898 resultados para Tool Use


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Euroopan energiamarkkinat ovat olleet viimeisen kymmenen vuoden aikana suurten muutosten alla. Markkinoiden kehitys on ollut huomattavaa myös Iso-Britanniassa, jossa sähkö- ja kaasumarkkinat ovat olleet avoinna kilpailulle jo muutamia vuosia. Ennen markkinoiden avautumista energiyhtiöt pystyivät siirtämään kaikki riskit suoraan asiakkaan kannettaviksi. Markkinoiden avautumisen myötä lisääntynyt kilpailu on kuitenkin pakottanut energiayhtiöitä ajanmukaistamaan näkemyksiään riskeistä. Riskitekijät, joista ei aiemmin tarvinnut välittää, on nyt pystyttävä tunnistamaan ja hallitsemaan. Tämä työ keskittyy hinta- ja volyymiriskien hallintaan. Rahoitusmarkkinoilla pitkään käytettyjä riskienhallintatyökaluja on otettu käyttöön myös energiamarkkinoilla. Energiamarkkinoiden piirteet poikkeavat kuitenkin rahoitusmarkkinoista, eikä näitä työkaluja voida ottaa käyttöön muutoksitta. Silti, jopa muutosten jälkeen rahoitusmarkkinoiden riskienhallitavälineet aliarvioivat energiamarkkinoiden hinta- ja volyymiriskejä. Tässä yhteydessä työssä esitetään Profit at Risk, PaR. PaR on skenaariopohjainen riskienhallinnan työkalu, joka on kehitetty erityisesti energiamarkkinoille ja täten huomioi niiden erikoispiirteet. Työn rungon muodostavat energiamarkkinoiden käyttäytyminen, hinta- ja volyymiriskitekijät sekä pohdinta miten hinta- ja volyymiriskeiltä voidaan suojautua ja miten niitä voidaan hallita. PaR-metodologiaa verrataan perinteisiin riskienhallintamenetelmiin ja työn tavoitteena on tuoda esiin ne tekijät, joiden ansiosta PaR on sopivampi työkalu energiamarkkinoiden riskienhallintaan kuin perinteiset menetelmät. Käytännön esimerkkinä työssä toimii Fortum Energy plus’n PaR –malli. Koska PaR on kehitetty erityisesti energiamarkkinoille, se huomioi täysin markkinoiden aiheuttamat hinta- ja volyymiriskit. Käytännön esimerkki kuitenkin osoittaa, että PaR menetelmästä ei ole riskienhallinnallista hyötyä ellei työkalun käyttäjällä ole täydellistä tietämystä niin energiamarkkinoista kuin markkinoiden muutoksiin vaikuttavien tekijöiden käyttäytymisestä.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Nopea teknologian kehitys sekä kansainvälistymisen mukana tuoma kilpailupaine pakottavat yritykset jatkuvaan liiketoimintaprosessien kehittämiseen. Muutoksista organisaation rakenteissa sekä yrityksen prosesseissa on tullut yleisiä toimenpiteitä. Yksi näkyvimmistä toiminnallisista uudistuksesta on ollut toiminnanohjausjärjestelmän käyttöönotto. Toiminnanohjausjärjestelmän rakenne ja kehitys aiheuttaa yleensä suurimmat vaikeudet pyrittäessä rakentamaan liiketoimintaprosessien läpinäkyvyyttä esittävä tietojärjestelmäympäristö. Tässä tutkimuksessa liiketoiminnan sekä toiminnanohjausjärjestelmän prosessien yhdistäminen on tehty ns. toiminnanohjausjärjestelmä muutostyökaluilla. Kyseiset muutostyökalut on järjestetty yrityksissä tietojärjestelmä ympäristöön ja niiden avulla voidaan korjata teknisiä ongelmia sekä muuttaa itse prosesseja. Tutkimuksen empiria osuudessa on käytetty case-tutkimusmenetelmää Kone Oyj:n prosessien kehittämisosastolla. Tutkimuksen tavoitteena oli parantaa toiminnanohjausjärjestelmän muutostyökalujen prosesseja, liiketoimintaprosessien sekä toiminnanohjausjärjestelmän yhdistämiseksi ja harmonisoimiseksi. Tutkimuksen tavoitteiden täyttämiseksi, prosessijohtamisen käsitteitä käytettiin muutostyökaluprosessien parannusehdotusten löytymiseksi. Prosessijohtamisen käsitteet tarkoittavat prosessikartan, prosessin toimintojen, sekä prosessin kustannusten tutkimista ja hyväksikäyttöä. Prosessijohtamisen käsitteeseen kuuluu myös liiketoimintaprosessien jatkuvan parantamisen sekä uudelleenjärjestämisen mallien kuvaus. Toiminnanohjausjärjestelmäympäristön kuvaus teorian toisena osuutena antaa pohjaa muutostyökalujen prosessien käytölle. Tutkimuksen tuloksina voidaan todeta että tutkimusalue on hyvin monimutkainen ja vaikea. Toimintajärjestelmistä ei ole kirjoitettu teoriaa kovinkaan runsaasti, lukuunottamatta yritysten itse tekemiä tutkimuksia. Tutkimuksessa tarkasteltaville prosesseille löytyi kuitenkin parannusehdotuksia sekä ns. optimaalisen prosessimallin ominaisuuksia.