A Stable Finite-Difference Scheme for Population Growth and Diffusion on a Map.

We describe a general Godunov-type splitting for numerical simulations of the Fisher-Kolmogorov-Petrovski-Piskunov growth and diffusion equation on a world map with Neumann boundary conditions. The procedure is semi-implicit, hence quite stable. Our principal application for this solver is modeling human population dispersal over geographical maps with changing paleovegetation and paleoclimate in the late Pleistocene. As a proxy for carrying capacity we use Net Primary Productivity (NPP) to predict times for human arrival in the Americas.

Effect of anisotropy on ventricular vulnerability to unidirectional block and reentry by single premature stimulation during normal sinus rhythm in rat heart.

Single high-intensity premature stimuli when applied to the ventricles during ventricular drive of an ectopic site, as in Winfree's "pinwheel experiment," usually induce reentry arrhythmias in the normal heart, while single low-intensity stimuli barely do. Yet ventricular arrhythmia vulnerability during normal sinus rhythm remains largely unexplored. With a view to define the role of anisotropy on ventricular vulnerability to unidirectional conduction block and reentry, we revisited the pinwheel experiment with reduced constraints in the in situ rat heart. New features included single premature stimulation during normal sinus rhythm, stimulation and unipolar potential mapping from the same high-resolution epicardial electrode array, and progressive increase in stimulation strength and prematurity from diastolic threshold until arrhythmia induction. Measurements were performed with 1-ms cathodal stimuli at multiple test sites (n = 26) in seven rats. Stimulus-induced virtual electrode polarization during sinus beat recovery phase influenced premature ventricular responses. Specifically, gradual increase in stimulus strength and prematurity progressively induced make, break, and graded-response stimulation mechanisms. Hence unidirectional conduction block occurred as follows: 1) along fiber direction, on right and left ventricular free walls (n = 23), initiating figure-eight reentry (n = 17) and tachycardia (n = 12), and 2) across fiber direction, on lower interventricular septum (n = 3), initiating spiral wave reentry (n = 2) and tachycardia (n = 1). Critical time window (55.1 ± 4.7 ms, 68.2 ± 6.0 ms) and stimulus strength lower limit (4.9 ± 0.6 mA) defined vulnerability to reentry. A novel finding of this study was that ventricular tachycardia evolves and is maintained by episodes of scroll-like wave and focal activation couplets. We also found that single low-intensity premature stimuli can induce repetitive ventricular response (n = 13) characterized by focal activations.NEW & NOTEWORTHY We performed ventricular cathodal point stimulation during sinus rhythm by progressively increasing stimulus strength and prematurity. Virtual electrode polarization and recovery gradient progressively induced make, break, and graded-response stimulation mechanisms. Unidirectional conduction block occurred along or across fiber direction, initiating figure-eight or spiral wave reentry, respectively, and tachycardia sustained by scroll wave and focal activations.

Direct formation of supermassive black holes via multi-scale gas inflows in galaxy mergers.

Observations of distant quasars indicate that supermassive black holes of billions of solar masses already existed less than a billion years after the Big Bang. Models in which the 'seeds' of such black holes form by the collapse of primordial metal-free stars cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient. Alternatively, these black holes may form by direct collapse of gas within isolated protogalaxies, but current models require idealized conditions, such as metal-free gas, to prevent cooling and star formation from consuming the gas reservoir. Here we report simulations showing that mergers between massive protogalaxies naturally produce the conditions for direct collapse into a supermassive black hole with no need to suppress cooling and star formation. Merger-driven gas inflows give rise to an unstable, massive nuclear gas disk of a few billion solar masses, which funnels more than 10(8) solar masses of gas to a sub-parsec-scale gas cloud in only 100,000 years. The cloud undergoes gravitational collapse, which eventually leads to the formation of a massive black hole. The black hole can subsequently grow to a billion solar masses on timescales of about 10(8) years by accreting gas from the surrounding disk.

[Caregiver Need Assessment: a questionnaire for caregiver demand]. / Caregiver Need Assessment: uno strumento di analisi dei bisogni del caregiver.

