732 research outputs found
Methods of Nature: Landscapes from the Gettysburg College Collection
Methods of Nature: Landscapes from the Gettysburg College Collection is the third annual exhibition curated by students enrolled in the Art History Methods course. The exhibition is an exciting academic endeavor and incredible opportunity for engaged learning, research, and curatorial experience. The five student curators are Molly Chason â17, Leah Falk â18, Shannon Gross â17, Bailey Harper â19 and Laura Waters â19. The selection of artworks in this exhibition includes the depiction of landscape in the nineteenth- and twentieth-century French, American and East Asian cultural traditions in various art forms from traditional media of paintings and prints to utilitarian artifacts of porcelain and a paper folding fan. Landscape paintings in this exhibition are inspired by nature, specific locales and literature. Each object carries a distinctive characteristic, a mood, and an ambience. Collectively, they present a multifaceted view of the landscape in the heart and mind of the artists and intended viewers. [excerpt]https://cupola.gettysburg.edu/artcatalogs/1020/thumbnail.jp
Snell\u27s Law of Refraction Observed in Thermal Frontal Polymerization
We demonstrate that Snellâs law of refraction can be applied to thermal fronts propagating through a boundary between regions that support distinct frontal velocities. We use the free-radical frontal polymerization of a triacrylate with clay filler that allows for two domains containing two different concentrations of a peroxide initiator to be molded together. Because the polymerization reaction rates depend on the initiator concentration, the propagation speed is different in each domain. We study fronts propagating in two parallel strips in which the incident angle is 90°. Our data fit Snellâs law vr/vi = sin Ξr/sin Ξi, where vr is the refracted velocity, vi is the incident velocity, Ξr is the angle of refraction, and Ξi is the incident angle. Further, we study circular fronts propagating radially from an initiation point in a high-velocity region into a low-velocity region (and vice versa). We demonstrate the close resemblance between the numerically simulated and experimentally observed thermal reaction fronts. By measuring the normal velocity and the angle of refraction of both simulated and experimental fronts, we establish that Snellâs law holds for thermal frontal polymerization in our experimental system. Finally we discuss the regimes in which Snellâs law may not be valid
Electrical Stimulation Modulates High Îł Activity and Human Memory Performance.
Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high Îł (62-118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with poor memory encoding. The high Îł modulation correlated with the behavioral effect of stimulation in a given brain region: it was negative, i.e., the induced high Îł activity was decreased, in the regions where stimulation decreased memory performance, and positive in the lateral TC where memory enhancement was observed. Our results suggest that the effect of electrical stimulation on high Îł activity induced by word presentation may be a useful biomarker for mapping memory networks and guiding therapeutic brain stimulation
Broadly neutralizing monoclonal antibodies protect against multiple tick-borne flaviviruses
Although Powassan virus (POWV) is an emerging tick-transmitted flavivirus that causes severe or fatal neuroinvasive disease in humans, medical countermeasures have not yet been developed. Here, we developed a panel of neutralizing anti-POWV mAbs recognizing six distinct antigenic sites. The most potent of these mAbs bind sites within domain II or III of the envelope (E) protein and inhibit postattachment viral entry steps. A subset of these mAbs cross-react with other flaviviruses. Both POWV type-specific and cross-reactive neutralizing mAbs confer protection in mice against POWV infection when given as prophylaxis or postexposure therapy. Several cross-reactive mAbs mapping to either domain II or III also protect in vivo against heterologous tick-transmitted flaviviruses including Langat and tick-borne encephalitis virus. Our experiments define structural and functional correlates of antibody protection against POWV infection and identify epitopes targeted by broadly neutralizing antibodies with therapeutic potential against multiple tick-borne flaviviruses
Evidence for impaired t cell dna methylation in systemic lupus erythematosus and rheumatoid arthritis
Procainamide and hydralazine inhibit T cell DNA methylation and induce autoreactivity in cloned CD4+ T cells. These drugs also induce an autoimmune syndrome, suggesting a possible relationship between DNA hypomethylation, T cell autoreactivity, and certain autoimmune diseases. To test this relationship, DNA methylation was studied in T cells from patients with rheumatoid arthritis and patients with systemic lupus erythematosus, and was found to be impaired. These results support a relationship between DNA hypomethylation and some forms of autoimmune disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37783/1/1780331109_ftp.pd
