1,997 research outputs found
Predicting Recurrent Venous Thromboembolism in Patients With Deep-Vein Thrombosis: Development and Internal Validation of a Potential New Prediction Model (Continu-8).
Background: Previous prediction models for recurrent thromboembolism (VTE) are often complicated to apply and have not been implemented widely. Aim: To develop and internally validate a potential new prediction model for recurrent VTE that can be used without stopping anticoagulant treatment for D-dimer measurements in patients with provoked and unprovoked DVT. Methods: Cohort data of 479 patients treated in a clinical care pathway at Maastricht University Medical Center were used. Predictors for the Cox proportional hazards model (unprovoked DVT, male gender, factor VIII levels) were derived from literature and using forward selection procedure. The scoring rule was internally validated using bootstrapping techniques and the predictive ability was compared to existing prediction models. Results: Patients were followed for a median of 3.12 years after stopping anticoagulation treatment (IQR 0.78, 3.90). Sixty-four of 479 patients developed recurrent VTE (13%). The scoring rule consisted of unprovoked DVT (yes: 2 points), male sex (yes: 1 point), and factor VIII > 213 % (yes: 2 points) and was categorized into three groups [i.e., low risk (score 0), medium risk (scores 1, 2, or 3) and high risk (scores 4 and 5)]. The concordance statistic was 0.68 (95% CI: 0.61, 0.75). Conclusion: The discriminative ability of the new Continu-8 score was adequate. Future studies shall verify this score in an independent setting without stopping anticoagulation treatment
Zebra finches (<i>Taeniopygia guttata</i>) demonstrate cognitive flexibility in using phonology and sequence of syllables in auditory discrimination
Zebra finches (Taeniopygia guttata) demonstrate cognitive flexibility in using phonology and sequence of syllables in auditory discrimination
Zebra finches rely mainly on syllable phonology rather than on syllable sequence when they discriminate between two songs. However, they can also learn to discriminate two strings of containing the same set of syllables by their sequence. How learning about the phonological characteristics of syllables and their sequence relate to each other and to the composition of the stimuli is still an open question. We compared whether and how the zebra finches’ relative sensitivity for syllable phonology and syllable sequence depends on the differences between syllable strings. Zebra finches were trained in a Go-Left/Go-Right task to discriminate either between two strings in which each string contained a unique set of song syllables or two strings in which both strings contained the same set of syllables, but in a different sequential order. We assessed to what extent the birds in the two experimental groups attend to the spectral characteristics and the sequence of the syllables by measuring the responses to test strings consisting of spectral modifications or sequence changes. Our results showed no difference in the number of trials needed to discriminate strings consisting of either different or identical sets of syllables. Both experimental groups attended to changes in spectral features in a similar way, but the group for which both training strings consisted of the same set of syllables responded more strongly to changes in sequence than the group for which the training strings consisted of different sets of syllables. This outcome suggests the presence of an additional learning process to learn about syllable sequence when learning about syllable phonology is not sufficient to discriminate two strings. Our study thus demonstrates that the relative importance of syllable phonology and sequence depends on which of these features vary among stimuli. This indicates cognitive flexibility in the acoustic features that songbirds might use in their song recognition
Low dose endotoxin priming is accountable for coagulation abnormalities and organ damage observed in the Shwartzman reaction. A comparison between a single-dose endotoxemia model and a double-hit endotoxin-induced Shwartzman reaction
The clinical response of sepsis to a systemic inflammatory infection may be complicated by disseminated intravascular coagulation or DIC. In order to experimentally study the syndrome of DIC, we aimed for a severe sepsis model complicated by disseminated coagulation. Most -simplified- experimental models describing coagulation abnormalities as a consequence of sepsis are based on single dose endotoxemia. The so called-Shwartzman reaction contrarily, is elicited by a low dose endotoxin priming followed by an LPS challenge and is characterized by pathological manifestations that represent the syndrome of DIC. In order to investigate whether the Shwartzman reaction is superior to a single endotoxin challenge as a model for sepsis-induced DIC and to determine what the pathological effect is of an encounter of low endotoxin prior to an LPS challenge, we undertook the present study. In this study we demonstrate that low-dose endotoxin priming prior to an LPS challenge in the Shwartzman reaction is accountable for micro-vascular thrombosis in lung and liver and subsequent (multi-) organ failure, not observed after a single-dose endotoxin challenge, which indicates that the Shwartzman reaction is well suited-model to study sepsis-induced DIC adversities. Remarkably, only minor differences in the innate immune response were established between the single-dose endotoxin challenge and the Shwartzman reaction
