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Tissues and organs are composed of distinct cell types that must operate in concert to perform physiological functions. Efforts to create high-dimensional biomarker catalogs of these cells have been largely based on single-cell sequencing approaches, which lack the spatial context required to understand critical cellular communication and correlated structural organization. To probe in situ biology with sufficient depth, several multiplexed protein imaging methods have been recently developed. Though these technologies differ in strategy and mode of immunolabeling and detection tags, they commonly utilize antibodies directed against protein biomarkers to provide detailed spatial and functional maps of complex tissues. As these promising antibody-based multiplexing approaches become more widely adopted, new frameworks and considerations are critical for training future users, generating molecular tools, validating antibody panels, and harmonizing datasets. In this Perspective, we provide essential resources, key considerations for obtaining robust and reproducible imaging data, and specialized knowledge from domain experts and technology developers., QC 20220608

Matrix-Assisted Laser Desorption/Ionization (MALDI) Imaging Mass Spectrometry (IMS) is a molecular technology that allows simultaneous investigation of the content and spatial distribution of molecules within tissue. In this work, we examine different classes of detergents, the anionic sodium dodecyl sulfate (SDS), the nonionic detergents Triton X-100, Tween 20 and Tween 80, and the zwitterionic 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) for use in MALDI IMS of analytes above m/z 4000. These detergents were found to be compatible with MALDI MS and did not cause signal suppression relative to non-detergent applications and did not produce interfering background signals. In general, these detergents enhanced signal acquisition within the mass range m/z 4-40 000. Adding detergents into the matrix was comparable with the separate application of detergent and matrix. Evaluation of spectra collected from organ-specific regions of a whole mouse pup section showed that different detergents perform optimally with different organs, indicating that detergent selection should be optimized on the specific tissue for maximum gain. These data show the utility of detergents towards enhancement of protein signals for on-tissue MALDI IMS analysis.

Circadian and ultradian rhythms were analyzed in Sabella spallanzanii tested in laboratory constant darkness conditions. A video camera took images per 30 s during a week. The number of times animals opened the fan per 30 min was counted by an observer. Resulting time series were subdivided into 24-h segments in order to assess the change of the activity rhythm over consecutive days. Periodogram and waveform analyses measured the periodicity and the pattern of fluctuation, at each cycle. Results indicate that animals express a major circadian peak in the first day of test, and this progressively spits into subcomponents from days 2 to 4. At days 5 and 6 the circadian peak is reconstituted. The activity phase of a rhythm (agr) and its amplitude of oscillation were also computed per 24-h segments. The values of different time series were averaged at corresponding 24-h stages. A significant increment of mean agr was observed from days 1 to 4, while conversely the amplitude decreased. From days 5 to day 6, an opposite trend in both variables was observed. These results are descriptive but can be interpreted in the context of models accounting for the generation of ultradian rhythms when controlling oscillators became transiently uncoupled.

[EN] The fan activity rhythm of Sabella spallanzanii (Gmelin, 1791) and its entrainment capability to light were studied. Animals were tested under constant darkness (DD) followed by two consecutive 24 h light-darkness regimes: a first 11 h light period (LD) and a second 9 h light period, with its phase inverted (DL). An infrared analogical video-camera took shots each 30 s. A number of pictures with open fan were counted every 15 min. In DD a weak free-running periodicity in the circadian range was found, thus reinforcing the matching of the 24 h period under study in both photoperiod regimes. A nocturnal activity was characterised with a consistent anticipation to lightOFF (i.e. entrainment). Moreover, this phase of entrainment differed between DL and LD. The presence of endogenous activity rhythm with a variable phase angle of entrainment is a distinctive feature of circadian pacemakers, [ES] En este trabajo, se estudiaron el ritmo de apertura del abanico del poliqueto Sabella spallanzanii (Gmelin, 1791) y su capacidad de encarrilamiento a la luz. Los animales fueron expuestos bajo oscuridad constante (DD) seguida por dos regímenes consecutivos de luz-oscuridad de 24 h, el primero compuesto por 11 h de luz (LD), y el segundo por 9 h de luz y con su fase invertida (DL). Dicha actividad se midió utilizando fotogramas tomados cada 30 s, mediante una videocámara analógica provista de iluminación infrarroja. Los fotogramas mostrando el abanico abierto fueron sumados cada 15 min. En DD, se detectó una periodicidad débil, en curso libre de rango circadiano en todos los animales. El ritmo se mostró más robusto y asumió un valor de 24 h bajo los dos fotoperíodos empleados. Se evidenció una actividad nocturna con anticipación (encarrilamiento) al apagado de la luz. Además, esta fase de encarrilamiento fue diferente entre LD y DL. La presencia de un ritmo de actividad endógeno con una fase de encarrilamiento variable, sugiere la presencia de un oscilador circadiano

A 42.2 m firn core was collected at the Hercules Neve plateau (100 km inland and 2960 m a.s.l.), northern Victoria Land, during the 1994-95 Italian Antarctic Expedition. Chemical (Cl-, NO3-, SO42- and H2O2) and isotope (delta(18)O) analyses were performed to evaluate the snow-accumulation rate at this site. Tritium measurements were performed in the upper part of the core to narrow down the dating of the core. High nssSO(4)(2-) concentrations seem to be related to some explosive volcanic eruptions, such as Tambora (AD 1815) and the preceding event called "Unknown" (AD 1809), Coseguina (AD 1835), Makjan (AD 1861), Krakatoa (IUD 1883) and Tarawera (AD 1886). A comparison between the seasonal variations observed in the isotope and chemical profiles was carried out in order to reduce the dating uncertainty, using the tritium and the volcanic markers as time constraints. A deposition period of 222 years was determined. The 3 year smoothed delta(18)O profile shows more negative values from the bottom of the core (dated AD 1770) throughout the 19th century, suggesting "cooler" conditions, in agreement with other East Antarctic ice-core records. Subsequently, a general increase in delta(18)O values is observed. The calculated average snow-accumulation rates between the above-mentioned time markers are 111-129 kg m(-2) a(-1)