Impact of Covid-19 on farming systems in Europe through the lens of resilience thinking.

Context: Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis. Objective: This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment. Methods: The 11 farming systems included have been analysed since 2017. This allows a comparison of pre-Covid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns. Results and conclusions: Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability. Significance: Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.

Early stratification of patients with chest pain and suspected acute coronary syndrome in the Emergency Department.

AIM: The aim of this study was to investigate the accuracy of a critical pathway in the early stratification and management of patients with chest pain and suspected acute coronary syndrome (ACS) in the Emergency Department (ED). METHODS: An observational study was performed enrolling all patients with non-traumatic chest pain and suspected ACS who presented during a one-year period in the ED, where a critical pathway with five-level risk stratification, based on risk factors, characteristics of pain and ECG, was implemented. Patients were prospectively evaluated for rates of death, unstable angina, myocardial infarction or revascularization procedure occurring during admission or in the 30 days following discharge from the ED. Receiver-Operating Characteristics (ROC) curve was used to measure the accuracy of the stratification method. RESULTS: Overall, 1813 patients were enrolled: 475 patients (26.1%, 95% CI: 24.0-28.1 ) were admitted and 1338 (73.8%, 95% CI: 71.7-75.8) were discharged. Main outcomes occurred in 233 (49.9%, 95% CI: 47.5-52.2) of patients admitted and in 6 (0.4%, 95% CI: 0.06-0.7) of those discharged. The risk stratification system showed a good accuracy with an AUC-ROC curve of 0.90 (95% CI: 0.88-0.93). A total of 1541 (85%) patients were managed according to critical pathway. Adverse events were significantly fewer in patients discharged according to pathway criteria than in those who were not (0.27% vs. 1.37%, difference: 1.1% CI 95%: 0.06-2.1), without significant increase of inappropriate admissions. CONCLUSION: A critical pathway, based on clinical and ECG features, is a safe and accurate tool to stratify and manage the patients with non-traumatic chest pain and suspected ACS in the ED.

Coherent control of stimulated emission inside one-dimensional photonic crystals.

In this paper, the quasinormal mode (QNM) theory is applied to discuss the quantum problem of an atom embedded inside a one-dimensional (1D) photonic band gap (PBG) cavity pumped by two counterpropagating laser beams. The e.m. field is quantized in terms of the QNMs in the 1D PBG and the atom modeled as a two-level system is assumed to be weakly coupled to just one of the QNMs. The main result of the paper is that the decay time depends on the position of the dipole inside the cavity, and can be controlled by the phase difference of the two laser beams.

Second quantization and atomic spontaneous emission inside one-dimensional photonic crystals via a quasinormal-modes approach.

An extension of the second quantization scheme based on the quasinormal-modes theory to one-dimensional photonic band gap (PBG) structures is discussed. Such structures, treated as double open optical cavities, are studied as part of a compound closed system including the electromagnetic radiative external bath. The electromagnetic field inside the photonic crystal is successfully represented by a new class of modes called quasinormal modes. Starting from this representation we introduce the Feynman's propagator to calculate the decay rate of a dipole inside a PBG structure, related to the density of modes, in the presence of the vacuum fluctuations outside the one-dimensional cavity.

Quasinormal-mode description of waves in one-dimensional photonic crystals.

Quasinormal-mode treatment is extended to the description of scalar field behavior in one-dimensional photonic crystals. A one-dimensional photonic crystal is a particular configuration of an open cavity, where discontinuities of the refractive index give rise to field confinement. This paper presents, for a one-dimensional photonic crystal, a discussion about the completeness of the quasinormal-mode representation and, moreover, a discussion on the complex eigenfrequencies, as well as the corresponding field distribution. The concept of density of modes is also discussed in terms of quasinormal modes.

Case report. Ultrasound and CT findings in lipoma of the inferior vena cava.

Several cases of a fat mass-like lesion adjacent to and/or projecting into the inferior vena cava have been presented as a normal variant of perioesophageal fat distribution or as intravascular lipoma. We report a case of a lipoma of the inferior vena cava, studied with coronal reformatted CT images, ultrasound and colour Doppler imaging, in a 78-year-old female patient.

Rhinitis, sinusitis and asthma: one linked airway disease.

