On the Reality of the Accelerating Universe

Two groups recently deduced the positive value for the cosmological constant, concluding at a high (>= 99%) confidence level that the Universe should be accelerating. This conclusion followed from the statistical analysis of dozens of high-redshift supernovae. In this paper this conclusion is discussed. From the conservative frequentist's point of view the validity of null hypothesis of the zero cosmological constant is tested by the classical statistical chi^2 test for the 60 supernovae listed in Perlmutter et al. 1999 (ApJ, 517, 565). This sample contains 42 objects discovered in the frame of Supernova Cosmology Project and 18 low-redshift object detected earlier. Excluding the event SN1997O, which is doubtlessly an outlier, one obtains the result: The probability for seeing a worse chi^2 - if the null hypothesis is true - is in the 5% to 8% range, a value that does not indicate significant evidence againts the null. If one excludes further five possible outliers, proposed to be done by Perlmutter et al. 1999, then the sample of 54 supernovae is in an excellent accordance with the null hypothesis. It also seems that upernovae from the High-z Supernova Search Team does not change the acceptance of null hypothesis. This means that the rejection of the Einstein equations with zero cosmological constant - based on the supernova data alone - is still premature.Comment: 11 pages, no figures, accepted for publication in Ap

On the Spectral Lags and Peak-Counts of the Gamma-Ray Bursts Detected by the RHESSI Satellite

A sample of 427 gamma-ray bursts from a database (February 2002 - April 2008) of the RHESSI satellite is analyzed statistically. The spectral lags and peak-count rates, which have been calculated for the first time in this paper, are studied completing an earlier analysis of durations and hardness ratios. The analysis of the RHESSI database has already inferred the existence of a third group with intermediate duration, apart from the so-called short and long groups. First aim of this article is to discuss the properties of these intermediate-duration bursts in terms of peak-count rates and spectral lags. Second aim is to discuss the number of GRB groups using another statistical method and by employing the peak-count rates and spectral lags as well. The standard parametric (model-based clustering) and non-parametric (K-means clustering) statistical tests together with the Kolmogorov-Smirnov and Anderson-Darling tests are used. Two new results are obtained: A. The intermediate-duration group has similar properties to the group of short bursts. Intermediate and long groups appear to be different. B. The intermediate-duration GRBs in the RHESSI and Swift databases seem to be represented by different phenomena.Comment: 41 pages, 10 figures, 9 tables, accepted to be published in The Astrophysical Journa

GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy

We propose to perform a continuously scanning all-sky survey from 200 keV to 80 MeV achieving a sensitivity which is better by a factor of 40 or more compared to the previous missions in this energy range. The Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS has its focus on the evolving, violent Universe, exploring a unique energy window. We propose to investigate $\gamma$-ray bursts and blazars, the mechanisms behind supernova explosions, nucleosynthesis and spallation, the enigmatic origin of positrons in our Galaxy, and the nature of radiation processes and particle acceleration in extreme cosmic sources including pulsars and magnetars. The natural energy scale for these non-thermal processes is of the order of MeV. Although they can be partially and indirectly studied using other methods, only the proposed GRIPS measurements will provide direct access to their primary photons. GRIPS will be a driver for the study of transient sources in the era of neutrino and gravitational wave observatories such as IceCUBE and LISA, establishing a new type of diagnostics in relativistic and nuclear astrophysics. This will support extrapolations to investigate star formation, galaxy evolution, and black hole formation at high redshifts.Comment: to appear in Exp. Astron., special vol. on M3-Call of ESA's Cosmic Vision 2010; 25 p., 25 figs; see also www.grips-mission.e

Caractérisation des périodes de sécheresse sur le domaine de l'Afrique simulée par le Modèle Régional Canadien du Climat (MRCC5)

Les conséquences des changements climatiques sur la fréquence ainsi que sur l'intensité des précipitations auront un impact direct sur les périodes de sécheresse et par conséquent sur différents secteurs économiques tels que le secteur de l'agriculture. Ainsi, dans cette étude, l'habilité du Modèle Régional Canadien du Climat (MRCC5) à simuler les différentes caractéristiques des périodes de sécheresse est évaluée pour 4 seuils de précipitation soit 0.5 mm, 1 mm, 2 mm et 3 mm. Ces caractéristiques incluent le nombre de jours secs, le nombre de périodes de sécheresse ainsi que le maximum de jours consécutifs sans précipitation associé à une récurrence de 5 ans. Les résultats sont présentés pour des moyennes annuelles et saisonnières. L'erreur de performance est évaluée en comparant le MRCC5 piloté par ERA-Interim aux données d'analyses du GPCP pour le climat présent (1997-2008). L'erreur due aux conditions aux frontières c'est-à-dire les erreurs de pilotage du MRCC5, soit par CanESM2 et par ERA-Interim ainsi que l'évaluation de la valeur ajoutée du MRCC5 face au CanESM2 sont également analysées. L'analyse de ces caractéristiques est également faite dans un contexte de climat changeant pour deux périodes futures, soit 2041-2070 et 2071-2100 à l'aide du MRCC5 piloté par le modèle de circulation générale CanESM2 de même que par le modèle CanESM2 sous le scénario RCP 4.5. Les résultats suggèrent que le MRCC5 piloté par ERA-Interim a tendance à surestimer la moyenne annuelle du nombre de jours secs ainsi que le maximum de jours consécutifs sans précipitation associé à une récurrence de 5 ans dans la plupart des régions de l'Afrique et une tendance à sous-estimer le nombre de périodes de sécheresse. En général, l'erreur de performance est plus importante que l'erreur due aux conditions aux frontières pour les différentes caractéristiques de périodes de sécheresse. Pour les régions équatoriales, les changements appréhendés par le MRCC5 piloté par CanESM2 pour les différentes caractéristiques de périodes de sécheresse et pour deux périodes futures (2041-2070 et 2071-2100), suggèrent une augmentation significatives du nombre de jours secs ainsi que du maximum de jours consécutifs sans précipitation associé à une récurrence de 5 ans. Une diminution significative du nombre de périodes de sécheresse est aussi prévue.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : Modèle Régional du Climat, Changement climatique, Jours secs, Nombre de périodes de sécheresse, Événement de faible récurrence, Afriqu

MIÉRT NEM LEGELTETIK A TEJELŐ TEHENEKET?

