TY - JOUR
AB - The cerebral cortex is composed of a large variety of distinct cell-types including projection neurons, interneurons and glial cells which emerge from distinct neural stem cell (NSC) lineages. The vast majority of cortical projection neurons and certain classes of glial cells are generated by radial glial progenitor cells (RGPs) in a highly orchestrated manner. Recent studies employing single cell analysis and clonal lineage tracing suggest that NSC and RGP lineage progression are regulated in a profound deterministic manner. In this review we focus on recent advances based mainly on correlative phenotypic data emerging from functional genetic studies in mice. We establish hypotheses to test in future research and outline a conceptual framework how epigenetic cues modulate the generation of cell-type diversity during cortical development. This article is protected by copyright. All rights reserved.
AU - Amberg, Nicole
AU - Laukoter, Susanne
AU - Hippenmeyer, Simon
ID - 27
IS - 1
JF - Journal of Neurochemistry
TI - Epigenetic cues modulating the generation of cell type diversity in the cerebral cortex
VL - 149
ER -
TY - JOUR
AB - Despite their different origins, Drosophila glia and hemocytes are related cell populations that provide an immune function. Drosophila hemocytes patrol the body cavity and act as macrophages outside the nervous system whereas glia originate from the neuroepithelium and provide the scavenger population of the nervous system. Drosophila glia are hence the functional orthologs of vertebrate microglia, even though the latter are cells of immune origin that subsequently move into the brain during development. Interestingly, the Drosophila immune cells within (glia) and outside the nervous system (hemocytes) require the same transcription factor Glide/Gcm for their development. This raises the issue of how do glia specifically differentiate in the nervous system and hemocytes in the procephalic mesoderm. The Repo homeodomain transcription factor and pan-glial direct target of Glide/Gcm is known to ensure glial terminal differentiation. Here we show that Repo also takes center stage in the process that discriminates between glia and hemocytes. First, Repo expression is repressed in the hemocyte anlagen by mesoderm-specific factors. Second, Repo ectopic activation in the procephalic mesoderm is sufficient to repress the expression of hemocyte-specific genes. Third, the lack of Repo triggers the expression of hemocyte markers in glia. Thus, a complex network of tissue-specific cues biases the potential of Glide/Gcm. These data allow us to revise the concept of fate determinants and help us understand the bases of cell specification. Both sexes were analyzed.SIGNIFICANCE STATEMENTDistinct cell types often require the same pioneer transcription factor, raising the issue of how does one factor trigger different fates. In Drosophila, glia and hemocytes provide a scavenger activity within and outside the nervous system, respectively. While they both require the Glide/Gcm transcription factor, glia originate from the ectoderm, hemocytes from the mesoderm. Here we show that tissue-specific factors inhibit the gliogenic potential of Glide/Gcm in the mesoderm by repressing the expression of the homeodomain protein Repo, a major glial-specific target of Glide/Gcm. Repo expression in turn inhibits the expression of hemocyte-specific genes in the nervous system. These cell-specific networks secure the establishment of the glial fate only in the nervous system and allow cell diversification.
AU - Trébuchet, Guillaume
AU - Cattenoz, Pierre B
AU - Zsámboki, János
AU - Mazaud, David
AU - Siekhaus, Daria E
AU - Fanto, Manolis
AU - Giangrande, Angela
ID - 8
IS - 2
JF - Journal of Neuroscience
TI - The Repo homeodomain transcription factor suppresses hematopoiesis in Drosophila and preserves the glial fate
VL - 39
ER -
TY - JOUR
AB - We consider an interacting, dilute Bose gas trapped in a harmonic potential at a positive temperature. The system is analyzed in a combination of a thermodynamic and a Gross–Pitaevskii (GP) limit where the trap frequency ω, the temperature T, and the particle number N are related by N∼ (T/ ω) 3→ ∞ while the scattering length is so small that the interaction energy per particle around the center of the trap is of the same order of magnitude as the spectral gap in the trap. We prove that the difference between the canonical free energy of the interacting gas and the one of the noninteracting system can be obtained by minimizing the GP energy functional. We also prove Bose–Einstein condensation in the following sense: The one-particle density matrix of any approximate minimizer of the canonical free energy functional is to leading order given by that of the noninteracting gas but with the free condensate wavefunction replaced by the GP minimizer.
AU - Deuchert, Andreas
AU - Seiringer, Robert
AU - Yngvason, Jakob
ID - 80
IS - 2
JF - Communications in Mathematical Physics
TI - Bose–Einstein condensation in a dilute, trapped gas at positive temperature
VL - 368
ER -
TY - JOUR
AU - Currin, Christopher B.
AU - Khoza, Phumlani N.
AU - Antrobus, Alexander D.
AU - Latham, Peter E.
AU - Vogels, Tim P
AU - Raimondo, Joseph V.
ID - 8013
IS - 7
JF - PLOS Computational Biology
SN - 1553-7358
TI - Think: Theory for Africa
VL - 15
ER -
TY - JOUR
AB - Working memory, the ability to keep recently accessed information available for immediate manipulation, has been proposed to rely on two mechanisms that appear difficult to reconcile: self-sustained neural firing, or the opposite—activity-silent synaptic traces. Here we review and contrast models of these two mechanisms, and then show that both phenomena can co-exist within a unified system in which neurons hold information in both activity and synapses. Rapid plasticity in flexibly-coding neurons allows features to be bound together into objects, with an important emergent property being the focus of attention. One memory item is held by persistent activity in an attended or “focused” state, and is thus remembered better than other items. Other, previously attended items can remain in memory but in the background, encoded in activity-silent synaptic traces. This dual functional architecture provides a unified common mechanism accounting for a diversity of perplexing attention and memory effects that have been hitherto difficult to explain in a single theoretical framework.