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Tutkimuksen tavoitteena oli selvittää sisäisen kommunikoinnin tilannetta case-yrityksissä. Yritykset kuuluvat kahteen case-arvoverkostoon, jotka toimivat informaatio- ja kommunikaatioteknologian alalla. Sisäinen kommunikointi valittiin tutkimusalueeksi, koska se muodostaa perustan ulkoiselle, yritysten väliselle kommunikoinnille. Tutkimuksen painopiste oli web-pohjaisessa kommunikoinnissa ja webin ominaisuuksissa arvoverkoston näkökulmasta. Tutkimusprosessissa käytettiin sekä kvalitatiivisia että kvantitatiivisia menetelmiä. Tutkimuksen kvantitatiivinen osa toteutettiin web-kyselynä, jonka tulokset osoittivat, että case-yritysten sisäinen kommunikointi perustuu pääasiassa perinteisten kommunikointivälineiden käyttöön. Toisin sanoen, webin hyödyntäminen on vähäistä, mihin vaikuttavat monet eri tekijät. Webissä on kuitenkin useita ominaisuuksia, jotka parantavat kommunikointia arvoverkostossa ja siksi nämä web-pohjaiset välineet tulisi huomioida, kun suunnitellaan yleistä kommunikointijärjestelmää. Tutkimuksen teoreettisessa osassa määriteltiin vuorovaikutteisuus-ominaisuuteen perustuva kommunikointivälineiden luokittelu. Tämän lisäksi määriteltiin myös arvoverkoston käsite. Empiirinen osa koostui web-kyselyn toteutuksen ja tulosten raportoinnista, jonka jälkeen yhteenvetokappale koosti merkittävimmät havainnot sekä mahdolliset jatkotutkimusaiheet.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Huolimatta korkeasta automaatioasteesta sorvausteollisuudessa, muutama keskeinen ongelma estää sorvauksen täydellisen automatisoinnin. Yksi näistä ongelmista on työkalun kuluminen. Tämä työ keskittyy toteuttamaan automaattisen järjestelmän kulumisen, erityisesti viistekulumisen, mittaukseen konenäön avulla. Kulumisen mittausjärjestelmä poistaa manuaalisen mittauksen tarpeen ja minimoi ajan, joka käytetään työkalun kulumisen mittaukseen. Mittauksen lisäksi tutkitaan kulumisen mallinnusta sekä ennustamista. Automaattinen mittausjärjestelmä sijoitettiin sorvin sisälle ja järjestelmä integroitiin onnistuneesti ulkopuolisten järjestelmien kanssa. Tehdyt kokeet osoittivat, että mittausjärjestelmä kykenee mittaamaan työkalun kulumisen järjestelmän oikeassa ympäristössä. Mittausjärjestelmä pystyy myös kestämään häiriöitä, jotka ovat konenäköjärjestelmille yleisiä. Työkalun kulumista mallinnusta tutkittiin useilla eri menetelmillä. Näihin kuuluivat muiden muassa neuroverkot ja tukivektoriregressio. Kokeet osoittivat, että tutkitut mallit pystyivät ennustamaan työkalun kulumisasteen käytetyn ajan perusteella. Parhaan tuloksen antoivat neuroverkot Bayesiläisellä regularisoinnilla.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVES: The aims of the study were to use cone beam computed tomography (CBCT) images of nasopalatine duct cysts (NPDC) and to calculate the diameter, surface area, and 3D-volume using a custom-made software program. Furthermore, any associations of dimensions of NPDC with age, gender, presence/absence of maxillary incisors/canines (MI/MC), endodontic treatment of MI/MC, presenting symptoms, and postoperative complications were evaluated. MATERIAL AND METHODS: The study comprised 40 patients with a histopathologically confirmed NPDC. On preoperative CBCT scans, curves delineating the cystic borders were drawn in all planes and the widest diameter (in millimeter), surface area (in square millimeter), and volume (in cubic millimeter) were calculated. RESULTS: The overall mean cyst diameter was 15 mm (range 7-47 mm), the mean cyst surface area 566 mm(2) (84-4,516 mm(2)), and the mean cyst volume 1,735 mm(3) (65-25,350 mm(3)). For 22 randomly allocated cases, a second measurement resulted in a mean absolute aberration of ±4.2 % for the volume, ±2.8 % for the surface, and ±4.9 % for the diameter. A statistically significant association was found for the CBCT determined cyst measurements and the need for preoperative endodontic treatment to MI/MC and for postoperative complications. CONCLUSION: In the hands of a single experienced operator, the novel software exhibited high repeatability for measurements of cyst dimensions. Further studies are needed to assess the application of this tool for dimensional analysis of different jaw cysts and lesions including treatment planning. CLINICAL RELEVANCE: Accurate radiographic information of the bone volume lost (osteolysis) due to expansion of a cystic lesion in three dimensions could help in personalized treatment planning.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cognitive impairment in schizophrenia and psychosis is ubiquitous and acknowledged as a core feature of clinical expression, pathophysiology, and prediction of functioning. However, assessment of cognitive functioning is excessively time-consuming in routine practice, and brief cognitive instruments specific to psychosis would be of value. Two screening tools have recently been created to address this issue, i.e., the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) and the Screen for Cognitive Impairment in Psychiatry (SCIP). The aim of this research was to examine the comparative validity of these two brief instruments in relation to a global cognitive score. 