46,880 research outputs found
A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda : Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam
A new root-knot nematode, parasitizing Robusta coffee in Dak Lak Province, Western Highlands of Vietnam, is described as Meloidogyne moensi n. sp. Morphological and molecular analyses demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by a swollen body of females with a small posterior protuberance that elongated from ovoid to saccate; perineal patterns with smooth striae, continuous and low dorsal arch; lateral lines marked as a faint space or linear depression at junction of the dorsal and ventral striate; distinct phasmids; perivulval region free of striae; visible and wide tail terminus surrounding by concentric circles of striae; medial lips of females in dumbbell-shaped and slightly raised above lateral lips; female stylet is normally straight with posteriorly sloping stylet knobs; lip region of second stage juvenile (J2) is not annulated; medial lips and labial disc of J2 formed dumbbell shape; lateral lips are large and triangular; tail of J2 is conoid with rounded unstriated tail tip; distinct phasmids and hyaline; dilated rectum. Meloidogyne moensi n. sp. is most similar to M. africana, M. ottersoni by prominent posterior protuberance. Results of molecular analysis of rDNA sequences including the D2-D3 expansion regions of 28S rDNA, COI, and partial COII/16S rRNA of mitochondrial DNA support for the new species status
Approximation by finite mixtures of continuous density functions that vanish at infinity
Given sufficiently many components, it is often cited that finite mixture
models can approximate any other probability density function (pdf) to an
arbitrary degree of accuracy. Unfortunately, the nature of this approximation
result is often left unclear. We prove that finite mixture models constructed
from pdfs in can be used to conduct approximation of various
classes of approximands in a number of different modes. That is, we prove
approximands in can be uniformly approximated, approximands
in can be uniformly approximated on compact sets, and
approximands in can be approximated with respect to the
, for . Furthermore, we also prove
that measurable functions can be approximated, almost everywhere
The Current Adoption of Dry-Direct Seeding Rice (DDSR) in Thailand and Lessons Learned for Mekong River Delta of Vietnam
The paper documents the joint study trip, organized by CCAFS Southeast Asia for Vietnamese rice researchers, extension workers, as well as local decision makers, to visit Thailand in April 2018. The goal of the study trip was to observe and learn the experience of Thai farmers on the large-scale adoption process of dry-direct seeding rice (DDSR), a viable alternative to address regional scarcity of fresh water in irrigation caused by the drought and salinity intrusion in the Mekong River Delta
Minority versus majority: the choice of acquisition in Asia-Pacific countries
This paper examines the relationship between the financial constraints of the acquiring firms and their choice of a minority over a majority acquisition. Our findings show that the likelihood of bidders undertaking a minority acquisition increases with financial constraints, including the deviation from target capital structure, and overleverage deficit. We also find that the impacts of leverage deviation on the likelihood of bidders engaging in a minority or majority acquisition is asymmetric for underleveraged and overleveraged firms. In addition, international bidders are less likely to take a minority acquisition if the target is operating in i) countries with a higher degree of Political Stability and Absence of Violence/Terrorism, ii) countries with higher degree to which individuals are able to participate in selecting their government, as well as having more freedom of expression, freedom of association, and a free media. Lastly, minority acquisitions are more common in a country with a more developed market. As such, in a fluid social order it looks like acquirers really need majority control
A Template for Implementing Fast Lock-free Trees Using HTM
Algorithms that use hardware transactional memory (HTM) must provide a
software-only fallback path to guarantee progress. The design of the fallback
path can have a profound impact on performance. If the fallback path is allowed
to run concurrently with hardware transactions, then hardware transactions must
be instrumented, adding significant overhead. Otherwise, hardware transactions
must wait for any processes on the fallback path, causing concurrency
bottlenecks, or move to the fallback path. We introduce an approach that
combines the best of both worlds. The key idea is to use three execution paths:
an HTM fast path, an HTM middle path, and a software fallback path, such that
the middle path can run concurrently with each of the other two. The fast path
and fallback path do not run concurrently, so the fast path incurs no
instrumentation overhead. Furthermore, fast path transactions can move to the
middle path instead of waiting or moving to the software path. We demonstrate
our approach by producing an accelerated version of the tree update template of
Brown et al., which can be used to implement fast lock-free data structures
based on down-trees. We used the accelerated template to implement two
lock-free trees: a binary search tree (BST), and an (a,b)-tree (a
generalization of a B-tree). Experiments show that, with 72 concurrent
processes, our accelerated (a,b)-tree performs between 4.0x and 4.2x as many
operations per second as an implementation obtained using the original tree
update template
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