Non-Specific Pleuritis after Medical Thoracoscopy: A Prospective Study

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Reliability and validity of the Chester step test in patients with interstitial lung disease

BACKGROUND

The Chester Step Test (CST) is a simple and inexpensive field test, which requires minimal physical space to assess exercise capacity. Such characteristics make the CST suitable to be used in different settings, however, its measurement properties in patients with interstitial lung diseases (ILD) are unknown.

METHODS

A cross-sectional study was conducted in patients with ILD. First, a CST-1 and a 6-minute walk test (6MWT) were performed. After 48-72 hours, a CST-2 was repeated. A 2nd rater was present in one of the sessions. Relative reliability was measured using intraclass correlation coefficient (ICC1,1 and ICC2,1). Absolute reliability was determined using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95) and the Bland-Altman method. The values of SEM and MDC95 were also expressed as a percentage of the mean. Construct validity was explored using Spearman correlation coefficient (rs) between the number of steps taken in the best CST and the distance performed in the 6MWT.

RESULTS

Sixty-six patients with ILD (65.5±12.9 years; 48.5%men; FVC 79.4±18.8pp; DLCO 49.0±18.3pp) participated in the study. Relative (ICC 0.95-1.0) and absolute reliability were excellent without evidence of systematic bias. The SEM and MDC95 were 11.8 (14.7%) and 32.6 steps (40.7%), respectively. The correlation between CST and 6MWT was significant, positive, and high (rs=0.85, p=0.001).

CONCLUSION

The CST is a reliable and valid test and might be especially useful to assess exercise capacity in patients with ILD in limited space environments.

Awareness towards the main ILD among primary care physicians

Background: Interstitial lung diseases (ILDs) comprise a group of multiple entities sharing some clinical, functional and radiological similarities. In many countries primary care setting has been devoid of pre- and post-graduate educational interventions focused on basic knowledge on ILD. This, along with usual nonspecificity of symptoms at presentation, may contribute to diagnostic delay in this disease setting.Methods: We designed a study questionnaire to assess the level of awareness on basic diagnostic and management aspects of core ILDs – idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis, sarcoidosis, connective tissue disease related-ILD and drug-induced ILD - among primary care physicians (GPs) from five “ACeS Baixo Vouga” health centres and to perceive possible weaknesses. Differences in awareness between GPs under 45 and over 45 years-old were also assessed.Results: Globally, 69% of questions were correctly answered but only 21.9% of GPs considered to have a satisfactory self-perceived level of knowledge on ILD. Except sarcoidosis (p=0.017) and some isolated questions on other diseases, no significant differences were found between physicians below 45 years and above. Though, there was a trend to higher awareness in the younger group. The best awareness was seen in sarcoidosis. IPF questions had the worst performance and only 48.5% of GPs recognized the importance of velcro-type crackles in suggesting a possible diagnosis.Conclusion: Specific attention should be devoted to educational interventions directed to GPs on basic notions on the main ILDs. This could improve the usual diagnostic delay in many ILDs, as a timely diagnosis is essential for an early treatment and prolonged patient survival.

Myopathy associated with anti-signal recognition particle antibodies with pulmonary involvement and response to rituximab

The authors present the case of a 76-year-old female patient with progressive decrease in proximal muscle strength, fatigue, dyspnea, diffuse hand edema and painful triphasic Raynaud's phenomenon. Anti-SRP and anti-SSA antibodies were detected, muscle biopsy revealed changes consistent with necrotizing myopathy and capillaroscopy had findings compatible with systemic sclerosis. High-resolution chest computed tomography revealed interstitial lung disease with a non-specific interstitial pneumonia pattern. Lung function tests demonstrated a forced vital capacity 93% and a diffusing capacity for carbon monoxide of 65% predicted. After multidisciplinary discussion, she was diagnosed with immune-mediated necrotizing myopathy/systemic sclerosis overlap syndrome with pulmonary involvement. Initially, dual immunomodulation therapy with high-dose steroids and intravenous immunoglobulin was started, but after 4 weeks, the patient had clinical and analytical deterioration. At this time, she was started on rituximab, with an excellent and sustained response at both muscle and lung, sustained after 12 months.