UNLABELLED: Many studies have focused on the importance of the informal care provided by caregivers and on its impact in terms of worsening quality of life and increased burden. The aim of the present study is to analyze the psychometric validity and reliability of the Caregiver Needs Assessment (CNA) questionnaire, which has been built to investigate the needs (related to assistance) perceived by caregivers of severely impaired patients, particularly in the first stages of their illness. METHODS: The CNA was administered to 226 family caregivers (24.3% males) of 197 patients (50.8% males) hospitalized for neuromotor rehabilitation after a stroke, head injury, Lateral Amyotrophic Sclerosis, Parkinson or other severely impairing diseases. RESULTS: The instrument was tested on a large sample (KMO = 0.83) of heterogeneous caregivers. Explorative and confirmatory factor analysis, performed on a two subgroup random subdivision of the sample, showed the presence of two factors with good internal consistency: the factor "needs of emotional and social support" (alpha = 0.765) and the factor "needs of information and communication" (alpha = 0.742). The structural equation modeling confirms the goodness of fit of the 2-factor structure (RMSEA = 0.073; SRMR = 0.1; CFI = 0.96). We observed a positive correlation (p < 0.01) between the factor "needs of emotional and social support" of the CNA and other questionnaires aimed at assessing psychological wellbeing, and between the factor "needs of information and communication" and the factor "needs for knowledge about the disease" of the Family Strain Questionnaire, showing good convergent validity. We also observed high Pearson correlation coefficients (0.942 and 0.965) between test-retest measurements of both factors in the CNA. CONCLUSION: The statistical analysis confirms the good psychometric properties of the CNA questionnaire. For its brevity and ease in compilation the CNA is promising practical tool aimed at assessing caregivers' needs in order to personalize a programme of psychological support, to measure it's outcome and to provide comparison of the different needs in different diseases.

[A traumatic brain injury patient: from rehabilitation to social-familial re-integration. Case report focusing on quality of life aspects]. / Dalla riabilitazione al reinserimento socio-familiare nel paziente con trauma cranio-encefalico. Lettura di un caso clinico attraverso i dati di qualità di vita.

WHO recommends that the biopsychosocial model be adopted in the rehabilitation and, particularly, in the multidisciplinary care of Traumatic Brain Injury (TBI) patients. The neuropsychological, psychological, and Quality of Life (QoL) assessment of TBI patients follows the evolution of their clinical conditions. The following evaluation battery is administered in our Unit: Specific Neuropsicological Tests, Wechsler Adult Intelligence Scales Revised (WAIS-R), and the Short Form-36 (SF-36) and Satisfaction Profile (SAT-P), two generic questionnaires measuring respectively health status and subjective aspects of QoL. Mauro is an 18-year old patient with TBI, complicated after one and a half years by epilepsy. The clinical report is divided into three phases (3, 5 and 18 months post-TBI)--ranging from the first psychological-neuropsychological assessment to the patient's socio-educational re-integration--and includes self-reports by the patient and/or his mother, a discussion of the QoL and neuropsychological data, and a presentation of the work carried out in the cognitive behavioural rehabilitation. The psychological topics that emerged are: memories of the traumatic event and the hospitalization period, enthusiasm about the "return to life", and difficulties and suffering due to the fact of "being different". This paper offers an example of both the assessment and treatment of TBI patients--following its course from where it begins in the Rehabilitation Center to its continuation in the patient's social environment. The purpose of such a global clinical management is to effectuate a psychosocial re-integration that is adequate in terms of the patient's cognitive resources and residual behavioural abilities.