AU - Manohar, Sanjay G.
AU - Zokaei, Nahid
AU - Fallon, Sean J.
AU - Vogels, Tim P
AU - Husain, Masud
ID - 8014
JF - Neuroscience and Biobehavioral Reviews
SN - 0149-7634
TI - Neural mechanisms of attending to items in working memory
VL - 101
ER -
TY - CONF
AB - We study edge asymptotics of poissonized Plancherel-type measures on skew Young diagrams (integer partitions). These measures can be seen as generalizations of those studied by Baik--Deift--Johansson and Baik--Rains in resolving Ulam's problem on longest increasing subsequences of random permutations and the last passage percolation (corner growth) discrete versions thereof. Moreover they interpolate between said measures and the uniform measure on partitions. In the new KPZ-like 1/3 exponent edge scaling limit with logarithmic corrections, we find new probability distributions generalizing the classical Tracy--Widom GUE, GOE and GSE distributions from the theory of random matrices.
AU - Betea, Dan
AU - Bouttier, Jérémie
AU - Nejjar, Peter
AU - Vuletíc, Mirjana
ID - 8175
T2 - Proceedings on the 31st International Conference on Formal Power Series and Algebraic Combinatorics
TI - New edge asymptotics of skew Young diagrams via free boundaries
ER -
TY - GEN
AB - Suppose that $n\neq p^k$ and $n\neq 2p^k$ for all $k$ and all primes $p$. We prove that for any Hausdorff compactum $X$ with a free action of the symmetric group $\mathfrak S_n$ there exists an $\mathfrak S_n$-equivariant map $X \to
{\mathbb R}^n$ whose image avoids the diagonal $\{(x,x\dots,x)\in {\mathbb R}^n|x\in {\mathbb R}\}$.
Previously, the special cases of this statement for certain $X$ were usually proved using the equivartiant obstruction theory. Such calculations are difficult and may become infeasible past the first (primary) obstruction. We
take a different approach which allows us to prove the vanishing of all obstructions simultaneously. The essential step in the proof is classifying the possible degrees of $\mathfrak S_n$-equivariant maps from the boundary
$\partial\Delta^{n-1}$ of $(n-1)$-simplex to itself. Existence of equivariant maps between spaces is important for many questions arising from discrete mathematics and geometry, such as Kneser's conjecture, the Square Peg conjecture, the Splitting Necklace problem, and the Topological Tverberg conjecture, etc. We demonstrate the utility of our result applying it to one such question, a specific instance of envy-free division problem.
AU - Avvakumov, Sergey
AU - Kudrya, Sergey
ID - 8182
T2 - arXiv
TI - Vanishing of all equivariant obstructions and the mapping degree
ER -
TY - GEN
AB - Denote by ∆N the N-dimensional simplex. A map f : ∆N → Rd is an almost r-embedding if fσ1∩. . .∩fσr = ∅ whenever σ1, . . . , σr are pairwise disjoint faces. A counterexample to the topological Tverberg conjecture asserts that if r is not a prime power and d ≥ 2r + 1, then there is an almost r-embedding ∆(d+1)(r−1) → Rd. This was improved by Blagojevi´c–Frick–Ziegler using a simple construction of higher-dimensional counterexamples by taking k-fold join power of lower-dimensional ones. We improve this further (for d large compared to r): If r is not a prime power and N := (d+ 1)r−r l
d + 2 r + 1 m−2, then there is an almost r-embedding ∆N → Rd. For the r-fold van Kampen–Flores conjecture we also produce counterexamples which are stronger than previously known. Our proof is based on generalizations of the Mabillard–Wagner theorem on construction of almost r-embeddings from equivariant maps, and of the Ozaydin theorem on existence of equivariant maps.
AU - Avvakumov, Sergey
AU - Karasev, R.
AU - Skopenkov, A.
ID - 8184
T2 - arXiv
TI - Stronger counterexamples to the topological Tverberg conjecture
ER -
TY - GEN
AB - In this paper we study envy-free division problems. The classical approach to some of such problems, used by David Gale, reduces to considering continuous maps of a simplex to itself and finding sufficient conditions when this map hits the center of the simplex. The mere continuity is not sufficient for such a conclusion, the usual assumption (for example, in the Knaster--Kuratowski--Mazurkiewicz and the Gale theorem) is a certain boundary condition.
We follow Erel Segal-Halevi, Fr\'ed\'eric Meunier, and Shira Zerbib, and replace the boundary condition by another assumption, which has the economic meaning of possibility for a player to prefer an empty part in the segment
partition problem. We solve the problem positively when $n$, the number of players that divide the segment, is a prime power, and we provide counterexamples for every $n$ which is not a prime power. We also provide counterexamples relevant to a wider class of fair or envy-free partition problems when $n$ is odd and not a prime power.
AU - Avvakumov, Sergey
AU - Karasev, Roman
ID - 8185
T2 - arXiv
TI - Envy-free division using mapping degree
ER -
TY - JOUR
AU - Ilieva, Kristina M.
AU - Fazekas-Singer, Judit
AU - Bax, Heather J.
AU - Crescioli, Silvia
AU - Montero‐Morales, Laura
AU - Mele, Silvia
AU - Sow, Heng Sheng
AU - Stavraka, Chara
AU - Josephs, Debra H.
AU - Spicer, James F.
AU - Steinkellner, Herta
AU - Jensen‐Jarolim, Erika
AU - Tutt, Andrew N. J.
AU - Karagiannis, Sophia N.
ID - 8227
IS - 10
JF - Allergy
SN - 0105-4538
TI - AllergoOncology: Expression platform development and functional profiling of an anti‐HER2 IgE antibody
VL - 74
ER -