Skipping breakfast is associated with adiposity markers especially when sleep time is adequate in adolescents
Adolescence is a critical stage of development and has an important influence on energy balancerelated
behaviours (EBRBs). When adolescents are associated with obesity it can lead to increased
cardiometabolic risk. Here we assess if EBRBs adopted by adolescents included in a subsample are
associated with markers of total and abdominal adiposity in a multicentre European study, Healthy
Lifestyle in Europe by Nutrition in Adolescence (HELENA-CSS) and a Brazilian study, Brazilian
Cardiovascular Adolescent Health (BRACAH study), and whether sleep duration influence the
association between skipping breakfast, physical activity and sedentary behaviours, with total and
abdominal obesity (AO). Multilevel linear regression models using fixed and random intercepts were
used to analyse the association between markers of obesity and EBRBs. Skipping breakfast was the
prevalent behaviour in association with obesity among European and Brazilian boys besides European
girls, even after stratification by sleep time. Moreover, European boys who slept properly and skipped
breakfast had an increased waist circumference (WC), while body mass index (BMI) increased in
Brazilian boys. Among Brazilian boys less sleep was protective for total obesity (ÎČ = â0.93 kg/m2;
95% CI: â1.80; â0.07). European girls when they were more sedentary, showed an increase in WC,
especially for those who reported they slept adequately. Skipping breakfast was associated with total
and AO in adolescents independent of sleep duration.The HELENA-CSS took place with the financial support of the European Community Sixth RTD
Framework Program (contract FOOD-CT-2005-007034). This study was also supported by a grant from the
Spanish Ministry of Health: Maternal, Child Health and Development Network (numberRD08/0072) and grants
from the Spanish Ministry of Education (EX-2008-0641) and the Swedish Heart-Lung Foundation (20090635). And
supported by grants from the Spanish Ministry of Science and Innovation (JCI-2010-07055 and RYC-2010-05957).
The authors thanked for the contribution of the HELENA Study Group. We are grateful for the financial support
to the authors: Dr. Elsie C. O. Forkert was given a post-doctoral schoolarship from the Sao Paulo Research
Foundation FAPESP (proc.2018/02887-6). Dr. Augusto CĂ©sar F. De Moraes was given a post-doctoral scholarship
from the National Council for Scientific and Technological Development (CNPq: proc. 313772/2014-2)
and the SĂŁo Paulo Research Foundation FAPESP (proc. 2014/13367-2 and 2015/14319-4). Full Prof. Luis A.
Moreno was given a scholarship of a visiting professor from SĂŁo Paulo Research Foundation FAPESP (proc.
2015/11406-3). Dr Prof HerĂĄclito B Carvalho is in receipt of an advanced scientist scholarship from the National
Council for Scientific and Technological Development (CNPq: proc. 300951/2015-9)
Prefrontal gamma oscillations reflect ongoing pain intensity in chronic back pain patients
Chronic pain is a major health care issue characterized by ongoing pain and a variety of sensory, cognitive, and affective abnormalities. The neural basis of chronic pain is still not completely understood. Previous work has implicated prefrontal brain areas in chronic pain. Furthermore, prefrontal neuronal oscillations at gamma frequencies (60â90âHz) have been shown to reflect the perceived intensity of longer lasting experimental pain in healthy human participants. In contrast, noxious stimulus intensity has been related to alpha (8â13âHz) and beta (14â29âHz) oscillations in sensorimotor areas. However, it is not fully understood how the intensity of ongoing pain as the key symptom of chronic pain is represented in the human brain. Here, we asked 31 chronic back pain patients to continuously rate their ongoing pain while simultaneously recording electroencephalography (EEG). Timeâfrequency analyses revealed a positive association between ongoing pain intensity and prefrontal beta and gamma oscillations. No association was found between pain and alpha or beta oscillations in sensorimotor areas. These findings indicate that ongoing pain as the key symptom of chronic pain is reflected by neuronal oscillations implicated in the subjective perception of longer lasting pain rather than by neuronal oscillations related to the processing of objective nociceptive input. The findings, thus, support a dissociation of pain intensity from nociceptive processing in chronic back pain patients. Furthermore, although possible confounds by muscle activity have to be taken into account, they might be useful for defining a neurophysiological marker of ongoing pain in the human brain
How much synthetic oxytocin is infused during labour? A review and analysis of regimens used in 12 countries.
