Doping driven magnetic instabilities and quantum criticality of NbFe2_{2}

Using density functional theory we investigate the evolution of the magnetic ground state of NbFe$_{2}$ due to doping by Nb-excess and Fe-excess. We find that non-rigid-band effects, due to the contribution of Fe-\textit{d} states to the density of states at the Fermi level are crucial to the evolution of the magnetic phase diagram. Furthermore, the influence of disorder is important to the development of ferromagnetism upon Nb doping. These findings give a framework in which to understand the evolution of the magnetic ground state in the temperature-doping phase diagram. We investigate the magnetic instabilities in NbFe$_{2}$. We find that explicit calculation of the Lindhard function, $\chi_{0}(\mathbf{q})$, indicates that the primary instability is to finite $\mathbf{q}$ antiferromagnetism driven by Fermi surface nesting. Total energy calculations indicate that $\mathbf{q}=0$ antiferromagnetism is the ground state. We discuss the influence of competing $\mathbf{q}=0$ and finite $\mathbf{q}$ instabilities on the presence of the non-Fermi liquid behavior in this material.Comment: 8 pages, 7 figure

Oxcarbazepine versus phenytoin monotherapy for epilepsy: an individual participant data review.

BACKGROUND:This is an updated version of the Cochrane Review previously published in 2013. This review is one in a series of Cochrane Reviews investigating pair-wise monotherapy comparisons.Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment, up to 70% of individuals with active epilepsy have the potential to become seizure-free and go into long-term remission shortly after starting drug therapy with a single antiepileptic drug in monotherapy.Worldwide, phenytoin is a commonly used antiepileptic drug. It is important to know how newer drugs, such as oxcarbazepine, compare with commonly used standard treatments. OBJECTIVES:To review the time to treatment failure, remission and first seizure with oxcarbazepine compared to phenytoin, when used as monotherapy in people with focal onset seizures or generalised tonic-clonic seizures (with or without other generalised seizure types). SEARCH METHODS:We searched the following databases on 20 August 2018: the Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid, 1946 to 20 August 2018), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators and experts in the field. SELECTION CRITERIA:We included randomised controlled trials comparing monotherapy with either oxcarbazepine or phenytoin in children or adults with focal onset seizures or generalised onset tonic-clonic seizures. DATA COLLECTION AND ANALYSIS:This was an individual participant data (IPD) review. Our primary outcome was time to treatment failure and our secondary outcomes were time to first seizure post-randomisation, time to six-month and 12-month remission, and incidence of adverse events. We used Cox proportional hazards regression models to obtain trial-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), using the generic inverse variance method to obtain the overall pooled HR and 95% CI. MAIN RESULTS:Individual participant data were available for 480 out of a total of 517 participants (93%), from two out of three included trials. For remission outcomes, a HR of less than one indicated an advantage for phenytoin; and for first seizure and treatment failure outcomes, a HR of less than one indicated an advantage for oxcarbazepine.The results for time to treatment failure for any reason related to treatment showed a potential advantage of oxcarbazepine over phenytoin, but this was not statistically significant (pooled HR adjusted for epilepsy type: 0.78 95% CI 0.53 to 1.14, 476 participants, two trials, moderate-quality evidence). Our analysis showed that treatment failure due to adverse events occurred later on with oxcarbazepine than phenytoin (pooled HR for all participants: 0.22 (95% CI 0.10 to 0.51, 480 participants, two trials, high-quality evidence). Our analysis of time to treatment failure due to lack of efficacy showed no clear difference between the drugs (pooled HR for all participants: 1.17 (95% CI 0.31 to 4.35), 480 participants, two trials, moderate-quality evidence).We found no clear or statistically significant differences between drugs for any of the secondary outcomes of the review: time to first seizure post-randomisation (pooled HR adjusted for epilepsy type: 0.97 95% CI 0.75 to 1.26, 468 participants, two trials, moderate-quality evidence); time to 12-month remission (pooled HR adjusted for epilepsy type 1.04 95% CI 0.77 to 1.41, 468 participants, two trials, moderate-quality evidence) and time to six-month remission (pooled HR adjusted for epilepsy type: 1.06 95% CI 0.82 to 1.36, 468 participants, two trials, moderate-quality evidence).The most common adverse events reported in more than 10% of participants on either drug were somnolence (28% of total participants, with similar rates for both drugs), headache (15% of total participants, with similar rates for both drugs), dizziness (14.5% of total participants, reported by slightly more participants on phenytoin (18%) than oxcarbazepine (11%)) and gum hyperplasia (reported by substantially more participants on phenytoin (18%) than oxcarbazepine (2%)).The results of this review are applicable mainly to individuals with focal onset seizures; 70% of included individuals experienced seizures of this type at baseline. The two studies included in IPD meta-analysis were generally of good methodological quality but the design of the studies may have biased the results for the secondary outcomes (time to first seizure post-randomisation, time to six-month and 12-month remission) as seizure recurrence data were not collected following treatment failure or withdrawal from the study. In addition, misclassification of epilepsy type may have impacted on results, particularly for individuals with generalised onset seizures. AUTHORS' CONCLUSIONS:High-quality evidence provided by this review indicates that treatment failure due to adverse events occurs significantly later with oxcarbazepine than phenytoin. For individuals with focal onset seizures, moderate-quality evidence suggests that oxcarbazepine may be superior to phenytoin in terms of treatment failure for any reason, seizure recurrence and seizure remission. Therefore, oxcarbazepine may be a preferable alternative treatment than phenytoin, particularly for individuals with focal onset seizures. The evidence in this review which relates to individuals with generalised onset seizures is of low quality and does not inform current treatment policy.We recommend that future trials should be designed to the highest quality possible with regards to choice of population, classification of seizure type, duration of follow-up (including continued follow-up after failure or withdrawal of randomised treatment), choice of outcomes and analysis, and presentation of results

