3,481 research outputs found
Origin Gaps and the Eternal Sunshine of the Second-Order Pendulum
The rich experiences of an intentional, goal-oriented life emerge, in an
unpredictable fashion, from the basic laws of physics. Here I argue that this
unpredictability is no mirage: there are true gaps between life and non-life,
mind and mindlessness, and even between functional societies and groups of
Hobbesian individuals. These gaps, I suggest, emerge from the mathematics of
self-reference, and the logical barriers to prediction that self-referring
systems present. Still, a mathematical truth does not imply a physical one: the
universe need not have made self-reference possible. It did, and the question
then is how. In the second half of this essay, I show how a basic move in
physics, known as renormalization, transforms the "forgetful" second-order
equations of fundamental physics into a rich, self-referential world that makes
possible the major transitions we care so much about. While the universe runs
in assembly code, the coarse-grained version runs in LISP, and it is from that
the world of aim and intention grows.Comment: FQXI Prize Essay 2017. 18 pages, including afterword on
Ostrogradsky's Theorem and an exchange with John Bova, Dresden Craig, and
Paul Livingsto
Engineering robust polar chiral clathrate crystals
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Royal Society of Chemistry 2013.The R-(+)-enantiomeric form of Dianin's compound and the S-(+)-enantiomeric form of its direct thiachroman analogue both obtained chromatographically employing a cellulose tris(3,5-dimethylphenylcarbamate) column, are shown to undergo supramolecular assembly to form a polar clathrate lattice which is stable even in the absence of a consolidating guest component
Achirality in the low temperature structure and lattice modes of tris(acetylacetonate)iron(iii)
Tris(acetylacteonate) iron(III) is a relatively ubiquitous mononuclear inorganic coordination complex. The bidentate nature of the three acetylacteonate ligands coordinating around a single centre inevitably leads to structural isomeric forms, however whether or not this relates to chirality in the solid state has been questioned in the literature. Variable temperature neutron diffraction data down to T = 3 K, highlights the dynamic nature of the ligand environment, including the motions of the hydrogen atoms. The Fourier transform of the molecular dynamics simulation based on the experimentally determined structure was shown to closely reproduce the low temperature vibrational density of states obtained using inelastic neutron scattering
Nurses\u27 Alumnae Association Bulletin - Volume 5 Number 8
Calling All Nurses
Financial Report
Calendar of Events
Lest You Forget!
Attention
Review of the Alumnae Association Meetings
President\u27s Report
Barton Memorial Division
Oxygen Therapy
Welcome, White Haven Alumnae
Clinical Use of Penicillin in Infections of the Ears, Nose and Throat
Address - Graduation of Nurses, 1945
Miscellaneous Items
The Blood that Kills
The Story of Malaria
Program
Prizes - May, 1946
Capping Exercises
The Economic Security Program of the Pennsylvania State Nurses\u27 Association
The Clara Melville Scholarship Fund
Card of Thanks
The Poet\u27s Corner
The Hospital Pharmacy
Jefferson Medical College Hospital School of Nursing Faculty
Jefferson Hospital Gray Lady Unite, A.R.R.
The Volunteer Nurses\u27 Aides Salute Jefferson Nurses
Changes in the Staff at Jefferson Hospital
Red Cross Recruits
Did You Know That
The Pennsylvania Nurse
Medical College News
Magazine and Newspaper Items
Central Dressing Room and Transfusion Unit
Rules Concerning Central Dressing Room
Radios and Electrical Appliances
Attending College
Nurses in Anesthesia
Condolences
Marriages
New Arrivals
Deaths
The Bulletin Committee
Attention, Alumnae
New Addresse
Nurses\u27 Alumnae Association Bulletin - Volume 6 Number 9
Remember the Relief Fund
Welcome! Miss Childs
Financial Report
Calendar of Coming Events
Lest You Forget!