OBJECTIVE: To compare synthetic oxytocin infusion regimens used during labour, calculate the International Units (IU) escalation rate and total amount of IU infused over eight hours. DESIGN: Observational study. SETTING: Twelve countries, eleven European and South Africa. SAMPLE: National, regional or institutional-level regimens on oxytocin for induction and augmentation labour. METHODS: Data on oxytocin IU dose, infusion fluid amount, start dose, escalation rate and maximum dose were collected. Values for each regimen were converted to IU in 1000ml diluent. One IU corresponded to 1.67ÎŒg for doses provided in grams/micrograms. IU hourly dose increase rates were based on escalation frequency. Cumulative doses and total IU amount infused were calculated by adding the dose administered for each previous hour. Main Outcome Measures Oxytocin IU dose infused. RESULTS: Data were obtained on 21 regimens used in 12 countries. Details on the start dose, escalation interval, escalation rate and maximum dose infused were available from 16 regimens. Starting rates varied from 0.06 IU/hour to 0.90 IU/hour, and the maximum dose rate varied from 0.90 IU/hour to 3.60 IU/hour. The total amount of IU oxytocin infused, estimated over eight hours, ranged from 2.38 IU to 27.00 IU, a variation of 24.62 IU and an 11-fold difference. CONCLUSION: Current variations in oxytocin regimens for induction and augmentation of labour are inexplicable. It is crucial that the appropriate minimum infusion regimen is administered because synthetic oxytocin is a potentially harmful medication with serious consequences for women and babies when inappropriately used. Estimating the total amount of oxytocin IU received by labouring women, alongside the institution's mode of birth and neonatal outcomes, may deepen our understanding and be the way forward to identifying the optimal infusion regimen
Heterozygous Vangl2(Looptail) mice reveal novel roles for the planar cell polarity pathway in adult lung homeostasis and repair
Lung diseases impose a huge economic and health burden worldwide. A key aspect of several adult lung diseases, such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), including emphysema, is aberrant tissue repair, which leads to an accumulation of damage and impaired respiratory function. Currently, there are few effective treatments available for these diseases and their incidence is rising. The planar cell polarity (PCP) pathway is critical for the embryonic development of many organs, including kidney and lung. We have previously shown that perturbation of the PCP pathway impairs tissue morphogenesis, which disrupts the number and shape of epithelial tubes formed within these organs during embryogenesis. However, very little is known about the role of the PCP pathway beyond birth, partly because of the perinatal lethality of many PCP mouse mutant lines. Here, we investigate heterozygous Looptail (Lp) mice, in which a single copy of the core PCP gene, Vangl2, is disrupted. We show that these mice are viable but display severe airspace enlargement and impaired adult lung function. Underlying these defects, we find that Vangl2Lp/+ lungs exhibit altered distribution of actin microfilaments and abnormal regulation of the actin-modifying protein cofilin. In addition, we show that Vangl2Lp/+ lungs exhibit many of the hallmarks of tissue damage, including an altered macrophage population, abnormal elastin deposition and elevated levels of the elastin-modifying enzyme, Mmp12, all of which are observed in emphysema. In vitro, disruption of VANGL2 impairs directed cell migration and reduces the rate of repair following scratch wounding of human alveolar epithelial cells. Moreover, using population data from a birth cohort of young adults, all aged 31, we found evidence of an interactive effect between VANGL2 and smoking on lung function. Finally, we show that PCP genes VANGL2 and SCRIB are significantly downregulated in lung tissue from patients with emphysema. Our data reveal an important novel role for the PCP pathway in adult lung homeostasis and repair and shed new light on the genetic factors which may modify destructive lung diseases such as emphysema.Peer reviewe
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