Understanding the relationship between upper and lower airways has greatly increased through epidemiological and pharmacological studies. Scientific evidence supports the concept that rhinosinusitis and asthma may be the expression of an inflammatory process which appears in different sites of the respiratory tract at different times. The implications are not only academic but are important for diagnostic and therapeutic purposes.

Quantum properties of optical field in photonic band gap structures.

A theoretical analysis of the quantum behaviour of radiation field's propagation in photonic band gaps structures is performed. In these initial calculations we consider linear inhomogeneous and nondispersive media.

Multiple jejunal angiodysplasia detected by enema-helical CT.

The small bowel angiodysplasia is a rare entity that causes lower intestinal bleeding; the diagnosis is difficult and based on selective angiogram. In our case, an 85-year-old woman was hospitalized after frequent episodes of melena. We performed an enema-helical CT abdominal examination before and after contrast medium administration per venam, detecting some increased intensity areas that surgery confirmed to be a vascular dysplasia on the jejunal first loop. We found the source of hemorrhage without performing an angiographic examination.

Intracellular pharmacokinetics of 2-chlorodeoxyadenosine in leukemia cells from patients with chronic lymphocytic leukemia.

2-Chlorodeoxyadenosine (2-CdA) is an important agent in the treatment of hairy cell leukemia and chronic lymphocytic leukemia (CLL). Others have reported that levels of 2-CdA phosphates present in human leukemia cells decline rapidly when the cells are in 2-CdA-free medium (Santana et al. J Clin Oncol 1991; 9: 416-422). In the present study, time-courses of 2-CdA loss from CLL cells were biexponential: the mean half-life of the initial phase was 0.30 +/- 0.18 h; the presence of 0.5 microM nitrobenzylthioinosine (NBMPR, a classical inhibitor of nucleoside transport) in the suspending medium, significantly decreased the initial rate of 2-CdA efflux (mean half-life, 0.43 +/- 0.22 h). As a consequence, AUCs (areas under time-course plots) were significantly higher in the NBMPR-treated cells (4.56 +/- 2.01 pmol.h/10(6) cells, n = 19) than in untreated control cells (3.83 +/- 1.74 pmol.h/10(6) cells; n = 19). 2-CdA was the principal efflux product released into the medium from 2-CdA-loaded CLL cells. We conclude that nucleoside transport processes contribute to the efflux of 2-CdA from CLL cells and that NBMPR may be useful as a retentive agent.

[Magnetic resonance in thoracic pathology: characterization by intensity values]. / Risonanza magnetica in patologia toracica: tipizzazione con rilievi di intensità.

The authors examined prospectively 100 patients with lung diseases--50 of them benign and 50 malignant. The mean value of all lesions was measured with a constant region of interest (ROI); the muscle was considered as the reference tissue. Histopathology was the gold standard for the patients who underwent CT-guided needle biopsy and/or surgery; clinical-radiologic follow-up (average time: 2 years) was the gold standard for nonsurgical patients. A superconductive 1.5-T magnet with circular polarization body coil was used; T1- and T2-weighted spin echo images were acquired on the coronal and axial planes, respectively. The mean values with the constant ROI were measured both on the lesions and on the reference tissue to calculate and compare the T1-lesion/T1-muscle and T2-lesion/T2-muscle ratios in benign and malignant conditions. The t-test, the linear regression and correlation test and the analysis of variance were used to analyze the data. T1 benign lung disease/T1 muscle ratio was 1.21, while T1 malignant lung disease/T1 muscle ratio was 1.27, with no statistically significant difference. T2 benign lung disease/T2 muscle ratio was 2.63, while T2 malignant lung disease/T2 muscle ratio was 4.80: the difference was statistically significant (p < 0.001). To conclude, in chest diseases, the measurement of mean values in T2 allowed malignancy-indicative values (> 4 ratio) and positively benign values (< 2.5 ratio) to be identified.

[Renal arteries: angiography with TOF 3D magnetic resonance with and without contrast media (Gd-DTPA)]. / Arterie renali: angiografia con Risonanza Magnetica TOF 3D senza e con mezzo di contrasto (Gd-DTPA).

