358 research outputs found
Robust Transmissions in Wireless Powered Multi-Relay Networks with Chance Interference Constraints
In this paper, we consider a wireless powered multi-relay network in which a
multi-antenna hybrid access point underlaying a cellular system transmits
information to distant receivers. Multiple relays capable of energy harvesting
are deployed in the network to assist the information transmission. The hybrid
access point can wirelessly supply energy to the relays, achieving multi-user
gains from signal and energy cooperation. We propose a joint optimization for
signal beamforming of the hybrid access point as well as wireless energy
harvesting and collaborative beamforming strategies of the relays. The
objective is to maximize network throughput subject to probabilistic
interference constraints at the cellular user equipment. We formulate the
throughput maximization with both the time-switching and power-splitting
schemes, which impose very different couplings between the operating parameters
for wireless power and information transfer. Although the optimization problems
are inherently non-convex, they share similar structural properties that can be
leveraged for efficient algorithm design. In particular, by exploiting
monotonicity in the throughput, we maximize it iteratively via customized
polyblock approximation with reduced complexity. The numerical results show
that the proposed algorithms can achieve close to optimal performance in terms
of the energy efficiency and throughput.Comment: 14 pages, 8 figure
Agent Alignment in Evolving Social Norms
Agents based on Large Language Models (LLMs) are increasingly permeating
various domains of human production and life, highlighting the importance of
aligning them with human values. The current alignment of AI systems primarily
focuses on passively aligning LLMs through human intervention. However, agents
possess characteristics like receiving environmental feedback and
self-evolution, rendering the LLM alignment methods inadequate. In response, we
propose an evolutionary framework for agent evolution and alignment, named
EvolutionaryAgent, which transforms agent alignment into a process of evolution
and selection under the principle of survival of the fittest. In an environment
where social norms continuously evolve, agents better adapted to the current
social norms will have a higher probability of survival and proliferation,
while those inadequately aligned dwindle over time. Experimental results
assessing the agents from multiple perspectives in aligning with social norms
demonstrate that EvolutionaryAgent can align progressively better with the
evolving social norms while maintaining its proficiency in general tasks.
Effectiveness tests conducted on various open and closed-source LLMs as the
foundation for agents also prove the applicability of our approach.Comment: Work in progres
Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization
As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded similar to 0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of similar to 81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs
Can AI Assistants Know What They Don't Know?
Recently, AI assistants based on large language models (LLMs) show surprising
performance in many tasks, such as dialogue, solving math problems, writing
code, and using tools. Although LLMs possess intensive world knowledge, they
still make factual errors when facing some knowledge intensive tasks, like
open-domain question answering. These untruthful responses from the AI
assistant may cause significant risks in practical applications. We believe
that an AI assistant's refusal to answer questions it does not know is a
crucial method for reducing hallucinations and making the assistant truthful.
