79 research outputs found
End-to-end binaural sound localisation from the raw waveform
A novel end-to-end binaural sound localisation approach is proposed which estimates the azimuth of a sound source directly from the waveform. Instead of employing hand-crafted features commonly employed for binaural sound localisation, such as the interaural time and level difference, our end-to-end system approach uses a convolutional neural network (CNN) to extract specific features from the waveform that are suitable for localisation. Two systems are proposed which differ in the initial frequency analysis stage. The first system is auditory-inspired and makes use of a gammatone filtering layer, while the second system is fully data-driven and exploits a trainable convolutional layer to perform frequency analysis. In both systems, a set of dedicated convolutional kernels are then employed to search for specific localisation cues, which are coupled with a localisation stage using fully connected layers. Localisation experiments using binaural simulation in both anechoic and reverberant environments show that the proposed systems outperform a state-of-the-art deep neural network system. Furthermore, our investigation of the frequency analysis stage in the second system suggests that the CNN is able to exploit different frequency bands for localisation according to the characteristics of the reverberant environment
Detection of activity and position of speakers by using deep neural networks and acoustic data augmentation
The task of Speaker LOCalization (SLOC) has been the focus of numerous works in the research field, where SLOC is performed on pure speech data, requiring the presence of an Oracle Voice Activity Detection (VAD) algorithm. Nevertheless, this perfect working condition is not satisfied in a real world scenario, where employed VADs do commit errors. This work addresses this issue with an extensive analysis focusing on the relationship between several data-driven VAD and SLOC models, finally proposing a reliable framework for VAD and SLOC. The effectiveness of the approach here discussed is assessed against a multi-room scenario, which is close to a real-world environment. Furthermore, up to the authors’ best knowledge, only one contribution proposes a unique framework for VAD and SLOC acting in this addressed scenario; however, this solution does not rely on data-driven approaches.
This work comes as an extension of the authors’ previous research addressing the VAD and SLOC tasks, by proposing numerous advancements to the original neural network architectures. In details, four different models based on convolutional neural networks (CNNs) are here tested, in order to easily highlight the advantages of the introduced novelties. In addition, two different CNN models go under study for SLOC. Furthermore, training of data-driven models is here improved through a specific data augmentation technique. During this procedure, the room impulse responses (RIRs) of two virtual rooms are generated from the knowledge of the room size, reverberation time and microphones and sources placement. Finally, the only other framework for simultaneous detection and localization in a multi-room scenario is here taken into account to fairly compare the proposed method.
As result, the proposed method is more accurate than the baseline framework, and remarkable improvements are specially observed when the data augmentation techniques are applied for both the VAD and SLOC tasks
Ethylene and Chitosan Affected the Seed Yield Components of Onion Depending More on the Dose than Timing of Application
(1) Background: the production of onion seeds is limited by the competition between seeds and the vegetative organs and by scape lodging. However, information on the effects of plant growth regulation on onion seed production is scarce. Aim of the present study was to evaluate the seed yield components and germination ability of onion seeds as affected by the timing and dose of an ethylene application, a plant growth regulator able to modulate shoot–flower competition; and chitosan, an elicitor of plant defense mechanisms able to increase its tolerance to various stresses. (2) Methods: Onion was treated with ethylene at the recommended dose (100% RD) of a commercial product, at 150% RD in two contrasting phenological phases or untreated (control), or ‘with’ or ‘without’ chitosan, and the seed yield components and germination trend were measured. (3) Results: 100% RD at an early phase of growth did not influence the seed yield and increased the thousand seed weight (TSW) by 3.2%. The application of 150% RD decreased the seed yield by 33.5%, and this occurred irrespective of the timing of application. Such decreases were due to a reduction in the number of seeds per flower. The application of chitosan did not affect the crop at 100% RD and increased the seed yield and slightly increased, but not significantly, the TSW under 150% RD. Germination of the fresh seed was 92%, and 17 months of aging reduced it by 14%, with no effects of the treatments on the germination pattern. (4) Conclusions: the ethylene application mostly affected TSW but not the yield, whereas high doses of ethylene reduced yields irrespective of the timing of application. Such a result may have been due to a delay in the flowering onset that occurred in a relatively dry month. Chitosan sustained its yield when the yield potential was reduced by 150% RD, and such a result was likely due to physical protection from the transpiration since the synthetic fungicides applied did not likely allow the pathogens to infections. These results have implications for establishing the timing and dose of application of plant growth regulators and elicitors in seed onions to sustain the seed quality
