Symptoms of anxiety and depression in patients with persistent asthma: a cross-sectional analysis of the INSPIRERS studies.

OBJECTIVES: Anxiety and depression are relevant comorbidities in asthma, but, in Portugal and Spain, data on this topic are scarce. We assessed, in patients with asthma, the frequency of anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) and the European Quality of Life Five Dimension Questionnaire (EQ-5D); the level of agreement between these questionnaires, and the factors associated with these symptoms. METHODS: This is a secondary analysis of the INSPIRERS studies. A total of 614 adolescents and adults with persistent asthma (32.6±16.9 years, 64.7% female) were recruited from 30 primary care centres and 32 allergy, pulmonology and paediatric clinics. Demographic and clinical characteristics, HADS and EQ-5D were collected. A score ≥8 on Hospital Anxiety and Depression Scale-Anxiety/Hospital Anxiety and Depression Scale-Depression or a positive answer to EQ-5D item 5 indicated the presence of these symptoms. Agreement was determined by Cohen's kappa. Two multivariable logistic regressions were built. RESULTS: According to HADS, 36% of the participants had symptoms of anxiety and 12% of depression. According to EQ-5D, 36% of the participants had anxiety/depression. The agreement between questionnaires in identifying anxiety/depression was moderate (k=0.55, 95% CI 0.48 to 0.62). Late asthma diagnosis, comorbidities and female gender were predictors of anxiety/depression, while better asthma control, health-related quality of life and perception of health were associated with lower odds for anxiety/depression. CONCLUSION: At least 1/3 of the patients with persistent asthma experience symptoms of anxiety/depression, showing the relevance of screening these disorders in patients with asthma. EQ-5D and HADS questionnaires showed a moderate agreement in the identification of anxiety/depression symptoms. The identified associated factors need to be further investigated in long-term studies.

Knowledge and Patterns of Use of Emergency Oral Contraception among Portuguese Female Users of Healthcare Services.

INTRODUCTION: The lack of knowledge about the existence, effectiveness, and supply of emergency contraception as well as access to it, its effective duration and the lack of recognition of the need for its use can prevent women from using it. The aim of this study was to ascertain the attitudes, experience, level of knowledge and information sources about emergency contraception of Portuguese female users of healthcare services. MATERIAL AND METHODS: We conducted a multicentre, cross-sectional, observational study among 280 Portuguese women users of health care services through an original and anonymous questionnaire composed of 30 questions. RESULTS: The mean age of the women who replied to the questionnaire was 33.83 ± 8.76 years. Of the observed sample, 27.7% used EC, 50% of whom with no counselling. Despite 92.1% of women claiming knowledge about emergency contraception, only 31.2% of these answered 8 - 10 questions correctly (14 in total). The media were the most frequent source of information (63.4%). Most participants (67.5%) considered that emergency contraception is associated with severe adverse reactions. Furthermore, 76% did not know the time range of effectiveness after unprotected sexual intercourse. Youngest age (p = 0.038), higher education level (p < 0.001), increasing parity (p = 0.051) and previous use of emergency contraception (p = 0.011) were identified as the determinant sociodemographic factors for a higher level of knowledge about emergency contraception. DISCUSSION: The use of emergency contraception after counselling by healthcare professionals was lower than reported in the literature. CONCLUSION: This study showed that female users of healthcare services were aware of the existence of emergency contraception, but they demonstrated a low level of knowledge about it, especially regarding the correct period of use, place of acquisition and safety issues.

