10,458 research outputs found
TransNets: Learning to Transform for Recommendation
Recently, deep learning methods have been shown to improve the performance of
recommender systems over traditional methods, especially when review text is
available. For example, a recent model, DeepCoNN, uses neural nets to learn one
latent representation for the text of all reviews written by a target user, and
a second latent representation for the text of all reviews for a target item,
and then combines these latent representations to obtain state-of-the-art
performance on recommendation tasks. We show that (unsurprisingly) much of the
predictive value of review text comes from reviews of the target user for the
target item. We then introduce a way in which this information can be used in
recommendation, even when the target user's review for the target item is not
available. Our model, called TransNets, extends the DeepCoNN model by
introducing an additional latent layer representing the target user-target item
pair. We then regularize this layer, at training time, to be similar to another
latent representation of the target user's review of the target item. We show
that TransNets and extensions of it improve substantially over the previous
state-of-the-art.Comment: Accepted for publication in the 11th ACM Conference on Recommender
Systems (RecSys 2017
Invariant Peano curves of expanding Thurston maps
We consider Thurston maps, i.e., branched covering maps
that are postcritically finite. In addition, we assume that is expanding in
a suitable sense. It is shown that each sufficiently high iterate of
is semi-conjugate to , where is equal to the
degree of . More precisely, for such an we construct a Peano curve
(onto), such that
(for all ).Comment: 63 pages, 12 figure
Village Baseline Study – Site Analysis Report Ma village-Yen Binh district, Vietnam
Ma village, Vinh Kien commune, Yen Binh district, Yen Bai province has been
selected to be one of Climate Smart Villages (CSVs) under the CGIAR Research Program on
Climate Change, Agriculture and Food Security (CCAFS) in Southeast Asia. The village
baseline survey (VBS) of Ma village, was therefore conducted as part of the baseline effort.
This VBS aimed to provide baseline information at the village level about some basic
indicators of natural resource utilization, organizational landscapes, and information
networks for weather and agricultural information, which can be compared across sites and
monitored over time. The study was conducted using the method developed and provided by
CCAFS. The study’s findings show that Ma Village is rich and diverse in natural resources.
There are three main resources of vital importance for the local people livelihoods, namely
farmland, forest and water resources. However, improper exploitation and management have
caused negative impacts on these resources. As mentioned by farmers, in the past, farmland
of the village used to be very fertile, but has now become severely degraded due to overexploitation
and improper management. Regarding forest resources: before 1980s, natural
forests existed in large areas and consisted of valuable timber and wild animals. Today, much
of the forest area has been converted to production forests or to food crop production land.
Water resources, including lakes, rivers and streams have been severely polluted with
pollutants from processing cassava, wood and also from animal husbandry and crop
production. Degradation of water, farmland and forest resources are causing increasing
challenges to agricultural production and also to other human activities. Results of farmer
group discussions also demonstrate that there are 34 organizations operating in the village.
Most of them are governmental. Very few are private or non-governmental organizations.
The number of organizations involving in food security accounts for nearly 50%, the figure
for those involving food crisis is 41.6% and in natural resources management is 25%. Those
organizations working in food security and food crisis focus mainly on providing support
(financial, seed and agricultural inputs) to local farmers to implement some production
activities. Insufficient attention and input spent for sustainable development by these 34
organizations, especially those working in the area of natural resources management, could
be one of the main reasons for the degradation and erosion of natural resources. There was no
activity supporting Ma Village to develop production systems which can respond well to
climate change. The study findings however show that local people are very flexible and
creative, especially in exploitation of information. Among media channels, television is the
most popular. Nevertheless, organizations, in particular, extension networks, Farmers’ Union,
local authorities, etc., also have an important role in information dissemination. Exploitation
of information from the internet and mobile phones has also been given attention, but mostly
by young people only
Village Baseline Study – Site Analysis Report for My Loi, Ky Anh district, Ha Tinh province – Viet Nam
Data collection for the Village Baseline Study (VBS) of My Loi village in the CCAFS
benchmark site of central Viet Nam took place on 17- 19 October 2014. Focus group
discussions were conducted separately for 45 men and 45 women villagers.. The VBS had
three main topics: map of (1) community resources, (2) organizational landscapes, and (3)
information networks. A seminar was held in December 2014 to seek participants’ feedback.