The structure and regulation of the Irish equine industries: Links to considerations of equine welfare
The equine industries in Ireland are vibrant and growing. They are broadly classified into two sectors: Thoroughbred racing, and sports and leisure. This paper describes these sectors in terms of governance, education and training in equine welfare, and available data concerning horse numbers, identification, traceability and disposal. Animal welfare, and specifically equine welfare, has received increasing attention internationally. There is general acceptance of concepts such as animal needs and persons' responsibilities toward animals in their care, as expressed in the 'Five Freedoms'. As yet, little has been published on standards of equine welfare pertaining to Ireland, or on measures to address welfare issues here. This paper highlights the central role of horse identification and legal registration of ownership to safeguard the health and welfare of horses
GENETIC ANALYSES ON BONE REMAINS: THE UNIVERSITY OF ROME “SAPIENZA” LABORATORY OF FORENSIC GENETICS’ EXPERIENCE
Genetic analyses on bone remains in the field of human identification represent one of the most stimulating and complex challenges for forensic geneticists. Unlike the analysis of biological traces such as blood, semen, saliva or urine, that usually do not present any particular technical and operational difficulty so that personal identification can be achieved, as appropriate, more or less easily through comparing the genetic profile obtained from the sample with the one available as reference, the identification of bone remains forces the analysts to face multiple and complex variable factors (e.g. the degradation of genetic material and the environmental contamination of the samples) that can affect the success of the analysis in the sense of obtaining a complete and interpretable STR profile. In such cases an accurate evaluation of the characteristics of the sample and the environmental conditions to which this finding has been exposed is extremely important.
This presentation describes the methods used in the Laboratory of Forensic Genetics of the Department S.A.I.M.L.A.L of the University of Rome "Sapienza" for the analysis of bone remains, to the purpose of either personal identification or the assessment of a parental relationship.
The authors will present a selection of 20 cases came under their observation during the years 2007-2011, for which the genetic analyses were performed on different bone samples (femur, tibia, humerus, mandible) using different extraction, amplification and STR typing methods. The results obtained will be compared in order to assess for each case the specific role of 3 important variable factors: the age of the remains, the environmental conditions of storage/finding and the cause of death.
6 out of the 20 cases showed interpretation problems related to the Low Copy Number (LCN, or Low Template -LT) DNA condition due to DNA degradation (i.e. the effects of high temperatures in case of charred remains; the acceleration of autolytic processes in case of hexumation of a corpse) and/or the presence of DNA inhibitors (e.g. Calcium Phosphate, Humic Acid) that likely were co-extracted with the DNA from the evidence sample. The results show that the possibility of obtaining a complete and interpretable genetic profile depends largely on the 3 variable factors mentioned above, particularly with regard to the environmental conditions of storage/finding of the remains, thus confirming the need to optimize the analytical methods in order to minimize the effects of environmental inhibitors.
After attending this presentation, attendees will understand some principles of genetic analysis on bone remains, the challenges related to this kind of investigation especially for what concerns criminal cases and the importance of the honesty of the forensic scientist when a certain and unequivocal interpretation of the DNA profile obtained cannot be provided.
This presentation will impact the forensic community by highlighting the importance of bone remains as an evidentiary sample in forensic caseworks and the difficulties related to the genetic analysis of such samples due to degradation and/or inhibition factors: in these cases it is fundamental for the scientist to consider that asserting that a complete and interpretable genetic profile is not obtained from a sample (thus the sample cannot be considered useful for a comparison) does not mean a failure but, on the contrary, reveals scientific honesty and should stimulate the necessary progress in this field
Indagini genetiche su reperti ossei: esperienza del laboratorio di genetica forense dell'Università di Roma "Sapienza"
L’analisi di reperti ossei in ambito identificativo rappresenta ad oggi una delle sfide più stimolanti e complesse per i genetisti forensi.
