1,177 research outputs found
The Arctic in World Environmental History
For millions of years, the Arctic has been the world\u27s most important barometer of global change and amplifier of global warming. For twenty thousand years, the Arctic has been the homeland of modern human settlement, and it has played a central role in the interplay between global climate change and human migration throughout Eurasia and the Americas. Since the late fifteenth century, Arctic aboriginal peoples, lands, and seas have been thoroughly integrated into the international history of European trade, capitalism, and colonization; the territorial expansion of modern nation states; and the transnational strategic history since the outset of the Cold War, including the continued basing of nuclear-armed missiles, bombers, and submarines throughout the Arctic region.
Appreciation of this international history can provide lessons for contemporary policymakers to help mitigate grave risks to human life and biodiversity in the Arctic and sub-Arctic. For example, this Article calls for negotiations between the U.S., NATO, and the Russian Federation on the basis of Russian President Mikhail Gorbachev\u27s 1987 proposal to transform the Arctic into a zone of peace and, specifically, to establish a nuclear free-zone in northern Europe.
In conclusion, this Article identifies how deeply embedded global systems of political economy and international relations continue to shape recent developments in the Arctic at this time of exacerbated climate change and resulting ecological crisis. Appreciation of the Arctic\u27s environmental history can help decision-makers to more knowledgeably and effectively support indigenous self-determination, resource conservation, and environmental stewardship throughout the circumpolar bioregion
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The Drosophila Forkhead Transcription Factor FOXO Mediates the Reduction in Cell Number Associated with Reduced Insulin Signaling
Background: Forkhead transcription factors belonging to the FOXO subfamily are negatively regulated by protein kinase B (PKB) in response to signaling by insulin and insulin-like growth factor in Caenorhabditis elegans and mammals. In Drosophila, the insulin-signaling pathway regulates the size of cells, organs, and the entire body in response to nutrient availability, by controlling both cell size and cell number. In this study, we present a genetic characterization of dFOXO, the only Drosophila FOXO ortholog. Results: Ectopic expression of dFOXO and human FOXO3a induced organ-size reduction and cell death in a manner dependent on phosphoinositide (PI) 3-kinase and nutrient levels. Surprisingly, flies homozygous for dFOXO null alleles are viable and of normal size. They are, however, more sensitive to oxidative stress. Furthermore, dFOXO function is required for growth inhibition associated with reduced insulin signaling. Loss of dFOXO suppresses the reduction in cell number but not the cell-size reduction elicited by mutations in the insulin-signaling pathway. By microarray analysis and subsequent genetic validation, we have identified d4E-BP, which encodes a translation inhibitor, as a relevant dFOXO target gene. Conclusion: Our results show that dFOXO is a crucial mediator of insulin signaling in Drosophila, mediating the reduction in cell number in insulin-signaling mutants. We propose that in response to cellular stresses, such as nutrient deprivation or increased levels of reactive oxygen species, dFOXO is activated and inhibits growth through the action of target genes such as d4E-BP
Clinical disease activity and acute phase reactant levels are discordant among patients with active rheumatoid arthritis: acute phase reactant levels contribute separately to predicting outcome at one year
INTRODUCTION: Clinical trials of new treatments for rheumatoid arthritis (RA) typically require subjects to have an elevated acute phase reactant (APR), in addition to tender and swollen joints. However, despite the elevation of individual components of the Clinical Disease Activity Index (CDAI) (tender and swollen joint counts and patient and physician global assessment), some patients with active RA may have normal erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) levels and thus fail to meet entry criteria for clinical trials. We assessed the relationship between CDAI and APRs in the Consortium of Rheumatology Researchers of North America (CORRONA) registry by comparing baseline characteristics and one-year clinical outcomes of patients with active RA, grouped by baseline APR levels.
METHODS: This was an observational study of 9,135 RA patients who had both ESR and CRP drawn and a visit at which CDAI was \u3e 2.8 (not in remission).
RESULTS: Of 9,135 patients with active RA, 58% had neither elevated ESR nor CRP; only 16% had both elevated ESR and CRP and 26% had either ESR or CRP elevated. Among the 4,228 patients who had a one-year follow-up visit, both baseline and one-year follow-up modified Health Assessment Questionnaire (mHAQ) and CDAI scores were lowest for patients with active RA but with neither APR elevated; both mHAQ and CDAI scores increased sequentially with the increase in number of elevated APR levels at baseline. Each individual component of the CDAI followed the same trend, both at baseline and at one-year follow-up. The magnitude of improvement in both CDAI and mHAQ scores at one year was associated positively with the number of APRs elevated at baseline.
