Observation of a Coherence Length Effect in Exclusive Rho^0 Electroproduction

Exclusive incoherent electroproduction of the rho^0(770) meson from 1H, 2H, 3He, and 14N targets has been studied by the HERMES experiment at squared four-momentum transfer Q**2>0.4 GeV**2 and positron energy loss nu from 9 to 20 GeV. The ratio of the 14N to 1H cross sections per nucleon, known as the nuclear transparency, was found to decrease with increasing coherence length of quark-antiquark fluctuations of the virtual photon. The data provide clear evidence of the interaction of the quark- antiquark fluctuations with the nuclear medium.Comment: RevTeX, 5 pages, 3 figure

Determination of the Deep Inelastic Contribution to the Generalised Gerasimov-Drell-Hearn Integral for the Proton and Neutron

The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant.Comment: 6 pages, 3 figures, 1 table, revte

Measurement of the Neutron Spin Structure Function g1ng_1^n with a Polarized ^3He Target

Results are reported from the HERMES experiment at HERA on a measurement of the neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident on a polarized $^3$He internal gas target. The data cover the kinematic range $0.023<x<0.6$ and $1 (GeV/c)^2 < Q^2 <15 (GeV/c)^2$. The integral $\int_{0.023}^{0.6} g_1^n(x) dx$ evaluated at a fixed $Q^2$ of $2.5 (GeV/c)^2$ is $-0.034\pm 0.013(stat.)\pm 0.005(syst.)$. Assuming Regge behavior at low $x$, the first moment $\Gamma_1^n=\int_0^1 g_1^n(x) dx$ is $-0.037\pm 0.013(stat.)\pm 0.005(syst.)\pm 0.006(extrapol.)$.Comment: 4 pages TEX, text available at http://www.krl.caltech.edu/preprints/OAP.htm

Flavor Decomposition of the Polarized Quark Distributions in the Nucleon from Inclusive and Semi-inclusive Deep-inelastic Scattering

Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and 3He targets, in the kinematic range 0.023<x<0.6 and 1 GeV^2<Q^2<10 GeV^2. Polarized quark distributions are extracted as a function of x for up $(u+u_bar) and down (d+d_bar) flavors. The up quark polarization is positive and the down quark polarization is negative in the measured range. The polarization of the sea is compatible with zero. The first moments of the polarized quark distributions are presented. The isospin non-singlet combination Delta_q_3 is consistent with the prediction based on the Bjorken sum rule. The moments of the polarized quark distributions are compared to predictions based on SU(3)_f flavor symmetry and to a prediction from lattice QCD.Comment: 14 pages, 6 figures (eps format), 10 tables in Latex New version contains tables of asymmetries and correlation matri

Potentially inappropriate medication use in institutionalized older adults according to the Beers Criteria

The need for specific care, coupled with new family arrangements, has contributed to the increasing institutionalization of elderly members. The purpose of this study was to evaluate drug use by institutionalized older adults according to Beers Criteria. This prospective, longitudinal study was conducted in the three non-profit long-stay geriatric care institutions of Campo Grande, in the Central-West region of Brazil. All subjects aged 60 years and above on November 2011 were included and followed until November 2012. Eighteen subjects were excluded and the final sample consisted of 133 individuals aged 60 to 113 years. Overall, 212 medications were used at geriatric care institution A, 532 at B, and 1329 at C. Thirty-four drugs were inappropriately prescribed 89 times at geriatric care institution A (41.98%), 49 prescribed 177 times at B (33.27%), and 91 prescribed 461 times at C (34.68%). Statistical differences in the inappropriate drug use were found between genders (p=0.007). The most commonly used potentially inappropriate medication were first-generation antihistamines (15.34%). There was a high frequency in the use of potentially inappropriate medications which can initiate marked side effects and may compromise the fragile health of institutionalized elderly. Thus, adopting the Beers Criteria in prescribing medication contributes to minimize adverse reactions and drug interactions

Potentially inappropriate medication use among institutionalized elderly individuals in southeastern Brazil

In recent decades, the elderly population in Brazil has grown rapidly, as has concern for the health of this population. Institutionalization in nursing homes has appeared as an alternative form of health care for frail elderly that live alone. The present study evaluated the pharmacotherapy and inappropriate drug prescriptions for institutionalized elderly patients living in long-term institutions in southeastern Brazil. This research was conducted at five institutions with a total sample of 151 individuals aged at least 60 years. Databases were used to identify drug interactions, defined daily dose and inappropriate prescriptions. The prevalence of drug intake among the elderly was 95.36%, and there were an average of 3.31 ± 1.80 drug prescriptions per individual. Based on Beers criteria, the prevalence of inappropriate prescriptions was 25.83%. In addition, 70.2% of prescriptions were prescribed at a higher dosage than the defined daily dose (ATC/WHO). Potential drug interactions were identified for 54.11% of prescriptions; 81.42% of these were of moderate severity. The main inappropriate drugs were prescribed for cardiovascular and nervous system problems. Institutionalized elderly individuals presented a high consumption and misuse of medications, requiring professional intervention to monitor prescriptions and improve the quality of service for this population