Introdução: A falta de conhecimento sobre a existência, eficácia e fornecimento da contraceção de emergência, bem como a sua acessibilidade, prazo efetivo e a falta de reconhecimento da possibilidade da sua utilização podem impedir as mulheres de a utilizarem. O objetivo do estudo foi conhecer a experiência, atitudes, as fontes de informação e nível de conhecimento sobre a contraceção de emergência entre mulheres portuguesas utilizadoras dos cuidados de saúde. Material e Métodos: Foi desenvolvido um estudo observacional, transversal e multicêntrico em 280 mulheres portuguesas utilizadoras dos cuidados de saúde, através da aplicação de um questionário original e anónimo constituido por 30 questões. Resultados: A idade média das mulheres que responderam ao questionário situou-se nos 33,83 ± 8,76 anos. Da amostra em estudo, 27,7% referiram utilização prévia de contraceção de emergência, das quais 50% sem aconselhamento. Apesar de 92,1% afirmar conhecer esta opção, apenas 35,9% respondeu corretamente a entre oito a 10 questões de avaliação de conhecimento (total de 14). Os media constituiram a fonte de informação mais frequente (63,4%). A maioria das participantes (67,5%) considera que a contraceção de emergência está associada a efeitos adversos graves e 76% desconhece o intervalo de tempo de eficácia da contraceção de emergência após relações sexuais desprotegidas. A idade jovem (p = 0,038), maior nível de escolaridade (p < 0,001), o aumento da paridade (p = 0,051) e a utilização prévia de contraceção de emergência (p = 0,031) foram os fatores sociodemográficos associados a maior nível de conhecimento sobre a mesma. Discussão: O uso de contraceção de emergência após aconselhamento por profissionais de saúde foi inferior ao descrito na literatura. Conclusão: O estudo demonstrou que apesar das utilizadoras dos cuidados de saúde de afirmarem ter conhecimento da existência da contraceção de emergência, revelaram baixo nível de conhecimento sobre este tipo de contraceção, particularmente em relação ao período correto de utilização, local de aquisição e questões de segurança.

Phosphorous and Silica Recovery from Rice Husk Poultry Litter Ash: A Sustainability Analysis Using a Zero-Waste Approach.

Phosphate rocks are a critical resource for the European Union, and alternative sources to assure the future production of a new generation of fertilizers are to be assessed. In this study, a statistical approach, combined with a sustainability evaluation for the recovery of materials from waste containing phosphorus (P), is presented. This work proposes a strategy to recover P and silica (SiO2) from rice husk poultry litter ash (RHPLA). The design of experiment (DoE) method was applied to maximize the P extraction using hydrochloric acid (HCl), with the aim to minimize the contamination that can occur by leachable heavy metals present in RHPLA, such as zinc (Zn). Two independent variables, the molar concentration of the acid, and the liquid-to-solid ratio (L/S) between the acid and RHPLA, were used in the experimental design to optimize the operating parameters. The statistical analysis showed that a HCl concentration of 0.34 mol/L and an L/S ratio of 50 are the best conditions to recover P with low Zn contamination. Concerning the SiO2, its content in RHPLA is too low to consider the proposed recovery process as advantageous. However, based on our analysis, this process should be sustainable to recover SiO2 when its content in the starting materials is more than 80%.

Simultaneous amorphous silica and phosphorus recovery from rice husk poultry litter ash.

The livestock sector is one of the most important sectors of the agricultural economy due to an increase in the demand for animal protein. This increase generates serious waste disposal concerns and has negative environmental consequences. Furthermore, the food production chain needs phosphorus (P), which is listed as a critical raw material due to its high demand and limited availability in Europe. Manure contains large amounts of P and other elements that may be recycled, in the frame of circular economy and "zero waste" principles, and reused as a by-product for fertilizer production and other applications. This paper focuses on the extraction and recovery of amorphous silica from rice husk poultry litter ash. Two different extraction procedures are proposed and compared, and the obtained silica is characterized. This work shows that amorphous silica can be recovered as an almost pure material rendering the residual ash free of P. It also addresses the possibility of more specific phosphorous extraction procedures via acid leaching.

STOP-Bang and NoSAS questionnaires as a screening tool for OSA: which one is the best choice?

