Involving citizen scientists in monitoring arthropod vectors of human and zoonotic diseases: The case of Mosquito Alert in Italy.

Citizen science has been particularly effective in gathering reliable, timely, large-scale data on the presence and distributions of animal species, including mosquito vectors of human and zoonotic pathogens. This involves the participation of citizen scientists in research projects, with success strongly dependent on the capacity to disseminate project information and engage citizen scientists to contribute their time. Mosquito Alert is a citizen science that aids in the system surveillances of vector mosquitoes. It involves citizen scientists providing expert-validated photos of targeted mosquitoes, along with records of bites and breeding sites. Since 2020 the system has been disseminated throughout Europe. This article uses models to analyze the effect of promotion activities carried out by the Mosquito Alert ITALIA team from October 2020 to December 2022 on the number of citizen scientists recruited and engaged in the project, and their performance in mosquito identification. Results show a high level of citizen scientist recruitment (N > 18.000; 37 % of overall European participants). This was achieved mostly through articles generated by ad hoc press releases detailing the app's goals and functioning. Press releases were more effective when carried out at the beginning and end of the mosquito season and when mosquito's public health significance was emphasized. Despite the high number of records received (N > 20.000), only 30 % of registered participants sent records, and the probability of a participant sending a record dropped off quickly over time after first registering. Among participants who contributed, ~50 % sent 1 record, ~30 % ≥3 and 4 % >10 records. Participants showed good capacity to identify mosquitoes and improve identification skills with app usage. The results will be valuable for anyone interested in evaluating citizen science, as participation and engagement are seldom quantitatively assessed. Our results are also useful for designing dissemination and education strategies in citizen science projects associated with arthropod vector monitoring.

How landscape heterogeneity frames optimal diffusivity in searching processes.

Theoretical and empirical investigations of search strategies typically have failed to distinguish the distinct roles played by density versus patchiness of resources. It is well known that motility and diffusivity of organisms often increase in environments with low density of resources, but thus far there has been little progress in understanding the specific role of landscape heterogeneity and disorder on random, non-oriented motility. Here we address the general question of how the landscape heterogeneity affects the efficiency of encounter interactions under global constant density of scarce resources. We unveil the key mechanism coupling the landscape structure with optimal search diffusivity. In particular, our main result leads to an empirically testable prediction: enhanced diffusivity (including superdiffusive searches), with shift in the diffusion exponent, favors the success of target encounters in heterogeneous landscapes.

Effect of the search space dimensionality for finding close and faraway targets in random searches.

We investigate the dependence on the search space dimension of statistical properties of random searches with Lévy α-stable and power-law distributions of step lengths. We find that the probabilities to return to the last target found (P_{0}) and to encounter faraway targets (P_{L}), as well as the associated Shannon entropy S, behave as a function of α quite differently in one (1D) and two (2D) dimensions, a somewhat surprising result not reported until now. While in 1D one always has P_{0}≥P_{L}, an interesting crossover takes place in 2D that separates the search regimes with P_{0}>P_{L} for higher α and P_{0}

Lévy walkers inside spherical shells with absorbing boundaries: Towards settling the optimal Lévy walk strategy for random searches.

The Lévy flight foraging hypothesis states that organisms must have evolved adaptations to exploit Lévy walk search strategies. Indeed, it is widely accepted that inverse square Lévy walks optimize the search efficiency in foraging with unrestricted revisits (also known as nondestructive foraging). However, a mathematically rigorous demonstration of this for dimensions D≥2 is still lacking. Here we study the very closely related problem of a Lévy walker inside annuli or spherical shells with absorbing boundaries. In the limit that corresponds to the foraging with unrestricted revisits, we show that inverse square Lévy walks optimize the search. This constitutes the strongest formal result to date supporting the optimality of inverse square Lévy walks search strategies.