CONCLUSIONS: In a large United States registry of RA patients, APR levels often do not correlate with disease activity as measured by joint counts and global assessments. These data strongly suggest that it is appropriate to obtain both ESR and CRP from RA patients at the initial visit. Requiring an elevation in APR levels as a criterion for inclusion of RA patients in studies of experimental agents may exclude some patients with active disease
Long-term, Real-world Safety of Adalimumab in Rheumatoid Arthritis: Analysis of a Prospective US-Based Registry
OBJECTIVE: To assess long-term safety in a US cohort of rheumatoid arthritis (RA) patients treated with adalimumab in real-world clinical care settings.
METHODS: This observational study analyzed the long-term incidence of safety outcomes among RA patients initiating adalimumab using data from the Corrona RA registry. Patients were adults ( \u3e /=18 years) who initiated adalimumab treatment between January 2008 and June 2017, and who had at least 1 follow-up visit.
RESULTS: In total, 2798 adalimumab initiators were available for analysis, with a mean age of 54.5 years, 77% female, and mean duration of disease of 8.3 years. Nearly half (48%) were biologic naive, and 9% were using prednisone \u3e /=10 mg at adalimumab initiation. The incidence rates per 100 person-years for serious infections, congestive heart failure requiring hospitalization, malignancy (excluding nonmelanoma skin cancer), and all-cause mortality were 1.86, 0.15, 0.64, and 0.33, respectively. The incidence of serious infections was higher in the first year of therapy (3.44 [95% confidence interval: 2.45-4.84]) than subsequent years, while other measured AEs did not vary substantially by duration of exposure. The median time to adalimumab discontinuation was 11 months, while the median time to first serious infection among those experiencing a serious infection event was 12 months.
CONCLUSION: Analysis of long-term data from this prospective real-world registry demonstrated a safety profile consistent with previous studies in patients with RA. This analysis did not identify any new safety signals associated with adalimumab treatment and provides valuable guidance for physicians prescribing adalimumab for extended periods of time
Leukocyte Count and Intracerebral Hemorrhage Expansion
BACKGROUND AND PURPOSE: Acute leukocytosis is a well-established response to intracerebral hemorrhage (ICH). Leukocytes, because of their interaction with platelets and coagulation factors, may in turn play a role in hemostasis. We investigated whether admission leukocytosis was associated with reduced bleeding following acute ICH. METHODS: Consecutive patients with primary ICH were prospectively collected from 1994 to 2015 and retrospectively analyzed. We included subjects with a follow-up CT scan available and automated complete white blood cell (WBC) count performed within 48 h from onset. Baseline and follow-up hematoma volumes were calculated with semi-automated software and hematoma expansion was defined as volume increase > 30% or 6 mL. The association between WBC count and ICH expansion was investigated with multivariate logistic regression. RESULTS: 1302 subjects met eligibility criteria (median age 75 years, 55.8 % males), of whom 207 (15.9 %) experienced hematoma expansion. Higher leukocyte count on admission was associated with reduced risk of hematoma expansion (Odds Ratio for 1000 cells increase [OR] 0.91, 95 % Confidence Interval [CI] 0.86–0.96, p=0.001). The risk of hematoma expansion was inversely associated with neutrophil count (OR 0.90, 95 % CI 0.85–0.96, p=0.001) and directly associated with monocyte count (OR 2.71, 95 % CI 1.08–6.83, p=0.034). There was no association between lymphocyte count and ICH expansion (OR 0.96, 95 % CI 0.79–1.17, p=0.718). CONCLUSIONS: Higher admission WBC count is associated with lower risk of hematoma expansion. This highlights a potential role of the inflammatory response in modulating the coagulation cascade following acute ICH
Model of the Quark Mixing Matrix
The structure of the Cabibbo-Kobayashi-Maskawa (CKM) matrix is analyzed from
the standpoint of a composite model. A model is constructed with three families
of quarks, by taking tensor products of sufficient numbers of spin-1/2
representations and imagining the dominant terms in the mass matrix to arise
from spin-spin interactions. Generic results then obtained include the familiar
relation , and a less frequently
seen relation . The magnitudes of
and come out naturally to be of the right order. The phase in
the CKM matrix can be put in by hand, but its origin remains obscure.Comment: Presented by Mihir P. Worah at DPF 92 Meeting, Fermilab, November,
1992. 3 pages, LaTeX fil
Screening for Familial APP Mutations in Sporadic Cerebral Amyloid Angiopathy
Background
Advances in genetic technology have revealed that variation in the same gene can cause both rare familial and common sporadic forms of the same disease. Cerebral amyloid angiopathy (CAA), a common cause of symptomatic intracerebral hemorrhage (ICH) in the elderly, can also occur in families in an autosomal dominant pattern. The majority of affected families harbor mutations in the Beta amyloid Peptide (Aβ) coding region of the gene for amyloid precursor protein (APP) or have duplications of chromosomal segments containing APP.
