Self-Fulfilling Price Cycles

This paper presents a model of a self-fulfilling price cycle in an asset market. Price oscillates deterministically even though the underlying environment is stationary. The mechanism that we uncover is driven by endogenous variation in the investment horizons of the different market participants, informed and uninformed. On even days, the price is high; on odd days it is low. On even days, informed traders are willing to jettison their good assets, knowing that they can buy them back the next day, when the price is low. The anticipated drop in price more than offsets any potential loss in dividend. Because of these asset sales, the informed build up their cash holdings. Understanding that the market is flooded with good assets, the uninformed traders are willing to pay a high price. But their investment horizon is longer than that of the informed traders: their intention is to hold the assets they purchase, not to resell. On odd days, the price is low because the uninformed recognise that the informed are using their cash holdings to cherry-pick good assets from the market. Now the uninformed, like the informed, are investing short-term. Rather than buy-and-hold as they do with assets purchased on even days, on odd days the uninformed are buying to sell. Notice that, at the root of the model, there lies a credit constraint. Although the informed are flush with cash on odd days, they are not deep pockets. On each cherry that they pick out of the market, they earn a high return: buying cheap, selling dear. However they don't have enough cash to strip the market of cherries and thereby bid the price up.

The Extent and Cyclicality of Career Changes: Evidence for the UK

Using quarterly data for the U.K. from 1993 through 2012, we document that in economic downturns a smaller fraction of unemployed workers change their career when starting a new job. Moreover, the proportion of total hires that involves a career change for the worker also drops in recessions. Together with a simultaneous drop in overall turnover, this implies that the number of career changes declines during recessions. These results indicate that recessions are times of subdued reallocation rather than of accelerated and involuntary structural transformation. We back this interpretation up with evidence on who changes careers, which industries and occupations they come from and go to, and at which wage gains.

T1-weighted MRI as a substitute to CT for refocusing planning in MR-guided focused ultrasound.

Precise focusing is essential for transcranial MRI-guided focused ultrasound (TcMRgFUS) to minimize collateral damage to non-diseased tissues and to achieve temperatures capable of inducing coagulative necrosis at acceptable power deposition levels. CT is usually used for this refocusing but requires a separate study (CT) ahead of the TcMRgFUS procedure. The goal of this study was to determine whether MRI using an appropriate sequence would be a viable alternative to CT for planning ultrasound refocusing in TcMRgFUS. We tested three MRI pulse sequences (3D T1 weighted 3D volume interpolated breath hold examination (VIBE), proton density weighted 3D sampling perfection with applications optimized contrasts using different flip angle evolution and 3D true fast imaging with steady state precision T2-weighted imaging) on patients who have already had a CT scan performed. We made detailed measurements of the calvarial structure based on the MRI data and compared those so-called 'virtual CT' to detailed measurements of the calvarial structure based on the CT data, used as a reference standard. We then loaded both standard and virtual CT in a TcMRgFUS device and compared the calculated phase correction values, as well as the temperature elevation in a phantom. A series of Bland-Altman measurement agreement analyses showed T1 3D VIBE as the optimal MRI sequence, with respect to minimizing the measurement discrepancy between the MRI derived total skull thickness measurement and the CT derived total skull thickness measurement (mean measurement discrepancy: 0.025; 95% CL (-0.22-0.27); p = 0.825). The T1-weighted sequence was also optimal in estimating skull CT density and skull layer thickness. The mean difference between the phase shifts calculated with the standard CT and the virtual CT reconstructed from the T1 dataset was 0.08 ± 1.2 rad on patients and 0.1 ± 0.9 rad on phantom. Compared to the real CT, the MR-based correction showed a 1 °C drop on the maximum temperature elevation in the phantom (7% relative drop). Without any correction, the maximum temperature was down 6 °C (43% relative drop). We have developed an approach that allows for a reconstruction of a virtual CT dataset from MRI to perform phase correction in TcMRgFUS.

The Analysis of Accounting Multipliers: The NAMEA Approach in the Case of Catalonia

The aim of this paper is the analysis of the Catalan economy (2001) with the use of a National Accounting Matrix with environmental accounts (NAMEA) for the Catalan economy with 2001 data. We will focus on the analysis of the emission multipliers and we will also analyse the impact of a 10% reduction in greenhouse emissions on emission multipliers. This emission-reduction percentage would bring the Catalan economy into compliance with the maximum emissions level allowed by the Kyoto Protocol. We consider three possible scenarios that would allow this goal to be met. First, we will simulate a 10% reduction in regional emissions and a 5% drop in the endogenous income of the multipliers' model (production, factorial and private income). Second, we will simulate a 10% reduction in emissions and a 10% increase in endogenous income. Finally, we will simulate a 10% reduction in emissions and a 5% increase in endogenous income. Additionally, we will analyse the decomposition of the emission multipliers into own effects, open effects and circular effects to capture the different channels of the emission generation process. Keywords: NAMEA, emission multipliers, Kyoto Protocol.