[A retrospective study about 11 cases of Esthesioneuroblastomas treated in Hospital Santa Creu i Sant Pau between 2000 and 2008 and literature review]. / Estudio retrospectivo de 11 casos de estesioneuroblastomas tratados en el Hospital Santa Creu i Sant Pau entre los años 2000 y 2008 más revisión de la literatura.

INTRODUCTION. Esthesioneuroblastoma (ENB) is a very uncommon malignant tumor with a neuroectodermal origin that usually involves the anterior cranial fossa and nasal cavity. OBJECTIVES. To review our experience in the management of ENB and assess the validity of the histopathological diagnosis, modality of treatment and prognostic factors of the disease comparing our findings with the literature. METHODS. A retrospective study of 11 cases with the diagnosis of esthesioneuroblastoma treated in our hospital between 2000 and 2008. Statistical analysis was performed in search for prognostic factors. The bibliography about ENB published between 1990 and 2009 was reviewed RESULTS. There were 3 women and 8 men, with a mean age of 42 years old (range 20-71y). Their symptoms upon admission were nasal obstruction (81%), epistaxis (27%), visual loss (18%), headache and others. According to the Kadish Stage, 2 were stage B and 9 were stage C. Dulguerov and Calcaterra Classification was also used: 2 were T2, 3 were T3 and 6 were T4. The hystopathological result according to the Hyams classification was: 2 cases in stage I, 4 in stage II, 3 in stage III and 2 in stage IV. The two cases classified in stage IV changed the diagnosis to undifferenciate tumor in the second biopsy. A subcranial approach was performed in 8 cases combined with endonasal endoscopy to confirm the total removal, followed by radiotherapy in all and chemotherapy in one case, resulting on 62% (5 patients) being alive without disease, 12,5% (1 p) alive with disease, and 25% (2 p) dead of disease. Another patient was operated by a single endonasal endoscopic approach and a subtotal removal was achieved. This patient is alive without disease. The other 2 patients were treated by biopsy plus radiotherapy and chemotherapy, because they were considered unresectable, and one of them is alive with disease and the other one is dead of disease. Radiotherapy was performed in all cases and chemotherapy in 5 cases. The hystopathological grading system of Hyams was considered statistically significant as a prognostic factor of disease-free survival. CONCLUSIONS. When the hystopathological diagnosis of ENB is considered, the Hyams classification can be valid considering grade IV as an advanced stage that is sometimes difficult to differentiate from other undiferentiated tumors. The subcranial approach or craneofacial resection in advanced stages (Kadish C and some B) should be considered as the first treatment of choice. Radiotherapy is indicated in all cases and chemotherapy in selected cases. Hyams' classification was the only staging system that proved useful as a prognostic factor in our series.

Landscape-scaled strategies can outperform Lévy random searches.

Information on the relevant global scales of the search space, even if partial, should conceivably enhance the performance of random searches. Here we show numerically and analytically that the paradigmatic uninformed optimal Lévy searches can be outperformed by informed multiple-scale random searches in one (1D) and two (2D) dimensions, even when the knowledge about the relevant landscape scales is incomplete. We show in the low-density nondestructive regime that the optimal efficiency of biexponential searches that incorporate all key scales of the 1D landscape of size L decays asymptotically as η_{opt}∼1/sqrt[L], overcoming the result η_{opt}∼1/(sqrt[L]lnL) of optimal Lévy searches. We further characterize the level of limited information the searcher can have on these scales. We obtain the phase diagram of bi- and triexponential searches in 1D and 2D. Remarkably, even for a certain degree of lack of information, partially informed searches can still outperform optimal Lévy searches. We discuss our results in connection with the foraging problem.

Optimising the success of random destructive searches: Lévy walks can outperform ballistic motions.

