285 research outputs found
Cataloguing CERN's archival records: principles and practice
This report summarises the main principles and standards relating to archival cataloguing, and describes the current practice in the CERN Archive. It is intended as background for discussion of possible improvements
Benzodiazepines: Uses, dangers, and clinical considerations
Benzodiazepines (BZDs) are among one of the most widely prescribed drug classes in the United States. BZDs are a class of psychoactive drugs known for their depressant effect on the central nervous system (CNS). They quickly diffuse through the blood–brain barrier to affect the inhibitory neurotransmitter GABA and exert sedative effects. Related to their rapid onset and immediate symptom relief, BZDs are used for those struggling with sleep, anxiety, spasticity due to CNS pathology, muscle relaxation, and epilepsy. One of the debilitating side effects of BZDs is their addictive potential. The dependence on BZDs generally leads to withdrawal symptoms, requiring careful tapering of the medication when prescribed. Regular use of BZDs has been shown to cause severe, harmful psychological and physical dependence, leading to withdrawal symptoms similar to that of alcohol withdrawal. Some of these withdrawal symptoms can be life threatening. The current treatment for withdrawal is through tapering with clonazepam. Many drugs have been tested as a treatment for withdrawal, with few proving efficacious in randomized control trials. Future research is warranted for further exploration into alternative methods of treating BZD withdrawal. This call to action proves especially relevant, as those seeking treatment for BZD dependence and withdrawal are on the rise in the United States
Catatonia: Clinical overview of the diagnosis, treatment, and clinical challenges
Catatonia is a syndrome that has been associated with several mental illness disorders but that has also presented as a result of other medical conditions. Schizophrenia and other psychiatric disorders such as mania and depression are known to be associated with catatonia; however, several case reports have been published of certain medical conditions inducing catatonia, including hypo-natremia, cerebral venous sinus thrombosis, and liver transplantation. Neuroleptic Malignant Syndrome and anti-NMDA receptor encephalitis are also prominent causes of catatonia. Patients taking benzodiazepines or clozapine are also at risk of developing catatonia following the withdrawal of these medications—it is speculated that the prolonged use of these medications increases gamma-aminobutyric acid (GABA) activity and that discontinuation may increase excitatory neurotrans-mission, leading to catatonia. The treatment of catatonia often involves the use of benzodiazepines, such as lorazepam, that can be used in combination therapy with antipsychotics. Definitive treatment may be found with electroconvulsive therapy (ECT). Aberrant neuronal activity in different motor pathways, defective neurotransmitter regulation, and impaired oligodendrocyte function have all been proposed as the pathophysiology behind catatonia. There are many clinical challenges that come with catatonia and, as early treatment is associated with better outcomes, it becomes imperative to understand these challenges. The purpose of this manuscript is to provide an overview of these challenges and to look at clinical studies regarding the pathophysiology, diagnosis, and treatment of as well as the complications and risk factors associated with catatonia
A model for fresh produce shelf-space allocation and inventory management with freshness-condition-dependent demand
Asignificant amount of work has investigated inventory control problems associated with fresh produce. Much of this work has considered deteriorating inventory control with many models having been proposed for various situations. However, no researchers have specifically studied fresh produce, which has its own special characteristics. Most research categorizes fresh produce into more general deteriorating categories with random lifetimes and nondecaying utilities. However, this classification is not reasonable or practical because the freshness of an item usually plays an important role in influencing the demand for the produce. In this paper, a single-period inventory and shelf-space allocation model is proposed for fresh produce. These items usually have a very short lifetime. The demand rate is assumed to be deterministic and dependent on both the displayed inventory (the number of facings of items on the shelves) and the items' freshness condition (which decreases over time). Several problem instances of different sizes are provided and solved by a modified generalized reduced gradient algorithm
Land Cover/Land Use Classification and Change Detection Analysis with Astronaut Photography and Geographic Object-Based Image Analysis
For over fifty years, NASA astronauts have taken exceptional photographs of the Earth from the unique vantage point of low Earth orbit (as well as from lunar orbit and surface of the Moon). The Crew Earth Observations (CEO) Facility is the NASA ISS payload supporting astronaut photography of the Earth surface and atmosphere. From aurora to mountain ranges, deltas, and cities, there are over two million images of the Earth's surface dating back to the Mercury missions in the early 1960s. The Gateway to Astronaut Photography of Earth website (eol.jsc.nasa.gov) provides a publically accessible platform to query and download these images at a variety of spatial resolutions and perform scientific research at no cost to the end user. As a demonstration to the science, application, and education user communities we examine astronaut photography of the Washington D.C. metropolitan area for three time steps between 1998 and 2016 using Geographic Object-Based Image Analysis (GEOBIA) to classify and quantify land cover/land use and provide a template for future change detection studies with astronaut photography
Toward a Quantization of Null Dust Collapse
Spherically symmetric, null dust clouds, like their time-like counterparts,
may collapse classically into black holes or naked singularities depending on
their initial conditions. We consider the Hamiltonian dynamics of the collapse
of an arbitrary distribution of null dust, expressed in terms of the physical
radius, , the null coordinates, for a collapsing cloud or for an
expanding cloud, the mass function, , of the null matter, and their
conjugate momenta. This description is obtained from the ADM description by a
Kucha\v{r}-type canonical transformation. The constraints are linear in the
canonical momenta and Dirac's constraint quantization program is implemented.