This work was aimed at investigating the value of Gd-DTPA to demonstrate distal renal artery branches with 3D TOF Magnetic Resonance angiography (MRA). Ten volunteers and two patients with proximal-distal renal artery stenoses were studied with MRA; all subjects were studied before and after Gd-DTPA. MRA was performed with a 1.5-T superconductive magnet (Magnetom Siemens); the FISP 3D sequence was used with the following setting: FA 25 degrees, TR 40 ms, TE 6 ms, slice thickness 64 mm with 64 partitions and MA 256 x 256. This setting was not changed from pre- to post-contrast scans. The images acquired on the z axis were rotated, according to the MIP, on the axial and the sagittal axes, from 0 degrees to 180 degrees, with a 15 degrees step. 0.2 ml/kg of Gd-DTPA were injected as bolus during 3D acquisitions; the injection was started half-way through acquisition. To evaluate and compare pre- and post-contrast MRA images, the signal-to-noise (S/N) ratio and the demonstration of the various renal artery segments were studied. Average S/N ratio was 2.3 in the right renal artery and 2.1 in the left renal artery on pre-contrast MRA images, while it was 0.9 in the left renal artery and 0.8 in the right renal artery on post-contrast MRA images. These differences were statistically significant (p < 0.01). As for the demonstration of the distal segments and of the bifurcations, enhanced MRA was no better than unenhanced MRA. As for the demonstration of distal segment stenoses, enhanced MRA proved no better than unenhanced MRA in both patients. To conclude, in our experience MRA after Gd-DTPA failed to allow the systematic demonstration of the distal segments and of the bifurcations of the renal arteries.

[Whole body MR angiography. Physiologic presaturation++ of the inferior vena cava]. / Angio-RM del corpo. Presaturazione fisiologica della vena cava inferiore.

Whole-body MRA, performed with the time-of-flight (TOF) technique requires presaturation pulses adequately positioned and to eliminate the arterial and/or venous signal (FRODO technique: "Flow Respiratory artifact Obliteration with Directed Orthogonal pulses"). Additional presaturation pulses involve an increase in the radiofrequency dose absorbed by the patient, frequently over 0.4 watt x kg, which is the threshold absorption per kg. In the present paper, the possible saturation of caval system exploiting the modulation of apnea in whole-body MRA was investigated. Ten volunteers and 10 patients with different diseases were studied. All subjects underwent abdominal MRA with the TOF 2D (FA 18 degrees, TR 22 ms, TE 10 ms) technique. Images were acquired with three modulations of apnea: maximum inspiration, expiration, Müller maneuver. With respect to the anteroposterior diameter of inferior vena cava in inspiration, the inferior cava was reduced by 21.7% in expiration and by 35.7% in Müller maneuver. The lower caliber of vena cava allowed selective angiogram of the aorta. Expiration maneuvers are suggested as an alternative to caval flow saturation by the FRODO technique. As for expiration maneuvers, the volunteers and patients studied preferred to modulate the apnea in forcible expiration. Müller maneuver, through more effective (in 4 cases total caval collapse was obtained) is nonetheless more difficult.

[Abdominal aorta: role of angiography with magnetic resonance]. / Aorta addominale: ruolo dell'angiografia con risonanza magnetica.

The diagnostic role of Magnetic Resonance angiography (MRA) was investigated in the study of the abdominal aorta. To obviate the problems relative to motion and respiratory artifacts, the TOF 2D (FISP 2D) technique was employed, together with a superconductive 1.5 T magnet. Fourteen volunteers were studied. The images acquired on the coronal and sagittal planes were processed according to MIP and target MIP, with a rotation on the z axis. The abdominal aorta was clearly demonstrated in 100% of cases, the celiac trunk in 42.8% of cases on coronal and in 100% on sagittal images. The superior mesenteric artery was depicted in 35.7% of cases on coronal and in 100% of subjects on sagittal acquisitions. The renal and iliac arteries were demonstrated in 100% of cases on coronal images only, while dorso-spinal and lumbar arteries were always clearly depicted on sagittal scans only. To evaluate the diagnostic reliability of MRA, 6 patients with abdominal aortic aneurysms were also studied and angiography and surgery were assumed as the gold standard. In all cases MRA yielded similar information to angiography and surgery as to aneurysm extent, vessel involvement and left renal vein course; moreover, MRA allowed the assessment of both the thrombotic and the calcific components of the aneurysm. Unenhanced MRA with the TOF 2D technique allows the detailed depiction of the aorta in about 20 minutes. Our preliminary results in the study of aneurysms are encouraging relative to the future diagnostic role of MRA in the abdominal aorta.