A magyar gyepgazdálkodás fejlesztése – a nyugat-európai színvonaltól elmara-dó részaránya és minősége következtében is – fontos feladat lenne, de a gazdál-kodók a tejelőállomány legelőre (is) alapozott takarmányozásában, a legeltetés gyakorlatának visszaállításában nem látnak jövőt. Legeltetést – a tejelő állomá-nyoknál – szinte csak a növendékek esetében alkalmaznak, jóllehet a gazdálkodók döntő hányada csatlakozott az egységes területalapú támogatás igénybevétele mellett valamelyik, a gyepterületeket, illetve gyephasználatot érintő célprog-ramhoz is. Véleményünk szerint a megoldást segítheti a magyar tarka fajta fel-karolása, illetve a húsmarhatartás. Tejelő tehenek legeltetésére a jó legelőkkel rendelkező, 20-30 tehenet tartó gazdaságok gondolhatnak. - Joining the European Union has opened up several new possibilities and challenges for farmers. One of these is grass farming and pasture feeding. Due to its low share and quality, the development of our grass farming is a very important task, because it doesn’t fulfil the role that it should. Farmers don’t realise the benefits of grassland-based feeding in the case of dairy cattle herds. Grazing is devoted only to young heifers. Nevertheless, nearly all of them have already joined various support programmes connected to grass farming or grassland usage. In their opinion the best solution would be Hungarian spotted cattle farming or beef cattle farming. Only the farmers with good pastures and 20-30 dairy cows can consider pasture feeding

Biological Inoculants in Forage Conservation

3rd generation biological inoculants –containing lactic acid bacteria and enzymes – are prefered nowadays in order to coordinate the fermentation in such a way that they increase lactic acid production by leaps and bounds at the beginning of the fermentation and improve the quality and stability of silage during the fermentation and feeding. The quality of raw material (maturity of plant, chop lenght, spreading of inoculant uniformly) and the proper filling, compacting, covering and wrapping have a great influence on the effectiveness of the inoculant. The mycotoxin content of malfermented silages is an undesirable risk factor. The authors established, that the  Lactobacillus buchneri and enzymes containing inoculant protected better the carotene content of low, medium- and high wilted lucerne haylages (P<0,05) compare to untreated ones Aerobic stability experiment by Honnig 1990 method was carried out with medium wilted (36 % DM) lucerne haylage which was treatedtreated before ensilage with , the dosage of 105 CFU/g Pediococcus acidilactici, 1,5x105 CFU/g Lactobacillus buchneri and cellulase and hemicellulase enzimes (20 000 CMC /g) remained stabyle, unspoiled after 9 days exposure to the air, while the untreated haylages spoiled after 2;4;or 7days on aerobic condition. The different Lactobacillus plantarum strains (50.000 CFU of Lactobacillus plantarum DSM 16568 + 50.000 CFU of Lactobacillus plantarum DSM 4784/ g FM of maize applied together were able to improve the aerobic stability of silomaize silage

MIÉRT NEM LEGELTETIK A TEJELŠTEHENEKET?

A magyar gyepgazdálkodás fejlesztése – a nyugat-európai színvonaltól elmara-dó részaránya és minÅ‘sége következtében is – fontos feladat lenne, de a gazdál-kodók a tejelőállomány legelÅ‘re (is) alapozott takarmányozásában, a legeltetés gyakorlatának visszaállításában nem látnak jövÅ‘t. Legeltetést – a tejelÅ‘ állomá-nyoknál – szinte csak a növendékek esetében alkalmaznak, jóllehet a gazdálkodók döntÅ‘ hányada csatlakozott az egységes területalapú támogatás igénybevétele mellett valamelyik, a gyepterületeket, illetve gyephasználatot érintÅ‘ célprog-ramhoz is. Véleményünk szerint a megoldást segítheti a magyar tarka fajta fel-karolása, illetve a húsmarhatartás. TejelÅ‘ tehenek legeltetésére a jó legelÅ‘kkel rendelkezÅ‘, 20-30 tehenet tartó gazdaságok gondolhatnak. - Joining the European Union has opened up several new possibilities and challenges for farmers. One of these is grass farming and pasture feeding. Due to its low share and quality, the development of our grass farming is a very important task, because it doesn’t fulfil the role that it should. Farmers don’t realise the benefits of grassland-based feeding in the case of dairy cattle herds. Grazing is devoted only to young heifers. Nevertheless, nearly all of them have already joined various support programmes connected to grass farming or grassland usage. In their opinion the best solution would be Hungarian spotted cattle farming or beef cattle farming. Only the farmers with good pastures and 20-30 dairy cows can consider pasture feeding.vidékfejlesztés, gyepgazdálkodás, szarvasmarhatartás, tejelÅ‘ szarvasmarha rural development, grass farming, cattle farming, dairy cows, Farm Management, Land Economics/Use, Livestock Production/Industries,