Decision analysis for the genotype designation in low-template-DNA profiles

What genotype should the scientist specify for conducting a database search to try to find the source of a low-template-DNA (lt-DNA) trace? When the scientist answers this question, he or she makes a decision. Here, we approach this decision problem from a normative point of view by defining a decision-theoretic framework for answering this question for one locus. This framework combines the probability distribution describing the uncertainty over the trace's donor's possible genotypes with a loss function describing the scientist's preferences concerning false exclusions and false inclusions that may result from the database search. According to this approach, the scientist should choose the genotype designation that minimizes the expected loss. To illustrate the results produced by this approach, we apply it to two hypothetical cases: (1) the case of observing one peak for allele xi on a single electropherogram, and (2) the case of observing one peak for allele xi on one replicate, and a pair of peaks for alleles xi and xj, i ≠ j, on a second replicate. Given that the probabilities of allele drop-out are defined as functions of the observed peak heights, the threshold values marking the turning points when the scientist should switch from one designation to another are derived in terms of the observed peak heights. For each case, sensitivity analyses show the impact of the model's parameters on these threshold values. The results support the conclusion that the procedure should not focus on a single threshold value for making this decision for all alleles, all loci and in all laboratories.

Efficacy of insecticide impregnated bed-nets to control malaria in a rural forested area in Southern Cameron

Due to current spreading of chemoresistant strains of Plasmodium falciparum malaria control must incorporate vector control programmes. Due to well known constraints house sprayings cannot be performed as before. Personal protection can be developed and a large scale use of insecticide treated bed-nets appeared to be very useful to reduce man-vector contact in Asia, South America and West and East Africa. No trial has done is forest Central Africa where transmission is permanent. We performed such a trial in the southern part of Cameroon (using deltamethrin, at 25mg/m*) and obtained similar data to those observed in the Gambia Burkina Faso and Tanzania with a noteworthy reduction of both transmission and high parasitaemia of P. falciparum (respectively 78% and 75%) meaning a drop of malaria morbidity.

Segmental bioelectrical impedance analysis to assess perioperative fluid changes.

OBJECTIVES: Perioperative fluid accumulation determination is a challenge for the clinician. Bioelectrical impedance analysis (BIA) is a noninvasive method based on the electrical properties of tissues, which can assess body fluid compartments. The study aimed at assessing their changes in three types of surgery (thoracic, abdominal, and intracranial) requiring various regimens of fluid administration. DESIGN: Prospective descriptive trial. PATIENTS: A total of 26 patients scheduled for elective surgery were separated into three groups according to site of surgery: thoracic (n = 8), abdominal aortic (n = 8), and brain surgery (n = 10). SETTING: University teaching hospital. INTERVENTION: None. MEASUREMENTS: Whole body, segmental (arm, trunk, and legs) BIA at multiple frequency (0.5, 50, 100 kHz) was used to assess perioperative fluid accumulation after surgery. The fluid balances were calculated from the charts. RESULTS: The patients were aged 62+/-4 yrs. Fluid balances were 4.8+/-1.0 L, 4.1+/-0.5 L, and 1.9+/-0.3 L, respectively, in the three groups. In trunk surgery patients, fluid accumulation was detected as a drop in impedance in the operated area at all frequencies. In the operated area, there was an expansion of both intra- and extracellular compartments. A reduction in high frequencies' impedance in the legs was only detected after aortic surgery. Fluid accumulation and trunk impedance changes were strongly correlated. Neurosurgery only induced minor body fluid changes. CONCLUSIONS: Segmental BIA is able to detect and localize perioperative fluid accumulation. It may become a bedside tool to quantify and to localize fluid accumulation.

A simple and economic slide micro-immunoenzymatic (Micro-SIA) test for epidemiological studies of toxoplasmosis

A slide micro-immunoenzymatic assay (micro-SIA) to detectantibodies to non-particulate Toxoplasma gondii antigens is described. This assay allows the diagnosis of toxoplasmosis infection in about 1 hr. Twenty-four determinations can be performed per slide. Five hundred ng of antigen and 5 or 10 µl drop of each reactive are necessary per well. The clear contrast of colours obtained for negative and positive sera after the test is finished, allows direct discrimination of the results. However, it is possible to quantify the results of the reaction using a minireader. Sera dilution cutoff value, determined as themost frequent titre for the general population, is 1:100. The toxoplasma micro-SIA correlates well with indirect immunofluorescence (IIF), its sensitivity is atleast three times as much as IIF. The test has an intra and inter assay variation coefficient of 5.46 per cent and of 6.24 per cent respectively. Sera obtained at random from argentinian people were analyzed and a 56 per cent of infection was found. The main features of the Toxoplasma micro-SIA are its simplicity, sensitivity, reproducibility, and the virtual absence of background making it very suitable for screening tests.

