Standardizing and Unbundling the Sub Rosa DIP Loan

In many recent chapter 11 cases, debtor-in-possession (“DIP”) loans determine reorganization plan payoffs at the outset of the case. Recent DIP loans are tied to plan terms including rights offerings, which give the DIP lender exclusive rights to purchase discounted equity in the reorganized company, and backstop fees, which pay the rights holder for committing to purchase them. Terms like these raise fears that DIP loan approval is being used to short circuit the chapter 11 reorganization plan process—in bankruptcy parlance, that the DIP loan is a sub rosa plan. How should bankruptcy law manage this sub rosa DIP loan problem? We argue that the problem is a common one affecting many types of pre-plan transactions that provide the estate with an asset (cash) but also fix the priority and/or payoff of liabilities. We argue that bankruptcy law uses a common set of tools to deal with these crossover transactions that simultaneously involve asset-side and liability-side effects. Where crossover is inherent to the transaction, the Bankruptcy Code standardizes the liability-side effect to protect the interests of the other creditors. Where crossover is strategic, courts police transactions by unbundling liability-side effects that are unnecessarily bundled into transactions involving the asset side. We conduct a case study of the J.C. Penney bankruptcy to understand how a non-standard, bundled DIP loan transaction can be used strategically to distort priorities. In that case, a DIP loan tied to a restructuring support agreement allowed a majority group to prime a minority group, roll up undersecured debt, and control the allocation of payoffs in the case. We find that a standardized, unbundled DIP loan would have required an interest rate of at least 545% to give the majority group the same payoff it received in the case. We argue that courts should revive and strengthen standardization and unbundling norms. This would better defend priorities by encouraging competition and increasing transparency of DIP loan terms

Lp⃗−Lq⃗L^{\vec{p}}-L^{\vec{q}} Boundedness of Multiparameter Forelli-Rudin Type Operators on the Product of Unit Balls of Cn\mathbb{C}^n

In this work, we provide a complete characterization of the boundedness of two classes of multiparameter Forelli-Rudin type operators from one mixed-norm Lebesgue space $L^{\vec p}$ to another space $L^{\vec q}$, when $1\leq \vec{p}\leq \vec q<\infty$, equipped with possibly different weights. Using these characterizations, we establish the necessary and sufficient conditions for both $L^{\vec p}-L^{\vec q}$ boundedness of the weighted multiparameter Berezin transform and $L^{\vec p}-A^{\vec q}$ boundedness of the weighted multiparameter Bergman projection, where $A^{\vec q}$ denotes the mixed-norm Bergman space. Our approach presents several novelties. Firstly, we conduct refined integral estimates of holomorphic functions on the unit ball in $\mathbb{C}^n$. Secondly, we adapt the classical Schur's test to different weighted mixed-norm Lebesgue spaces. These improvements are crucial in our proofs and allow us to establish the desired characterization and sharp conditions.Comment: 42 page

Parallel Polyadenine Duplex Formation at Low pH Facilitates DNA Conjugation onto Gold Nanoparticles

DNA-functionalized gold nanoparticles (AuNPs) have been extensively used in sensing, drug delivery, and materials science. A key step is to attach DNA onto AuNPs forming a stable and functional conjugate. While the traditional salt-aging method takes a full day or longer, a recent low-pH method allows DNA conjugation to happen in a few minutes. The effect of low pH was previously attributed to protonation of adenine (A) and cytosine (C), resulting in an overall lower negative charge density on DNA which is helpful for conjugating onto citrate-capped AuNPs. However, this simple charge argument does not answer why poly-A DNA works better than poly-C DNA. In addition to protonation, at low pH, DNA rich in adenine and cytosine could form higher secondary structures (e.g. the A-motif for poly-A DNA and i-motif for poly-C DNA). We suspect that such DNA folding might also play a role in DNA conjugation to AuNPs. In this thesis, the effect of DNA conformation at low pH is studied. Using circular dichroism (CD) spectroscopy, parallel poly-A duplex (A-motif) is detected when a poly-A segment is linked to a random DNA, a design typically used for DNA conjugation. A DNA staining dye, thiazole orange, is identified for detecting such A-motifs. We found that the A-motif structure is ideal for DNA conjugation since it exposes the terminal thiol group adjacent to the poly-A for directly reacting with the gold surface while minimizing non-specific DNA base adsorption. Keeping this in mind, the order of reagent addition was further studied. However, for non-thiolated DNA, if the A-motif structure can be formed before the DNA is mixed with AuNPs, alternatively, the sample can be acidified after mixing AuNPs and DNA to then promote A-motif formation. Our results showed that the latter method is better. By taking DNA conformation into consideration, we can also explain the less optimal performance of the C-rich DNA. The i-motif formed by poly-C DNA at low pH is less favorable for the conjugation reaction due to its unique way of folding. Finally, the stability of poly-A and poly-G DNA in low pH also is examined due to the concerns related to DNA depurination and subsequent cleavage. An excellent stability of poly-A DNA is confirmed, while poly-G has slightly lower stability. Overall, the stability is sufficient for the low pH method for DNA attachment. This study provides new fundamental insights into a practically useful technique of conjugating DNA to AuNPs

マルチスケールの格子欠陥を導入したp型のMg2Sn単結晶熱電材料の開発

要約のみTohoku University宮﨑讓課

DNA and Metal Ion Mediated Modification of Nanomaterials

DNA-modified nanomaterials have been applied in diverse areas such as biosensing, catalysis, drug delivery, and biomedical diagnostics. Metal ion mediated DNA conjugation is an important strategy for the construction of DNA/nanomaterials. The interactions between metal ions and DNA phosphate backbones were found critical for DNA adsorption. Most previously reported metal ion mediated DNA/nanomaterial conjugates focused on the role of metal ions for charge screening but ignored the potential formation of DNA/metal complexes, especially for multivalent ions. Since the report of DNA/Fe2+ coordination polymers (CPs), Fe2+ has become attractive in the modification of nanomaterials. One popular nanomaterial is gold nanoparticle (AuNP) which exhibits unique localized surface plasma resonance (LSPR) and enzyme-mimic catalytic activities. The primary focus of this thesis has two main parts: (a) the fundamental understandings of metal ion mediated adsorption of DNA oligonucleotides on 2D nanosheets such as graphene oxide (GO) and Ti2C MXene; (b) the exploration of Fe2+ containing complexes and their applications in designing AuNP-based colorimetric sensors

MCP: Self-supervised Pre-training for Personalized Chatbots with Multi-level Contrastive Sampling

Personalized chatbots focus on endowing the chatbots with a consistent personality to behave like real users and further act as personal assistants. Previous studies have explored generating implicit user profiles from the user's dialogue history for building personalized chatbots. However, these studies only use the response generation loss to train the entire model, thus it is prone to suffer from the problem of data sparsity. Besides, they overemphasize the final generated response's quality while ignoring the correlations and fusions between the user's dialogue history, leading to rough data representations and performance degradation. To tackle these problems, we propose a self-supervised learning framework MCP for capturing better representations from users' dialogue history for personalized chatbots. Specifically, we apply contrastive sampling methods to leverage the supervised signals hidden in user dialog history, and generate the pre-training samples for enhancing the model. We design three pre-training tasks based on three types of contrastive pairs from user dialogue history, namely response pairs, sequence augmentation pairs, and user pairs. We pre-train the utterance encoder and the history encoder towards the contrastive objectives and use these pre-trained encoders for generating user profiles while personalized response generation. Experimental results on two real-world datasets show a significant improvement in our proposed model MCP compared with the existing methods