Search

The field of behavioral economics (BE) has been defined by the study of anomalies in choice, that is, choices that do not obey what is called rational choice theory or expected utility theory. Expected utility theory holds that an intelligent and well-informed agent (‘economic man’) will make choices that maximize his expected utility, which by implication means avoiding choice patterns that would make him (her hereafter) vulnerable in competitive markets—for instance, to be money pumped, or make intransitive choices or choices that could be reversed by reframing. Research in two disparate schools has found that people commit a number of apparent violations of the maximizing principle. These traditions have formed the two legs on which BE stands: behavioral and cognitive. During the 1970s and 1980s, both schools found anomalies in expected utility theory that called for new approaches. The behavioral school revealed anomalies in choice as a function of intertemporal differences in motivation, thus creating the topics of dynamic inconsistency and hyperbolic and quasihyperbolic delay discounting. The cognitive school revealed anomalies in choice as a function of cognitive framing, which are summarized in prospect theory. These anomalies have remained the cardinal phenomena of BE. Critics have called the resulting literature ‘a ragbag’, but I argue that the 12 best-known framing effects have coherent motivational roots. Most anomalies that persist after reflection can be understood as strategies in intertemporal bargaining, for maximizing hyperbolically discounted utility (or reward). Published 2015. This article is a U.S. Government work and is in the public domain in the USA

Background:The aim of this study was to compare micropuncture laparoscopic cholecystectomy (MPLC), with three 3.3-mm cannulas and one 10-mm cannula with conventional laparoscopic cholecystectomy (CLC). Methods: Patients were randomized to undergo either CLC or MPLC. The duration of each operative stage and the procedure were recorded. Interleukin-6 (IL-6), adrenocorticotropic hormone (ACTH), and vasopressin were sampled for 24 h. Visual analogue pain scores (VAPS) and analgesic consumption were recorded for 1 week. Pulmonary function and quality of life (EQ-5D) were monitored for 4 weeks. Statistical analysis was performed using the Mann–Whitney test or Fisher’s exact test. Results are expressed as median (interquartile range). Results: Forty-four patients entered the study, but four were excluded due to unsuspected choledocholithiasis (n = 3) or the need to reschedule surgery (n = 1). The groups were comparable in terms of age, duration of symptoms, and indications for surgery. Total operative time was similar (CLC, 63 [52–81] min vs MPLC 74 [58–95] min; p = 0.126). However, time to place the cannulas after skin incision (CLC, 5:42 [3:45–6:37] min vs MPLC, 7:38 [5:57–10:15] min; p = 0.015) and to clip the cystic duct after cholangiography (CLC, 1:05 [0:40–1:35] min vs MPLC, 3:45 [2:26–7:49] min; p < 0.001) were significantly longer for MPLC. Six CLC patients and one MPLC patient required postoperative parenteral opiates (p = 0.04). Oral analgesic consumption was similar in both groups (p = 0.217). Median VAPS were lower at all time points for MPLC, but this finding was not significant (p = 0.431). There were no significant differences in postoperative stay, IL-6, ACTH or vasopressin responses, pulmonary function, or EQ-5D scores. Conclusions: The thinner instruments did not significantly increase the total duration of the procedure. MPLC reduced the use of parenteral analgesia postoperatively, which may prove beneficial for day case patients, but it did not have a significant impact on laboratory variables, lung function or quality of life.

Kikuyu grass (Pennisetum clandestinum) is widely used as a grazing pasture in Africa and, although it is extensively cultivated as a lawn for sports fields and domestic gardens, its allergenicity has never been studied in vitro. Using an extract of Kikuyu grass pollen, polyacrylamide gel electrophoresis, Western blotting and a monoclonal anti-human IgE antibody, the specific IgE binding, in the serum of 160 allergic and non-allergic patients in the Cape Town area, to a Kikuyu grass extract was studied. IgE in the sera of 43/104 known grass-allergic individuals bound to Kikuyu grass on the Western blots. In addition, 4/28 'non-allergic' control subjects were found to have Kikuyu grass-specific IgE. Five different profiles of specific IgE reactivity to Kikuyu grass antigens were observed. In 29/43 patients, IgE bound to two dominant 48 and 70 kD allergens in the Kikuyu extract. Although a degree of cross-reactivity with Bermuda grass (Cynodon dactylis) was found in immunoabsorption studies, the 48 and 70 kD allergens appear to be unique to Kikuyu grass. Exposure of heparinized blood from Kikuyu grass-positive patients to the Kikuyu extract stimulated the release of histamine from their basophils in vitro. Kikuyu grass pollen is thus identified as an important aero-allergen in South Africa.