Therefore, in this paper, we ask the question "Can AI assistants know what they
don't know and express them through natural language?" To answer this question,
we construct a model-specific "I don't know" (Idk) dataset for an assistant,
which contains its known and unknown questions, based on existing open-domain
question answering datasets. Then we align the assistant with its corresponding
Idk dataset and observe whether it can refuse to answer its unknown questions
after alignment. Experimental results show that after alignment with Idk
datasets, the assistant can refuse to answer most its unknown questions. For
questions they attempt to answer, the accuracy is significantly higher than
before the alignment.Comment: Work in progres
Cross-Modality Safety Alignment
As Artificial General Intelligence (AGI) becomes increasingly integrated into
various facets of human life, ensuring the safety and ethical alignment of such
systems is paramount. Previous studies primarily focus on single-modality
threats, which may not suffice given the integrated and complex nature of
cross-modality interactions. We introduce a novel safety alignment challenge
called Safe Inputs but Unsafe Output (SIUO) to evaluate cross-modality safety
alignment. Specifically, it considers cases where single modalities are safe
independently but could potentially lead to unsafe or unethical outputs when
combined. To empirically investigate this problem, we developed the SIUO, a
cross-modality benchmark encompassing 9 critical safety domains, such as
self-harm, illegal activities, and privacy violations. Our findings reveal
substantial safety vulnerabilities in both closed- and open-source LVLMs, such
as GPT-4V and LLaVA, underscoring the inadequacy of current models to reliably
interpret and respond to complex, real-world scenarios
Case2Code: Learning Inductive Reasoning with Synthetic Data
Complex reasoning is an impressive ability shown by large language models
(LLMs). Most LLMs are skilled in deductive reasoning, such as chain-of-thought
prompting or iterative tool-using to solve challenging tasks step-by-step. In
this paper, we hope to focus on evaluating and teaching LLMs to conduct
inductive reasoning, that is, LLMs are supposed to infer underlying rules by
observing examples or sequential transformations. However, collecting
large-scale and diverse human-generated inductive data is challenging. We focus
on data synthesis in the code domain and propose a \textbf{Case2Code} task by
exploiting the expressiveness and correctness of programs. Specifically, we
collect a diverse set of executable programs, synthesize input-output
transformations for each program, and force LLMs to infer the underlying code
implementations based on the synthetic I/O cases. We first evaluate
representative LLMs on the synthesized Case2Code task and demonstrate that the
Case-to-code induction is challenging for LLMs. Then, we synthesize large-scale
Case2Code training samples to train LLMs to perform inductive reasoning.
Experimental results show that such induction training benefits not only in
distribution Case2Code performance but also enhances various coding abilities
of trained LLMs, demonstrating the great potential of learning inductive
reasoning via synthetic data
Targeting tissue factor on tumour cells and angiogenic vascular endothelial cells by factor VII-targeted verteporfin photodynamic therapy for breast cancer in vitro and in vivo in mice
<p>Abstract</p> <p>Background</p> <p>The objective of this study was to develop a ligand-targeted photodynamic therapy (tPDT) by conjugating factor VII (fVII) protein with photosensitiser verteporfin in order to overcome the poor selectivity and enhance the effect of non-targeted PDT (ntPDT) for cancer. fVII is a natural ligand for receptor tissue factor (TF) with high affinity and specificity. The reason for targeting receptor TF for the development of tPDT is that TF is a common but specific target on angiogenic tumour vascular endothelial cells (VEC) and many types of tumour cells, including solid tumours and leukaemia.</p> <p>Methods</p> <p>Murine factor VII protein (mfVII) containing a mutation (Lys341Ala) was covalently conjugated via a cross linker EDC with Veterporfin (VP) that was extracted from liposomal Visudyne, and then free VP was separated by Sephadex G50 spin columns. fVII-tPDT using mfVII-VP conjugate, compared to ntPDT, was tested <it>in vitro </it>for the killing of breast cancer cells and VEGF-stimulated VEC and <it>in vivo </it>for inhibiting the tumour growth of breast tumours in a mouse xenograft model.</p> <p>Results</p> <p>We showed that: (i) fVII protein could be conjugated with VP without affecting its binding activity; (ii) fVII-tPDT could selectively kill TF-expressing breast cancer cells and VEGF-stimulated angiogenic HUVECs but had no side effects on non-TF expressing unstimulated HUVEC, CHO-K1 and 293 cells; (iii) fVII targeting enhanced the effect of VP PDT by three to four fold; (iii) fVII-tPDT induced significantly stronger levels of apoptosis and necrosis than ntPDT; and (iv) fVII-tPDT had a significantly stronger effect on inhibiting breast tumour growth in mice than ntPDT.</p> <p>Conclusions</p> <p>We conclude that the fVII-targeted VP PDT that we report here is a novel and effective therapeutic with improved selectivity for the treatment of breast cancer. Since TF is expressed on many types of cancer cells including leukaemic cells and selectively on angiogenic tumour VECs, fVII-tPDT could have broad therapeutic applications for other solid cancers and leukaemia.</p
Sex differences in oncogenic mutational processes.
Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research
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