Accidente cerebro-vascular: análisis de la población reclutada durante 20 años. Su relación con factores de riesgo y evolución intrahospitalaira / Stroke: analysis of a population studied during a 20-year period

831 pacientes mayores de 18 años con accidente cerebro-vascular (ACV) fueron analizados durante el período 1985-2005. A todos se realizó tomografía axial computada a su ingreso lo que permitió identificar los ACV isquémicos de los hemorrágicos...En esta serie consecutiva se encontró peor evolución en los ACV hemorrágicos, sin diferencia con respecto a edad o sexo. El análisis de los factores de riesgo ubica a la diabetes, la hipertensión, la cardiopatía isquémica concomitante, el sexo masculino y la hipertrofia ventricular izquierda como determinantes de mayor mortalidad

Accidente cerebro-vascular: análisis de la población reclutada durante 20 años. Su relación con factores de riesgo y evolución intrahospitalaira / Stroke: analysis of a population studied during a 20-year period

831 pacientes mayores de 18 años con accidente cerebro-vascular (ACV) fueron analizados durante el período 1985-2005. A todos se realizó tomografía axial computada a su ingreso lo que permitió identificar los ACV isquémicos de los hemorrágicos...En esta serie consecutiva se encontró peor evolución en los ACV hemorrágicos, sin diferencia con respecto a edad o sexo. El análisis de los factores de riesgo ubica a la diabetes, la hipertensión, la cardiopatía isquémica concomitante, el sexo masculino y la hipertrofia ventricular izquierda como determinantes de mayor mortalidad

[Neuropsychological course of patients with craniocerebral injuries in rehabilitation]. / Percorso neuropsicologico del paziente con trauma cranio-encefalico in riabilitazione.

The aim of the present paper is to describe a neuropsychological assessment and intervention model in Traumatic Brain Injury (TBI) patients. The theoretical and methodological frameworks are described and the following diagnostic and rehabilitative flowchart is fully explained: 1. first visit with patient and his relatives; 2. clinical and testing assessment; 3. diagnostic balance and its communication to patient and his relatives; 4. neuropsychological rehabilitation and psychological counseling. Whenever necessary, patient's relatives are involved. Furthermore, TBI patients' health related quality of life is outlined as an important clinical and scientific issue deserving more attention, in spite of the objective methodological difficulties which its evaluation implies.

Relationship between cognitive impairment and clinical status in chronic heart failure patients.

BACKGROUND: In spite of its clinical importance, cognitive functioning is not always taken into account in studies on patients with chronic heart failure. The aim of the present study is to analyse the relationship between cognitive impairment and cardiovascular variables in a sample of patients with chronic heart failure for assessment or candidated for heart transplant. METHODS: Sixty-four male patients with chronic heart failure in NYHA class I-III, in a stable clinical condition, underwent cardiological evaluation and neuropsychological assessment by means of a wide battery of tests: Spinnler and Tognoni's tests and WAIS scale. RESULTS: Compared to the normative group, only 9% of patients did not have impairment in any cognitive function. 26% of patients had impairment of one cognitive function, and 30% of four or more cognitive functions. The cognitive functions that were most often impaired were short-term verbal memory, short-term visual spatial memory, differed verbal memory and verbal learning and visual spatial logical ability. On the whole, no statistical significant relationship was found between cognitive scores and the considered cardiovascular variables. CONCLUSIONS: Our data support the need to take into account the risk of cognitive impairment in CHF patients, regardless of age, disease severity or functional status. The high prevalence of short-term verbal memory impairment has important implications in clinical practice, since CHF patients should be actively involved in the medical management of their disease. Memory deficits could compromise patient's adherence to treatment as well as doctor-patient interactions. The practical consequences of these difficulties require some changes in doctors' behaviour and suggest the need for specific medical staff member training.

[Guidelines and clinical practice: anticoagulant therapy and cardioversion in atrial fibrillation]. / Linee guida e pratica clinica: terapia anticoagulante e cardioversione della fibrillazione atriale.