A baseline evaluation of PAH body burden in sardines from the southern Brazilian shelf

The concentrations of 37 polycyclic aromatic hydrocarbons (PAHs) and their potential risk to human health were determined in fifty sardine muscle (Sardinella brasiliensis) samples collected along the southern Brazilian shelf. Parental and alkylated PAHs were identified and quantified using a pressurized liquid extraction with in-cell purification method and gas chromatography-mass spectrometry identification and quantification. The concentrations of Σ37 PAHs in muscle ranged between 6.02 and 4074 μg kg^-1 wet weight, which are comparable to levels reported for commercially important fish worldwide. The most abundant compounds were pyrene and fluoranthene, which originate from both petrogenic and pyrolytic hydrocarbon inputs. In only 4% of the samples the benzo[a] pyrene equivalent concentration was above the threshold of 6 μg kg^-1 suggested for safe fish consumption in Brazil. These findings will serve as baseline data for monitoring the quality of sardines consumed in the country and for studying fish populations.

Strong Constraints on Cosmological Gravity from GW170817 and GRB 170817A

The detection of an electromagnetic counterpart (GRB 170817A) to the gravitational-wave signal (GW170817) from the merger of two neutron stars opens a completely new arena for testing theories of gravity. We show that this measurement allows us to place stringent constraints on general scalar-tensor and vector-tensor theories, while allowing us to place an independent bound on the graviton mass in bimetric theories of gravity. These constraints severely reduce the viable range of cosmological models that have been proposed as alternatives to general relativistic cosmology.

Saturated salt solution: a further step to a formaldehyde-free embalming method for veterinary gross anatomy

In the field of veterinary anatomy, most of the specimens used in practical sessions are perfused with fixatives. Thus, they can be used for a longer time_, reducing the number of animals for educational purposes. Formalin is the most commonly used fixative, consisting of a 37% formaldehyde solution. However, formaldehyde is a powerful irritant of the eyes and airways and is considered carcinogenic, causing nasopharyngeal cancer in exposed workers and professionals. In the present study, we explored an alternative method to avoid the use of formaldehyde in specimens used for gross anatomy practical sessions. We propose an inexpensive, non-toxic fixative that is available worldwide, such as sea salt. This method consists of a continuous perfusion of saturated salt solution for a period of 6-8 h, enabling drainage of the solution to avoid a weight increase of the specimen, and allowing salt to be retained in the tissue. The method is based on recirculation of the saturated salt solution instead of maceration. Perfused specimens retained their natural consistency and joint mobility, with no blood, resembling a piece of meat from the slaughterhouse. They could be used immediately without a maceration period, or stored in the fridge until use and then kept in a bath of saturated salt solution for future conservation. In the case of the former, no refrigeration was needed. The specimens did not have an irritating or offensive smell, and could be used for long sessions (several hours per day) and stored for long periods. However, the blood vessels used for perfusion determine the results: a less invasive approach (through common carotid arteries) gave good preservation of the musculoskeletal system, whereas more invasive access to cannulate the abdominal aorta and vena cava caudalis was required to achieve better preservation of the viscera. In conclusion, we propose that perfusion followed by immersion in a saturated salt solution is a good alternative method for the preservation of specimens used in the practical teaching of gross veterinary anatomy. It is a very simple and inexpensive technique, and is much healthier for users than traditional formalin. Moreover, specimens can be preserved for prolonged periods, and maintain a similar appearance and consistency to fresh material.

Simultaneous interstitial pneumonitis and cardiomyopathy induced by venlafaxine

Venlafaxine is a serotonin-norepinephrine reuptake inhibitor used as an antidepressant. Interindividual variability and herb-drug interactions can lead to drug-induced toxicity. We report the case of a 35-year-old female patient diagnosed with synchronous pneumonitis and acute cardiomyopathy attributed to venlafaxine. The patient sought medical attention due to dyspnea and dry cough that started three months after initiating treatment with venlafaxine for depression. The patient was concomitantly taking Centella asiatica and Fucus vesiculosus as phytotherapeutic agents. Chest CT angiography and chest X-ray revealed parenchymal lung disease (diffuse micronodules and focal ground-glass opacities) and simultaneous dilated cardiomyopathy. Ecocardiography revealed a left ventricular ejection fraction (LVEF) of 21%. A thorough investigation was carried out, including BAL, imaging studies, autoimmune testing, right heart catheterization, and myocardial biopsy. After excluding other etiologies and applying the Naranjo Adverse Drug Reaction Probability Scale, a diagnosis of synchronous pneumonitis/cardiomyopathy associated with venlafaxine was assumed. The herbal supplements taken by the patient have a known potential to inhibit cytochrome P450 enzyme complex, which is responsible for the metabolization of venlafaxine. After venlafaxine discontinuation, there was rapid improvement, with regression of the radiological abnormalities and normalization of the LVEF. This was an important case of drug-induced cardiopulmonary toxicity. The circumstantial intake of inhibitors of the CYP2D6 isoenzyme and the presence of a CYP2D6 slow metabolism phenotype might have resulted in the toxic accumulation of venlafaxine and the subsequent clinical manifestations. Here, we also discuss why macrophage-dominant phospholipidosis was the most likely mechanism of toxicity in this case.