Antidepressants for people with epilepsy and depression.

Background Depressive disorders are the most common psychiatric comorbidity in people with epilepsy, affecting around one‐third, with a significant negative impact on quality of life. There is concern that people may not be receiving appropriate treatment for their depression because of uncertainty regarding which antidepressant or class works best, and the perceived risk of exacerbating seizures. This review aimed to address these issues, and inform clinical practice and future research. This is an updated version of the original Cochrane Review published in Issue 12, 2014. Objectives To evaluate the efficacy and safety of antidepressants in treating depressive symptoms and the effect on seizure recurrence, in people with epilepsy and depression. Search methods For this update, we searched CRS Web, MEDLINE, SCOPUS, PsycINFO, and ClinicalTrials.gov (February 2021). We searched the World Health Organization Clinical Trials Registry in October 2019, but were unable to update it because it was inaccessible. There were no language restrictions. Selection criteria We included randomised controlled trials (RCTs) and prospective non‐randomised studies of interventions (NRSIs), investigating children or adults with epilepsy, who were treated with an antidepressant and compared to placebo, comparative antidepressant, psychotherapy, or no treatment for depressive symptoms. Data collection and analysis The primary outcomes were changes in depression scores (proportion with a greater than 50% improvement, mean difference, and proportion who achieved complete remission) and change in seizure frequency (mean difference, proportion with a seizure recurrence, or episode of status epilepticus). Secondary outcomes included the number of participants who withdrew from the study and reasons for withdrawal, quality of life, cognitive functioning, and adverse events. Two review authors independently extracted data for each included study. We then cross‐checked the data extraction. We assessed risk of bias using the Cochrane tool for RCTs, and the ROBINS‐I for NRSIs. We presented binary outcomes as risk ratios (RRs) with 95% confidence intervals (CIs) or 99% CIs for specific adverse events. We presented continuous outcomes as standardised mean differences (SMDs) with 95% CIs, and mean differences (MDs) with 95% CIs. Main results We included 10 studies in the review (four RCTs and six NRSIs), with 626 participants with epilepsy and depression, examining the effects of antidepressants. One RCT was a multi‐centre study comparing an antidepressant with cognitive behavioural therapy (CBT). The other three RCTs were single‐centre studies comparing an antidepressant with an active control, placebo, or no treatment. The NRSIs reported on outcomes mainly in participants with focal epilepsy before and after treatment for depression with a selective serotonin reuptake inhibitor (SSRI); one NRSI compared SSRIs to CBT. We rated one RCT at low risk of bias, three RCTs at unclear risk of bias, and all six NRSIs at serious risk of bias. We were unable to conduct any meta‐analysis of RCT data due to heterogeneity of treatment comparisons. We judged the certainty of evidence to be moderate to very low across comparisons, because single studies contributed limited outcome data, and because of risk of bias, particularly for NRSIs, which did not adjust for confounding variables. More than 50% improvement in depressive symptoms ranged from 43% to 82% in RCTs, and from 24% to 97% in NRSIs, depending on the antidepressant given. Venlafaxine improved depressive symptoms by more than 50% compared to no treatment (mean difference (MD) ‐7.59 (95% confidence interval (CI) ‐11.52 to ‐3.66; 1 study, 64 participants; low‐certainty evidence); the results between other comparisons were inconclusive. Two studies comparing SSRIs to CBT reported inconclusive results for the proportion of participants who achieved complete remission of depressive symptoms. Seizure frequency data did not suggest an increased risk of seizures with antidepressants compared to control treatments or baseline. Two studies measured quality of life; antidepressants did not appear to improve quality of life over control. No studies reported on cognitive functioning. Two RCTs and one NRSI reported comparative data on adverse events; antidepressants did not appear to increase the severity or number of adverse events compared to controls. The NSRIs reported higher rates of withdrawals due to adverse events than lack of efficacy. Reported adverse events for antidepressants included nausea, dizziness, sedation, headache, gastrointestinal disturbance, insomnia, and sexual dysfunction. Authors' conclusions Existing evidence on the effectiveness of antidepressants in treating depressive symptoms associated with epilepsy is still very limited. Rates of response to antidepressants were highly variable. There is low certainty evidence from one small RCT (64 participants) that venlafaxine may improve depressive symptoms more than no treatment; this evidence is limited to treatment between 8 and 16 weeks, and does not inform longer‐term effects. Moderate to low evidence suggests neither an increase nor exacerbation of seizures with SSRIs. There are no available comparative data to inform the choice of antidepressant drug or classes of drug for efficacy or safety for treating people with epilepsy and depression. RCTs of antidepressants utilising interventions from other treatment classes besides SSRIs, in large samples of patients with epilepsy and depression, are needed to better inform treatment policy. Future studies should assess interventions across a longer treatment duration to account for delayed onset of action, sustainability of treatment responses, and to provide a better understanding of the impact on seizure control