161 patients with psychosis (96 patients diagnosed with schizophrenia and 65 patients diagnosed with bipolar disorder) and 76 healthy control subjects were tested with both instruments to examine their concurrent validity relative to a more comprehensive neuropsychological assessment battery. Scores from the B-CATS and the SCIP were highly correlated in the three diagnostic groups, and both scales showed good to excellent concurrent validity relative to a Global Cognitive Composite Score (GCCS) derived from the more comprehensive examination. The SCIP-S showed better predictive value of global cognitive impairment than the B-CATS. Partial and semi-partial correlations showed slightly higher percentages of both shared and unique variance between the SCIP-S and the GCCS than between the B-CATS and the GCCS. Brief instruments for assessing cognition in schizophrenia and bipolar disorders, such as the SCIP-S and B-CATS, seem to be reliable and promising tools for use in routine clinical practice.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Nowadays, Species Distribution Models (SDMs) are a widely used tool. Using different statistical approaches these models reconstruct the realized niche of a species using presence data and a set of variables, often topoclimatic. There utilization range is quite large from understanding single species requirements, to the creation of nature reserve based on species hotspots, or modeling of climate change impact, etc... Most of the time these models are using variables at a resolution of 50km x 50km or 1 km x 1 km. However in some cases these models are used with resolutions below the kilometer scale and thus called high resolution models (100 m x 100 m or 25 m x 25 m). Quite recently a new kind of data has emerged enabling precision up to lm x lm and thus allowing very high resolution modeling. However these new variables are very costly and need an important amount of time to be processed. This is especially the case when these variables are used in complex calculation like models projections over large areas. Moreover the importance of very high resolution data in SDMs has not been assessed yet and is not well understood. Some basic knowledge on what drive species presence-absences is still missing. Indeed, it is not clear whether in mountain areas like the Alps coarse topoclimatic gradients are driving species distributions or if fine scale temperature or topography are more important or if their importance can be neglected when balance to competition or stochasticity. In this thesis I investigated the importance of very high resolution data (2-5m) in species distribution models using either very high resolution topographic, climatic or edaphic variables over a 2000m elevation gradient in the Western Swiss Alps. I also investigated more local responses of these variables for a subset of species living in this area at two precise elvation belts. During this thesis I showed that high resolution data necessitates very good datasets (species and variables for the models) to produce satisfactory results. Indeed, in mountain areas, temperature is the most important factor driving species distribution and needs to be modeled at very fine resolution instead of being interpolated over large surface to produce satisfactory results. Despite the instinctive idea that topographic should be very important at high resolution, results are mitigated. However looking at the importance of variables over a large gradient buffers the importance of the variables. Indeed topographic factors have been shown to be highly important at the subalpine level but their importance decrease at lower elevations. Wether at the mountane level edaphic and land use factors are more important high resolution topographic data is more imporatant at the subalpine level. Finally the biggest improvement in the models happens when edaphic variables are added. Indeed, adding soil variables is of high importance and variables like pH are overpassing the usual topographic variables in SDMs in term of importance in the models. To conclude high resolution is very important in modeling but necessitate very good datasets. Only increasing the resolution of the usual topoclimatic predictors is not sufficient and the use of edaphic predictors has been highlighted as fundamental to produce significantly better models. This is of primary importance, especially if these models are used to reconstruct communities or as basis for biodiversity assessments. -- Ces dernières