Anti-TNF Therapy in the Swiss Inflammatory Bowel Disease G8 Cohort

Background: A nti-TNF d rugs (Infliximab (IFX), Adalimumab (ADA), Certolizumab pegol (CZP)) are effective in inducing and maintaining response a nd remission in i nflammatory bowel disease (IBD). Insufficient response or side effects may lead to a switch o f the anti-TNF d rug. W e aimed to e valuate the frequency and reasons for anti-TNF switches. Methods: Analysis of data from the Swiss Inflammatory Bowel Disease Cohort (SIBDCS). Eighty percent of included patients were recruited in hospitals and 20% from private practice. Results: From 2,058 patients ( 1,172 with Crohn's disease (CD), 842 with ulcerative colitis (UC) and 44 with indeterminate colitis (IC)), 772 received at least one anti-TNF. Forty-eight % of patients w ith CD, 23% with U C, a nd 30% with IC w ere ever treated with an anti-TNF drug. There was no gender difference with respect to the frequency of a nti-TNF treatment. A total of 584 patients (76%) were treated with one, 142 (18%) with two, and 46 (6%) with three anti-TNF (of which 32 were female). A total of 89% patients were treated with IFX, 28% ADA and 13% with CZP. Overall response rate (defined as drop in CDAI >100 points) to anti-TNF was 50%, with best response rates for the first used anti-TNF. Reasons t o switch t he anti-TNF w ere in 11% a primary non-response, in 38% a loss of response and in 36% anti-TNF s ide effects o r intolerance ( reasons for 15% of treatment failures not documented). Conclusion: A nti-TNF d rugs were used in h alf of the CD patients a nd in o ne quarter of U C patients. Anti-TNF d rug switch d ue to insufficient response a nd/or side effects w as necessary in one quarter of IBD patients. IFX was mainly used as first-line therapy. Best response rates were observed for the first used anti-TNF. Following analyses will identify risk median treatment duration as well as risk factors for anti-TNF switch.

Infusion of atrial natriuretic peptide to patients with congestive heart failure.

Atrial natriuretic peptides (ANP) exert vasodilating and natriuretic actions. The present study was undertaken to test the effect of low dose infusions of synthetic ANP on hemodynamic and humoral variables of patients with severe heart failure. Eight patients, aged 26 to 71 years, with severe congestive heart failure due to ischemic heart disease or idiopathic dilated cardiomyopathy were included in the study. Synthetic human (3-28) ANP was infused at doses ranging from 0.5 to 2 micrograms/min for up to 3 h. Pulmonary capillary wedge pressure fell from 24 +/- 1 to 16 +/- 2 mm Hg (mean +/- SEM) (p less than 0.01) and cardiac index tended to rise from 2 +/- 0.2 to 2.3 +/- 0.2 L/min/m2 (NS), while blood pressure and heart rate did not change. One patient experienced a marked drop in pulmonary capillary wedge and arterial blood pressure that necessitated the administration of saline. ANP infusion did not alter plasma renin activity or plasma aldosterone, norepinephrine, or vasopressin levels. It decreased plasma epinephrine levels from 0.472 +/- 0.077 to 0.267 +/- 0.024 nmol/L (p less than 0.05). Plasma ANP levels were markedly elevated in all patients before initiating the infusion. They had no predictive value for the hemodynamic response to exogenous ANP. No correlation was observed between the hemodynamic effects of ANP and those induced by the subsequently administered converting enzyme inhibitor captopril, which seemed to improve cardiac function more consistently.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal sensitivity to negative feedback in late-life depression.

AIMS: The purpose of the present study was to probe sensitivity to potentially misleading negative feedback on cognitive tasks as a possible mechanism of cognitive impairment in elderly patients with mild depression. METHODS: A total of 22 mildly depressed elderly subjects were compared to 22 healthy controls, using a computerized Tower-of-London task. RESULTS: Failure and magnitude of failure were significantly worse after negative but not positive feedback. Depression predicted failure after negative feedback but not the magnitude of failure. Neither failure nor magnitude of failure increased as a consequence of repeated negative feedback. CONCLUSIONS: Altered sensitivity to negative feedback occurs in mild late-life unipolar depression and may represent a subtle context-specific phenomenon.