My Loi village has experienced multiple extreme weather events (temperature and water
stresses, storms and typhoons) throughout the years. The main constraints for agricultural
development and livelihoods are limited water resources and poor conditions of irrigation
systems, which are challenges to improving the agricultural production situation. Moreover,
sand and rock mining have caused water pollution, erosion on riverbanks and loss of
farmland area. Another constraint is marketing, as villagers are not aware of any organization
involved in finding outlets for agricultural products. The potentials for developing innovative
climate-smart solutions in the village are several: farmers have experiences and are interested
in trying new varieties and adjusting farming calendars to improve the situation. Livestock
expansion and agroforests/reforestation hold opportunities for improving household incomes.
Furthermore, at least half of the organisations identified in the region are working to address
food security issues
Situation Analysis and Needs Assessment Report for My Loi village and Ha Tinh province, Viet Nam
My Loi village is located in the uplands of Ky Son commune, Ky Anh district, Ha Tinh province on the north
central coast of Viet Nam. In 2014, it was chosen as a site for Climate-Smart Village because of its exposure
to multiple extreme weather events (temperature and water stress, storm and typhoon) and the potential for
climate-smart solutions. The purpose of situation analysis and needs assessment was to understand the current situation at
the village and province levels, on a number of issues, including food security and natural resources
management, and to identify and prioritize the needs for My Loi to develop agriculture and livelihoods in
synergy with climate adaptation and mitigation interventions. Data collection was conducted in October
2014 alongside a Village Baseline Study. The findings were shared during a feedback meeting in December
2014.
The major findings for My Loi Village included: 1) main livelihood sources are in forestry (140 ha acacia
and eucalyptus planted in near 200 ha) and rainfed agriculture (55 ha, paddy rice, peanut, maize, green
bean, and sweet potato); 2) main constraints for production are water scarcity and poor soil quality; 3)
livestock was promoted to improve livelihood diversification; Low investment capital and diseases are the
households’ main challenges for expansion from an average of 1-2 cows per household. Larger herds could
open up opportunities for biogas production. Feed sources, however, are unclear.
The villagers identified 21 stakeholders active within food security (the majority), food crisis and natural
resource management. The village experienced temporary periods of food insecurity during natural
disasters. While the main issues relating to natural resources were pollution (mining) and land degradation,
there was little awareness of the potential impacts due to progressing climate variability and change. The
CCAFS CSV projects, therefore, are a timely complement to help implement the province action plan and
policies in response to climate change
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Chloride channels regulate differentiation and barrier functions of the mammalian airway.
