Will the reddit rebellion take you to the moon? Evidence from WallStreetBets.

In early 2021, several stocks receiving attention from retail traders known as "meme stocks" soared in value. A primary source of information regarding these stocks is from the social media platform Reddit, specifically from a subreddit known as WallStreetBets (WSB).This paper investigates whether a simple and easily implementable trading strategy following the WallStreetBets (WSB) subreddit can produce alpha. We document no evidence this is the case. Though we do observe a positive relation between WSB submissions and abnormal trading volume, we find that a portfolio that goes long buy recommendations and short sell recommendations each day is not profitable on a risk-adjusted basis. Holding periods from one day to one year fail to produce alpha. These findings are robust to a variety of different portfolio formation strategies. Our results provide an early look at the data following the explosion of interest in social media inspired retail investing.

Estudio biomecánico de resistencia en fémur porcino y predictibilidad de zona de fractura / Biomechanical study of porcine femur resistance and predictability of fracture zone

During everyday activities, bones are submitted to the action of different strengths. While walking, the femur must support loads up to 3 times the body weight. It is for this that the need of knowing the mechanical behavior of the femur submitted to different loads and the place where the fracture would occur is born. This study analyzes, through experimental testing, the maximum resistance of the porcine femur, mechanically comparable to the human femur, submitted to different strengths, to obtain the location of fracture and compare the results obtained with computational simulation and with information described for human femur.

Durante actividades de la vida diaria, los huesos se ven sometidos a la acción de diferentes fuerzas. En la marcha, el fémur debe soportar cargas de hasta 3 veces el peso corporal. Es por esto que nace la inquietud de conocer el comportamiento mecánico del fémur sometido a distintos tipos de cargas, y el lugar de falla donde se produciría una fractura. Este estudio analiza, mediante ensayo experimental, la resistencia máxima del fémur porcino, mecánicamente comparable al fémur humano, frente a distintas cargas, para obtener así el sitio de fractura y luego comparar los resultados obtenidos con simulación computacional y con datos descritos para el fémur humano.

Meta-analysis of the risk of venous thrombosis in individuals with antiphospholipid antibodies without underlying autoimmune disease or previous thrombosis.

Patients with systemic lupus erythematosus (SLE) and antiphospholipid antibodies (aPL) are at a greater risk for venous thromboembolism (VTE) than SLE patients without these antibodies. For patients without SLE there is a controversy about the risk associated with these antibodies and about their prognostic significance. We reviewed the degree of evidence and describe the odds ratio for VTE associated with aPL, namely the lupus anticoagulant (LA) and anticardiolipin antibodies (aCL), in patients without SLE. The study was a meta-analysis of seven observational studies of risk for antiphospholipid associated venous thromboembolism (VTE), excluding SLE patients. The strategies to identify published research included a computerized literature search and the review of citations in primarily relevant articles for the period 1983 to 1997. A summary of study characteristics and a critical appraisal of study quality were done. Summary odds ratios were obtained conducted using a random and a fixed effects-model. The overall odds ratio for aCL associated VTE obtained by fixed-effects model was 1.56 (95% CI, 1.10-2.24) and 1.64 (95% CI, 0.93-2.89) by random-effects model. The heterogeneity of these results appeared to be due in part to the detection limit of the aCL assay: the odds ratio was 3.21 (95% CI, 1.11-9.28) with both models when high titres only were considered. The overall odds ratio for LA associated VTE was 11.1 (95% CI, 3.81-32.3). In conclusion meta-analysis of the risk for antiphospholipid associated thrombosis demonstrated a higher risk in patients with the LA than in other patients. This risk was also higher than in patients with aCL even when high titres only were considered.

[Prevention of venous thrombosis: role of heparins]. / Prophylaxie de la thrombose veineuse: place des héparines.

Prevention of venous thromboembolism is of major importance because deep vein thrombosis is an economic burden. To prevent pulmonary embolism, whether fatal or not, and the postphlebitic syndrome, virtually all patients' level of risk should be assessed in order to provide adequate prophylactic measures against venous thromboembolism. Non-pharmacological, pharmacological or combined modalities can reduce the frequency of venous thrombosis. Evidence-based guidelines are available for most situations in surgical patients. However, in medical patients there are fewer data and there are wide variations of opinion. Systematic reviews should be performed and updated to obtain practice guidelines. Cost and effectiveness as well as patients' preferences should be taken into account. Randomized control trials are ongoing: low-molecular-weight heparins are being evaluated in general medical patients; other forms of prophylaxis or combined methods are also being investigated.

Risk for venous thrombosis related to antiphospholipid antibodies in systemic lupus erythematosus--a meta-analysis.

OBJECTIVE: To describe the relative risk for venous thrombosis (VT) associated with antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE). DESIGN: Systematic review and meta-analysis of 26 articles that examined the association between aPL and VT in SLE. SETTING: Mostly secondary and tertiary referral centres. PATIENTS: 2249 patients with SLE, 1120 tested for LA (lupus anticoagulant) and 1563 tested for aCL (anticardiolipin antibodies). MAIN OUTCOME MEASURES: A summary of study characteristics and a critical appraisal of study quality were done. Two statistical combinations of 18 primary studies that examined the association of VT and LA and of 14 studies that examined the association of VT and aCL were performed to estimate the risk for VT associated with aPL. RESULTS: The odds ratios of the risk of VT related to the LA summarized from 18 studies were 5.61 [95% CI; 3.80-8.27] overall, 6.32 [CI; 3.71-10.78] for deep venous thrombosis and pulmonary embolism, 11.6 [3.65-36.91] for recurrent venous thrombosis after the first event. The odds ratios of the risk of VT related to aCL summarized from 14 studies were 2.17 [95% CI; 1.51-3.11] overall, 2.50 [CI; 1.51-4.14] for deep venous thrombosis and pulmonary embolism, 3.91 [1.14-13.38] for recurrent venous thrombosis after the first event. CONCLUSIONS: Patients with SLE and LA are at approximately six times greater risk for VT than patients without LA, whereas patients with SLE and aCL are approximately two times greater risk for VT than patients without aCL. We have identified important methodologic limitations and differences in study characteristics. Other risk factors for VT have not been thoroughly evaluated in these studies. Further studies are needed that provide an accurate estimate of the absolute risk for aPL related VT.

