7,963 research outputs found
Towards learning free naive bayes nearest neighbor-based domain adaptation
As of today, object categorization algorithms are not able to achieve the level of robustness and generality necessary to work reliably in the real world. Even the most powerful convolutional neural network we can train fails to perform satisfactorily when trained and tested on data from different databases. This issue, known as domain adaptation and/or dataset bias in the literature, is due to a distribution mismatch between data collections. Methods addressing it go from max-margin classifiers to learning how to modify the features and obtain a more robust representation. Recent work showed that by casting the problem into the image-to-class recognition framework, the domain adaptation problem is significantly alleviated [23]. Here we follow this approach, and show how a very simple, learning free Naive Bayes Nearest Neighbor (NBNN)-based domain adaptation algorithm can significantly alleviate the distribution mismatch among source and target data, especially when the number of classes and the number of sources grow. Experiments on standard benchmarks used in the literature show that our approach (a) is competitive with the current state of the art on small scale problems, and (b) achieves the current state of the art as the number of classes and sources grows, with minimal computational requirements. © Springer International Publishing Switzerland 2015
Preliminary results from the ESA STSE project on SST diurnal variability, its regional extent and implications in atmospheric modelling (SSTDV:R.EX.–IM.A.M.)
Twenty-First Century Middle Schooling in New York: Teachers Share Experiences and Perspectives on Remote Teaching and Learning Early in the Global Pandemic
In early 2020, the Covid-19 virus hit many places, including New York City, with such a force that nobody could have foreseen the events following its spread. The education system was pushed to transition itself to meet with 21st century technology. This study explores this disruption in the education system and how middle school teachers in several New York counties responded. What are middle school teachers’ perspectives and practices during the rapid switch to remote teaching? Professor and graduate students in a Curriculum, Instruction, and Assessment class on middle level schooling designed the interview protocol focused on five related areas of the remote learning endeavor: 1) Preparation, 2) Teaching, Learning, and Participation, 3) Social and Emotional effects on Students, 4) Monitoring and Assessment, 5) Looking forward. The findings demonstrate a primarily reactive response and limited preparation. Teachers express a mixed review of successes and struggles with online teaching and the challenges of engagement, participation, and meeting the social emotional needs of restless students who sometimes do not have the parent support or the technological devices that could further assist their success with online learning. Each teacher had their own unique experiences and challenges teaching students through a computer screen
Heritability of the Symbiodinium community in vertically-and horizontally-transmitting broadcast spawning corals
The dinoflagellate-coral partnership influences the coral holobiont's tolerance to thermal stress and bleaching. However, the comparative roles of host genetic versus environmental factors in determining the composition of this symbiosis are largely unknown. Here we quantify the heritability of the initial Symbiodinium communities for two broadcast-spawning corals with different symbiont transmission modes: Acropora tenuis has environmental acquisition, whereas Montipora digitata has maternal transmission. Using high throughput sequencing of the ITS-2 region to characterize communities in parents, juveniles and eggs, we describe previously undocumented Symbiodinium diversity and dynamics in both corals. After one month of uptake in the field, Symbiodinium communities associated with A. tenuis juveniles were dominated by A3, C1, D1, A-type CCMP828, and D1a in proportional abundances conserved between experiments in two years. M. digitata eggs were predominantly characterized by C15, D1, and A3. In contrast to current paradigms, host genetic influences accounted for a surprising 29% of phenotypic variation in Symbiodinium communities in the horizontally-transmitting A. tenuis, but only 62% in the vertically-transmitting M. digitata. Our results reveal hitherto unknown flexibility in the acquisition of Symbiodinium communities and substantial heritability in both species, providing material for selection to produce partnerships that are locally adapted to changing environmental conditions
Maternal effects and Symbiodinium community composition drive differential patterns in juvenile survival in the coral Acropora tenuis
Coral endosymbionts in the dinoflagellate genus Symbiodinium are known to impact host physiology and have led to the evolution of reef-building, but less is known about how symbiotic communities in early life-history stages and their interactions with host parental identity shape the structure of coral communities on reefs. Differentiating the roles of environmental and biological factors driving variation in population demographic processes, particularly larval settlement, early juvenile survival and the onset of symbiosis is key to understanding how coral communities are structured and to predicting how they are likely to respond to climate change. We show that maternal effects (that here include genetic and/or effects related to the maternal environment) can explain nearly 24% of variation in larval settlement success and 5–17% of variation in juvenile survival in an experimental study of the reef-building scleractinian coral, Acropora tenuis. After 25 days on the reef, Symbiodinium communities associated with juvenile corals differed significantly between high mortality and low mortality families based on estimates of taxonomic richness, composition and relative abundance of taxa. Our results highlight that maternal and familial effects significantly explain variation in juvenile survival and symbiont communities in a broadcast-spawning coral, with Symbiodinium type A3 possibly a critical symbiotic partner during this early life stage
Maternal effects and Symbiodinium community composition drive differential patterns in juvenile survival in the coral Acropora tenuis
Coral endosymbionts in the dinoflagellate genus Symbiodinium are known to impact host physiology and have led to the evolution of reef-building, but less is known about how symbiotic communities in early life-history stages and their interactions with host parental identity shape the structure of coral communities on reefs. Differentiating the roles of environmental and biological factors driving variation in population demographic processes, particularly larval settlement, early juvenile survival and the onset of symbiosis is key to understanding how coral communities are structured and to predicting how they are likely to respond to climate change. We show that maternal effects (that here include genetic and/or effects related to the maternal environment) can explain nearly 24% of variation in larval settlement success and 5–17% of variation in juvenile survival in an experimental study of the reef-building scleractinian coral, Acropora tenuis. After 25 days on the reef, Symbiodinium communities associated with juvenile corals differed significantly between high mortality and low mortality families based on estimates of taxonomic richness, composition and relative abundance of taxa. Our results highlight that maternal and familial effects significantly explain variation in juvenile survival and symbiont communities in a broadcast-spawning coral, with Symbiodinium type A3 possibly a critical symbiotic partner during this early life stage
Normative Grip Strength Values in Males and Females, ages 50 to 89 years old
Purpose. To develop normative reference values for grip strength of males and females between the ages of 50 and 89 years old that can be used by health care professionals in clinical settings.
Methods. This study assessed data from a sample of males and females between the ages of 50 and 89 years old who participated in the Health and Retirement Study (HRS) sponsored by the National Institute on Aging. The Health and Retirement Study collected data from 6,266 participants in a physical measures sub-study. Grip strength was assessed in a standing position with the shoulder adducted and elbow flexed to 90 degrees. One practice trial was allowed and then the participant performed 2 maximal effort trials using each hand. Right and left hand mean scores were calculated. The HRS data were reported in kilograms.
Results. Subjects were stratified by sex and age. Each stratum was defined using 5-year intervals, male or female, and by right or left hand. Mean grip strength, standard deviation, sample size, and percentile ranks from 5 to 95 at intervals of 5 are reported for each stratum in both kilograms and pounds.
Conclusion. The normative values provided in this report should advance the clinical utility of grip strength as a physical measure. Percentile ranks are easy to determine and interpret for both the patient and clinician. Clinicians will benefit from the results of this study by better assessing the physical status of their patients, developing better goals for their patients, and providing better education to their patients on this aspect of physical health
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