We re-evaluate the long standing and widely held belief that ballistic movements (i.e. straight-lines movements) outperform Lévy walks when searching for targets that once located are not revisited. The belief stems from the results of analyses of one-dimensional searches, analyses which have not accounted for the fact that target numbers can be continually depleted during the search process. This is a crucial oversight because continual depletion promotes the searching efficiencies of some Lévy walks above that of ballistic motion. The continual depletion effect is not so important for two- and three-dimensional searches. Nevertheless, we show that Lévy walks and ballistic movements can be equally or almost equally effective when searching within two- and three-dimensional environments for randomly and sparsely distributed targets or when searching for targets that are occasionally concealed. We also show that Lévy walks are advantageous when searching for targets that can occasionally evade capture. These situations represent common predator-prey interactions in which predators are involved in 'imperfect destructive' searches. Our model suggests that accounting for coevolutionary arms races at the predator-prey detection/reaction scales can explain to some extent Lévy walk searching patterns of predators at larger scales. This result provides new insights into the Lévy walk movement patterns of some destructive foragers.

A novel integrative approach elucidates fine-scale dispersal patchiness in marine populations.

Dispersal is one of the main determining factors of population structure. In the marine habitat, well-connected populations with large numbers of reproducing individuals are common but even so population structure can exist on a small-scale. Variation in dispersal patterns between populations or over time is often associated to geographic distance or changing oceanographic barriers. Consequently, detecting structure and variation in dispersal on a fine-scale within marine populations still remains a challenge. Here we propose and use a novel approach of combining a clustering model, early-life history trait information from fish otoliths, spatial coordinates and genetic markers to detect very fine-scale dispersal patterns. We collected 1573 individuals (946 adults and 627 juveniles) of the black-faced blenny across a small-scale (2 km) coastline as well as at a larger-scale area (<50 kms). A total of 178 single nucleotide polymorphism markers were used to evaluate relatedness patterns within this well-connected population. In our clustering models we categorized SHORT-range dispersers to be potential local recruits based on their high relatedness within and low relatedness towards other spatial clusters. Local retention and/or dispersal of this potential local recruitment varied across the 2 km coastline with higher frequency of SHORT-range dispersers towards the southwest of the area for adults. An inverse pattern was found for juveniles, showing an increase of SHORT-range dispersers towards the northeast. As we rule out selective movement and mortality from one year to the next, this pattern reveals a complex but not full genetic mixing, and variability in coastal circulation is most likely the main driver of this fine-scale chaotic genetic patchiness within this otherwise homogeneous population. When focusing on the patterns within one recruitment season, we found large differences in temperatures (from approx. 17 °C to 25 °C) as well as pelagic larval duration (PLD) for juveniles from the beginning of the season and the end of the season. We were able to detect fine-scale differences in LONG-range juvenile dispersers, representing distant migrants, depending on whether they were born at the beginning of the season with a longer PLD, or at the end of the reproductive season. The ability to detect such fine-scale dispersal patchiness will aid in our understanding of the underlying mechanisms of population structuring and chaotic patchiness in a wide range of species even with high potential dispersal abilities.

The influence of turning angles on the success of non-oriented animal searches.

Animal searches cover a full range of possibilities from highly deterministic to apparently completely random behaviors. However, even those stochastic components of animal movement can be adaptive, since not all random distributions lead to similar success in finding targets. Here we address the general problem of optimizing encounter rates in non-deterministic, non-oriented searches, both in homogeneous and patchy target landscapes. Specifically, we investigate how two different features related to turning angle distributions influence encounter success: (i) the shape (relative kurtosis) of the angular distribution and (ii) the correlations between successive relative orientations (directional memory). Such influence is analyzed in correlated random walk models using a proper choice of representative turning angle distributions of the recently proposed Jones and Pewsey class. We consider the cases of distributions with nearly the same shape but considerably distinct correlation lengths, and distributions with same correlation but with contrasting relative kurtosis. In homogeneous landscapes, we find that the correlation length has a large influence in the search efficiency. Moreover, similar search efficiencies can be reached by means of distinctly shaped turning angle distributions, provided that the resulting correlation length is the same. In contrast, in patchy landscapes the particular shape of the distribution also becomes relevant for the search efficiency, specially at high target densities. Excessively sharp distributions generate very inefficient searches in landscapes where local target density fluctuations are large. These results are of evolutionary interest. On the one hand, it is shown that equally successful directional memory can arise from contrasting turning behaviors, therefore increasing the likelihood of robust adaptive stochastic behavior. On the other hand, when target landscape is patchy, adequate tumbling may help to explore better local scale heterogeneities, being some details of the shape of the distribution also potentially adaptive.