UNLABELLED: The cardioversion of atrial fibrillation is linked to a substantial risk of systemic embolization. In an effort to reduce it, the American College of Chest Physicians (ACCP) periodically publishes guidelines for the use of anticoagulation in the conversion of atrial fibrillation. OBJECTIVE: Determination of the physician's compliance with the recommendations of the "Fourth ACCP Consensus Conference on Antithrombotic Therapy". METHODS: The charts of people admitted to a community hospital in 1998 with a diagnosis of atrial fibrillation (n = 202) were evaluated retrospectively. Consideration was given to the ACCP's recommendation to give anticoagulants 3 weeks before and 4 weeks after elective cardioversion to patients who had been in atrial fibrillation for more than 2 days. RESULTS: Ninety-one of the 202 patients admitted with atrial fibrillation reported the onset of arrhythmia more than 48 hours before. Thirty-four of them underwent elective cardioversion and 13 cases (33%) went without anticoagulation in the preceding 2 weeks. Of these 13 cases, 8 were patients aged over 75 (range 78-88, mean 84). After sinus rhythm had been restored in 30 people (spontaneously in 5 of them), the anticoagulant therapy was not administered during the 4 recommended weeks in 10 people (33%), all of them over 75 (range 77.94, mean 84). CONCLUSIONS: Anticoagulation for cardioversion of atrial fibrillation is underused, especially among elderly patients. In order not to let age itself be an obstacle to the correct treatment of patients with high embolic risk, our efforts must be improved in order to identify the correct therapeutic choice in each particular case. Initiatives aimed at identifying and removing any impediment to the application of guidelines may contribute to stimulating physicians in the process of evaluating the quality of hospital treatment.

Relationship between psychological profile and cardiological variables in chronic heart failure. The role of patient subjectivity.

AIM: To analyse the relationships between the psychological profile, the satisfaction profile and cardiological variables in patients with chronic heart failure. MATERIAL AND METHODS: One hundred and fifty-two male patients with chronic heart failure in a stable clinical condition underwent cardiological evaluation and psychological assessment by means of two instruments: the Cognitive Behavioural Assessment 2.0 Battery and the Satisfaction Profile. RESULTS: Patients scored higher than healthy subjects in terms of psychophysiological disorders and depression. Patients in NYHA class III reported higher anxiety and depression scores and had more frequent problems in daily life than patients in NYHA classes I and II. Class III patients also reported lower satisfaction levels in many aspects of psychological and physical functioning. Pulmonary resistances >2.5 Wood units, pulmonary capillary wedge pressure >0. 18 mmHg and a diagnosis of ischaemic cardiomyopathy were associated with low satisfaction levels in the Satisfaction Profile 'physical functioning' factor. To be listed for heart transplantation and a history of more than three hospitalizations were related to low satisfaction levels in many items of the Satisfaction Profile. Finally, stepwise multiple regression showed that NYHA class, depression score and pulmonary capillary resistance accounted for 32% of the variance in the Satisfaction Profile physical functioning factor score. CONCLUSION: On the basis of chronic heart failure diagnosis only, a generic pattern of psychological distress can be predicted, common to many severe chronic diseases. Shifting from objective mental health measures towards the domain of subjective satisfaction, the only link which emerges is between objective cardiological data and satisfaction with physical functioning. Satisfaction in terms of other life aspects does not seem to be related to cardiological variables. These results support the importance of subjectivity in health related quality of life, as well as objective measures.

[The psychological side of chronic heart failure. A pluriannual experience]. / Il versante psicologico dello scompenso cardiaco cronico. Considerazioni da un'esperienza pluriennale.

The present study summarizes the authors' experience reached in the last four years with chronic heart failure patients', particularly referring to the psychological aspects. The 218 male patients (age 51.7 +/- 8.3) psychological profile (obtained by means of the CBA 2.0 Primary Scales) has shown higher scores in the anxiety, depression and psychophysiological disorders scales and lower scores in some of the fear scales, compared with the reference normative group. The CBA 2.0 Schedule 4 has enlightened suicidal ideas, eating and sleep disorders, economic and sexual problems. The comparison between the psychological and the many cardiological variables taken into account, has not allowed to highlight significant relationships on the whole. Our data support the necessity to introduce other--likely subjective--variables in the studies aimed at analyzing the relationships between psychological and cardiological factors in the chronic heart failure patients.

The effects of a cognitive behavioural intervention in asthmatic patients.

