New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMA... more New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMATSU company, tested, selected and installed in the DAMA/LIBRA set-up at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. In this paper the results obtained in the measurements of various features of these high Q.E. PMTs are reported, and some performances of DAMA/LIBRA in this new configuration
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
The main features of the low background DAMA pure liquid xenon scintillator set-up running deep u... more The main features of the low background DAMA pure liquid xenon scintillator set-up running deep underground in the Gran Sasso National Laboratory of the INFN are described. r
Journal of Clinical Monitoring and Computing, 2014
The gold standard methods to measure cardiac output (CO) are invasive and expose the patient to h... more The gold standard methods to measure cardiac output (CO) are invasive and expose the patient to high risks of various complications. The aim of this study is to assess an innovative non-invasive method for CO monitoring in mechanically ventilated patients after cardiac surgery and its agreement with values obtained by thermodilution technique. Continuous monitoring of respiratory gas concentrations and airflow allows the estimation of CO through a newly developed algorithm derived from a modified version of the Fick equation. It consists of two phases: the first involves measurements during steady breathing state, and the second starts when a sudden perturbation into the carbon dioxide elimination process is introduced by a prolonged expiration. This prospective clinical study involved thirty-five adult patients, undergone cardiac surgery. The measurements were performed in curarized and haemodynamically stable patients, during the post-surgery recovery in intensive care unit. The study protocol, which lasted 1 h for each patient, consisted of 20 measurements obtained by prolonged expiration-based method and 10 by thermodilution. The estimation of CO using the proposed method (COK) agreed with the thermodilution (COT) as demonstrated by: a low mean bias between COK and COT considering all patients (i.e., -0.11 L min(-1)); a best fitting line having slope = 0.98, r = 0.81, p < 0.0001; the lower and upper limits of agreement were -0.77 and +0.54 L min(-1), respectively. COK shows a mean percentage error of 34 %. In stable mechanically ventilated patients, undergone cardiac surgery, the proposed method is reliable if compared to the thermodilution. Considering the non-invasivity of the technique, further evaluations of its performances are encouraged.
New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMA... more New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMATSU company, tested, selected and installed in the DAMA/LIBRA set-up at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. In this paper the results obtained in the measurements of various features of these high Q.E. PMTs are reported, and some performances of DAMA/LIBRA in this new configuration
Propensityscoremethodsareanincreasinglypopulartechniqueforcausal inference. To estimate propensit... more Propensityscoremethodsareanincreasinglypopulartechniqueforcausal inference. To estimate propensity scores, we must model the distribution of the treat- mentindicatorgivenavectorofcovariates.Muchworkhasbeendoneinthecasewhere the covariates are fully observed. Unfortunately, many large scale and complex sur- veys, such as longitudinal surveys, suffer from missing covariate values. In this paper, we compare three different approaches and their underlying assumptions of handling missing background data in the estimation and use of
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998
We present a full-scale MDT prototype for the Atlas muon spectrometer. The chamber consists of tw... more We present a full-scale MDT prototype for the Atlas muon spectrometer. The chamber consists of two multilayers made of three layers of 96 drift tubes each. The main feature of this chamber is the very accurate mechanical construction (20 m accuracy on single wire positioning) together with a very good individual tube spatial resolution. In this paper we present results both on the mechanical accuracy of the chamber, and on the performances obtained on the H8 test beam at CERN. In particular, we present an autocalibration method that allows to obtain the space-to-time relation of the tubes with a systematic error less than 20 m, the space resolution and the efficiency of the chamber.
This study analyzes the effect of weather variables, such as solar radiation, indoor and outdoor ... more This study analyzes the effect of weather variables, such as solar radiation, indoor and outdoor air temperature, relative humidity and time spent outdoor, on the behavior of 2-year-old children and their affects across different seasons: winter, spring and summer. Participants were a group of 61 children (33 males and 28 females) attending four day-care centers in Florence (Central Italy). Mean age of children at the beginning of the study was 24.1 months (SD03.6). We used multilevel linear analyses to account for the hierarchical structure of our data. The study analyzed the following behavioral variables: Activity Level, Attentional Focusing, Frustration, and Aggression. Results showed a different impact of some weather variables on children's behavior across seasons, indicating that the weather variable that affects children's behavior is usually the one that shows extreme values during the studied seasons, such as air temperature and relative humidity in winter and summer. Studying children and their reactions to weather conditions could have potentially wide-reaching implications for parenting and teaching practices, as well as for researchers studying social relationships development.