QUALITEL : Qualitat Docent als estudis d'Enginyeria de Telecomunicació

L'objectiu del projecte QUALITEL dut a terme durant el curs 2007/2008 fou millorar l'aprenentatge dels estudiants de primer curs (fase selectiva) d'enginyeria de telecomunicació de l'ETSETB, introduint una nova metodologia docent basada en l'EEES. Es a dir, programació del treball de l'estudiant dins i fora de l'aula, increment de la interacció entre el professors i els seus estudiants mitjançant un sistema de tutories i la utilització d'eines de suport a l'aprenentatge com la utilització del Campus Digital ATENEA. La millora de l'aprenentatge s'hauria de traduir en un augment significatiu del percentatge d'aprovats a la fase selectiva que permetés capgirar la dinàmica de l'ETSETB en els darrers anys que ha sofert una davallada molt important d'estudiants matriculats. Aquesta davallada es va originar per una disminució de la demanda dels nostres estudis, la qual va provocar una baixada de la nota de tall que, a la seva vegada, va comportar un elevat fracàs a la fase selectiva.

Initial clinical experience with the admiral oxygenator combined with separated suction.

The Admiral, a new microporous membrane oxygenator with a low surface area, decreased priming volume and two separate reservoirs, was tested in 30 adult patients. This study was undertaken to evaluate blood path resistance, gas exchange capabilities and blood trauma in clinical use, with and without shed blood separation. Patients were divided into 3 groups. Group 1 had valve surgery without separation of suction, Group 2 had coronary artery bypass grafting (CABG) with direct blood aspiration and Group 3 had coronary artery bypass grafting with shed blood separation. The suctioned, separated, cardiotomy blood in Group 3 was treated with an autotransfusion device at the end of bypass before being returned to the patient. Theoretical blood flow could be achieved in all cases without problem. The pressure drop through the oxygenator averaged 88 +/- 13 mmHg at 4 l/min and 109 +/- 12 mmHg at 5 l/min. O(2) transfer was 163 +/- 27 ml/min. Free plasma haemoglobin rose in all groups, but significantly less in group 3. Lactate dehydrogenase (LDH) rose significantly in Groups 1 and 2. Platelets decreased in all groups without significant differences. Clinical experience with this new oxygenator was safe, the reduced membrane surface did not impair gas exchange and blood trauma could be minimized easily by separating shed blood, using the second cardiotomy reservoir.

Three Generation Family With Pattern Dystrophy and a Successful Treatment of Subfoveal Cnv Related to Pattern Dystrophy With Anti-vegf Intravitreal Injections

Purpose: To phenotype a large 3 generation Swiss family with pattern dystrophy and to report a successful result of treatment with ranibizumab of a subfoveal choroidal neovascularisation (CNV) associated with pattern dystrophy in 1 patient Patients and methods: 4 affected and 3 unaffected patients (3 female 4 male, age range: 19 - 80 years) were assessed with a complete ophthalmologic examination. AF images were taken using Heidelberg Retina Angiograph and the digital color photos, fluorescein angiogragraphy (FFA) using the same TOPCON 501 camera. Electroretinogram (full-field and multifocal) was performed in 1 affected patient. One 48 years old patient developed a subfoveal CNV, which was treated with 2 injections of ranibizumab, at 3 months interval. Blood sample was taken for molecular analysis (screening of the gene RDS). Results: Two patients had a typical fundoscopic appearance of pattern dystrophy with butterfly shaped deposit at the fovea and some peripheral flecks, as shown with AF imaging.. Two others affected patients had a more unusual appearance with some macular atrophy in one or both eyes, surrounded by flecks. The visual acuity ranged from 1.0 to 0.1 according to Snellen EDTRS chart. The patient with subfoveal CNV presented a drop of vision form 1.0 to 0.6 within 10 days prior to the diagnosis and also reported some metamorphopsia. FFA and optical computerized tomography (OCT) confirmed a classic CNV. After the 1st injection her vision improved to 1.0 but persistent metamorphopsia and fluid on OCT motivated a second injection. One month after the second injection the OCT was flat and the patient had no symptoms. The results of RDS screening will be presented at the meeting. Conclusion: We present a family with pattern dystrophy, with some members having an unusual fundus appearance, which was mistaken for an early onset dry AMD. The AF imaging is a useful tool in diagnosing this condition. A CNV associated with pattern dystrophy a rare. This is the first report of a successful treatment of the CNV with anti-VEGF intravitreal injections.

Impending status epilepticus and anxiety in a pregnant woman treated with levetiracetam.

Levetiracetam (LEV) has been considered to undergo no significant change in bioavailability during pregnancy; however, it was recently demonstrated to display modifications leading to a drop in its serum level. We describe a patient who displayed impending status epilepticus following a fall in her LEV level during the first trimester. The oral LEV dosage was increased, and phenytoin and benzodiazepines were transiently prescribed. She experienced severe anxiety and an unbearable fear over the deleterious consequences for her baby despite repeated, reassuring explanations. Her anxiety was so strong that she aborted electively shortly after leaving the hospital. This observation emphasizes the need for LEV level monitoring during pregnancy to prevent unexpected seizure relapses. The rapid increase in levetiracetam dosage in parallel with the loss of seizure control is suspected of facilitating the induction of significant psychiatric changes.