Carbamazepine versus phenobarbitone monotherapy for epilepsy: an individual participant data review.

BACKGROUND:This is an updated version of the Cochrane Review previously published in 2016. This review is one in a series of Cochrane Reviews investigating pair-wise monotherapy comparisons.Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment, up to 70% of individuals with active epilepsy have the potential to become seizure-free and go into long-term remission shortly after starting drug therapy with a single antiepileptic drug in monotherapy.Worldwide, carbamazepine and phenobarbitone are commonly used broad-spectrum antiepileptic drugs, suitable for most epileptic seizure types. Carbamazepine is a current first-line treatment for focal onset seizures, and is used in the USA and Europe. Phenobarbitone is no longer considered a first-line treatment because of concerns over associated adverse events, particularly documented behavioural adverse events in children treated with the drug. However, phenobarbitone is still commonly used in low- and middle-income countries because of its low cost. No consistent differences in efficacy have been found between carbamazepine and phenobarbitone in individual trials; however, the confidence intervals generated by these trials are wide, and therefore, synthesising the data of the individual trials may show differences in efficacy. OBJECTIVES:To review the time to treatment failure, remission and first seizure with carbamazepine compared with phenobarbitone when used as monotherapy in people with focal onset seizures (simple or complex focal and secondarily generalised), or generalised onset tonic-clonic seizures (with or without other generalised seizure types). SEARCH METHODS:For the latest update, we searched the following databases on 24 May 2018: the Cochrane Register of Studies (CRS Web), which includes Cochrane Epilepsy's Specialized Register and CENTRAL; MEDLINE; the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov); and the World Health Organization International Clinical Trials Registry Platform (ICTRP). We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. SELECTION CRITERIA:Randomised controlled trials comparing monotherapy with either carbamazepine or phenobarbitone in children or adults with focal onset seizures or generalised onset tonic-clonic seizures. DATA COLLECTION AND ANALYSIS:This was an individual participant data (IPD), review. Our primary outcome was time to treatment failure. Our secondary outcomes were time to first seizure post-randomisation, time to six-month remission, time to 12-month remission, and incidence of adverse events. We used Cox proportional hazards regression models to obtain trial-specific estimates of hazard ratios (HRs), with 95% confidence intervals (CIs), using the generic inverse variance method to obtain the overall pooled HR and 95% CI. MAIN RESULTS:We included 13 trials in this review and IPD were available for 836 individuals out of 1455 eligible individuals from six trials, 57% of the potential data. For remission outcomes, a HR of less than 1 indicates an advantage for phenobarbitone and for first seizure and treatment failure outcomes a HR of less than 1 indicates an advantage for carbamazepine.Results for the primary outcome of the review were: time to treatment failure for any reason related to treatment (pooled HR adjusted for seizure type for 676 participants: 0.66, 95% CI 0.50 to 0.86, moderate-quality evidence), time to treatment failure due to adverse events (pooled HR adjusted for seizure type for 619 participants: 0.69, 95% CI 0.49 to 0.97, low-quality evidence), time to treatment failure due to lack of efficacy (pooled HR adjusted for seizure type for 487 participants: 0.54, 95% CI 0.38 to 0.78, moderate-quality evidence), showing a statistically significant advantage for carbamazepine compared to phenobarbitone.For our secondary outcomes, we did not find any statistically significant differences between carbamazepine and phenobarbitone: time to first seizure post-randomisation (pooled HR adjusted for seizure type for 822 participants: 1.13, 95% CI 0.93 to 1.38, moderate-quality evidence), time to 12-month remission (pooled HR adjusted for seizure type for 683 participants: 1.09, 95% CI 0.84 to 1.40, low-quality evidence), and time to six-month remission pooled HR adjusted for seizure type for 683 participants: 1.01, 95% CI 0.81 to 1.24, low-quality evidence).Results of these secondary outcomes suggest that there may be an association between treatment effect in terms of efficacy and seizure type; that is, that participants with focal onset seizures experience seizure recurrence later and hence remission of seizures earlier on phenobarbitone than carbamazepine, and vice versa for individuals with generalised seizures. It is likely that the analyses of these outcomes were confounded by several methodological issues and misclassification of seizure type, which could have introduced the heterogeneity and bias into the results of this review.Limited information was available regarding adverse events in the trials and we could not compare the rates of adverse events between carbamazepine and phenobarbitone. Some adverse events reported on both drugs were abdominal pain, nausea, and vomiting, drowsiness, motor and cognitive disturbances, dysmorphic side effects (such as rash), and behavioural side effects in three paediatric trials. AUTHORS' CONCLUSIONS:Moderate-quality evidence from this review suggests that carbamazepine is likely to be a more effective drug than phenobarbitone in terms of treatment retention (treatment failures due to lack of efficacy or adverse events or both). Moderate- to low-quality evidence from this review also suggests an association between treatment efficacy and seizure type in terms of seizure recurrence and seizure remission, with an advantage for phenobarbitone for focal onset seizures and an advantage for carbamazepine for generalised onset seizures.However, some of the trials contributing to the analyses had methodological inadequacies and inconsistencies that may have impacted upon the results of this review. Therefore, we do not suggest that results of this review alone should form the basis of a treatment choice for a patient with newly onset seizures. We recommend that future trials should be designed to the highest quality possible with consideration of masking, choice of population, classification of seizure type, duration of follow-up, choice of outcomes and analysis, and presentation of results