Methodology/Principal Findings
A total of 58 subjects with a diagnosis of probable or definite CAA according to validated criteria were included in the present study. We sequenced the Aβ coding region of APP in 58 individuals and performed multiplex ligation-dependent probe amplification to determine APP gene dosage in 60. No patient harbored a known or novel APP mutation or gene duplication. The frequency of mutations investigated in the present study is estimated to range from 0% to 8% in individuals with probable CAA in the general population, based on the ascertained sample size.
Conclusions/Significance
We found no evidence that variants at loci associated with familial CAA play a role in sporadic CAA. Based on our findings, these rare highly-penetrant mutations are unlikely to be seen in sporadic CAA patients. Therefore, our results do not support systematic genetic screening of CAA patients who lack a strong family history of hemorrhage or dementia.National Institute of Neurological Disorders and Stroke (U.S.) (grant K23NS042695)American Heart AssociationAmerican Stroke Association (Bugher Foundation for Stroke Prevention Research
Health services use among children diagnosed with medium-chain acyl-CoA dehydrogenase deficiency through newborn screening: A cohort study in Ontario, Canada
Background: We describe early health services utilization for children diagnosed with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency through newborn screening in Ontario, Canada, relative to a screen negative comparison cohort. Methods: Eligible children were identified via newborn screening between April 1, 2006 and March 31, 2010. Age-stratified rates of physician encounters, emergency department (ED) visits and inpatient hospitalizations to March 31, 2012 were compared using incidence rate ratios (IRR) and incidence rate differences (IRD). We used negative binomial regression to adjust IRRs for sex, gestational age, birth weight, socioeconomic status and rural/urban residence. Results: Throughout the first few years of life, children with MCAD deficiency (n = 40) experienced statistically significantly higher rates of physician encounters, ED visits, and hospital stays compared with the screen negative cohort. The highest rates of ED visits and hospitalizations in the MCAD deficiency cohort occurred from 6 months to 2 years of age (ED use: 2.1-2.5 visits per child per year; hospitalization: 0.5-0.6 visits per child per year), after which rates gradually declined. Conclusions: This study confirms that young children with MCAD deficiency use health services more frequently than the general population throughout the first few years of life. Rates of service use in this population gradually diminish after 24 months of age
A Bayesian statistical analysis of behavioral facilitation associated with deep brain stimulation
Deep brain stimulation (DBS) is an established therapy for Parkinson's Disease and is being investigated as a treatment for chronic depression, obsessive compulsive disorder and for facilitating functional recovery of patients in minimally conscious states following brain injury. For all of these applications, quantitative assessments of the behavioral effects of DBS are crucial to determine whether the therapy is effective and, if so, how stimulation parameters can be optimized. Behavioral analyses for DBS are challenging because subject performance is typically assessed from only a small set of discrete measurements made on a discrete rating scale, the time course of DBS effects is unknown, and between-subject differences are often large. We demonstrate how Bayesian state-space methods can be used to characterize the relationship between DBS and behavior comparing our approach with logistic regression in two experiments: the effects of DBS on attention of a macaque monkey performing a reaction-time task, and the effects of DBS on motor behavior of a human patient in a minimally conscious state. The state-space analysis can assess the magnitude of DBS behavioral facilitation (positive or negative) at specific time points and has important implications for developing principled strategies to optimize DBS paradigms.National Institutes of Health (U.S.)(R01 MH-071847)National Institutes of Health (U.S.) (DP1 OD003646)National Institutes of Health (U.S.)(NS02172)IntElect Medical (Firm
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