A Poetics of the Self. Ricoeur’s Philosophy of the Will and Living Metaphor as Creative Praxis

This article presents the conceptual groundwork for a “poetics of the self” by theorizing how and why a creative praxis rooted in Ricoeur’s philosophy of the will and hermeneutics of the living metaphor contributes to an individual’s on-going development of self-awareness. Its focus is on the affective fragility that manifests in an individual’s intermediary status of polarities – finitude and infinitude, freedom and nature – in conjunction with Ricœur’s tensional status of metaphorical truth. The act of writing poetry, it suggests, can be an aesthetic mediation that develops insight into the primordial discord of the servile will

Transcriptional reprogramming during floral fate acquisition

Coordinating growth and patterning is essential for eukaryote morphogenesis. In plants, auxin is a key regulator of morphogenesis implicated throughout development. Despite this central role, our understanding of how auxin coordinates cell fate and growth changes is still limited. Here, we addressed this question using a combination of genomic screens to delve into the transcriptional network induced by auxin at the earliest stage of flower development, prior to morphological changes. We identify a shoot-specific network suggesting that auxin initiates growth through an antagonistic regulation of growth-promoting and growth-repressive hormones, quasi-synchronously to floral fate specification. We further identify two DNA-binding One Zinc Finger (DOF) transcription factors acting in an auxin-dependent network that could interface growth and cell fate from the early stages of flower development onward.Peer reviewe

A root phloem pole cell atlas reveals common transcriptional states in protophloem-adjacent cells

The phloem pole atlas has over 10,000 cells, with an unprecedented resolution of the transcriptional dynamics in phloem development. Despite distinct mature transcriptional states, co-expression networks show common states in protophloem-adjacent cells. Single-cell sequencing has recently allowed the generation of exhaustive root cell atlases. However, some cell types are elusive and remain underrepresented. Here we use a second-generation single-cell approach, where we zoom in on the root transcriptome sorting with specific markers to profile the phloem poles at an unprecedented resolution. Our data highlight the similarities among the developmental trajectories and gene regulatory networks common to protophloem sieve element (PSE)-adjacent lineages in relation to PSE enucleation, a key event in phloem biology. As a signature for early PSE-adjacent lineages, we have identified a set of DNA-binding with one finger (DOF) transcription factors, the PINEAPPLEs (PAPL), that act downstream of PHLOEM EARLY DOF (PEAR) genes and are important to guarantee a proper root nutrition in the transition to autotrophy. Our data provide a holistic view of the phloem poles that act as a functional unit in root development.Peer reviewe

The Colours of Forgiveness: Visual Art, Spirituality, Trauma & Mental Health

These images explore the intersections of childhood trauma, mental health and spirituality.&nbsp

Improving signal strength in serial crystallography with DIALS geometry refinement.

The DIALS diffraction-modeling software package has been applied to serial crystallography data. Diffraction modeling is an exercise in determining the experimental parameters, such as incident beam wavelength, crystal unit cell and orientation, and detector geometry, that are most consistent with the observed positions of Bragg spots. These parameters can be refined by nonlinear least-squares fitting. In previous work, it has been challenging to refine both the positions of the sensors (metrology) on multipanel imaging detectors such as the CSPAD and the orientations of all of the crystals studied. Since the optimal models for metrology and crystal orientation are interdependent, alternate cycles of panel refinement and crystal refinement have been required. To simplify the process, a sparse linear algebra technique for solving the normal equations was implemented, allowing the detector panels to be refined simultaneously against the diffraction from thousands of crystals with excellent computational performance. Separately, it is shown how to refine the metrology of a second CSPAD detector, positioned at a distance of 2.5 m from the crystal, used for recording low-angle reflections. With the ability to jointly refine the detector position against the ensemble of all crystals used for structure determination, it is shown that ensemble refinement greatly reduces the apparent nonisomorphism that is often observed in the unit-cell distributions from still-shot serial crystallography. In addition, it is shown that batching the images by timestamp and re-refining the detector position can realistically model small, time-dependent variations in detector position relative to the sample, and thereby improve the integrated structure-factor intensity signal and heavy-atom anomalous peak heights

Improving signal strength in serial crystallography with DIALS geometry refinement.