Explicit solutions the constraints are obtained for both expanding and
contracting null dust clouds with arbitrary mass functions.Comment: 10 pages, 2 figures (eps), RevTeX4. The last two sections have been
revised and corrected. To appear in Phys. Rev.
The perinatal androgen to estrogen ratio and autistic-like traits in the general population: a longitudinal pregnancy cohort study
Risk of Birth Abnormalities in the Offspring of Men With a History of Cancer: A Cohort Study Using Danish and Swedish National Registries
Background The potential mutagenic effects of cancer therapies and the growing number of young male cancer survivors have given rise to concern about the health of their offspring. Methods We identified all singleton children born alive in Denmark between 1994 and 2004 and in Sweden between 1994 and 2005 (n = 1 777 765). Of the 8670 children with a paternal history of cancer, 8162 were conceived naturally and 508 were conceived using assisted reproductive technologies (ARTs) (in vitro fertilization or intracytoplasmatic sperm injection). Of the 1 769 0795 children without a paternal history of cancer, 25 926 were conceived using ARTs. Associations between paternal history of cancer and risk of adverse birth outcomes of children conceived naturally or by ARTs were investigated using log-linear binomial models, yielding risk ratios (RRs) with 95% confidence intervals (CIs). All statistical tests were two-sided. Results The offspring of male cancer survivors were more likely to have major congenital abnormalities than the offspring of fathers with no history of cancer (RR = 1.17, 95% CI = 1.05 to 1.31, P = .0043, 3.7% vs 3.2%). However, the mode of conception (natural conception or ARTs) did not modify the association between paternal history of cancer and risk of congenital abnormalities (natural conception, RR = 1.17, 95% CI = 1.04 to 1.31; ARTs, RR = 1.22, 95% CI = 0.80 to 1.87, P(interaction) = .84). Conclusion We observed a statistically significant but modest increase in the risk of major congenital abnormalities among offspring of males with a history of cancer, independent of the mode of conception
Transcription factors that mediate epithelial–mesenchymal transition lead to multidrug resistance by upregulating ABC transporters
Development of multidrug resistance (MDR) is a major deterrent in the effective treatment of metastatic cancers by chemotherapy. Even though MDR and cancer invasiveness have been correlated, the molecular basis of this link remains obscure. We show here that treatment with chemotherapeutic drugs increases the expression of several ATP binding cassette transporters (ABC transporters) associated with MDR, as well as epithelial–mesenchymal transition (EMT) markers, selectively in invasive breast cancer cells, but not in immortalized or non-invasive cells. Interestingly, the mere induction of an EMT in immortalized and non-invasive cell lines increased their expression of ABC transporters, migration, invasion, and drug resistance. Conversely, reversal of EMT in invasive cells by downregulating EMT-inducing transcription factors reduced their expression of ABC transporters, invasion, and rendered them more chemosensitive. Mechanistically, we demonstrate that the promoters of ABC transporters carry several binding sites for EMT-inducing transcription factors, and overexpression of Twist, Snail, and FOXC2 increases the promoter activity of ABC transporters. Furthermore, chromatin immunoprecipitation studies revealed that Twist binds directly to the E-box elements of ABC transporters. Thus, our study identifies EMT inducers as novel regulators of ABC transporters, thereby providing molecular insights into the long-standing association between invasiveness and MDR. Targeting EMT transcription factors could hence serve as novel strategies to curb both metastasis and the associated drug resistance
Cardiovascular Risk Reduction is Important for Improving Patient and Graft Survival After Ligation and Bypass Surgery for Popliteal Artery Aneurysm
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