These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer‐reviewed by leading experts in the field, making this an essential research companion.

International audienceThe classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127(-) and CD127(+) early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127(-) and CD127(+) ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127(-) ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127(+) ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis

A carefully spoken vowel can generally be identified from the pattern of peaks and valleys in the envelope of its short-term power spectrum, and such patterning is usually necessary for the identification of the vowel. The present experiments demonstrate that segments of sound with uniform spectra, devoid of peaks and valleys, can be identified reliably as vowels under certain circumstances. In Experiment 1, 1,000 msec of a segment whose spectrum contained peaks in place of valleys and vice versa (i.e., the complement of a vowel) preceded a 25-msec spectral amplitude transition, during which the valleys became filled, leading into a 250-msec segment with a uniform spectrum. The segment with the uniform spectrum was identified as the vowel whose complement had preceded it. Experiment 2 showed that this effect was eliminated if the duration of the complement was less than 150 msec, if more than 500 msec of silence separated the uniform spectrum from the complement, or if the uniform spectrum and the complement were presented to different ears. This third result and comparisons with parameters of auditory aftereffects obtained by others with nonspeech stimuli suggest that the effect is rooted in peripheral adaptation processes and that central processes responsible for selective attention and perceptual grouping play only a minor role at most. Experiment 3 demonstrated that valleys in the spectral structure of a complement need be only 2 dB deep to generate the effect. The effect should therefore serve to enhance changes in spectral structure in natural speech and to alleviate the consequences of uneven frequency responses in communication channels.In a pilot experiment, we established that waveforms with uniform spectra, devoid of peaks and valleys, can be identified reliably as different vowels under certain circumstances. We synthesized waveforms whose spectra were complementary to those of rectangular approximations to the vowels Iii and /e/, These complementary spectra had peaks in place of valleysand vice versa. We created stimuli in which a 4OO-msec segment of waveform with a uniform flat spectrum was surrounded by two SOO-msec segments of one of the two vowelcomplements. Fifty-millisecond spectral amplitude transitions linked the two types of waveform. The segments with uniform spectra sounded like the vowels whose complements surrounded them. Taking a more realistic vowel spectrum as a starting point, Figure I displays a progression of power spectra computed at SO-msec intervals during a sequence in which the complement of the vowel lal surrounds a segment with a uniform spec-

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The linguistic properties of the FAAF test material are expounded in relation to its objectives. It is shown from reference data that there are lexical effects inherent in the use of real-word minimal pairs rather than nonsense syllables. These are word-frequency effects upon phonemes in initial position and effects of imageability upon phonemes in final position. However, those effects are not large enough to undermine the use of the FAAF as an acoustical phonetically structured material reflecting the analysis of auditory information. Normative data on a range of signal-to-noise ratios are presented. These data have helped to delimit the subsets of items that best reflect variations in performance under easy and under difficult conditions. This offers a mapping of the percentage correct from scores at one or two fixed S/N ratios required for a given level of performance and hence permits comparison with SRT(N) measures.