années, l'utilisation des modèles de distribution d'espèces (SDMs) a continuellement augmenté. Ces modèles utilisent différents outils statistiques afin de reconstruire la niche réalisée d'une espèce à l'aide de variables, notamment climatiques ou topographiques, et de données de présence récoltées sur le terrain. Leur utilisation couvre de nombreux domaines allant de l'étude de l'écologie d'une espèce à la reconstruction de communautés ou à l'impact du réchauffement climatique. La plupart du temps, ces modèles utilisent des occur-rences issues des bases de données mondiales à une résolution plutôt large (1 km ou même 50 km). Certaines bases de données permettent cependant de travailler à haute résolution, par conséquent de descendre en dessous de l'échelle du kilomètre et de travailler avec des résolutions de 100 m x 100 m ou de 25 m x 25 m. Récemment, une nouvelle génération de données à très haute résolution est apparue et permet de travailler à l'échelle du mètre. Les variables qui peuvent être générées sur la base de ces nouvelles données sont cependant très coûteuses et nécessitent un temps conséquent quant à leur traitement. En effet, tout calcul statistique complexe, comme des projections de distribution d'espèces sur de larges surfaces, demande des calculateurs puissants et beaucoup de temps. De plus, les facteurs régissant la distribution des espèces à fine échelle sont encore mal connus et l'importance de variables à haute résolution comme la microtopographie ou la température dans les modèles n'est pas certaine. D'autres facteurs comme la compétition ou la stochasticité naturelle pourraient avoir une influence toute aussi forte. C'est dans ce contexte que se situe mon travail de thèse. J'ai cherché à comprendre l'importance de la haute résolution dans les modèles de distribution d'espèces, que ce soit pour la température, la microtopographie ou les variables édaphiques le long d'un important gradient d'altitude dans les Préalpes vaudoises. J'ai également cherché à comprendre l'impact local de certaines variables potentiellement négligées en raison d'effets confondants le long du gradient altitudinal. Durant cette thèse, j'ai pu monter que les variables à haute résolution, qu'elles soient liées à la température ou à la microtopographie, ne permettent qu'une amélioration substantielle des modèles. Afin de distinguer une amélioration conséquente, il est nécessaire de travailler avec des jeux de données plus importants, tant au niveau des espèces que des variables utilisées. Par exemple, les couches climatiques habituellement interpolées doivent être remplacées par des couches de température modélisées à haute résolution sur la base de données de terrain. Le fait de travailler le long d'un gradient de température de 2000m rend naturellement la température très importante au niveau des modèles. L'importance de la microtopographie est négligeable par rapport à la topographie à une résolution de 25m. Cependant, lorsque l'on regarde à une échelle plus locale, la haute résolution est une variable extrêmement importante dans le milieu subalpin. À l'étage montagnard par contre, les variables liées aux sols et à l'utilisation du sol sont très importantes. Finalement, les modèles de distribution d'espèces ont été particulièrement améliorés par l'addition de variables édaphiques, principalement le pH, dont l'importance supplante ou égale les variables topographique lors de leur ajout aux modèles de distribution d'espèces habituels.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The purpose of this study is to validate the Pulvers silhouette showcard as a measure of weight status in a population in the African region. This tool is particularly beneficial when scarce resources do not allow for direct anthropometric measurements due to limited survey time or lack of measurement technology in face-to-face general-purpose surveys or in mailed, online, or mobile device-based surveys. METHODS: A cross-sectional study was conducted in the Republic of Seychelles with a sample of 1240 adults. We compared self-reported body sizes measured by Pulvers' silhouette showcards to four measurements of body size and adiposity: body mass index (BMI), body fat percent measured, waist circumference, and waist to height ratio. The accuracy of silhouettes as an obesity indicator was examined using sex-specific receiver operator curve (ROC) analysis and the reliability of this tool to detect socioeconomic gradients in obesity was compared to BMI-based measurements. RESULTS: Our study supports silhouette body size showcards as a valid and reliable survey tool to measure self-reported body