[Current management of arteriovenous malformations. Retrospective study of 31 cases and literature review]. / Manejo actual de las malformaciones arteriovenosas. Estudio retrospectivo de 31 casos y revisión de la literatura.

OBJECTIVE: To establish some therapeutic criteria about the treatment of AVMs of III, IV and V grade of Spetzler and Martin and to analyse the results in the subgroup of preoperative embolization plus surgery. METHODS: We perform a retrospective analysis of a group of 31 patients with arteriovenous malformations (AVMs) treated in our center between 1999 and 2004. There were 19 women and 12 men, with a mean age of 31.6 years old (range, 1-62a). Their symptoms upon admission were intracranial hemorrhage in 77.4%, seizures in 12.9%, headache, ischemic event and incidental finding in 3.2% each group. Diagnostic angiography was performed in 29 cases and anatomopathologic diagnostic in 2 cases. The malformations were classified with Spetzler and Martin Grading Scale, in 10.3% grade I, 24.1% grade II, 37.9% grade III, 24.1% grade IV and 3.4% grade V. Patients were classified in 6 subgroups of treatment (surgery, embolization, radiosurgery, embolization plus surgery, embolization plus radiosurgery and conservative treatment). RESULTS: AVMs grade III, IV and V (19 patients) were treated with surgery (6 cases), embolization plus surgery (5 cases), but also other kind of treatments (embolization alone, radiosurgery and conservative) were used. Functional results in these groups of patients were 36.8% (7 cases) with no symptoms or slights symptoms (modified Rankin 0-1), 52.6% (10 cases) minor disability (mRankin 2), 5.3% (1 case) moderate disability and 5.3% (1 case) mortality. We observe a high rate of postembolization hemorrhage in the group of patients in which the combination of preoperative embolization plus surgery was used. In these cases, early surgery was performed with a good functional recovery. There was one case of postoperative mortality. CONCLUSION: We should consider some factors like the natural history, clinical presentation (hemorrhage), angiographic features (deep arterial supply, aneurisms), Spetzler and Martin Grading and the clinical condition of the patient before treating a cerebral AVM. In the subgroup of treatment with embolization plus surgery, we recommend to achieve a subtotal preoperative embolization > 50%, not to obliterate more than 50% in one session, to perform staged embolization waiting from 4 to 6 weeks between procedures, and from 1 to 3 weeks between the last embolization and surgery.

Active and reactive behaviour in human mobility: the influence of attraction points on pedestrians.

Human mobility is becoming an accessible field of study, thanks to the progress and availability of tracking technologies as a common feature of smart phones. We describe an example of a scalable experiment exploiting these circumstances at a public, outdoor fair in Barcelona (Spain). Participants were tracked while wandering through an open space with activity stands attracting their attention. We develop a general modelling framework based on Langevin dynamics, which allows us to test the influence of two distinct types of ingredients on mobility: reactive or context-dependent factors, modelled by means of a force field generated by attraction points in a given spatial configuration and active or inherent factors, modelled from intrinsic movement patterns of the subjects. The additive and constructive framework model accounts for some observed features. Starting with the simplest model (purely random walkers) as a reference, we progressively introduce different ingredients such as persistence, memory and perceptual landscape, aiming to untangle active and reactive contributions and quantify their respective relevance. The proposed approach may help in anticipating the spatial distribution of citizens in alternative scenarios and in improving the design of public events based on a facts-based approach.