Urinothorax as an unusual type of pleural effusion - clinical report and review

BACKGROUND

Despite the fact that there are a great number of established etiologies for pleural effusion, there are grounds for believing that there are also causes from unusual pathophysiological mechanisms, seen in certain clinical contexts and from potential iatrogenic interventions. Urinothorax is such a rare type of pleural effusion as there are fewer than 70 cases reported worldwide.

CLINICAL CASE

A patient with a persistent left pleural effusion was admitted to the Urology ward for a lithiasic obstructive uropathy with hydronephrosis. A left percutaneous nephrostomy was performed. The effusion was unclassified at the initial workup and recurred after first drainage. A second approach confirmed a citrine fluid with borderline criteria for exudate, ammoniacal odour and an elusive pleural fluid-to-serum creatinine ratio. A retroperitoneal urinoma was recognized on CT, and the patient underwent a left nephrectomy with resolution of the pleural effusion.

CONCLUSIONS

Urinothorax most frequently develops in patients with excretory uropathy or blunt abdominal trauma, although other mechanisms have been reported. Traditionally, a pleural fluid to serum creatinine ratio higher than one is a hallmark of this condition. In certain settings, taking this diagnosis into account at an early stage might be crucial for a good outcome.

[Acute onset pulmonary toxicity associated to amiodarone]

Amiodarone is a potent anti-arrhythmic drug with a well-known potential chronic pulmonary toxicity. We describe a case of acute pulmonary toxicity (APT) induced by amiodarone in a 57 year old patient submitted to a perfusion of 900 mg in just 6 hours, to control an auricular flutter with rapid ventricular response. During the administration, the patient developed hemodynamic instability and oxygen dessaturation that led to an electrical cardioversion with return of sinus rhythm. Still, the patient continued in progressive respiratory deterioration with acute bilateral infiltrates on chest x-ray and apparent normal cardiac filling pressures confirmed by echocardiography. Anon-cardiogenic pulmonar edema progressing to clinico-physiological ARDS criteria was diagnosed. Expeditive therapeutic measures were undertaken, namely by initiation of non-invasive positive airway pressure support, that attained a good result.Albeit rare, amiodarone-induced APT might have severe consequences, namely progression to ALI/ARDS with a high mortality index.As it is a frequently prescribed drug, there should be a high clinical suspicion towards this phenomenon, allowing precocious therapeutic measures to be taken in a timely fashion to prevent the associated unfavorable outcome.

Constraining Lorentz violation with cosmology

The Einstein-aether theory provides a simple, dynamical mechanism for breaking Lorentz invariance. It does so within a generally covariant context and may emerge from quantum effects in more fundamental theories. The theory leads to a preferred frame and can have distinct experimental signatures. In this Letter, we perform a comprehensive study of the cosmological effects of the Einstein-aether theory and use observational data to constrain it. Allied to previously determined consistency and experimental constraints, we find that an Einstein-aether universe can fit experimental data over a wide range of its parameter space, but requires a specific rescaling of the other cosmological densities.

Adult rabbits acquire resistance to lethal calicivirus infection by adoptive transfer of sera from infected young rabbits

Calicivirus infection of adult rabbits induces the so-called rabbit haemorrhagic disease (RHD) that kills 90% or more of the infected animals; in contrast, young rabbits (up to 8-week-old animals) are resistant to the same infectious agent. We report that calicivirus inoculation of young rabbits induced moderate titres of antiviral antibodies. When these rabbits reached adulthood, a second calicivirus inoculation resulted in resistance to RHD and boosting of antibody titres in half of the rabbits. Adoptive transfer of sera from calicivirus-infected young rabbits to naïve adult rabbits conferred resistance to RHD. We conclude that calicivirus infection of young rabbits induces specific anti-calicivirus antibodies that will protect them from RHD when they reach adulthood.