New Development in NASA's Rodent Research Hardware for Conducting Long Duration Biomedical and Basic Research in Space

Animal models, particularly rodents, are the foundation of pre-clinical research to understand human diseases and evaluate new therapeutics, and play a key role in advancing biomedical discoveries both on Earth and in space. The National Research Councils Decadal survey emphasized the importance of expanding NASAs life sciences research to perform long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, flight hardware, operations, and science capabilities were developed at NASA Ames Research Center (ARC) to enhance science return for both commercial (CASIS) and government-sponsored rodent research. The Rodent Research program at NASA ARC has pioneered a new research capability on the International Space Station and has progressed toward translating research to the ISS utilizing commercial rockets, collaborating with academia and science industry, while training crewmembers to assist in performing research on orbit. Throughout phases of these missions, our practices, hardware and operations have evolved from tested to developed standards, and we are able to modify and customize our procedure and operations for mission specific requirements. The Rodent Research Habitat is capable of providing a living environment for animals on ISS according to standard animal welfare requirements. Using the cameras in the Habitat, the Rodent Research team has the ability to perform daily health checks on animals, and further analyze the collected videos for behavioral studies. A recent development of the Rodent Research hardware is inclusion of enrichment, to provide the animals the ability to rest and huddle. The Enrichment Hut is designed carefully for adult mice (up to 35 week old) within animal welfare, engineering, and operations constraints. The Hut is made out of the same stainless steel mesh as the cage interior, it has an ingress and an egress to allow animals move freely, and a hinge door to allow crewmembers remove the animals easily. The Rodent Research team has also developed Live Animal Return (LAR) capability, which will be implemented during Rodent Research-5 mission for the first time. The animals will be transported from the Habitat to a Transporter, which will return on the Dragon capsule and splashes down in the Pacific Ocean. Once SpaceX retrieves the Dragon, all powered payloads will be transferred to a SeaVan and transferred to the Long Beach pier. The NASA team then receives the transporter and delivers to a PI-designated laboratory within 120 mile radius of Long Beach. This is a significant improvement allowing researchers to examine animals within 72 hrs. of reentry or to conduct recovery experiments. Together, the hardware improvements and experience that the Rodent Research team has gained working with principal investigators and ISS crew to conduct complex experiments on orbit are expanding capabilities for long duration rodent research on the ISS to achieve both basic science and biomedical objectives