INTRODUCTION: Currently there has been significant growth in the number of patients with suspected obstructive sleep apnea (OSA) referred to sleep clinics. In this sense, screening and stratification methods of the severity of this pathology have become increasingly relevant. OBJECTIVE: To evaluate the performance of the NoSAS and STOP-Bang scores in the screening of OSA in a sleep clinic. METHODS: Prospectively, for 12 months, all patients referred by primary care physicians to our sleep unit for clinical evaluation and who underwent in-lab polysomnography (PSG), also completed the NoSAS score (Neck circumference, Obesity, Snoring, Age, Sex) and STOP-Bang (Snoring, Tiredness, Observed apnea, Pressure (high blood), BMI, Age, Neck circumference, Gender). A ROC (receiver operating characteristic) analysis was used to find the scores that simultaneously maximize sensitivity and specificity for each diagnosis. RESULTS: Of the 294 individuals included, 84% had OSA, of which 28.8% were mild, 34.8% moderate, and 36.4% were severe. USING THE NOSAS SCORE FOR PREDICTING OSA, MODERATE TO SEVERE OSA, AND SEVERE OSA, THE ROC AREA WAS: 0.770 (95% CI: 0.703-0.837), p<0.001, sensitivity of 57.5%, and specificity of 83.0% for a score of 12; 0.746 (95% CI: 0.691-0.802), p<0.001, sensitivity of 68.2% and specificity of 75.4% for a score of 13; 0.686 (95% CI: 0.622-0.749), p<0.001, sensitivity of 71.1% and specificity of 58.3% for a score of 13, respectively. USING THE STOP-BANG SCORE FOR PREDICTING OSA, MODERATE TO SEVERE OSA, AND SEVERE OSA, THE ROC AREA WAS: 0.862 (95% CI: 0.808-0.916), p<0.001, sensitivity of 68.4% and specificity of 85.1% for a score of 5; 0.813 (95% CI: 0.756-0.861), p<0.001, sensitivity of 77.3% and specificity of 66.1% for a score of 5; 0.787 (95% CI: 0.732-0.841), p<0.001, sensitivity of 70.0% and specificity of 79.9% for a score of 6, respectively. CONCLUSIONS: The ROC area was consistently high for both scores confirming the diagnostic ability of the NoSAS and STOP-Bang questionnaires for all OSA severities. Thus, our results suggest that these questionnaires may be a powerful tool for the screening and stratification of patients in the diagnosis of OSA. Overall, the diagnostic ability of the STOP-Bang was higher than the NoSAS.

STOP-Bang and NoSAS questionnaires as a screening tool for OSA: which one is the best choice?

SUMMARY INTRODUCTION: Currently there has been significant growth in the number of patients with suspected obstructive sleep apnea (OSA) referred to sleep clinics. In this sense, screening and stratification methods of the severity of this pathology have become increasingly relevant. OBJECTIVE: To evaluate the performance of the NoSAS and STOP-Bang scores in the screening of OSA in a sleep clinic. METHODS: Prospectively, for 12 months, all patients referred by primary care physicians to our sleep unit for clinical evaluation and who underwent in-lab polysomnography (PSG), also completed the NoSAS score (Neck circumference, Obesity, Snoring, Age, Sex) and STOP-Bang (Snoring, Tiredness, Observed apnea, Pressure (high blood), BMI, Age, Neck circumference, Gender). A ROC (receiver operating characteristic) analysis was used to find the scores that simultaneously maximize sensitivity and specificity for each diagnosis. RESULTS: Of the 294 individuals included, 84% had OSA, of which 28.8% were mild, 34.8% moderate, and 36.4% were severe. USING THE NOSAS SCORE FOR PREDICTING OSA, MODERATE TO SEVERE OSA, AND SEVERE OSA, THE ROC AREA WAS: 0.770 (95% CI: 0.703-0.837), p<0.001, sensitivity of 57.5%, and specificity of 83.0% for a score of 12; 0.746 (95% CI: 0.691-0.802), p<0.001, sensitivity of 68.2% and specificity of 75.4% for a score of 13; 0.686 (95% CI: 0.622-0.749), p<0.001, sensitivity of 71.1% and specificity of 58.3% for a score of 13, respectively. USING THE STOP-BANG SCORE FOR PREDICTING OSA, MODERATE TO SEVERE OSA, AND SEVERE OSA, THE ROC AREA WAS: 0.862 (95% CI: 0.808-0.916), p<0.001, sensitivity of 68.4% and specificity of 85.1% for a score of 5; 0.813 (95% CI: 0.756-0.861), p<0.001, sensitivity of 77.3% and specificity of 66.1% for a score of 5; 0.787 (95% CI: 0.732-0.841), p<0.001, sensitivity of 70.0% and specificity of 79.9% for a score of 6, respectively. CONCLUSIONS: The ROC area was consistently high for both scores confirming the diagnostic ability of the NoSAS and STOP-Bang questionnaires for all OSA severities. Thus, our results suggest that these questionnaires may be a powerful tool for the screening and stratification of patients in the diagnosis of OSA. Overall, the diagnostic ability of the STOP-Bang was higher than the NoSAS.