Attention
Review of the Alumnae Association Meetings
Institutional Staff Nurses\u27 Section
Report of Staff Activities - 1947-1948
Private Duty Section
The White Haven Division
Barton Memorial Division
Remember the Relief Fund
Student Nurses\u27 Activities
Jefferson Scores Again
The Clara Melville Scholarship Fund
Interesting Activities of the Nurses\u27 Home Committee of the Women\u27s Board
Exclusive for Nurses
Changes in the Maternity Division
Gray Lady Musical Therapy Service
Memorial Service Honoring Mrs. Bessie Dobson Altemus
The Blood Donor Center
The Hospital Pharmacy
Medical College News
Remember the Relief Fund
Administrative Staff and Faculty of the School of Nursing
Streptomycin
Changes in the Staff at Jefferson Hospital
Care of the Thoracic Surgical Patient
Miscellaneous Items
Marriages
New Arrivals
Deaths
The Bulletin Committee
Attention, Alumnae
New Addresse
Efficiency improvement and power loss breakdown for a Lundell-alternator/active-rectifier system in automotive applications
A control strategy for a conventional Lundell alternator and an active-rectifier using different modulation schemes was proposed in previous work. The modulation techniques examined indicated that the system could operate more efficiently than a passive rectifier over a certain speed and power range. This paper extends the modulation scheme analysis using a SVM scheme with six commutations per switching cycle, giving better electrical and overall efficiency. Furthermore, a power loss breakdown is performed for the active-rectifier with the assistance of experimental and simulation results of double pulse tests. Switching loss estimation curves are produced allowing the loss examination of the active-rectifier. Switching losses account only for a minor portion of the total rectifier losses in comparison to conduction losses. Finally, a higher dc-link voltage of 14.5 V was introduced using SVM scheme, giving better efficiency, in order to exploit further the rectifier loss distribution
Structural, functional, and genetic analyses of the actinobacterial transcription factor RbpA
Gene expression is highly regulated at the step of transcription initiation, and transcription activators play a critical role in this process. RbpA, an actinobacterial transcription activator that is essential in Mycobacterium tuberculosis (Mtb), binds selectively to group 1 and certain group 2 σ-factors. To delineate the molecular mechanism of RbpA, we show that the Mtb RbpA σ-interacting domain (SID) and basic linker are sufficient for transcription activation. We also present the crystal structure of the Mtb RbpA-SID in complex with domain 2 of the housekeeping σ-factor, σ(A). The structure explains the basis of σ-selectivity by RbpA, showing that RbpA interacts with conserved regions of σ(A) as well as the nonconserved region (NCR), which is present only in housekeeping σ-factors. Thus, the structure is the first, to our knowledge, to show a protein interacting with the NCR of a σ-factor. We confirm the basis of selectivity and the observed interactions using mutagenesis and functional studies. In addition, the structure allows for a model of the RbpA-SID in the context of a transcription initiation complex. Unexpectedly, the structural modeling suggests that RbpA contacts the promoter DNA, and we present in vivo and in vitro studies supporting this finding. Our combined data lead to a better understanding of the mechanism of RbpA function as a transcription activator
Effect of Long-Term Exposure to Lower Low-Density Lipoprotein Cholesterol Beginning Early in Life on the Risk of Coronary Heart Disease A Mendelian Randomization Analysis
ObjectivesThe purpose of this study was to estimate the effect of long-term exposure to lower plasma low-density lipoprotein cholesterol (LDL-C) on the risk of coronary heart disease (CHD).BackgroundLDL-C is causally related to the risk of CHD. However, the association between long-term exposure to lower LDL-C beginning early in life and the risk of CHD has not been reliably quantified.MethodsWe conducted a series of meta-analyses to estimate the effect of long-term exposure to lower LDL-C on the risk of CHD mediated by 9 polymorphisms in 6 different genes. We then combined these Mendelian randomization studies in a meta-analysis to obtain a more precise estimate of the effect of long-term exposure to lower LDL-C and compared it with the clinical benefit associated with the same magnitude of LDL-C reduction during treatment with a statin.ResultsAll 9 polymorphisms were associated with a highly consistent reduction in the risk of CHD per unit lower LDL-C, with no evidence of heterogeneity of effect (I2 = 0.0%). In a meta-analysis combining nonoverlapping data from 312,321 participants, naturally random allocation to long-term exposure to lower LDL-C was associated with a 54.5% (95% confidence interval: 48.8% to 59.5%) reduction in the risk of CHD for each mmol/l (38.7 mg/dl) lower LDL-C. This represents a 3-fold greater reduction in the risk of CHD per unit lower LDL-C than that observed during treatment with a statin started later in life (p = 8.43 × 10−19).ConclusionsProlonged exposure to lower LDL-C beginning early in life is associated with a substantially greater reduction in the risk of CHD than the current practice of lowering LDL-C beginning later in life
Control and efficiency analysis for a Lundell-alternator/active-rectifier system in automotive applications
This paper presents a control strategy for a conventional Lundell alternator and an active-rectifier. The control scheme focuses on the minimisation of the stator copper losses of the alternator in an effort to maximise its efficiency. The modulation scheme of the active-rectifier is being investigated with the introduction of three different modulation techniques in order to quantify the effect they have on the alternator’s efficiency. Steady-state results from experimental measurements of the alternator rectifier system are compared against a standard passive rectifier. The comparison indicates that the modulation scheme of the active-rectifier is significant to the alternator’s efficiency as well as to the overall system efficiency
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