size and adiposity in an African population. The mean correlation coefficients of self-reported silhouettes with measured BMI were 0.80 in men and 0.81 in women (P < 0.001). The silhouette showcards also showed high accuracy for detecting obesity as per a BMI ≥ 30 (Area under curve, AUC: 0.91/0.89, SE: 0.01), which was comparable to other measured adiposity indicators: fat percent (AUC: 0.94/0.94, SE: 0.01), waist circumference (AUC: 0.95/0.94, SE: 0.01), and waist to height ratio (AUC: 0.95/0.94, SE: 0.01) amongst men and women, respectively. The use of silhouettes in detecting obesity differences among different socioeconomic groups resulted in similar magnitude, direction, and significance of association between obesity and socioeconomic status as when using measured BMI. CONCLUSIONS: This study highlights the validity and reliability of silhouettes as a survey tool for measuring obesity in a population in the African region. The ease of use and cost-effectiveness of this tool makes it an attractive alternative to measured BMI in the design of non-face-to-face online- or mobile device-based surveys as well as in-person general-purpose surveys of obesity in social sciences, where limited resources do not allow for direct anthropometric measurements.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Neurophysiology is an essential tool for clinicians dealing with patients in the intensive care unit. Because of consciousness disorders, clinical examination is frequently limited. In this setting, neurophysiological examination provides valuable information about seizure detection, treatment guidance, and neurological outcome. However, to acquire reliable signals, some technical precautions need to be known. EEG is prone to artifacts, and the intensive care unit environment is rich in artifact sources (electrical devices including mechanical ventilation, dialysis, and sedative medications, and frequent noise, etc.). This review will discuss and summarize the current technical guidelines for EEG acquisition and also some practical pitfalls specific for the intensive care unit.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The availability of stem cells is of great promise to study early developmental stages and to generate adequate cells for cell transfer therapies. Although many researchers using stem cells were successful in dissecting intrinsic and extrinsic mechanisms and in generating specific cell phenotypes, few of the stem cells or the differentiated cells show the capacity to repair a tissue. Advances in cell and stem cell cultivation during the last years made tremendous progress in the generation of bona fide differentiated cells able to integrate into a tissue after transplantation, opening new perspectives for developmental biology studies and for regenerative medicine. In this review, we focus on the main works attempting to create in vitro conditions mimicking the natural environment of CNS structures such as the neural tube and its development in different brain region areas including the optic cup. The use of protocols growing cells in 3D organoids is a key strategy to produce cells resembling endogenous ones. An emphasis on the generation of retina tissue and photoreceptor cells is provided to highlight the promising developments in this field. Other examples are presented and discussed, such as the formation of cortical tissue, the epithelial gut or the kidney organoids. The generation of differentiated tissues and well-defined cell phenotypes from embryonic stem (ES) cells or induced pluripotent cells (iPSCs) opens several new strategies in the field of biology and regenerative medicine. A 3D organ/tissue development in vitro derived from human cells brings a unique tool to study human cell biology and pathophysiology of an organ or a specific cell population. The perspective of tissue repair is discussed as well as the necessity of cell banking to accelerate the progress of this promising field.