Liver disease in young rabbits infected by calicivirus through nasal and oral routes

Calicivirus infection causes rabbit haemorrhagic disease (RHD) that kills more than 90% of adult animals, whereas young rabbits are naturally resistant to this viral disease. It has been proposed that the different response of adult and young rabbits to calicivirus infection is due to absence of viral receptors in respiratory and digestive systems of young animals. We have searched for liver disease in 4-week-old rabbits inoculated with a calicivirus suspension by intranasal and oral routes. These young rabbits showed cell damage and mononuclear infiltration of the liver. The hepatic lesions were associated with mild to moderate increase in circulating transaminases. We conclude that the previously reported reduction of viral receptors in the epithelium of respiratory and digestive systems of young rabbits does not inhibit calicivirus from inducing liver disease in these hosts.

Severe leukopenia and liver biochemistry changes in adult rabbits after calicivirus infection

Calicivirus infection is the major cause of the severe decrease in the stocks of wild and farm rabbits that has occurred worldwide during the last two decades. Adult rabbits (10-weeks-old) were experimentally infected with a calicivirus inoculum that killed all animals by causing rabbit haemorrhagic disease (RHD) within 24-62 h of infection. The rabbits were used to evaluate blood cell numbers and serum biochemistry every 6h, starting 12h after the inoculation of the caliciviruses. No significant changes in blood parameters were observed in most of the rabbits up to 18 h of infection. Severe leukopenia was seen 6h before death of the infected rabbits; both heterophils and lymphocytes contributed to the decrease in circulating white blood cells. Platelets were also severely decreased in number. Marked enhancement in liver enzymes was seen 6-12 h before death of the infected rabbits. There was also evidence both for cholestasis, as expressed by the elevated levels of direct (conjugated) bilirubin, and for hypoglycemia, an alteration that it is likely to contribute for the seizures that rabbits show during the late stages of RHD. Liver ultrastructure of rabbits that died from RHD revealed extensive hepatocyte vacuolization, severe changes in mitochondrial structure, and depletion of glycogen granules. We conclude that: (i) severe leukopenia characterizes the final hours of calicivirus-induced RHD; (ii) hypoglycemia and cholestasis precede death of rabbits from RHD; (iii) the kinetics of liver enzymes allows an accurate prediction of the time of death of rabbits from calicivirus-induced RHD.

Liver enzymes and ultrastructure in rabbit haemorrhagic disease (RHD)

Rabbit haemorrhagic disease (RHD) is caused by a calicivirus infection that kills most adult rabbits 24-72 h after viral inoculation. Two liver enzymes (AST, aspartate aminotransferase, and ALT, alanine aminotransferase) were monitored in blood samples of calicivirus-infected rabbits during the short course of RHD. Values of AST were used to differentiate three stages of hepatocellular degeneration in RHD: mild (up to 20-fold increase in AST), moderate (150-200-fold elevation of AST) and severe (more than 1000-fold elevation in AST). Liver samples of rabbits from these three biochemical stages of hepatocellular degeneration of RHD were studied by transmission electron microscopy to define the fine structure of the hepatocytes. In the mild hepatocellular degeneration there was proliferation (microvesiculation) of the smooth endoplasmic reticulum and swelling of mitochondria into spheroid bodies with loss of cristae. In moderate hepatocellular degeneration, vacuolization of cytoplasm and mitochondrial damage continued to be present, and there was also formation of autophagic vesicles. In the severe hepatocellular degeneration of RHD, the altered mitochondria also showed loss of density of their matrix; rupture of cytoplasmic vacuoles led to the formation of large vesicles. Marked depletion of liver glycogen was also found in this late stage of RHD. These data offer a correlation between biochemical and cytological features of the liver during the hepatocellular degeneration of RHD.