We consider a new approach to identify the causal effects of a binary treatment when the outcome ... more We consider a new approach to identify the causal effects of a binary treatment when the outcome is missing on a subset of units and dependence of nonresponse on the outcome cannot be ruled out even after conditioning on observed covariates. We provide sufficient conditions under which the availability of a binary instrument for nonresponse allows us to derive tighter identification intervals for causal effects in the whole population and to partially identify causal effects in some latent subgroups of units, named Principal Strata, defined by the nonresponse behavior in all possible combinations of treatment and instrument. A simulation study is used to assess the benefits of the presence versus the absence of an instrument for nonresponse. The simulation design is based on real health data, coming from a randomized trial on breast self-examination (BSE) affected by a large proportion of missing outcome data. An instrument for nonresponse is simulated considering alternative scenarios to discuss the key role of the instrument for nonresponse in identifying average causal effects in presence of nonignorable missing outcomes. We also investigate the potential inferential gains from using an instrument for nonresponse adopting a Bayesian approach for inference. In virtue of our theoretical and empirical results, we provide some recommendations on study designs for causal inference.
The influence of an extremely low frequency (ELF) magnetic field (50 Hz and 1 mT, EMF) on the act... more The influence of an extremely low frequency (ELF) magnetic field (50 Hz and 1 mT, EMF) on the activity of a soluble and insoluble horseradish peroxidase (E.C. 1.11.17) has been studied as a function of time. Insoluble derivatives were obtained by enzyme entrapment into two different gelatin membranes or by covalent attachment of the enzyme on two nylon membranes, differently preactivated. Results have shown that the field affects the inactivation rate of the soluble enzyme, while no effects are observed with insoluble derivatives. Since in vivo enzymes are immobilised into the biomembrane bilayer or entrapped into the cytoplasmic mixture, one might speculate that our experimental conditions do not reflect the catalytic activity of the enzymes in vivo.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2008
The ≃ 250 kg highly radiopure NaI(Tl) DAMA/LIBRA apparatus, running at the Gran Sasso National La... more The ≃ 250 kg highly radiopure NaI(Tl) DAMA/LIBRA apparatus, running at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N., is described.
New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMA... more New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMATSU company, tested, selected and installed in the DAMA/LIBRA set-up at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. In this paper the results obtained in the measurements of various features of these high Q.E. PMTs are reported, and some performances of DAMA/LIBRA in this new configuration
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
The main features of the low background DAMA pure liquid xenon scintillator set-up running deep u... more The main features of the low background DAMA pure liquid xenon scintillator set-up running deep underground in the Gran Sasso National Laboratory of the INFN are described. r
Journal of Clinical Monitoring and Computing, 2014
The gold standard methods to measure cardiac output (CO) are invasive and expose the patient to h... more The gold standard methods to measure cardiac output (CO) are invasive and expose the patient to high risks of various complications. The aim of this study is to assess an innovative non-invasive method for CO monitoring in mechanically ventilated patients after cardiac surgery and its agreement with values obtained by thermodilution technique. Continuous monitoring of respiratory gas concentrations and airflow allows the estimation of CO through a newly developed algorithm derived from a modified version of the Fick equation. It consists of two phases: the first involves measurements during steady breathing state, and the second starts when a sudden perturbation into the carbon dioxide elimination process is introduced by a prolonged expiration. This prospective clinical study involved thirty-five adult patients, undergone cardiac surgery. The measurements were performed in curarized and haemodynamically stable patients, during the post-surgery recovery in intensive care unit. The study protocol, which lasted 1 h for each patient, consisted of 20 measurements obtained by prolonged expiration-based method and 10 by thermodilution. The estimation of CO using the proposed method (COK) agreed with the thermodilution (COT) as demonstrated by: a low mean bias between COK and COT considering all patients (i.e., -0.11 L min(-1)); a best fitting line having slope = 0.98, r = 0.81, p < 0.0001; the lower and upper limits of agreement were -0.77 and +0.54 L min(-1), respectively. COK shows a mean percentage error of 34 %. In stable mechanically ventilated patients, undergone cardiac surgery, the proposed method is reliable if compared to the thermodilution. Considering the non-invasivity of the technique, further evaluations of its performances are encouraged.