Necessary criterion for distinguishing true superdiffusion from correlated random walk processes.

A difficulty in interpreting phenomena related to anomalous diffusion concerns how to identify scale invariant superdiffusive from Markovian correlated random walk processes. Here we propose a criterion that can distinguish between these two kinds of random walks and describe its usefulness in interpreting real data. To do so, we estimate the correlation time tau of the orientation persistence of a general correlated random walk. If the experimentally observed random walk appears diffusive on scales larger than tau, then the data cannot support the possibility of superdiffusion. We argue that the criterion is a necessary but not sufficient condition for establishing true superdiffusive behavior.

[Intraoperative neurophysiological monitoring of brain stem in a case of cavernoma in the pons]. / Monitorización neurofisiológica intraoperatoria del tronco del encéfalo en un caso de cavernoma en protuberancia.

Neurophysiological monitoring during surgery to avoid damaging of eloquent brain areas is a useful tool. We are performing intraoperative neurophysiological test to locate motor, sensitive and speech areas with cortical stimulation and cranial nerves during cerebellopontine cranial base surgery. Neurophysiological monitoring during brain stem surgery has been less described. Brain stem surgery implies a careful selection of patients for surgery given the high risk of morbidity and mortality. For this reason, conservative treatment is usually indicated when an asymptomatic cavernoma is incidentally found. Instead, when bleeding or neurological deficit appear, operative treatment may be indicated and then the goal of surgery is to avoid the disability linked to the natural history. We present the case of a 29 year old woman with diagnosis of multiple cavernomas. She was admitted at our hospital because she presented weakness and sensitive disturbance of left limbs and dizziness. The CT scan and MRI showed a pontine haemorrhage caused by a cavernous hemangioma. We operated her on using neurophysiological monitoring of VII, VIII, X and XII cranial nerves with electromyographic recordings. Postoperative disability could be reduced with a better knowledge of entry zone into the brain stem and early physiotherapy.

Inferring Lévy walks from curved trajectories: A rescaling method.

An important problem in the study of anomalous diffusion and transport concerns the proper analysis of trajectory data. The analysis and inference of Lévy walk patterns from empirical or simulated trajectories of particles in two and three-dimensional spaces (2D and 3D) is much more difficult than in 1D because path curvature is nonexistent in 1D but quite common in higher dimensions. Recently, a new method for detecting Lévy walks, which considers 1D projections of 2D or 3D trajectory data, has been proposed by Humphries et al. The key new idea is to exploit the fact that the 1D projection of a high-dimensional Lévy walk is itself a Lévy walk. Here, we ask whether or not this projection method is powerful enough to cleanly distinguish 2D Lévy walk with added curvature from a simple Markovian correlated random walk. We study the especially challenging case in which both 2D walks have exactly identical probability density functions (pdf) of step sizes as well as of turning angles between successive steps. Our approach extends the original projection method by introducing a rescaling of the projected data. Upon projection and coarse-graining, the renormalized pdf for the travel distances between successive turnings is seen to possess a fat tail when there is an underlying Lévy process. We exploit this effect to infer a Lévy walk process in the original high-dimensional curved trajectory. In contrast, no fat tail appears when a (Markovian) correlated random walk is analyzed in this way. We show that this procedure works extremely well in clearly identifying a Lévy walk even when there is noise from curvature. The present protocol may be useful in realistic contexts involving ongoing debates on the presence (or not) of Lévy walks related to animal movement on land (2D) and in air and oceans (3D).

Recovery of hypopituitarism after neurosurgical treatment of pituitary adenomas.

