3,739 research outputs found
'The world is full of big bad wolves': investigating the experimental therapeutic spaces of R.D. Laing and Aaron Esterson
In conjunction with the recent critical assessments of the life and work of R.D. Laing, this paper seeks to demonstrate what is revealed when Laing’s work on families and created spaces of mental health care are examined through a geographical lens. The paper begins with an exploration of Laing’s time at the Tavistock Clinic in London during the 1960s, and of the co-authored text with Aaron Esterson entitled, Sanity, Madness and the Family (1964). The study then seeks to demonstrate the importance Laing and his colleague placed on the time-space situatedness of patients and their worlds. Finally, an account is provided of Laing’s and Esterson’s spatial thinking in relation to their creation of both real and imagined spaces of therapeutic care
Rearrangements of unsaturated steroid alcohols
The action of toluene-p-sulphonyl chloride in pyridine on
cholest-4-en-3ß-ol and on 5a-cholest-l-en-3ß-ol has been investigated; in neither case was a tosyl ester isolated. The former
reaction produced 3a,5-cyclo-5a-cholest-6-ene, cholesta-3,5-diene
and N-(cholest-4-en-3a-yl)-pyridinium tosylate. In the latter
case, the products isolated were la,5-cyclo-5a-cholest-2-ene and
N-(cholest-l-en-3a-yl)-pyridinum tosylate.la,5-Cyclo-5a-cholest-2-ene has been characterised by both
its spectral properties and chemical reactions. The ultra violet
and infra red spectra are consistent with the assigned alkyl-cyclopropane structure; indeed the proton magnetic resonance
spectrum also supports the structure, but assignment of peaks
was uncertain. The ambiguity was resolved by consideration of
the p.m.r. spectrum of 17ß- methoxy-la,5-cyclo-5a-androst-2-ene,
synthesised from 17ß-methoxy-5a-androst-l-en-3ß-ol by the same
method. This reaction also produced l7ß- methoxy- 5a- androsta-1,3-diene in addition to the cyclosteroid.The major reactions of la,5-cyclo-5a-cholest-2-ene are
summarised below. Catalytic reduction using palladium on
charcoal catalyst afforded 5a-cholestane, but use of the soluble
catalyst, tris(triphenylphosphine)rhodium chloride, gave la,5-cyclo-5a-cholestane. Oxidative fission of the olefinic bond
followed by reductive cleavage of the cyclopropane ring afforded
the known diacid, 2,3-seco-cholestan-2,3-dioic. Reaction of
peracid with the hydrocarbon gave a mono-oxide, cleaved with
lithium aluminium hydride to give 1a,5-cyclo-5a-cholestan-2a-ol.
The cyclopropyl-ketone obtained from the oxidation of this alcohol
was reduced catalytically to dive 5a-cholestan-2-one. la,5-Cyclo-5a-cholestane was obtained from this ketone by Wolff- Kishner reduction.la,5-Cyclo-5a-cholestane has also been synthesised by a
separate reaction sequence, the cyclopropane ring being introduced
by dehydration of a suitably substituted 5ß-hydroxy compound, and
proved to be identical with the material obtained in the above
reactions.A possible mechanism for the formation la,5-cyclo-5a-cholest-2-ene from 5a-cholest-l-en-3ß-ol has been proposed, involving
transannular migration of the 5a-hydrogen atom. Results from
tosylation experiments on 5a-deutero and 5a-fluoro-cholest-l-en3ß-ol have substantiated this mechanism.Attempted tosylation of 19-nor-androst-4-en-3ß-ol and 19-nor5a-androst-l-en-3ß-ol gave estra-3,5(10)-diene and estra-l,3-diene
respectively; no cyclosteroids were isolated.A synthesis of estradiol from 17ß-acetoxy-androst-1,4,6-trien3-one has been carried out. Aromatisation of this trienone with
sulphuric acid under anhydrous conditions gave 17ß-acetoxy-l-methyl-estra-1,3,5(10) -trien-3-one. Removal of the l-methyl
group was effected in two stages: Oxidation with cerium (IV)
gave the l-formyl derivative, which was decarbonylated with tris-(triphenylphosphine) rhodium chloride
Gained in Translation: The Sudden Pivot Taking Physics Labs to the Cloud as a Reform Opportunity
I will report on a positive experience with using the forced transition to online learning as an opportunity to adopt one of many best-practice examples from the world of Physics Education Research. Following the example in Developing scientific decision making by structuring and supporting student agency by N.G. Holmes, et al [1], (and the instructional materials shared on Physport.org), my efforts were directed toward cueing students to make decisions to design their research question during our online meetings, rather than developing materials to micro-manage their behaviors. Characteristics of the new online medium influenced instructional design and accessibility in surprising ways. The centrality of group scientific presentation to their peers prompted responses such as for the first time, I actually cared what the answer was.” Students participated in a belonging intervention,” and what was once their least-favorite class became a refuge of supportive relationships during a difficult time. How can we make that the new normal for physics lab? \\ N.G. Holmes, Benjamin Keep, and Carl E. Wieman, Phys. Rev. Phys. Educ. Res. 16, 010109 (2020
On the Use of Group Theoretical and Graphical Techniques toward the Solution of the General N-body Problem
Group theoretic and graphical techniques are used to derive the N-body wave
function for a system of identical bosons with general interactions through
first-order in a perturbation approach. This method is based on the maximal
symmetry present at lowest order in a perturbation series in inverse spatial