Measurement of lymphatic flow variation by noninvasive method cases of lymphedema.

The purpose of this study was to measure the variations of lymphatic flow. A noninvasive isotopic method was used to achieve a functional exploration of lymphatic circulation. Fifteen subjects were used in the study: 10 healthy subjects and 5 patients with lower extremity lymphedema. A first subcutaneous injection of technetium 99m rhenium sulfate (99mTc) was performed in the first interdigital space of both feet. The radioactivity was recorded in two places: the first one on the inguinal site by a gamma camera; the second, below the first, on the precordial site by a multichannel analyzer. With the two types of recording procedures, it was possible to obtain a curve that showed the amount of radioactivity in relation to time. In order to obtain a muscular activity fifty-five minutes after the injection, each subject or patient spent ten minutes on an ergometric bike. A second subcutaneous injection was performed one week later, but prior to the injection, the subject or patient took orally 1800 mg of heptaminol adenosine phosphate (HAP) per day for three days. The radioactivity recording was made under the same conditions as with the muscular activity. The statistical results of the experiment without treatment on the two types of recording show that in the healthy subjects the amount of radioactivity increased during muscular activity. Moreover, the treatment indicated higher radioactivity values, which remained at a higher level. However, the muscular activity performed by a patient was unable to increase the radioactivity. On the other hand, the drug gave radioactivity values that were higher than the previous values of the first curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Levamisole in chronic lymphocytic leukaemia: a prospective study of 15 patients.

Several haematological and immunological parameters were studied before and after a 4-week trial of oral levamisole (300 mg/week) in 15 patients with chronic lymphocytic leukaemia. We found no statistically significant difference in the mean peripheral blood counts of total lymphocytes, E-rosette-forming lymphocytes, monocytes, polymorphonuclear neutrophils, eosinophils and platelets. Mean serum levels of IgG, IgA, IgM, IgD, C3 and C4 were not statistically affected by levamisole nor was the mean lymphocyte stimulation modified by various mitogens (phytohaemagglutinin, concanavalin A, pokeweed mitogen, tuberculin, candidin). The mean IgE level was statistically increased (p less than 0.05) after levamisole administration but remained below the normal upper limit. A high rate (46%) of clinical and haematological adverse reactions (1 patient developed thrombocytopenia) was associated with levamisole administration. These results suggest that levamisole, as given in this trial, has no obvious beneficial effect and cannot be recommended in patients with chronic lymphocytic leukaemia.

[Pulmonary intoxication by accidental inhalation of a household aerosol water repellent]. / Intoxication pulmonaire par l'inhalation accidentelle d'un produit domestique imperméabilisant présenté en aérosol.

Two young people, a 23 year man and his wife aged 21, are admitted in hospital because they complain of headache; nausea, dyspnea. These symptoms are related with the use of a water-reppellent spray in bad conditions; troubles appear because the product is used in an insufficiently ventilated room. At the admission time, the man suffers from coughing, polypnea, giddiness, the fever is 38 degrees, 3 C. The blood gas values are normal. The thoracic Xray is also normal. The woman is more affected the fever is 38,8 degrees C. The signs are worse and the blood value of Co is 5%. The blood gas values are: PO2 64,8 mm HG, SaO2 92,4%, PCO2 28,8 mm Hg. The chest Xray shows signs of acute pulmonary oedema. Corticoïds and furosemide give a progressive improvement. 48 h later a favorable evolution is noted in the two cases. The german manufacturer of the product gave its composition which is as follows: - petrol 17,3% - essence 15,3% - methylen chloride 13,7% - freon (trichlorofluoro-methane - dichlorofluoromethane) 42,2% - impregnant (melamine resin; organic methylic soap) 2,6% - propan butan 9,2%. The compound responsible for the symptomatology is petrol vapour which, if inhalated, is well known to produce pulmonary toxicity. The woman's condition was worse because she used the spray herself and therefore inhaled a lot a vapours. With this type of product the direction for use have to be strictly followed ie the operation must take place in a well ventilated room.

[Pericarditis as the presenting manifestation of acute monoblastic leukemia-Report of a case and review of the literature (author's transl)]. / Péricardite inaugurale d'une leucémie aiguë monoblastique. Description d'un cas et revue de la littérature.

A case of acute monoblastic leukemia in a 68-year-old man is reported in which one of the presenting manifestations was a pericardial effusion. A blood-stained fluid was removed from the pericardium. The pericardial fluid showed blast cells on microscopical examination. The patient was treated with 6-Mercaptopurine and Methotrexate and achieved a short partial remission. He died of general infection, 4 months after the start of his illness. We found in the medical literature 30 additional cases with a mean age of 24 +/- 16 years and a striking male predominance (68. p. 100). We found 15 acute lymphoid leukemias, 9 acute myeloid leukemias, 4 acute indifferentiated leukemias, and 2 acute nontyped leukemias. The leukemic pericardial involvement is often associated with splenomegaly, adenopathy and pleural effusion. The management procedures include pericardiocentesis, general of local chemotherapy, irradiation of the cardiac area. The prognosis is generally poor, with a mean survival of 5 months.