Surgery is the treatment of choice for many pituitary tumors; pituitary function may suffer after operation, but relief of pressure on the normal pituitary may also favor postoperative recovery of hypopituitarism. The aim of this study was to investigate the frequency of new appearance and recovery of hypopituitarism after neurosurgery and try to identify features associated with it. Pre- and postoperative anterior pituitary functions were investigated in 234 patients with pituitary adenomas (56 nonfunctioning, 71 PRL-secreting, 66 GH-secreting, 39 ACTH-secreting, 1 LH/FSH-secreting, and 1 TSH-secreting tumors). Eighty-eight new postoperative pituitary hypofunctions appeared in 52 patients (12 NF, 14 PRL-secreting, 15 GH-secreting, 10 ACTH-secreting, and 1 LH/FSH-secreting adenomas). They corresponded to 27% ACTH deficiencies (in 29 of the 107 patients with normal preoperative ACTH in whom postoperative evaluation was complete), 14.5% (15 of 103) new GH deficiencies, 10.5% (15 of 143; P < 0.0005, significantly less than ACTH deficiency) new TSH deficiencies, 16.5% (20 of 121) new gonadotropin deficiencies, and 13% (9 of 71) new PRL deficiencies. Preoperatively, 93 were deficient in at least 1 pituitary hormone; after surgery, 45 (48%) recovered between 1 and 3 hormones. The 2 patients with LH/FSH- and TSH-secreting macroadenomas did not recover pituitary function. Factors associated with a higher probability of postoperative pituitary function recovery were: no tumor rests on postoperative pituitary imaging (P = 0.001) and no neurosurgical (P = 0.001) or pathological evidence (P = 0.049) of an invasive nature. Tumor size did not differ significantly between those who did and those who did not recover pituitary function after surgery. Even if clear hypofunction is observed at initial work-up, patients should be reassessed after surgery without substitution therapy, because practically half the preoperative pituitary hormone deficiencies recover postoperatively, eliminating the need for life-long substitution therapy.

Neurinomas of the facial nerve. Report of three cases.

Three cases of neurinomas of the facial nerve are reported. Two of them originated from the labyrinthine portion of the nerve and the other from the vertical portion. Neurinomas of the first part of the facial nerve can be suspected preoperatively since they seem to give rise to specific clinical and radiological manifestations that can be distinguished from tumors of other portions of the nerve, the petrous bone area, or the cerebellopontine angle. The reported cases of neurinomas of the facial nerve are reviewed and analyzed.

Cavernous angiomas of the cranial nerves. Report of two cases.

Two cavernous hemangiomas arising in the third and eighth cranial nerves, respectively, and presenting as space-occupying lesions are reported. The tumors posed problems in the preoperative differential diagnosis. The main clinicopathological features of these tumors are discussed.

Spontaneous thrombosis of an intracranial aneurysm.

A case of spontaneous thrombosis of a previously ruptured anterior communicating artery aneurysm is reported. The patient was referred by another hospital to our service 4 months after the bleeding episode. He had developed a symptomatic normal pressure hydrocephalus, successfully treated by ventriculoperitoneal shunt. Follow-up angiographies, the first performed 4 months and the second 1 year after the bleeding, did not show the aneurysm. Furthermore, the parent artery was not occluded. The literature relative to the subject is reviewed and the possible mechanisms of spontaneous thrombosis are discussed.

[Surgical treatment of brain metastases]. / Tratamiento quirúrgico de las metástasis cerebrales.

INTRODUCTION: Up to 40% of the patients with cancer have cerebral metastases, so that their incidence in the general population reaches 0.15%. Different treatments for metastases have been described. Most aim to eradicate one or several metastases so as to improve the quality of life and life expectancy of the patients. DEVELOPMENT: The main factors determining the prognosis and indication for surgery are age, functional state and extent of the neoplastic disease. The presence of more than one metastasis does not contraindicate surgery. CONCLUSIONS: The development of new surgical techniques over the past twenty years has led to a reduction in operative morbidity and mortality. Surgery followed by holocranial radiotherapy is still the method of choice for the treatment of metastases. In cases in which surgical treatment is not indicated, radiosurgery may be done.