Large scale structure in Bekenstein's theory of relativistic modified Newtonian dynamics

A relativistic theory of modified gravity has been recently proposed by Bekenstein. The tensor field in Einstein's theory of gravity is replaced by a scalar, a vector, and a tensor field which interact in such a way to give modified Newtonian dynamics (MOND) in the weak-field nonrelativistic limit. We study the evolution of the Universe in such a theory, identifying its key properties and comparing it with the standard cosmology obtained in Einstein gravity. The evolution of the scalar field is akin to that of tracker quintessence fields. We expand the theory to linear order to find the evolution of perturbations on large scales. The impact on galaxy distributions and the cosmic microwave background is calculated in detail. We show that it may be possible to reproduce observations of the cosmic microwave background and galaxy distributions with Bekenstein's theory of MOND.

Measuring the geometry of the universe in the presence of isocurvature modes

The cosmic microwave background (CMB) anisotropy constrains the geometry of the Universe because the positions of the acoustic peaks of the angular power spectrum depend strongly on the curvature of three-dimensional space. In this Letter we exploit current observations to determine the geometry in the presence of isocurvature modes. Most previous analyses assumed that the primordial perturbations were adiabatic. A priori one might expect that allowing isocurvature modes would substantially degrade constraints on the curvature. We find, however, that with additional data sets, the geometry remains well constrained. When the most general isocurvature perturbation is allowed, the CMB alone can only poorly constrain the geometry to . Including large-scale structure data, one obtains Ohm(0) = 1.07 +/- 0.03, and 1.06 +/- 0.02 when supplemented by supernova data and the determination of H(0).

Leukocyte-hepatocyte interaction in calicivirus infection: differences between rabbits that are resistant or susceptible to rabbit haemorrhagic disease (RHD)

Calicivirus infection is lethal for adult rabbits, whereas young rabbits (less than 8-weeks-old) are resistant to the same infectious agent. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to rabbit haemorrhagic disease (RHD); this is in contrast with the mild and transient hepatitis observed in infected young rabbits. We have used electron microscopy to compare liver leukocyte infiltrates between young (resistant) and adult (susceptible) rabbits, 36-48 h after inoculation of the animals with caliciviruses. In adult rabbits, liver infiltrates were made up mostly of heterophils, and they were located near hepatocytes showing severe cellular damage. In contrast, liver leukocyte infiltrates of RHD-resistant young rabbits were dominated by lymphocytes that depicted membrane contacts with the cell surface of undamaged hepatocytes. We conclude that: (i) the cellular inflammatory response of the liver to calicivirus infection is different in rabbits that are susceptible (adult) or resistant (young) to RHD; (ii) leukocyte infiltration of the adult liver by heterophils is probably directed at the removal of dead hepatocytes, whereas the liver lymphocytic infiltration of young rabbits suggests the expression of viral antigens on the surface of liver cells of the RHD-resistant animals.

Initial conditions of the universe: how much isocurvature is allowed?

We investigate the constraints imposed by current data on correlated mixtures of adiabatic and nonadiabatic primordial perturbations. We discover subtle flat directions in parameter space that tolerate large (approximately 60%) fractions of nonadiabatic fluctuations. In particular, larger values of the baryon density and a spectral tilt are allowed. The cancellations in the degenerate directions are explored and the role of priors is elucidated.

Transient decrease in blood heterophils and sustained liver damage caused by calicivirus infection of young rabbits that are naturally resistant to rabbit haemorrhagic disease

Young rabbits are naturally resistant to rabbit haemorrhagic disease (RHD) caused by the same calicivirus that kills, within 3 days, nearly all adult animals. We have investigated changes in blood leukocytes, and in the morphology and biochemistry of the liver (the organ where caliciviruses replicate) of young rabbits undergoing benign infection by the RHD virus. Four-week-old rabbits were infected with a calicivirus inoculum having a titre of 2(12) haemagglutination units either sacrificed 18, 24, 48 and 72 h later, or kept for follow-up studies up to 21 days after inoculation. The infection caused an acute and transient decrease in blood heterophils, and sustained enhancement in hepatic transaminases. Inflammatory infiltrates of the liver were seen in all animals after 24 h of infection; they had a predominant midlobular location. Hepatocytes could present different degrees of cell damage, including cell death; these lesions were limited to the liver cells located around the inflammatory infiltrates. Liver transaminases peaked 24-48 h after calicivirus infection; this was the same timing when liver infiltration and hepatocyte damage were more evident. No alterations of other parameters of liver biochemistry were observed. We conclude that calicivirus infection of young rabbits causes a subclinical disorder characterised by an acute and transient decrease in circulating heterophils, and focal liver damage that is expressed by intralobular infiltration by heterophils, initially, and, later on, by mononuclear cells. Our finding of persistence of increased values of liver transaminases suggests chronicity of the infection in young rabbits. We propose that, although resistant to RHD, young rabbits infected by calicivirus may be long-term carriers of the infectious agent and, thus, become a major source of transmission of the virus.