High-performance liquid chromatographic analysis of methocarbamol enantiomers in biological fluids.

Methocarbamol enantiomers in rat and human plasma were quantified using a stereospecific high-performance liquid chromatographic method. Racemic methocarbamol and internal standard, (R)-(-)-flecainide, were isolated from plasma by a single-step extraction with ethyl acetate. After derivatization with the enantiomerically pure reagent (S)-(+)-1-(1-naphthyl)ethyl isocyanate, methocarbamol diastereomers and the (R)-flecainide derivative were separated on a normal-phase silica column with a mobile phase consisting of hexane-isopropanol (95:5, v/v) at a flow-rate of 1.6 ml/min. Ultraviolet detection was carried out at a wavelength of 280 nm. The resolution factor between the diastereomers was 2.1 (alpha = 1.24). An excellent linearity was observed between the methocarbamol diastereomers/internal standard derivative peak-area ratios and plasma concentrations, and the intra- and inter-day coefficients of variation were always < 9.8%. The lowest quantifiable concentration was 0.5 microgram/ml for each enantiomer (coefficients of variation of 9.8 and 8.8% for (S)- and (R)-methocarbamol, respectively), while the limit of detection (signal-to-noise ratio 3:1) was approximately 10 ng/ml. The assay was used to study the pharmacokinetics of methocarbamol enantiomers in a rat following intravenous administration of a 120 mg/kg dose of racemic methocarbamol and to evaluate plasma and urine concentrations in a human volunteer after oral administration of a 1000-mg dose of the racemate. The method is suitable for stereoselective pharmacokinetic studies in humans as well as in animal models.

[Magnetic resonance angiography with gadolinium (Gd-DTPA) versus baseline magnetic resonance angiography in the study of the intracranial circulation]. / Angiografia a risonanza magnetica con gadolinio (GdDTPA) versus angiografia a risonanza magnetica di base nello studio del circolo intracranico.

The authors evaluated the role of GdDTPA in magnetic resonance angiography (MRA) of intracranial vessels. Fifteen patients affected with different conditions underwent MRA of intracranial vessels before and after paramagnetic contrast medium infusion. A superconductive 1.5-T magnet (Magnetom Siemens) was used, and a head circular coil, together with the 3DFT TOF technique. The enhanced exam was performed following the infusion of 0.2 ml/kg of GdDTPA in about 2 minutes, with simultaneous MRA image acquisition. To compare enhanced with unenhanced images relative to signal intensity, the signal increase at the basilar artery and carotid sinus was studied, together with signal-to-noise (S/N) ratio and spatial resolution. During acquisition, enhanced MRA images at the basilar artery showed a mean intensity value of 423.8 +/- 33.2 vs 357.8 +/- 53.2 of unenhanced scans; a statistically significant difference (p < 0.05; p < 0.01) was observed in favor of enhanced images. At the carotid sinus, enhanced MRA showed 184.5 +/- 28.4 mean intensity value vs 190.5 +/- 19.8 of unenhanced exams; no statistically significant difference was observed (p < 0.05; p < 0.01) in favor of unenhanced exams. At the basilar artery the S/N ratio of baseline exams was 1.9 vs 2.2 for enhanced scans; at the carotid sinus S/N ratio was 2.4 (unenhanced) vs 2.3 (enhanced). Thus, MRA allowed better visualization of peripheral branches of arterial (95.6%) and venous vessels, which unenhanced scans always failed to depict; on the other hand, enhanced images exhibited poorer definition of arterial vessels which were never isolated from the background. The simultaneous visualization of arterial and venous vessels, of choroid plexus and mucosae, affect the quality of enhanced angiograms. At present, GdDTPA is the sole contrast medium suitable for MRA intracranial vessels even though, due to its pharmacokinetic features, it is not the optimum medium.

Colangitis esclerosante secundaria Presentación de dos casos

Presentamos dos casos de colangitis esclerosante secundaria. En el primero, la enfermedad fue consecuencia de litiasis biliar y, en el segundo, la colangitis esclerosante se presentó en el contexto de un paciente con diarrea crónica y SIDA. Se discuten los principales aspectos etiológicos y fisipatológicos