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The Nutritional Risk Score (NRS) is a validated tool to identify patients who should benefit of nutritional interventions. Nutritional screening however has not yet been widely adopted by surgeons. Furthermore, the question about reliability of nutritional assessment performed by surgeons is still unanswered. METHODS: Data was obtained from a recent randomised trial including 146 patients with an NRS ≥3 as assessed by the surgeons. Additional detailed nutritional assessment was performed for all patients by nutritional specialists and entered prospectively in a dedicated database. In this retrospective, surgeons' scoring of NRS and its components was compared to the assessment by nutritionists (considered as gold standard). RESULTS: Prospective NRS scores by surgeons and nutritionists were available for 141 patients (97%). Surgeons calculated a NRS of 7, 6, 5, 4 and 3 in 2, 8, 38, 21 and 72 patients respectively. Nutritionists calculated a NRS of 6, 5, 4, 3 and 2 in 8, 26, 47, 57, 3 patients, respectively. Surgeons' assessment was entirely correct in 56 patients (40%), while at least the final score was consistent in 63 patients (45%). Surgeons overrated the NRS in 21% of patients and underestimated the score in 29%. Evaluation of the nutritional status showed most of the discrepancies (54%). CONCLUSION: Surgeon's assessment of nutritional status is modest at best. Close collaboration with nutritional specialists should be recommended in order to avoid misdiagnosis and under-treatment of patients at nutritional risk.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Past research in using ICTs (Information and Communication Technologies) in interpersonal communication showed that age plays an important role. There is a general assumption that the elderly are left behind regarding the adoption and the use of ICTs. Furthermore, elders tend to use ICTs mainly for instrumental purposes and the use is rather non-sophisticated. When elders are using ICTs to maintain their social network, similar patterns could be found: They start using internet, or intensify its use, when their children move abroad while they might decrease using the tool if the motivation ends. In this research we explore elders' incentives to go online and use internet services to communicate; the type of agencies they use to communicate with children and grandchildren abroad; and the situations that make them stop using the ICTs or even reject internet mediated communications. We base our discussion on the empirical evidence the two authors gathered in different cities and countries: Barcelona, Romania, Toronto, Los Angeles, Montevideo and Lima, through semi-structured interviews and observation, with people aged 60 years old and over. The results show that the ability for using ICT tools in an autonomous way is a better explanation than age. In this, we distinguish between assisted users and autonomous users. We found that oldest seniors and those seniors who are less socially active are more likely to be assisted users than those who are socially or professionally active. For them communication with their children and grandchildren abroad follows no agency or it is mediated by significant others from their local social network, who are able to use ICTs and select specific information to share, in the second step, with the elder. For some younger participants the use of ICTs is rather situational and imposed by their children or grandchildren, who installed the tool in the first place and assisted them in using it. Finally, other elders describe a proficient and independent use of ICTs so they use the devices and services the way they want to.We discuss the implications of the patterns in using ICTs, for elders' social life and their relationships with children and grandchildren. First, we emphasis the fact that those elders rejecting the ICTs or being unskilled in using them to communicate might be left out from their family circle, particularly when children are abroad -they would experience more isolation. Second, we underline the fact that when children and grandchildren are the ones that control the ICTs used by their parents and grandparents, they are controlling also the information flow and this will redefine the power relations between elders and their younger relatives.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the recent years, many protocols aimed at reproducibly sequencing reduced-genome subsets in non-model organisms have been published. Among them, RAD-sequencing is one of the most widely used. It relies on digesting DNA with specific restriction enzymes and performing size selection on the resulting fragments. Despite its acknowledged utility, this method is of limited use with degraded DNA samples, such as those isolated from museum specimens, as these samples are less likely to harbor fragments long enough to comprise two restriction sites making possible ligation of the adapter sequences (in the case of double-digest RAD) or performing size selection of the resulting fragments (in the case of single-digest RAD). Here, we address these limitations by presenting a novel method called hybridization RAD (hyRAD). In this approach, biotinylated RAD fragments, covering a random fraction