The DIALS diffraction-modeling software package has been applied to serial crystallography data. Diffraction modeling is an exercise in determining the experimental parameters, such as incident beam wavelength, crystal unit cell and orientation, and detector geometry, that are most consistent with the observed positions of Bragg spots. These parameters can be refined by nonlinear least-squares fitting. In previous work, it has been challenging to refine both the positions of the sensors (metrology) on multipanel imaging detectors such as the CSPAD and the orientations of all of the crystals studied. Since the optimal models for metrology and crystal orientation are interdependent, alternate cycles of panel refinement and crystal refinement have been required. To simplify the process, a sparse linear algebra technique for solving the normal equations was implemented, allowing the detector panels to be refined simultaneously against the diffraction from thousands of crystals with excellent computational performance. Separately, it is shown how to refine the metrology of a second CSPAD detector, positioned at a distance of 2.5 m from the crystal, used for recording low-angle reflections. With the ability to jointly refine the detector position against the ensemble of all crystals used for structure determination, it is shown that ensemble refinement greatly reduces the apparent nonisomorphism that is often observed in the unit-cell distributions from still-shot serial crystallography. In addition, it is shown that batching the images by timestamp and re-refining the detector position can realistically model small, time-dependent variations in detector position relative to the sample, and thereby improve the integrated structure-factor intensity signal and heavy-atom anomalous peak heights

A root phloem pole cell atlas reveals common transcriptional states in protophloem-adjacent cells

The phloem pole atlas has over 10,000 cells, with an unprecedented resolution of the transcriptional dynamics in phloem development. Despite distinct mature transcriptional states, co-expression networks show common states in protophloem-adjacent cells. Single-cell sequencing has recently allowed the generation of exhaustive root cell atlases. However, some cell types are elusive and remain underrepresented. Here we use a second-generation single-cell approach, where we zoom in on the root transcriptome sorting with specific markers to profile the phloem poles at an unprecedented resolution. Our data highlight the similarities among the developmental trajectories and gene regulatory networks common to protophloem sieve element (PSE)-adjacent lineages in relation to PSE enucleation, a key event in phloem biology. As a signature for early PSE-adjacent lineages, we have identified a set of DNA-binding with one finger (DOF) transcription factors, the PINEAPPLEs (PAPL), that act downstream of PHLOEM EARLY DOF (PEAR) genes and are important to guarantee a proper root nutrition in the transition to autotrophy. Our data provide a holistic view of the phloem poles that act as a functional unit in root development.Peer reviewe

Transcriptional reprogramming during floral fate acquisition

Coordinating growth and patterning is essential for eukaryote morphogenesis. In plants, auxin is a key regulator of morphogenesis implicated throughout development. Despite this central role, our understanding of how auxin coordinates cell fate and growth changes is still limited. Here, we addressed this question using a combination of genomic screens to delve into the transcriptional network induced by auxin at the earliest stage of flower development, prior to morphological changes. We identify a shoot-specific network suggesting that auxin initiates growth through an antagonistic regulation of growth-promoting and growth-repressive hormones, quasi-synchronously to floral fate specification. We further identify two DNA-binding One Zinc Finger (DOF) transcription factors acting in an auxin-dependent network that could interface growth and cell fate from the early stages of flower development onward.Peer reviewe

DIALS: implementation and evaluation of a new integration package.

The DIALS project is a collaboration between Diamond Light Source, Lawrence Berkeley National Laboratory and CCP4 to develop a new software suite for the analysis of crystallographic X-ray diffraction data, initially encompassing spot finding, indexing, refinement and integration. The design, core algorithms and structure of the software are introduced, alongside results from the analysis of data from biological and chemical crystallography experiments

DIALS: implementation and evaluation of a new integration package.

The DIALS project is a collaboration between Diamond Light Source, Lawrence Berkeley National Laboratory and CCP4 to develop a new software suite for the analysis of crystallographic X-ray diffraction data, initially encompassing spot finding, indexing, refinement and integration. The design, core algorithms and structure of the software are introduced, alongside results from the analysis of data from biological and chemical crystallography experiments