RESUMO INTRODUÇÃO: Na atualidade tem se verificado um crescimento significativo no número de doentes com suspeita de apneia obstrutiva do sono (AOS) referenciados para consulta do sono. Nesse sentido, instrumentos de rastreio e estratificação da gravidade dessa patologia têm se tornado cada vez mais relevantes. OBJETIVO: Avaliar e comparar o desempenho da escala NoSAS e Stop-Bang para o rastreio de AOS. MÉTODOS: Estudo prospectivo durante 12 meses. Avaliados todos os doentes encaminhados aos cuidados de saúde primários do centro de medicina do sono que completaram o questionário NoSAS (Neck circumference, Obesity, Snoring, Age, Sex), Stop-Bang (Snoring, Tiredness, Observed apnea, Pressure [high blood], BMI, Age, Neck circumference, Gender) e foram submetidos a polissonografia. Utilizou-se uma análise ROC (receiver operating characteristic) para encontrar as pontuações que maximizam simultaneamente a sensibilidade e especificidade para cada diagnóstico. RESULTADOS: Incluídos 294 indivíduos, 84% apresentavam AOS, sendo que em 28,8% a OAS era ligeira, 34,8% moderada e 36,4% grave. USANDO A ESCALA NOSAS PARA PREVISÃO DE AOS, AOS MODERADA A GRAVE E AOS GRAVE, A ÁREA ROC FOI: 0,770 (IC95%: 0,703-0,837), p<0,001, sensibilidade de 57,5% e especificidade de 83,0% para a pontuação 12); 0,746 (IC95%: 0,691- 0,802), p<0,001, sensibilidade de 68,2% e especificidade de 75,4% para a pontuação 13); 0,686 (IC95%: 0,622-0,749), p<0,001, sensibilidade de 71,1% e especificidade de 58,3% para a pontuação 13), respectivamente. USANDO A ESCALA STOP-BANG PARA A PREVISÃO DE AOS, AOS MODERADA A GRAVE E AOS GRAVE, A ÁREA ROC FOI: 0,862 (IC95%: 0,808-0,916), p<0,001, sensibilidade de 68,4% e especificidade de 85,1% para pontuação 5); 0,813 (IC95%: 0,756-0,861), p<0,001, sensibilidade de 77,3% e especificidade de 66,1% para a pontuação 5); 0,787 (IC95%: 0,732-0,841), p<0,001, sensibilidade de 70,0% e especificidade de 79,9% para a pontuação 6), respectivamente. CONCLUSÕES: A área ROC foi consistentemente alta para as duas escalas, confirmando a capacidade diagnóstica dos questionários NoSAS e Stop-Bang para todos os graus de gravidade de AOS. Assim, os nossos resultados sugerem que esses questionários podem ser um importante instrumento para rastreio e estratificação de doentes no diagnóstico de AOS. Globalmente, a capacidade de diagnóstico do Stop-Bang foi superior à do NoSAS.

Poultry litter ash characterisation and recovery.

