268 research outputs found
The apterous endemic genus Omphra Dejean (Coleoptera: Carabidae: Helluonini) of the Indian subcontinent : taxonomy with notes on habits and distributional patterns
Among the four oriental genera of the tribe Helluonini, Omphra Dejean (Coleoptera: Carabidae), is unique for its endemism to the Indian subcontinent and aptery. High intraspecies variability in morphological characters and limited diagnostic information makes species differentiation of the genus Omphra a complicated task. The present study provides a description of a new species, Omphra drumonti n. sp. from the Western Ghats, redescriptions and a key to the species of Omphra, details of intraspecies variation, discussion of relationships between taxa and distributional patterns of the genus. Based on the distributional patterns in the Indian subcontinent and flightlessness of the genus, inability to cross the physical barrier of the Ganges–Brahmaputra delta between north and peninsular India is indicated as the reason for its absence in the northeastern Indian subcontinent and endemism to the lower Indian subcontinent
Essays on family structures, education, health and well-being in old age in China
The first chapter investigates the health and social impacts of a new pension system in China. China initiated the new rural pension scheme targeting the large rural population in 2009. This new scheme was claimed to be a huge improvement to the previous welfare institution and a strong defense to rural people's elderly life. Using panel data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), I apply the PSM-DID approach to identify causal relationships between the pension and multiple covariates at the individual level. I have found that the pension significantly reduced systolic and diastolic pressures, as well as improved overall health and life quality of participants. I acknowledge the positive influences of China's new rural pension on elderly life of the rural population, and discuss potential directions for future research.The second chapter explores the impacts of co-residing grandparents on children from a Chinese perspective. The matrilateral bias hypothesis (MBH) implies that children may expect more supports from their maternal grandparents. Nevertheless, the current literature has not shed much light on how different genders are affected by grandparental lineage under the multi-generational coresidence context. In this chapter, I document and discuss lineage heterogeneity of grandparental impacts on grandchildren, and as well explore whether girls benefit more from the maternal grandparents than boys do. To resolve endogeneity bias where the standard IV approach is infeasible, I fit panel data from the China Family Panel Studies (CFPS) into a fixed effects model and then apply the heteroskedasticity-based instruments of Lewbel (2012) as a robustness check. The results suggest that compared to direct interaction with co-residing grandparents, grandchildren are more likely to be influenced through parents. There are no consistent evidences for the MBH found
Local generation of hydrogen for enhanced photothermal therapy.
By delivering the concept of clean hydrogen energy and green catalysis to the biomedical field, engineering of hydrogen-generating nanomaterials for treatment of major diseases holds great promise. Leveraging virtue of versatile abilities of Pd hydride nanomaterials in high/stable hydrogen storage, self-catalytic hydrogenation, near-infrared (NIR) light absorption and photothermal conversion, here we utilize the cubic PdH0.2 nanocrystals for tumour-targeted and photoacoustic imaging (PAI)-guided hydrogenothermal therapy of cancer. The synthesized PdH0.2 nanocrystals have exhibited high intratumoural accumulation capability, clear NIR-controlled hydrogen release behaviours, NIR-enhanced self-catalysis bio-reductivity, high NIR-photothermal effect and PAI performance. With these unique properties of PdH0.2 nanocrystals, synergetic hydrogenothermal therapy with limited systematic toxicity has been achieved by tumour-targeted delivery and PAI-guided NIR-controlled release of bio-reductive hydrogen as well as generation of heat. This hydrogenothermal approach has presented a cancer-selective strategy for synergistic cancer treatment
Training Overparametrized Neural Networks in Sublinear Time
The success of deep learning comes at a tremendous computational and energy
cost, and the scalability of training massively overparametrized neural
networks is becoming a real barrier to the progress of artificial intelligence
(AI). Despite the popularity and low cost-per-iteration of traditional
backpropagation via gradient decent, stochastic gradient descent (SGD) has
prohibitive convergence rate in non-convex settings, both in theory and
practice.