This study investigated whether serious adverse events (SAEs) during antituberculosis therapy occur more frequently in HIV co-infected patients in a South African population. A retrospective analysis examined incidences of hepatotoxicity, peripheral neuropathy, severe arthralgia, persistent vomiting and severe rash in 400 patients treated for tuberculosis in a community clinic. A total of 141 patients were co-infected with HIV, among whom only 16.3% were receiving antiretrovirals. Details of SAEs were ascertainable in 331/400 patients, and occurred in 26.7% of HIV-infected and 13.3% of HIV-uninfected individuals ( P = 0.003). The excess was attributable to increased peripheral neuropathy (8.3% and 1.9%, respectively, P = 0.009) and persistent vomiting (13.3% and 3.3%, P = 0.001). SAE occurrence was not related to antiretroviral use, although median CD4 counts were lower in those experiencing side-effects (130 and 259 cells/µL, P = 0.008). The treatment completion did not differ significantly between the two groups (76.6% and 84.2%, P = 0.08).

Croissant de Garengeot's hernia is defined as the presence of an appendix in the femoral hernial sac. It is rare and occurs mostly in females. We report this hernia in a male patient along with the surgical management and review of literature.

The use of diagnostic ultrasonography has profoundly enhanced the practice of obstetrics. Its use on a routine basis in pregnancy, though, is still debated. We evaluated a policy of routine second trimester ultrasonography in our base population to determine if it improved obstetrical care. In comparison to a historical control group, our study group had fewer patients going beyond 42 weeks and a significantly lower Cesarean section rate for those requiring an induction for post dates. The use of routine antenatal ultrasonography improved obstetrical care in our population.

We read with interest the article by Sekimoto et al. in theDecember 1998 issue of Surgical Endoscopy [6]. We weresomewhat surprised to see the liver retraction techniquedescribed as “new” since it was previously published in thisJournal in 1995 [2] and later illustrated in a 1996 article [3].It has been in routine use in our Leeds clinic since 1991.We use Diamond-Flex retractors (Genzyme SurgicalProducts, Tucker, GA, USA), which were developed spe-cifically for liver retraction during laparoscopic cholecys-tectomy. These are malleable retractors which, when in-serted through a 5-mm cannula, are tightened to produce apredefined shape. The retractors have a rounded profile andcan be placed under the liver without causing trauma [Fig. 1].We agree with the authors’ observation that the tech-nique allows good exposure of the undersurface of the liver.It also avoids distortion of Calot’s triangle caused by fundaltraction [5]. The retractors were developed in accordancewith a principle established earlier at open cholecystecto-my—namely, they are designed to open the angle betweenthe cystic duct and bile duct. Other shapes of retractor areavailable to cope with a large quadrate lobe. We have nowemployed this method of retraction in >1,000 laparoscopiccholecystectomies, with a conversion rate of 0.5% duringthe last 2 years. Despite an “all-comers” policy since theintroduction of the procedure to our unit [4], there have beenno deaths and no bile duct injuries.We disagree with the Osaka group over the use of thereverse Trendelenburg position when the retractor is em-ployed. We routinely use low-pressure insufflation (7mmHg) and find the exposure to be more than adequate inmost cases. Should intraabdominal fat obscure the view, weroutinely insert an additional retractor through a 5-mm can-nula placed in the left upper quadrant to hold down the fat.The dangers associated with capnoperitoneum and the re-verse Trendelenburg position were recently highlighted inThe Report of the National Confidential Enquiry into Peri-operative Deaths 1996/1997 (NCEPOD) [1]. We believethat maintenance of the supine position with low pressurereduces the physiological insult [7], especially among pa-tients who are elderly and have poor cardiorespiratory func-tion. The lower pressure also reduces postoperative pain[8].The liver retractor obviates the need for traction to beapplied to the fundus of the gallbladder to gain exposure; italso permits a fundus-first technique of dissection to beemployed when needed [2]. This technique confers an in-valuable advantage in difficult cholecystectomies, and wehave no doubt that it has contributed to our low conversionrate.References

Crambus laqueatellus is one of the largest and most beautifully marked species in this genus and is easily distinguished from all other North American forms by the two parallel silver stripes running almost the full length of the fore wing. SYSTEMATIC HISTORY Crambus laqueatellus was first described by Clemens in 1860. Walker redescribed it in 1863 from specimens from “North America” as C. semifusellus , a name reduced to synonomy in 1891 by Smith. Aside from its inclusion in various lists and the few references to it as an economic species its literature is meager. Fernald (1896) and Holland (1903) both figure the moth in colors. Nothing has ever been written about any stages other than the adult, except Felt’s (1894) description of the egg and first stage larva. In other respects also his notes are hitherto the most extensive of any relating to this species.

n/a

A summary of the results of experiments to determine the magnetic aging characteristics of ``Chainstore'' memory elements as a function of time, temperature, and electrical exercise is presented. A phenomenological theory of anisotropy kinetics is constructed which provides an account of aging in magnetic films in agreement with the ``Chainstore'' experiments. The theory, which is capable of simple geometric representation, describes the kinetics by which the uniaxial anisotropy constant and skew angle change when a device is subjected to magnetic annealing at an elevated temperature. Conclusions are also drawn in regard to the phenomena of angle and amplitude dispersion.

