Il libro del mercante: tipicità ed eccezioni

Il saggio è diviso in due parti : nella prima vengono messe a fuoco alcune tipicità di carattere paleografico e codicologico che contraddistinguono il libro del mercante inteso come strumento di carattere tecnico-professionale, esaminando alcuni registri appartenenti al sistema contabile delle aziende commerciali fondate sul finire del Trecento da Francesco Datini; nella seconda si tratta del libro del mercante in un’accezione più ampia, presentando alcuni manoscritti di contenuto letterario che circolarono in ambienti mercanteschi, prevalentemente toscani, nella seconda metà del Trecento e lungo il corso del Quattrocento. Quei codici non sono esaminati per la loro fattura fisica, visto che si conformano coerentemente al modello del libro-zibaldone, che dominò sino al Cinquecento la produzione manoscritta privata in lingua volgare (cartacei, di formato medio, in scritture corsive quasi sempre mercantesche o di base mercantesca), ma piuttosto per la presenza in essi di alcune tracce, talvolta minutissime, in altri casi molto evidenti, che consentono di mettere a fuoco il sempre sfuggente rapporto di lettura che i mercanti che li commissionarono, li copiarono, li annotarono, avevano stabilito con essi, tanto da poter essere definiti, parafrasando una celebre espressione di Vittore Branca riferita all’attività mercantesca di copia, lettori per passione

Action observation and motor imagery in performance of complex movements: Evidence from EEG and kinematics analysis

Motor imagery (MI) and action observation (AO) are considered effective cognitive tools for motor learning, but little work directly compared their cortical activation correlate in relation with subsequent performance. We compared AO and MI in promoting early learning of a complex four-limb, hand?foot coordination task, using electroencephalographic (EEG) and kinematic analysis. Thirty healthy subjects were randomly assigned into three groups to perform a training period in which AO watched a video of the task, MI had to imagine it, and Control (C) was involved in a distracting computation task. Subjects were then asked to actually perform the motor task with kinematic measurement of error time with respect to the correct motor performance. EEG was recorded during baseline, training and task execution, with task-related power (TRPow) calculation for sensorimotor (alpha and beta) rhythms reactive with respect to rest. During training, the AO group had a stronger alpha desynchronization than the MI and C over frontocentral and bilateral parietal areas. However, during task execution, AO group had greater beta synchronization over bilateral parietal regions than MI and C groups. This beta synchrony furthermore demonstrated the strongest association with kinematic errors, which was also significantly lower in AO than in MI. These data suggest that sensorimotor activation elicited by action observation enhanced motor learning according to motor performance, corresponding to a more efficient activation of cortical resources during task execution. Action observation may be more effective than motor imagery in promoting early learning of a new complex coordination task

Loss of Either Rac1 or Rac3 GTPase Differentially Affects the Behavior of Mutant Mice and the Development of Functional GABAergic Networks

Rac GTPases regulate the development of cortical/hippocampal GABAergic interneurons by affecting the early development and migration of GABAergic precursors. We have addressed the function of Rac1 and Rac3 proteins during the late maturation of hippocampal interneurons. We observed specific phenotypic differences between conditional Rac1 and full Rac3 knockout mice. Rac1 deletion caused greater generalized hyperactivity and cognitive impairment compared with Rac3 deletion. This phenotype matched with a more evident functional impairment of the inhibitory circuits in Rac1 mutants, showing higher excitability and reduced spontaneous inhibitory currents in the CA hippocampal pyramidal neurons. Morphological analysis confirmed a differential modification of the inhibitory circuits: deletion of either Rac caused a similar reduction of parvalbumin-positive inhibitory terminals in the pyramidal layer. Intriguingly, cannabinoid receptor-1-positive terminals were strongly increased only in the CA1 of Rac1-depleted mice. This increase may underlie the stronger electrophysiological defects in this mutant. Accordingly, incubation with an antagonist for cannabinoid receptors partially rescued the reduction of spontaneous inhibitory currents in the pyramidal cells of Rac1 mutants. Our results show that Rac1 and Rac3 have independent roles in the formation of GABAergic circuits, as highlighted by the differential effects of their deletion on the late maturation of specific populations of interneurons