To mitigate this cost, recent works have proposed to employ alternative
(Newton-type) training methods with much faster convergence rate, albeit with
higher cost-per-iteration. For a typical neural network with
parameters and input batch of datapoints in
, the previous work of [Brand, Peng, Song, and Weinstein,
ITCS'2021] requires time per iteration. In this paper, we
present a novel training method that requires only
amortized time in the same overparametrized regime, where
is some fixed constant. This method relies on a new and alternative view of
neural networks, as a set of binary search trees, where each iteration
corresponds to modifying a small subset of the nodes in the tree. We believe
this view would have further applications in the design and analysis of deep
neural networks (DNNs)
A Faster -means++ Algorithm
K-means++ is an important algorithm to choose initial cluster centers for the
k-means clustering algorithm. In this work, we present a new algorithm that can
solve the -means++ problem with near optimal running time. Given data
points in , the current state-of-the-art algorithm runs in
iterations, and each iteration takes
time. The overall running time is thus . We propose a
new algorithm \textsc{FastKmeans++} that only takes in time, in total
Query Complexity of Active Learning for Function Family With Nearly Orthogonal Basis
Many machine learning algorithms require large numbers of labeled data to
deliver state-of-the-art results. In applications such as medical diagnosis and
fraud detection, though there is an abundance of unlabeled data, it is costly
to label the data by experts, experiments, or simulations. Active learning
algorithms aim to reduce the number of required labeled data points while
preserving performance. For many convex optimization problems such as linear
regression and -norm regression, there are theoretical bounds on the number
of required labels to achieve a certain accuracy. We call this the query
complexity of active learning. However, today's active learning algorithms
require the underlying learned function to have an orthogonal basis. For
example, when applying active learning to linear regression, the requirement is
the target function is a linear composition of a set of orthogonal linear
functions, and active learning can find the coefficients of these linear
functions. We present a theoretical result to show that active learning does
not need an orthogonal basis but rather only requires a nearly orthogonal
basis. We provide the corresponding theoretical proofs for the function family
of nearly orthogonal basis, and its applications associated with the
algorithmically efficient active learning framework
Don't Ignore Dual Logic Ability of LLMs while Privatizing: A Data-Intensive Analysis in Medical Domain
Extensive studies have been devoted to privatizing general-domain Large
Language Models (LLMs) as Domain-Specific LLMs via feeding specific-domain
data. However, these privatization efforts often ignored a critical aspect:
Dual Logic Ability, which is a core reasoning ability for LLMs. The dual logic
ability of LLMs ensures that they can maintain a consistent stance when
confronted with both positive and negative statements about the same fact. Our
study focuses on how the dual logic ability of LLMs is affected during the
privatization process in the medical domain. We conduct several experiments to
analyze the dual logic ability of LLMs by examining the consistency of the
stance in responses to paired questions about the same fact. In our
experiments, interestingly, we observed a significant decrease in the dual
logic ability of existing LLMs after privatization. Besides, our results
indicate that incorporating general domain dual logic data into LLMs not only
enhances LLMs' dual logic ability but also further improves their accuracy.
These findings underscore the importance of prioritizing LLMs' dual logic
ability during the privatization process. Our study establishes a benchmark for
future research aimed at exploring LLMs' dual logic ability during the
privatization process and offers valuable guidance for privatization efforts in
real-world applications
Large Language Models Are Semi-Parametric Reinforcement Learning Agents
Inspired by the insights in cognitive science with respect to human memory
and reasoning mechanism, a novel evolvable LLM-based (Large Language Model)
agent framework is proposed as REMEMBERER. By equipping the LLM with a
long-term experience memory, REMEMBERER is capable of exploiting the
experiences from the past episodes even for different task goals, which excels
an LLM-based agent with fixed exemplars or equipped with a transient working
memory. We further introduce Reinforcement Learning with Experience Memory
(RLEM) to update the memory. Thus, the whole system can learn from the
experiences of both success and failure, and evolve its capability without
fine-tuning the parameters of the LLM. In this way, the proposed REMEMBERER
constitutes a semi-parametric RL agent. Extensive experiments are conducted on
two RL task sets to evaluate the proposed framework. The average results with
different initialization and training sets exceed the prior SOTA by 4% and 2%
for the success rate on two task sets and demonstrate the superiority and
robustness of REMEMBERER
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