Since undertaking a study of the Pyralid subfamily Crambime it has been found that the little that has been published concerning it is so widely scattered and so fragmentary that it is very difficult of access. In the present series of papers the writer proposes to bring together all the available information concerning each species, both that previously published and that which has resulted from his own work. Both systematic and biological data will be included when available but the papers cannot be exhaustive for our knowledge of many points is too scanty. They are designed to afford a convenient starting point for further work by making it unnecessary for others to go repeatedly over this same ground and to put within reach of economic workers the available facts which may be useful in economic studies of these insects. The bibliographies are intended to be complete and the writer will welcome corrections and additions thereto.

GaAs grown in a horizontal Bridgman crystal growth apparatus to which oxygen has been added exhibits lower silicon content than that grown without oxygen. Material grown under oxygen additions of 10–20 Torr exhibits, at room temperature, carrier densities in the 2–4×1015 cm−3 range and mobilities between 7500–8650 cm2 V−1 sec−1.Silicon concentrations computed from the reaction 4Ga+SiO2 → 2Ga2O+Si are compared with electrical determinations of donor densities and spectroscopic determinations of silicon concentrations with reasonably good agreement. It is concluded that suppression of SiO2 dissociation at the walls of the silica reaction tube is the most important action of oxygen on GaAs properties although oxygen doping may play a role in the production of high resistivity GaAs.

The addition of copper to aluminum thin films has previously been shown to reduce the rate of electromigration failure considerably. The effective “activation energy” for failure time has been found to be a function of the concentration of copper. A model is presented which attributes the increase in activation energy (about 0.2–0.3 eV) caused by copper to the dissolution of Al2Cu precipitates and to the adsorption of copper atoms on aluminum grain boundaries.

A 0.65‐eV luminescence peak has been observed in GaAs crystals grown in oxygen. The strength of the peak increases with increasing oxygen pressure during crystal growth. The 0.93‐eV peak previously reported from electroluminescence measurements on GaAs diodes is observed in photoluminescence to decrease with increasing oxygen pressure and is absent in samples grown under high oxygen pressure. The 0.65‐eV emission is not found in GaAs crystals pulled from AlN crucibles or in crystals grown in quartz without added oxygen. These two luminescence emissions appear to be related to the levels observed in optical absorption and photoconductivity measurements on n‐type GaAs.

It is a clinical impression that less fentanyl is needed for anesthesia during hyperventilation and hypocarbia. If true, it might be due to both increased penetration of fentanyl, a highly lipid-soluble agent, into the brain and increased brain tissue binding. Serum and brain concentrations of fentanyl were determined in dogs anesthetized with halothane during normocarbia, hypocarbia by hyperventilation, and hypercarbia by addition of CO2 to the inspired mixture. Fentanyl, 12.5 micrograms/kg, was injected iv, and serum and brain samples were taken for fentanyl analysis by radioimmunoassay. Brain fentanyl values peaked latest (15--20 min) and were highest during hypocarbia; brain fentanyl values peaked earliest (0--5 min) and were lowest during hypercarbia; values during normocarbia were intermediate in time to peak (10--15 min) and concentration. Thereafter, brain levels declined, but during hypocarbia were significantly higher and during hypercarbia were significantly lower than during normocarbia. Interestingly, serum fentanyl levels were also significantly higher during hypocarbia. The brain--blood fentanyl ratios for each of the three CO2 levels increased for 30 min and thereafter stayed relatively constant. The brain--blood ratios were highest with hypocarbia and lowest with hypercarbia. At 35 min, when clinical analgesia may be considered terminated, hypocarbic brain levels were double those of normocarbia. The authors feel this reflects, to a large extent, higher serum fentanyl concentrations and delayed cerebral wash-out because of decreased blood flow. To a small but unknown extent the higher brain fentanyl levels result from increased brain--blood penetration due to increased lipid solubility, and increased brain tissue binding of fentanyl during respiratory alkalosis.

Revised edition. This report discusses a pale, dark-spotted caterpillar known as the larger cornstalk-borer which bores into and weakens cornstalks. "Only corn is injured seriously by this insect; some of the larger grasses are food plants, and sugar cane sometimes is damaged slightly. There are two generations in a season. As the second generation passes the winter in the corn roots, if the roots are destroyed or plowed, the pest will be largely subdued. The injury is worst where corn follows corn, so rotation of crops will help to destroy the borer. This bulletin gives the life history of the borer, its feeding habits, and methods of combating it." -- p. ii

The effect of the mechanical constraints exerted by coatings upon electromigration in thin films is evaluated on the basis of known pressure effects upon diffusion.