dimensions. The symmetric structure at lowest order has a point group
isomorphic with the S_N group, the symmetric group of N particles, and the
resulting perturbation expansion of the Hamiltonian is order-by-order invariant
under the permutations of the S_N group. This invariance under S_N imposes
severe symmetry requirements on the tensor blocks needed at each order in the
perturbation series. We show here that these blocks can be decomposed into a
basis of binary tensors invariant under S_N. This basis is small (25 terms at
first order in the wave function), independent of N, and is derived using
graphical techniques. This checks the N^6 scaling of these terms at first order
by effectively separating the N scaling problem away from the rest of the
physics. The transformation of each binary tensor to the final normal
coordinate basis requires the derivation of Clebsch-Gordon coefficients of S_N
for arbitrary N. This has been accomplished using the group theory of the
symmetric group. This achievement results in an analytic solution for the wave
function, exact through first order, that scales as N^0, effectively
circumventing intensive numerical work. This solution can be systematically
improved with further analytic work by going to yet higher orders in the
perturbation series.Comment: This paper was submitted to the Journal of Mathematical physics, and
is under revie
Energy Injection Episodes in Gamma Ray Bursts: The Light Curves and Polarization Properties of GRB 021004
Several GRB afterglow light curves deviate strongly from the power law decay
observed in most bursts. We show that these variations can be accounted for by
including refreshed shocks in the standard fireball model previously used to
interpret the overall afterglow behavior. As an example we consider GRB 021004
that exhibited strong light curve variations and has a reasonably well
time-resolved polarimetry. We show that the light curves in the R-band, X-rays
and in the radio can be accounted for by four energy injection episodes in
addition to the initial event. The polarization variations are shown to be a
consequence of the injections.Comment: 4 pages, 2 figures. To appear in ApJ
The IRAS Revised Bright Galaxy Sample (RBGS)
IRAS flux densities, redshifts, and infrared luminosities are reported for
all sources identified in the IRAS Revised Bright Galaxy Sample (RBGS), a
complete flux-limited survey of all extragalactic objects with total 60 micron
flux density greater than 5.24 Jy, covering the entire sky surveyed by IRAS at
Galactic latitude |b| > 5 degrees. The RBGS includes 629 objects, with a median
(mean) sample redshift of 0.0082 (0.0126) and a maximum redshift of 0.0876. The
RBGS supersedes the previous two-part IRAS Bright Galaxy Samples, which were
compiled before the final ("Pass 3") calibration of the IRAS Level 1 Archive in
May 1990. The RBGS also makes use of more accurate and consistent automated
methods to measure the flux of objects with extended emission. Basic properties
of the RBGS sources are summarized, including estimated total infrared
luminosities, as well as updates to cross-identifications with sources from
optical galaxy catalogs established using the NASA/IPAC Extragalactic Database
(NED). In addition, an atlas of images from the Digitized Sky Survey with
overlays of the IRAS position uncertainty ellipse and annotated scale bars is
provided for ease in visualizing the optical morphology in context with the
angular and metric size of each object. The revised bolometric infrared
luminosity function, phi(L_ir), for infrared bright galaxies in the local
Universe remains best fit by a double power law, phi(L_ir) ~ L_ir^alpha, with
alpha = -0.6 (+/- 0.1), and alpha = -2.2 (+/- 0.1) below and above the
"characteristic" infrared luminosity L_ir ~ 10^{10.5} L_solar, respectively.
(Abridged)Comment: Accepted for publication in the Astronomical Journal. Contains 50
pages, 7 tables, 16 figures. Due to astro-ph space limits, only 1 of 26 pages
of Figure 1, and 1 of 11 pages of Table 7, are included; full resolution
Postscript files are available at
http://nedwww.ipac.caltech.edu/level5/March03/IRAS_RBGS/Figures/ .
Replacement: Corrected insertion of Fig. 15 (MethodCodes.ps) in LaTe
Maybe I Could Use this Again! Two IDEAL Labs Introducing Instrumentation
Physics lab students are introduced to custom instrumentation using Arduino-like microcontrollers which have allowed us to implement two labs of particular utility for life-science majors. Constructing a fluid circuit using the sponge-resistor model, flow sensors and an LCD display show the current through each section of pipe. The instrument can simultaneously measure and record 18 voltages, which enables us to record high-frequency “snap shots” of a signal generated on an RC-circuit model of an axon. The IDEAL lab collaboration is developing labs that are open, applied to life, and rigorously quantitative
The Physics of Human Performance: An IDEAL Lab
Physics lab goes to the gymnasium, where students calculate the mechanical power required to walk on an inclined treadmill in watts and convert to units power used to measure human performance: VO2, and METs. Students learn how to use two linear regression models: the ACSM walking equation to estimate the actual power expenditure of walking and the Rockport 1 mile test to estimate their own VO2max. Students use models to prescribe exercise parameters for themselves and for two cases. The IDEAL lab collaboration is developing labs that are open, applied to life, and rigorously quantitative
- …