Bulging mesothelial cells of the visceral pleura of the rat mimic the network of subpleural lymphatics

The mesothelial surface of the visceral pleura of the Wistar rat was viewed at high resolution by scanning electron microscopy (SEM). The pleural surface showed exquisite linear arrangements made up of bulging mesothelial cells. They were organized in irregular circles that often presented anastomotic junctures. This arrangement of pleural mesothelial cells mimics the organization of subpleural lymphatics of the lung. A low density of microvilli was seen inside the irregular circles, contrasting with the microvilli-rich mesothelial cells seen on or outside these arrangements. These SEM features of the mesothelium may be related with the formation of microdomains for fluid absorption across the visceral pleura into subpleural lymphatics.

Estimate of the cosmological bispectrum from the MAXIMA-1 cosmic microwave background map

We use the measurement of the cosmic microwave background taken during the MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We propose an estimator for the bispectrum that is appropriate in the flat sky approximation, apply it to the MAXIMA-1 data, and evaluate errors using bootstrap methods. We compare the estimated value with what would be expected if the sky signal were Gaussian and find that it is indeed consistent, with a chi(2) per degree of freedom of approximately unity. This measurement places constraints on models of inflation.

Tests for Gaussianity of the MAXIMA-1 cosmic microwave background map

Gaussianity of the cosmological perturbations is one of the key predictions of standard inflation, but it is violated by other models of structure formation such as cosmic defects. We present the first test of the Gaussianity of the cosmic microwave background (CMB) on subdegree angular scales, where deviations from Gaussianity are most likely to occur. We apply the methods of moments, cumulants, the Kolmogorov test, the chi(2) test, and Minkowski functionals in eigen, real, Wiener-filtered, and signal-whitened spaces, to the MAXIMA-1 CMB anisotropy data. We find that the data, which probe angular scales between 10 arcmin and 5 deg, are consistent with Gaussianity. These results show consistency with the standard inflation and place constraints on the existence of cosmic defects.

Cosmology from MAXIMA-1, BOOMERANG, and COBE DMR cosmic microwave background observations

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE DMR, provide consistent and high signal-to-noise measurements of the cosmic microwave background power spectrum at spherical harmonic multipole bands over 2<l less similar to 800. Analysis of the combined data yields 68% (95%) confidence limits on the total density, Omega(tot) approximately 1.11+/-0.07 (+0.13)(-0.12), the baryon density, Omega(b)h(2) approximately 0.032(+0.005)(-0.004) (+0.009)(-0.008), and the scalar spectral tilt, n(s) approximately 1.01(+0.09)(-0.07) (+0.17)(-0.14). These data are consistent with inflationary initial conditions for structure formation. Taken together with other cosmological observations, they imply the existence of both nonbaryonic dark matter and dark energy in the Universe.

A Measurement of Omega from the North American Test Flight of Boomerang

We use the angular power spectrum of the cosmic microwave background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe. Within the class of cold dark matter models, we find that the overall fractional energy density of the universe Omega is constrained to be 0.85</=Omega</=1.25 at the 68% confidence level. Combined with the COBE measurement, the data on degree scales from the Microwave Anisotropy Telescope in Chile, and the high-redshift supernovae data, we obtain new constraints on the fractional matter density and the cosmological constant.

Measurement of a Peak in the Cosmic Microwave Background Power Spectrum from the North American Test Flight of Boomerang

We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 0&fdg;3 to 5 degrees from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system in 1997, we mapped more than 200 deg(2) at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26&arcmin; and 16&farcm;5 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1 degrees with an amplitude 70 µK(CMB).

Evidence for a low-density universe from the relative velocities of galaxies

The motions of galaxies can be used to constrain the cosmological density parameter Omega and the clustering amplitude of matter on large scales. The mean relative velocity of galaxy pairs, estimated from the Mark III survey, indicates that Omega = 0.35(-0.25)(+0.35). If the clustering of galaxies is unbiased on large scales, Omega = 0. 35 +/- 0.15, so that an unbiased Einstein-de Sitter model (Omega = 1) is inconsistent with the data.