A differenza dell’analisi di tracce biologiche quali sangue, sperma, saliva o urina, le quali non presentano particolari difficoltà dal punto di vista tecnico-operativo per cui l’identificazione personale può essere raggiunta, a seconda dei casi, più o meno facilmente tramite il confronto del profilo genetico ottenuto con quello di riferimento disponibile caso per caso, nell’identificazione di resti ossei ci si trova a dover affrontare molteplici e complesse variabili (degradazione del materiale genetico nonché contaminazione ambientale dei reperti) in grado di condizionare il buon esito dell’analisi nel senso dell’ottenimento di un profilo STR completo ed interpretabile. In tali casi risulta infatti spesso tanto difficile quanto auspicabile riconoscere e valutare a priori la specifica tipologia del reperto in esame e le condizioni ambientali a cui tale reperto è stato esposto.
Nel presente lavoro vengono illustrate le metodiche impiegate nel Laboratorio di Genetica Forense del Dipartimento SAIMLAL dell'Università di Roma “Sapienza” nell’analisi di resti ossei, ai fini sia identificativi che di accertamento del rapporto parentale. Nei casi esaminati, le analisi genetiche sono state eseguite su campioni ossei diversi (femore, tibia, omero, mandibola) utilizzando la medesima metodica di estrazione del DNA abbinata a kit commerciali di amplificazione e tipizzazione degli STR differenti ed i risultati ottenuti sono stati confrontati al fine di evidenziare il ruolo specifico, per ogni singolo caso in esame, dei seguenti fattori variabili: età dei reperti, condizioni ambientali di conservazione/ritrovamento e modalità del decesso.
I risultati ottenuti mostrano che la possibilità di ottenere un profilo genetico utile dipende strettamente dalle variabili precedentemente indicate, con particolare riguardo alle condizioni ambientali di conservazione/ritrovamento dei resti ossei, confermando la necessità di approfondire le conoscenze sulla natura e gli effetti degli inibitori dell’amplificazione del DNA al fine di ottimizzare le metodiche analitiche riducendo al minimo gli effetti inibenti di tali sostanze
Identificazione del liquido seminale: metodiche a confronto
Nei casi di violenza sessuale è di fondamentale importanza, oltre ad un accurato esame obiettivo della vittima, la raccolta di tutti gli elementi che possono costituire la prova dell’abuso subito. Tra gli elementi di prova assume particolare rilievo la ricerca del liquido seminale che, come altri fluidi corporei, può essere evidenziato su reperti diversi quali indumenti, lenzuola, fazzoletti, ecc. Tra le metodiche attualmente impiegate nei laboratori medico-legali vanno segnalate quelle basate su metodi immunocromatografici finalizzati all’identificazione di sostanze presenti in elevata concentrazione nel liquido seminale quali l’Antigene Prostatico Specifico (PSA) e la Semenogelina (Sg). Nel presente lavoro illustriamo i risultati da noi ottenuti utilizzando in parallelo due diversi kit commerciali per l’identificazione del PSA e della Sg. Al fine di verificare la sensibilità dei kit le indagini sono state condotte su reperti di interesse forense conservati nel nostro laboratorio per un periodo di tempo variabile da 3 mesi a 10 anni. Sebbene le metodiche immunocromatografiche, per la rapidità e l’efficacia dei test stessi, rappresentino un valido mezzo per l’identificazione del liquido seminale, è comunque necessario, per i campioni risultati negativi e/o con risultati discordanti nei test, eseguire le analisi genetiche al fine di giungere ad una corretta definizione del caso
Beneficial Effects of Trichoderma harzianum combined with fructans on tomato plant growth.
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