Exposure to potentially inappropriate medications in Brazilian elderly outpatients with metabolic diseases

ABSTRACT Management of pharmacotherapy in elderly with metabolic diseases is challenging and potentially inappropriate medications (PIMs) are risk factors for drug interactions and adverse events. The exposure to PIMs in elderly outpatients with metabolic diseases and its relationship with polypharmacy and other variables was investigated. PIMs prescribed to 207 elderly patients (aged 60 to 96 years) with metabolic diseases who attended a University Hospital of Sao Paulo city, Brazil, from April/2010 to January/2011, were evaluated. PIMs were detected using both 2003 Beers and 2008 STOPP criteria. The association between PIMs and age, gender and polypharmacy was also examined. 2008 STOPP criteria detected more PIMs (44.4 %) than 2003 Beers criteria (16.0%, p<0.001). Beers detected mainly PIMs antihypertensive (clonidine, 20.0%; doxazosin, 10.0%) and antidepressant (fluoxetine, 15.0%; amitriptyline, 10.0%) PIMs. Medicines used for cardiovascular (aspirin, 53.7%) and endocrine system (glibenclamide, 21.3%) were PIMs more frequently detected by 2008 STOPP. Unlike age and gender, polypharmacy increased the risk of PIMs by both 2003 Beers (OR: 4.0, CI95%: 1.2-13.8, p<0.031) and 2008 STOPP (OR: 6.8, CI95%: 3.0-15.3, p<0.001). Beers and STOPP criteria are important tools to evaluate the exposure to PIMs, which is strongly associated with polypharmacy in elderly outpatients with metabolic diseases

Safety assessment of essential medicines for elderly people: a bibliographic survey

Certain medicines are considered potentially inappropriate (PIM) for elderly people as they increase the risk of adverse drug events (ADE) and because safer alternative therapies are available on the market. In this context, in order to identify the instruments that assess the quality of medical prescriptions for elderly and to determine which drugs are considered PIM, a bibliographic survey was conducted in PUBMED, LILACS and PAHO databases, in February and March/2010. The search strategy included the use of health descriptors and a manual search in the references cited by selected papers. During the period of data collection, 15 instruments were identified. In 2012, with the publication of the update of Beers criteria, this instrument was included in the study. We identified 163 PIM of 25 therapeutic classes, of which 125 (76.7%) are marketed in Brazil. Of these, 31 (24.8%) are essential medicines (RENAME 2012), of which 13 have safer therapeutic equivalents and 19 (15.2%) are over-the-counter drugs. Data suggest the need for inclusion of safer alternatives for the elderly in the national list of essential medicines and the pharmaceutical care for early detection of ADE in this age group, in order to contribute to the safe use of medicines

Identification of inappropriate prescribing in a Brazilian nursing home using STOPP/START screening tools and the Beers' Criteria

The objective of this study was to determine the prevalence of Potentially Inappropriate Medication (PIM) use and associated factors, as well as the prevalence of Prescribing Omissions (PO). A cross-sectional study was conducted in a philanthropic Brazilian nursing home involving 46 individuals aged 60 years or older. The following information was collected from medical records and drug prescriptions: gender, age, health conditions and drugs used in the past thirty days. PIM and PO were identified according to the Beers' Criteria and the STOPP/START screening tools. Over one third (37%) of the population used at least one PIM according to the Beers' Criteria (n=17) and 60.9% according to the STOPP tool. A significant association was found between polypharmacy (use of five or more drugs) and use of PIM according to the Beers' Criteria, but not according to the STOPP. Eight residents (17.4%) were exposed to eight PO. This study allowed the diagnosis of a concerning drug utilization profile with use of a high number of PIMs. Thus, there is an evident need to implement strategies for improving geriatric prescription

Ultrahigh energy neutrinos at the pierre auger observatory

The observation of ultrahigh energy neutrinos (UHEs) has become a priority in experimental astroparticle physics. UHEs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ) or in the Earth crust (Earth-skimming ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEs in the data collected with the ground array of the Pierre Auger Observatory.This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEs in the EeV range and above