Can Birds Perceive Rhythmic Patterns? A Review and Experiments on a Songbird and a Parrot Species
Article / Letter to editorInstituut Biologie Leide
A general auditory bias for handling speaker variability in speech? Evidence in humans and songbirds
Different speakers produce the same speech sound differently, yet listeners are still able to reliably identify the speech sound. How listeners can adjust their perception to compensate for speaker differences in speech, and whether these compensatory processes are unique only to humans, is still not fully understood. In this study we compare the ability of humans and zebra finches to categorize vowels despite speaker variation in speech in order to test the hypothesis that accommodating speaker and gender differences in isolated vowels can be achieved without prior experience with speaker-related variability. Using a behavioral Go/No-go task and identical stimuli, we compared Australian English adults’ (naïve to Dutch) and zebra finches’ (naïve to human speech) ability to categorize / I/ and /ε/ vowels of an novel Dutch speaker after learning to discriminate those vowels from only one other speaker. Experiments 1 and 2 presented vowels of two speakers interspersed or blocked, respectively. Results demonstrate that categorization of vowels is possible without prior exposure to speaker-related variability in speech for zebra finches, and in non-native vowel categories for humans. Therefore, this study is the first to provide evidence for what might be a species-shared auditory bias that may supersede speaker-related information during vowel categorization. It additionally provides behavioral evidence contradicting a prior hypothesis that accommodation of speaker differences is achieved via the use of formant ratios. Therefore, investigations of alternative accounts of vowel normalization that incorporate the possibility of an auditory bias for disregarding inter-speaker variability are warranted.Publisher PDFPeer reviewe
De bodemgesteldheid van het herinrichtingsgebied Winterswijk - Oost : resultaten van een bodemgeografisch onderzoek
De bodem in het herinrichtingsgebied Winterswijk-Oost bestaat voornamelijk uit zandgronden; verder komen veengronden, moerige gronden, beekkleigronden en oude kleigronden voor. De zandgronden bestaan uit moderpodzolgronden, humuspodzolgronden, eerdgronden en vaaggronden. Ze komen verspreid in het hele gebied voor. De oude kleigronden komen in het noordoosten en zuiden van het gebied voor. De beekkleigronden zijn in het dal van de Boven Slinge aangetroffen. De veen- en moerige komen in het zuiden van het gebied tegen de Duitse grens (o.a. Wooldsche veen) voor. De waterbeheersing is goed, er zijn veel nieuwe afwateringssloten gegraven; de fluctuatie van het grondwater varieert van 40-150 cm. De meeste gronden hebben een gemiddeld hoogste grondwaterstand ondieper dan 40 cm - mv. De resultaten van het onderzoek staan op een bodem- en grondwatertrappenkaart en een kaart met de diepte van de tertiaire klei en/of keileem
The role of spectral features and song duration in zebra finch, <i>Taeniopygia guttata</i>, song recognition
Zebra finch song perception is assumed to primarily involve a high sensitivity to fine spectral features of song elements while other features like element sequence and song duration do not seem to have a notable effect. However, the specific features that zebra finches focus on when identifying or discriminating sounds may not be as fixed as seems to be assumed and might depend on the characteristics of the stimuli. This apparent flexibility in auditory processing, along with the potential salience of differences in song duration for song perception, highlights the need for systematic research on the acoustic parameters that zebra finches can use to differentiate between songs. By employing a Go-Left/Go-Right operant task, we examined whether and how differences in song duration affect zebra finches' relative sensitivity for spectral features and duration in song recognition. Two groups of zebra finches were trained in a Go-Left/Go-Right operant task to discriminate between either two songs with similar durations (‘Equal-duration group’) or two songs with different durations (‘Unequal-duration group’). We assessed to what extent the birds in the two experimental groups attend to the spectral characteristics and the absolute duration of the songs by measuring the responses to test stimuli consisting of spectral modifications or temporal changes. Our results showed that zebra finches use both spectral features and song duration to discriminate between two songs, but the importance of these acoustic parameters depended on whether the songs differed in duration or not. When duration can be used as an additional feature to distinguish two songs, spectral features have a less prominent role. This outcome shows that zebra finches have cognitive flexibility in their attention to different acoustic parameters
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