The conducting airway forms a protective mucosal barrier and is the primary target of airway disorders. The molecular events required for the formation and function of the airway mucosal barrier, as well as the mechanisms by which barrier dysfunction leads to early onset airway diseases, remain unclear. In this study, we systematically characterized the developmental landscape of the mouse airway using single-cell RNA sequencing and identified remarkably conserved cellular programs operating during human fetal development. We demonstrated that in mouse, genetic inactivation of chloride channel Ano1/Tmem16a compromises airway barrier function, results in early signs of inflammation, and alters the airway cellular landscape by depleting epithelial progenitors. Mouse Ano1-/-mutants exhibited mucus obstruction and abnormal mucociliary clearance that resemble the airway defects associated with cystic fibrosis. The data reveal critical and non-redundant roles for Ano1 in organogenesis, and show that chloride channels are essential for mammalian airway formation and function
A High Efficiency Ultra High Vacuum Compatible Flat Field Spectrometer for EUV Wavelengths
A custom, flat field, extreme ultraviolet EUV spectrometer built specifically
for use with low power light sources that operate under ultrahigh vacuum
conditions is reported. The spectral range of the spectrometer extends from 4
nm to 40 nm. The instrument optimizes the light gathering power and signal to
noise ratio while achieving good resolution. A detailed description of the
spectrometer and design considerations are presented, as well as a novel
procedure that could be used to obtain a synthetic wavelength calibration with
the aid of only a single known spectral feature. This synthetic wavelength
calibration is compared to a standard wavelength calibration obtained from
previously reported spectral lines of Xe, Ar and Ne ions recorded with this
spectrometer
Crystallography of a Lewis-Binding Norovirus, Elucidation of Strain-Specificity to the Polymorphic Human Histo-Blood Group Antigens
Noroviruses, an important cause of acute gastroenteritis in humans, recognize the histo-blood group antigens (HBGAs) as host susceptible factors in a strain-specific manner. The crystal structures of the HBGA-binding interfaces of two A/B/H-binding noroviruses, the prototype Norwalk virus (GI.1) and a predominant GII.4 strain (VA387), have been elucidated. In this study we determined the crystal structures of the P domain protein of the first Lewis-binding norovirus (VA207, GII.9) that has a distinct binding property from those of Norwalk virus and VA387. Co-crystallization of the VA207 P dimer with Ley or sialyl Lex tetrasaccharides showed that VA207 interacts with these antigens through a common site found on the VA387 P protein which is highly conserved among most GII noroviruses. However, the HBGA-binding site of VA207 targeted at the Lewis antigens through the α-1, 3 fucose (the Lewis epitope) as major and the β-N-acetyl glucosamine of the precursor as minor interacting sites. This completely differs from the binding mode of VA387 and Norwalk virus that target at the secretor epitopes. Binding pocket of VA207 is formed by seven amino acids, of which five residues build up the core structure that is essential for the basic binding function, while the other two are involved in strain-specificity. Our results elucidate for the first time the genetic and structural basis of strain-specificity by a direct comparison of two genetically related noroviruses in their interaction with different HBGAs. The results provide insight into the complex interaction between the diverse noroviruses and the polymorphic HBGAs and highlight the role of human HBGA as a critical factor in norovirus evolution
The Impact of Transcatheter Atrial Septal Defect Closure in the Older Population A Prospective Study
ObjectivesWe sought to prove that device closure of atrial septal defect (ASD) in older patients not only improves cardiac function but also results in symptomatic relief by improving functional class.BackgroundAtrial septal defect accounts for approximately 10% of all congenital cardiac defects. It is possible that ASD closure in older patients may derive benefits, though this is not well established. We therefore aim to prospectively assess the clinical status and functional class of older patients after transcatheter ASD closure.MethodsThis was a prospective study of all patients age 40 years or more who underwent device closure of a secundum ASD between April 2004 and August 2006. Investigations including atrial and brain natriuretic peptide levels, electrocardiography, chest X-ray, transthoracic echocardiogram, 6-min walk test, and quality of life questionnaire were performed before and at 6 weeks and 1 year after the procedure.ResultsTwenty-three patients (median age 70 years, 13 women) had transcatheter device closure of ASD. Median ASD size was 18 mm (range 9 to 30 mm). Median pulmonary artery pressure was 22 mm Hg (range 12 to 27 mm Hg). At 1 year, New York Heart Association functional class improved (p = 0.004) in 16 patients with significant improvement in 6-min walk-test distance (p = 0.004) and physical (p = 0.002) as well as mental health score (p = 0.03). There were no major complications. One year following closure there was a significant change in left ventricular end-diastolic (p = 0.001) and end-systolic dimensions (p = 0.001) and also significant reduction in right ventricular end-diastolic dimension (p < 0.001).ConclusionsOur data demonstrated that ASD closure at advanced age results in favorable cardiac remodeling and improvement of functional class
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