined baseline sequence variability among subtypes and the potential impact on treatment outcome, and analyzed the development of viral resistance in patients who received a regimen of ombitasvir (nonstructural protein 5A [NS5A] inhibitor) plus ritonavir-boosted paritaprevir (NS3/4A inhibitor) with or without ribavirin (RBV) for the treatment of HCV GT4 infection. Phylogenetic analysis of HCV NS3/4A, NS5A, and NS5B nucleotide sequences identified 7 subtypes (4a, 4b, 4c, 4d, 4f, 4g/4k, and 4o) among 132 patient samples. Subtype prevalence varied by country, and the distributions of patient birth cohort and race were significantly different across GT4 subtypes 4a, 4d, and non-4a/4d. Baseline amino acid variability was detected in NS5A across GT4 subtypes but had no impact on treatment outcome. Three patients experienced virologic failure and were infected with subtype 4d, and the predominant resistance-associated variants at the time of failure were D168V in NS3 and L28V in NS5A. Overall, high response rates were observed among patients infected with 7 HCV GT4 subtypes, with no impact of baseline variants on treatment outcome. GT4 subtype distribution in this study differed based on patient demographics and geography.
Viable but Nonculturable and Persister Cells Coexist Stochastically and Are Induced by Human Serum
Authors: Ayrapetyan M. , Williams T. C. , Baxter R. , Oliver J. D.
Published: August 2015

Dormancy holds a vital role in the ecological dynamics of microorganisms. Specifically, entry into dormancy allows cells to withstand times of stress while maintaining the potential for reentry into an active existence. The viable but nonculturable (VBNC) state and antibiotic persistence are two well-recognized conditions of dormancy demonstrated to contribute to bacterial stress tolerance and, as a consequence, yield populations that are tolerant to high-dose antibiotics. Aside from this commonality, more evidence is being presented that indicates the relatedness of these two states. Here, we demonstrate that VBNC cells are present during persister isolation experiments, further indicating that these cells coexist and are induced by the same conditions. Interestingly, we reveal that VBNC cells can exist stochastically in unstressed growing cultures, a finding that is characteristic of persisters. Furthermore, human serum induces the formation of both VBNC cells and persisters, a finding not previously described for either dormancy state. Lastly, we describe the role of toxin-antitoxin systems (TAS) in the induction of the VBNC state and report that these TAS, which are classically implicated in persister cell formation, are also induced during incubation in human serum. This study provides evidence for the recently proposed “dormancy continuum hypothesis” and substantiates the physical and molecular relatedness of VBNC and persister cells in a standardized model organism. Notably, these results provide new evidence for the clinical significance of VBNC and persister cells.