This paper reports a complete characterisation of poultry litter ash and its potential use as a heavy metal stabiliser. We propose a novel approach, in which the ashes deriving from municipal solid waste incineration (MSWI) are combined with poultry litter ash, rather than with coal combustion flue gas desulfurisation (FGD) residues. Heavy metals stabilisation was demonstrated by comparing the elemental concentrations in the leaching solutions of the starting raw and stabilised materials: leachable Pb and Zn showed a reduced solubility. The characterisation was conducted by total reflection X-ray fluorescence (TXRF), X-ray diffraction (XRD), micro-Raman spectroscopy and scanning electron microscopy combined with energy-dispersive X-ray spectrometry (SEM-EDX). The results showed that the poultry litter ash was Ca-, P-, K- and S-rich (>29 g/kg). It contained amorphous materials (i.e. fly ash economiser (FAECO) 73% and fly ash cyclone (FACYC) 61%) and soluble phases (e.g. arkanite and sylvite; up to 13% FAECO and 28% FACYC), as well as resilient crystalline (up to 2% of FAECO and FACYC) and amorphous phases (e.g. hydroxyapatite). After two months, the Pb and Zn concentrations in the leachate solutions were below the limit set by the European regulations for waste disposal (<0.2 mg/L and 1.5 mg/L, respectively). We propose a mechanism for the heavy metals stabilisation based on the carbonation process and high amounts of P, Ca and reactive amorphous phases. In conclusion, it is demonstrated that poultry litter ash can be an effective secondary source of heavy metals, allowing their immobilisation through P- and Ca-based reactive amorphous phases.

STOP-Bang questionnaire: the validation of a Portuguese version as a screening tool for obstructive sleep apnea (OSA) in primary care.

INTRODUCTION: The growing number of suspected patients diagnosed with obstructive sleep apnea (OSA) that are observed in sleep units has increased in the last decade. Therefore, screening methods have become important, especially in primary care (PC). AIM: This work aimed to test the performance of the STOP-Bang questionnaire for the suspicion/diagnosis of obstructive sleep apnea. METHODS: Eight-month prospective study; all patients referred from PC to the respective sleep clinic accompanied by a completed and translated version of the STOP-Bang questionnaire for a clinical evaluation. RESULTS: Two hundred fifty-nine observed patients were the study object. The age was 55.14 ± 12.07 years, 71.03% were male patients with a neck circumference of 40.97 ± 3.07 cm and BMI of 31.1 ± 5.14 kg/m2. The diagnosis was confirmed in 82.6% of the patients: 34.6% having moderate and 36.8% severe disease. A STOP-Bang score of 3 or more resulted in positive predictive value (PPV) of 88.4% and a sensitivity for OSA of 98.6%. Has the questionnaire score raises, OSA's probability also raises in a proportional basis. For a STOP-Bang score of 6, the OSA probability reaches 98% and for a score of 8, it reaches 80% for severe OSA. Lower scores, 3 or 2, had a negative predictive value (NPV) for moderate-to-severe OSA of 86.96 and 87.5%, respectively. CONCLUSION: As much as we know, our study is the first that applied the STOP-Bang questionnaire in Portuguese PC. We demonstrate that these is a useful tool for the stratification of patients with suspicion and diagnosis of OSA, showing a high sensitivity and PPV. Besides that, the probability of severe OSA steadily increases along with its score and we show an excellent NPV with lower scores.

Design and Evaluation of Novel Textile Wearable Systems for the Surveillance of Vital Signals.

This article addresses the design, development, and evaluation of T-shirt prototypes that embed novel textile sensors for the capture of cardio and respiratory signals. The sensors are connected through textile interconnects to either an embedded custom-designed data acquisition and transmission unit or to snap fastener terminals for connection to external monitoring devices. The performance of the T-shirt prototype is evaluated in terms of signal-to-noise ratio amplitude and signal interference caused by baseline wander and motion artefacts, through laboratory tests with subjects in standing and walking conditions. Performance tests were also conducted in a hospital environment using a T-shirt prototype connected to a commercial three-channel Holter monitoring device. The textile sensors and interconnects were realized with the assistance of an industrial six-needle digital embroidery tool and their resistance to wear addressed with normalized tests of laundering and abrasion. The performance of these wearable systems is discussed, and pathways and methods for their optimization are highlighted.