Úlcera de perna: um estudo de casos em Juiz de Fora-MG (Brasil) e região

BACKGROUND: Leg ulcers are characterized as tissue loss in the lower extremities, generally caused by vascular dysfunction.OBJECTIVES: Verify the clinical and epidemiological profiles of the population sample with leg ulcers treated at the health centers of Juiz deFora (Brazil).MATERIAL ANDMETHODS: 124 leg-wound patients were evaluated between January 1999 and August 2001 and submitted to aclinical protocol.RESULTS: The mean age was 64 years, with females in the majority (65.3%). The mean family composition was 3.7 persons, and family inco-me was around US$200.00 (86.8OBJETIVOS: Caracterizar clínica e epidemiologicamente a amostra populacional com UP atendida nos centros de saúde de Juiz de Fora. PACIENTES E MÉTODOS: Submetidos ao protocolo clínico 124 pacientes com UP, de Juiz de Fora e região de janeiro/1999 a agosto/2001. RESULTADOS: A média de idade foi 64 anos, 65,3$540,00 (86,8%). Associavam-se às úlceras insuficiência venosa (90,3%), hipertensão arterial sistêmica (54%), obesidade (20,2%) e diabetes mellitus (16,1%). A associação insuficiência venosa e hipertensão arterial foi freqüente (43,7%) e significante (p5cm) em cerca de 90% da amostra, com médias de 8,7cm e 9,6cm para os eixos vertical e horizontal, respectivamente. Estavam acompanhadas de hipercromia (92,7%), lipodermatoesclerose (68,5%) e varicosidades (66,9%), com duração média de 94,2 meses, e 50% das úlceras eram recidivantes. CONCLUSÕES: Os dados sugerem que a úlcera de perna seja doença crônica significativa na população idosa e de baixa renda de Juiz de Fora e região

Pediatric tuberculosis in Italian children: Epidemiological and clinical data from the Italian register of pediatric tuberculosis

Tuberculosis (TB) is one of the leading causes of death worldwide. Over the last decades, TB has also emerged in the pediatric population. Epidemiologic data of childhood TB are still limited and there is an urgent need of more data on very large cohorts. A multicenter study was conducted in 27 pediatric hospitals, pediatric wards, and public health centers in Italy using a standardized form, covering the period of time between 1 January 2010 and 31 December 2012. Children with active TB, latent TB, and those recently exposed to TB or recently adopted/immigrated from a high TB incidence country were enrolled. Overall, 4234 children were included; 554 (13.1%) children had active TB, 594 (14.0%) latent TB and 3086 (72.9%) were uninfected. Among children with active TB, 481 (86.8%) patients had pulmonary TB. The treatment of active TB cases was known for 96.4% (n = 534) of the cases. Overall, 210 (39.3%) out of these 534 children were treated with three and 216 (40.4%) with four first-line drugs. Second-line drugs where used in 87 (16.3%) children with active TB. Drug-resistant strains of Mycobacterium tuberculosis were reported in 39 (7%) children. Improving the surveillance of childhood TB is important for public health care workers and pediatricians. A non-negligible proportion of children had drug-resistant TB and was treated with second-line drugs, most of which are off-label in the pediatric age. Future efforts should concentrate on improving active surveillance, diagnostic tools, and the availability of antitubercular pediatric formulations, also in low-endemic countries

Multicentre Italian study of SARS-CoV-2 infection in children and adolescents, preliminary data as at 10 April 2020

Data on features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents are scarce. We report preliminary results of an Italian multicentre study comprising 168 laboratory-confirmed paediatric cases (median: 2.3 years, range: 1 day-17.7 years, 55.9% males), of which 67.9% were hospitalised and 19.6% had comorbidities. Fever was the most common symptom, gastrointestinal manifestations were frequent; two children required intensive care, five had seizures, 49 received experimental treatments and all recovered