New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMA... more New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMATSU company, tested, selected and installed in the DAMA/LIBRA set-up at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. In this paper the results obtained in the measurements of various features of these high Q.E. PMTs are reported, and some performances of DAMA/LIBRA in this new configuration
Propensityscoremethodsareanincreasinglypopulartechniqueforcausal inference. To estimate propensit... more Propensityscoremethodsareanincreasinglypopulartechniqueforcausal inference. To estimate propensity scores, we must model the distribution of the treat- mentindicatorgivenavectorofcovariates.Muchworkhasbeendoneinthecasewhere the covariates are fully observed. Unfortunately, many large scale and complex sur- veys, such as longitudinal surveys, suffer from missing covariate values. In this paper, we compare three different approaches and their underlying assumptions of handling missing background data in the estimation and use of
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998
We present a full-scale MDT prototype for the Atlas muon spectrometer. The chamber consists of tw... more We present a full-scale MDT prototype for the Atlas muon spectrometer. The chamber consists of two multilayers made of three layers of 96 drift tubes each. The main feature of this chamber is the very accurate mechanical construction (20 m accuracy on single wire positioning) together with a very good individual tube spatial resolution. In this paper we present results both on the mechanical accuracy of the chamber, and on the performances obtained on the H8 test beam at CERN. In particular, we present an autocalibration method that allows to obtain the space-to-time relation of the tubes with a systematic error less than 20 m, the space resolution and the efficiency of the chamber.
This study analyzes the effect of weather variables, such as solar radiation, indoor and outdoor ... more This study analyzes the effect of weather variables, such as solar radiation, indoor and outdoor air temperature, relative humidity and time spent outdoor, on the behavior of 2-year-old children and their affects across different seasons: winter, spring and summer. Participants were a group of 61 children (33 males and 28 females) attending four day-care centers in Florence (Central Italy). Mean age of children at the beginning of the study was 24.1 months (SD03.6). We used multilevel linear analyses to account for the hierarchical structure of our data. The study analyzed the following behavioral variables: Activity Level, Attentional Focusing, Frustration, and Aggression. Results showed a different impact of some weather variables on children's behavior across seasons, indicating that the weather variable that affects children's behavior is usually the one that shows extreme values during the studied seasons, such as air temperature and relative humidity in winter and summer. Studying children and their reactions to weather conditions could have potentially wide-reaching implications for parenting and teaching practices, as well as for researchers studying social relationships development.
We consider a new approach to identify the causal effects of a binary treatment when the outcome ... more We consider a new approach to identify the causal effects of a binary treatment when the outcome is missing on a subset of units and dependence of nonresponse on the outcome cannot be ruled out even after conditioning on observed covariates. We provide sufficient conditions under which the availability of a binary instrument for nonresponse allows us to derive tighter identification intervals for causal effects in the whole population and to partially identify causal effects in some latent subgroups of units, named Principal Strata, defined by the nonresponse behavior in all possible combinations of treatment and instrument. A simulation study is used to assess the benefits of the presence versus the absence of an instrument for nonresponse. The simulation design is based on real health data, coming from a randomized trial on breast self-examination (BSE) affected by a large proportion of missing outcome data. An instrument for nonresponse is simulated considering alternative scenarios to discuss the key role of the instrument for nonresponse in identifying average causal effects in presence of nonignorable missing outcomes. We also investigate the potential inferential gains from using an instrument for nonresponse adopting a Bayesian approach for inference. In virtue of our theoretical and empirical results, we provide some recommendations on study designs for causal inference.
The influence of an extremely low frequency (ELF) magnetic field (50 Hz and 1 mT, EMF) on the act... more The influence of an extremely low frequency (ELF) magnetic field (50 Hz and 1 mT, EMF) on the activity of a soluble and insoluble horseradish peroxidase (E.C. 1.11.17) has been studied as a function of time. Insoluble derivatives were obtained by enzyme entrapment into two different gelatin membranes or by covalent attachment of the enzyme on two nylon membranes, differently preactivated. Results have shown that the field affects the inactivation rate of the soluble enzyme, while no effects are observed with insoluble derivatives. Since in vivo enzymes are immobilised into the biomembrane bilayer or entrapped into the cytoplasmic mixture, one might speculate that our experimental conditions do not reflect the catalytic activity of the enzymes in vivo.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2008
The ≃ 250 kg highly radiopure NaI(Tl) DAMA/LIBRA apparatus, running at the Gran Sasso National La... more The ≃ 250 kg highly radiopure NaI(Tl) DAMA/LIBRA apparatus, running at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N., is described.
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Papers by A. Mattei