Study of ventricular electrical systole in patients with end-stage kidney disease on hemodialysis.

BACKGROUND: Patients with end-stage kidney disease (ESKD) experience elevated cardiac stress because of the repetitive and intermittent character of dialysis. Changes in ventricular electrical systole induced by necessary dialysis significantly contribute to predict sudden death due to arrhythmia in ESKD. OBJECTIVE: The major objective of this study was to assess the behavior of ventricular repolarization in dialysis by analyzing QTc interval and QTc dispersion. METHODS: This study sample consisted of 47 patients undergoing hemodialysis (61.7% males and 38.3% females), whose mean age was 66.79±13.16 years. All of them underwent three electrocardiograms performed before, during and after one dialysis session. Ventricular electrical systole was analyzed later. RESULTS: An increase in maximum QTc interval and QTc dispersion associated with dialysis was observed. In addition, an increase in the number of individuals meeting the electrocardiographic criteria for left ventricular hypertrophy (LVH) was observed. After dialysis, higher means of the maximum QTc interval (473 ± 27.63 mseg) and of the QTc dispersion (58.95 ± 18.87 mseg) were observed in individuals with LVH as compared with those in individuals without LVH (455.21 ± 26.85 mseg and 44 ± 16.41 mseg, respectively). CONCLUSION: This study confirmed an increase in the QTc interval and QTc dispersion associated with dialysis. That emphasizes the dependence of ventricular repolarization on fluid and electrolyte balance, and suggests a profile of higher vulnerability to arrhythmia associated with dialysis .

Estudo da sístole elétrica ventricular nos insuficientes renais crônicos hemodialisados / Study of ventricular electrical systole in patients with end-stage kidney disease on hemodialysis

FUNDAMENTO: Os indivíduos com insuficiência renal crônica terminal estão sujeitos a um elevado estresse cardíaco pelo carácter repetitivo e intermitente da terapia dialítica. As alterações na sístole elétrica ventricular induzidas pela necessária terapia dialítica são um contributo importante na predição da ocorrência de morte súbita arrítmica na insuficiência renal crônica terminal. OBJETIVO: O objetivo principal desta investigação é avaliar o comportamento da repolarização ventricular em face da terapia dialítica, mediante o estudo do intervalo QTc e dispersão do QTc. MÉTODOS: A amostra em estudo inclui 47 indivíduos sujeitos a hemodiálise (61,7% do sexo masculino e 38,3% do sexo feminino) com idade média de 66,79 ± 13,16 anos. Todos os indivíduos foram sujeitos a três eletrocardiogramas realizados em três momentos durante a terapia dialítica (pré, durante e após a sessão), sendo posteriormente analisada a sístole elétrica ventricular. RESULTADOS: Ocorreu um aumento do intervalo QTc máximo e da dispersão do QTc associado à terapia dialítica. Aliado ao aumento desses intervalos ocorreu um aumento do número de indivíduos com critérios eletrocardiográficos para hipertrofia ventricular esquerda, registando-se no período pós-diálise uma média superior do intervalo QTc máximo (473 ± 27,63 mseg) e da dispersão do QTc (58,95 ± 18,87 mseg) desses indivíduos, comparativamente aos indivíduos sem HVE, 455,21 ± 26,85 mseg e 44 ± 16,41 mseg, respectivamente. CONCLUSÃO: O presente estudo confirmou um aumento do intervalo QTc e da dispersão do QTc associado à terapia dialítica. Esse aspecto reforça a dependência da repolarização ventricular em relação ao equilíbrio hídrico e eletrolítico e sugere um perfil de maior vulnerabilidade arrítmica associada à terapia dialítica.