There is evidence that educational programmes may improve patient's compliance with asthma treatment and control symptoms. Whilst medical parameters have been thoroughly studied, few data are available concerning psychological intervention. The aim of our open pilot study was to verify whether any difference in perceived illness and response style to asthma existed in the patients enrolled in an Asthma Rehabilitation Group (ARG) and in a Control Group (CG). Forty consecutive asthmatics were randomly enrolled, all of whom were diagnosed, treated and followed-up according to the International Guidelines. Both groups underwent a psychological assessment at baseline and after one year. A battery of questionnaires was used to obtain data relating to baseline characteristics (anxiety, depression, psychophysiological disorders), emotional reactions to asthma attacks (panic-fear, etc,) and cognitive variables (external control, psychological stigma, internal beliefs, external chance, etc.) involved in the perceived illness. In addition, the Asthma Rehabilitation Group patients underwent an educational programme and a cognitive-behavioural intervention. In both groups, a reduction of anxiety and depression scores was observed, as well as a significant improvement of the medical parameters evaluated. Only the Asthma Rehabilitation Group reported lower scores on the Psychophysiological Questionnaire and on the External Control Subscale after 1 year. The Control Group reported higher score on the External Chance Scale. The data of our study seem to confirm the effectiveness of psychological intervention on the cognitive skills involved in the perception and management of asthma. Larger scale studies on this topic are suggested.

Human lymphoblastoid interferon as vaccine adjuvant in cattle.

Human lymphoblastoid interferon from Namalwa cells was purified for clinical use by ethanol fractionation, and used as adjuvant of an inactivated Bovid Herpesvirus 1 vaccine in calves. In agreement with other in vitro and in vivo models, low and high interferon doses were shown to increase and depress the specific antibody response, respectively. The low, effective interferon dose (100 International Units/kg) also reduced the variability of antibody titres after the first vaccine injection. This latter dose had apparently no influence on the regulatory T cell circuits, as opposed to the other doses under study.

Multiple learning tasks in patients with ideomotor apraxia.

The Authors studied a group of patients with ideomotor apraxia (LBD+) to verify if these patients had some difficulties in multiple learning tasks in respect to non-apraxic patients and normal control subjects. All five groups were submitted to gesture learning task, motor skill learning task, supra-span (Corsi) learning task. The results indicate that learning difficulties were present in LBD+ patients, as demonstrated by their low performance in gesture sequence, motor skill and score of block-tapping supra-span task. This fact may be seen as a basic learning deficit and therefore linked to memory impairment. On the other hand, this could be tied to an aspecific more diffuse deterioration of attention if we consider that our apraxic patients had a greater cerebral lesion than non-apraxic patients.

[Retrospective study on 778 patients with acute myocardial infarct: relation between sex, age and blood lipid picture]. / Indagine retrospettiva su 778 pazienti con infarto miocardico acuto: rapporti tra sesso, età e quadro lipemico.

To evaluate the relationship between myocardial infarction and serum lipid levels, 778 patients admitted to the Fidenza Coronary Unit were studied. These patients were divided by sex and into groups by age decade and the frequency of hyperlipidemia was investigated. In the first place the association between myocardial infarction (MI) with hypercholesterolemia, second with hypertriglyceridemias was considered. In addition the population was subdivided in respect to the 3 more frequent types of hyperlipidemia (hypercholesterolemia, hypercholesterolemia and hypertriglyceridemia, hypertriglyceridemia). The results show the presence at a positive correlation between MI and hypercholesterolemia in the younger groups in both sexes, but mainly in female. Similar results are obtained when the correlation between MI and hypertriglyceridemia was considered, but at a lower statistical significance. The statistical analysis of the different types of hyperlipidemia confines the important pathogenetic role of hypercholesterolemia by itself and in association with hypertriglyceridemia. On the other hand hypertriglyceridemia does not show any primary influence on MI, but it acts synergistically with hypercholesterolemia. The strong association of hyperlipidemia and MI in the younger group and in female, documented in this study, confirms the importance of hypercholesterolemia and hypertriglyceridemia as a risk factor in the early development of coronary heart disease.