Physical and biological variables affecting seabird distributions during the upwelling season of the northern California Current

Author Posting. © The Authors, 2004. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 52 (2005): 123-143, doi:10.1016/j.dsr2.2004.08.016.As a part of the GLOBEC-Northeast Pacific project, we investigated variation in the abundance of marine birds in the context of biological and physical habitat conditions in the northern portion of the California Current System (CCS) during cruises during the upwelling season 2000. Continuous surveys of seabirds were conducted simultaneously in June (onset of upwelling) and August (mature phase of upwelling) with ocean properties quantified using a towed, undulating vehicle and a multi-frequency bioacoustic instrument (38-420 kHz). Twelve species of seabirds contributed 99% of the total community density and biomass. Species composition and densities were similar to those recorded elsewhere in the CCS during earlier studies of the upwelling season. At a scale of 2-4 km, physical and biological oceanographic variables explained an average of 25% of the variation in the distributions and abundance of the 12 species. The most important explanatory variables (among 14 initially included in each multiple regression model) were distance to upwelling-derived frontal features (center and edge of coastal jet, and an abrupt, inshore temperature gradient), sea-surface salinity, acoustic backscatter representing various sizes of prey (smaller seabird species were associated with smaller prey and the reverse for larger seabird species), and chlorophyll concentration. We discuss the importance of these variables in the context of what factors may be that seabirds use to find food. The high seabird density in the Heceta Bank and Cape Blanco areas indicate them to be refuges contrasting the low seabird densities currently found in most other parts of the CCS, following decline during the recent warm regime of the Pacific Decadal Oscillation.Support from National Science Foundation Grant OCE-0001035, National Oceanic and Atmospheric Administration (NOAA)/Woods Hole Oceanographic Institution-CICOR Grant NA17RJ1223 is gratefully acknowledged

Assessment of the radioanatomic positioning of the osteoarthritic knee in serial radiographs: comparison of three acquisition techniques

SummaryObjectiveRecent studies using various standardized radiographic acquisition techniques have demonstrated the necessity of reproducible radioanatomic alignment of the knee to assure precise measurements of medial tibiofemoral joint space width (JSW). The objective of the present study was to characterize the longitudinal performance of several acquisition techniques with respect to long-term reproducibility of positioning of the knee, and the impact of changes in positioning on the rate and variability of joint space narrowing (JSN).MethodsEighty subjects were randomly selected from each of three cohorts followed in recent studies of the radiographic progression of knee osteoarthritis (OA): the Health ABC study (paired fixed-flexion [FF] radiographs taken at a 36-month interval); the Glucosamine Arthritis Intervention Trial (GAIT) (paired metatarsophalangeal [MTP] radiographs obtained at a 12-month interval), and a randomized clinical trial of doxycycline (fluoroscopically assisted semiflexed anteroposterior (AP) radiographs taken at a 16-month interval).Manual measurements were obtained from each radiograph to represent markers of radioanatomic positioning of the knee (alignment of the medial tibial plateau and X-ray beam, knee rotation, femorotibial angle) and to evaluate minimum JSW (mJSW) in the medial tibiofemoral compartment. The effects on the mean annualized rate of JSN and on the variability of that rate of highly reproduced vs variable positioning of the knee in serial radiographs were evaluated.ResultsParallel or near-parallel alignment was achieved significantly more frequently with the fluoroscopically guided positioning used in the semiflexed AP protocol than with either the non-fluoroscopic FF or MTP protocol (68% vs 14% for both FF and MTP protocols when measured at the midpoint of the medial compartment; 75% vs 26% and 34% for the FF and MTP protocols, respectively, when measured at the site of mJSW; P<0.001 for each). Knee rotation was reproduced more frequently in semiflexed AP radiographs than in FF radiographs (66% vs 45%, P<0.01). In contrast, the FF technique yielded a greater proportion of paired radiographs in which the femorotibial angle was accurately reproduced than the semiflexed AP or MTP protocol (78% vs 59% and 56%, respectively, P<0.01 for each). Notably, only paired radiographs with parallel or near-parallel alignment exhibited a mean rate of JSN (±SD) in the OA knee that was more rapid and less variable than that measured in all knees (0.186±0.274mm/year, standardized response to mean [SRM]=0.68 vs 0.128±0.291mm/year, SRM=0.44).ConclusionThis study confirms the importance of parallel radioanatomic alignment of the anterior and posterior margins of the medial tibial plateau in detecting JSN in subjects with knee OA. The use of radiographic methods that assure parallel alignment during serial X-ray examinations will permit the design of more efficient studies of biomarkers of OA progression and of structure modification in knee OA