BACKGROUND: Patients with end-stage kidney disease (ESKD) experience elevated cardiac stress because of the repetitive and intermittent character of dialysis. Changes in ventricular electrical systole induced by necessary dialysis significantly contribute to predict sudden death due to arrhythmia in ESKD. OBJECTIVE: The major objective of this study was to assess the behavior of ventricular repolarization in dialysis by analyzing QTc interval and QTc dispersion. METHODS: This study sample consisted of 47 patients undergoing hemodialysis (61.7% males and 38.3% females), whose mean age was 66.79±13.16 years. All of them underwent three electrocardiograms performed before, during and after one dialysis session. Ventricular electrical systole was analyzed later. RESULTS: An increase in maximum QTc interval and QTc dispersion associated with dialysis was observed. In addition, an increase in the number of individuals meeting the electrocardiographic criteria for left ventricular hypertrophy (LVH) was observed. After dialysis, higher means of the maximum QTc interval (473 ± 27.63 mseg) and of the QTc dispersion (58.95 ± 18.87 mseg) were observed in individuals with LVH as compared with those in individuals without LVH (455.21 ± 26.85 mseg and 44 ± 16.41 mseg, respectively). CONCLUSION: This study confirmed an increase in the QTc interval and QTc dispersion associated with dialysis. That emphasizes the dependence of ventricular repolarization on fluid and electrolyte balance, and suggests a profile of higher vulnerability to arrhythmia associated with dialysis .

Characterization of soils from the Algarve region (Portugal): a multidisciplinary approach for forensic applications.

The Algarve is located at a very short distance from North Africa, in Southern Portugal, and as one of the most touristic regions of Portugal, it is accessible by air, land and sea. It is very susceptible to many illegal activities, such as illegal migration, drug trafficking, kidnapping, and murder, among others. Therefore, an Algarve soils database for forensic purposes is being conducted with the conjunction of geological and palynological methodologies on soils characterization, since this is of fundamental importance to assess reliable evidence on forensic investigations. In this study, the properties of soils from several proximate sites from the Algarve were investigated, namely: (i) colour determined by spectrophotometry; (ii) particle size distribution determined by laser granulometry; (iii) low-field magnetic susceptibility by a susceptibility meter; and (iv) pollen content using a light microscope. Finally, a hierarchical cluster analysis was applied to ascertain the capacity of the different soil properties for discrimination between samples. The study reveals the utility of geobotanical techniques for forensic discrimination of soils. Even though some similarities between some of the samples were found, each one presented a combination of colour, particle size distribution, magnetic susceptibility and pollen features that enable the determination of a fingerprint expected to reveal a specific site for future selection of coastal search areas in the Algarve region.

Quantitative colour analysis of beach and dune sediments for forensic applications: a Portuguese example.

In this study, the colour of 23 sediment samples collected in different Portuguese beaches in the North (Entre-Douro and Minho) and 33 in the South (Algarve) was tested. Spectral colour parameters (L*a*b*) were measured after several presentation/pre-treatment methods: drying at 40 degrees C, sieving (<150 and <63 microm) and ashing at 850 degrees C, using a Konica Minolta CM-2600d spectrophotometer. A descriptive statistical analysis with L*a*b* values for each presentation/pre-treatment method was performed to ascertain within-sample reproducibility followed by a hierarchical cluster analysis to obtain significant discrimination between samples using colour analysis. The samples analysed presented a colour closest to red and yellow continuums and a lightness close to the pale side of the L*a*b* system colour sphere with samples collected in the North presenting analysis on average darker L values than the samples collected in the South. The cluster analysis, dried, unsieved bulk samples L*a*b* values gave the best discrimination between samples. The clusters analysis dried, unsieved bulk samples-dried, sieved <150 microm fraction set allowed better discrimination between samples compared with the dried, sieved <63 microm fraction set or dried, unsieved bulk samples-ashed bulk, unsieved samples set and even with dried, unsieved bulk samples/dried, sieved <150 microm fraction/dried, sieved <63 microm fraction/ashed bulk, unsieved samples considered all together.