of the genome, are used as baits for capturing homologous fragments from genomic shotgun sequencing libraries. This simple and cost-effective approach allows sequencing of orthologous loci even from highly degraded DNA samples, opening new avenues of research in the field of museum genomics. Not relying on the restriction site presence, it improves among-sample loci coverage. In a trial study, hyRAD allowed us to obtain a large set of orthologous loci from fresh and museum samples from a non-model butterfly species, with a high proportion of single nucleotide polymorphisms present in all eight analyzed specimens, including 58-year-old museum samples. The utility of the method was further validated using 49 museum and fresh samples of a Palearctic grasshopper species for which the spatial genetic structure was previously assessed using mtDNA amplicons. The application of the method is eventually discussed in a wider context. As it does not rely on the restriction site presence, it is therefore not sensitive to among-sample loci polymorphisms in the restriction sites that usually causes loci dropout. This should enable the application of hyRAD to analyses at broader evolutionary scales.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Free-living amoebae are distributed worldwide and are frequently in contact with humans and animals. As cysts, they can survive in very harsh conditions and resist biocides and most disinfection procedures. Several microorganisms, called amoeba-resisting microorganisms (ARMs), have evolved to survive and multiply within these protozoa. Among them are many important pathogens, such as Legionella and Mycobacteria, and also several newly discovered Chlamydia-related bacteria, such as Parachlamydia acanthamoebae, Estrella lausannensis, Simkania negevensis or Waddlia chondrophila whose pathogenic role towards human or animal is strongly suspected. Amoebae represent an evolutionary crib for their resistant microorganisms since they can exchange genetic material with other ARMs and develop virulence traits that will be further used to infect other professional phagocytes. Moreover, amoebae constitute an ideal tool to isolate strict intracellular microorganisms from complex microbiota, since they will feed on other fast-growing bacteria, such as coliforms potentially present in the investigated samples. The paradigm that ARMs are likely resistant to macrophages, another phagocytic cell, and that they are likely virulent towards humans and animals is only partially true. Indeed, we provide examples of the Chlamydiales order that challenge this assumption and suggest that the ability to multiply in protozoa does not strictly correlate with pathogenicity and that we should rather use the ability to replicate in multiple and diverse eukaryotic cells as an indirect marker of virulence towards mammals. Thus, cell-culture-based microbial culturomics should be used in the future to try to discover new pathogenic bacterial species.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aim. To evaluate the usefulness of COOP/WONCA charts as a screening tool for mental disorders in primary care in the immigrant healthcare users in Salt. To measure self-rated health of Salt immigration population using the COOP / WONCA charts and to assess its associated factorsDesign. Descriptive and transversal study, Participants. 370 non-EU immigrants seniors selected by consecutive sampling stratified by sexMain measures. Personal information will be collected (age, sex, country of origin, years of residency in Spain, number of people living in the household and associated comorbidities). Each participant will complete the COOP/WONCA charts. An analysis of the validity of the diagnostic test will be done: sensibility, specificity, positive predictive value, negative predictive value, ROC curve and area under the curve (AUC). All variables will be subjected to descriptive analysis. Bivariate and multivariate analysis between the variables collected (sex, years of residency in Spain... ) and the results of COOP / WONCA charts will be performedResults. Preliminary results are available on a pilot test with 30 patients. The mental disorder prevalence is around 30%. Sensibility (0,89), specificity (0,89), VPP (0,80), VPN (0,94) cutoff score (3.5) and AUC (0,941). Women, people with 10 or more years of residency in Spain and unemployed people have worse self-rated healthConclusions. Based on the preliminary results, is possible to conclude that COOP/WONCA charts could be an useful, valid and applicable screening test for mental disorders in primary care with immigrant population