To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Our main purpose is to extend several results of interest that have been proved for modules over integral domains to modules over arbitrary commutative rings
with identity. The classical ring of quotients
will play the role of the field of quotients when zero-divisors are present. After discussing torsion-freeness and divisibility (Sections 2–3), we study Matlis-cotorsion modules and their roles in two category equivalences (Sections 4–5). These equivalences are established via the same functors as in the domain case, but instead of injective direct sums
one has to take the full subcategory of
-modules into consideration. Finally, we prove results on Matlis rings, i.e. on rings for which
has projective dimension
A mega-RTA such as the planned Trans-Pacific Partnership (TPP) or the Regional Comprehensive Economic Partnership (RCEP) may overlap another RTA, with the result that some of the parties to the mega-RTA's overlapping RTA may become common parties, while others may remain as single-agreement parties. If the mega-RTA provides rules of origin based on the change in tariff classification (CTC)-with-exception criterion such as yarn-forward rules, the rules of origin will become more restrictive with respect to the imports of the excluded intermediate goods from the single-agreement parties after the formation of the mega-RTA than before, thus failing to meet the requirement under GATT Article XXIV:5. The exclusionary rules of origin of the mega-RTA draw the trade away from the single-agreement parties, causing ‘fracture’ in the mega-RTA's overlapping RTA. As a legal remedy to the problem, the mega-RTA should eliminate the restriction from the CTC-with-exception criterion by adopting the rules of origin based on the non-exclusionary criteria such as the value-added or the CTC criterion that does not presumptively exclude the use of certain non-originating intermediate inputs.
Salmonella enterica is an important food borne pathogen that is frequently carried by swine. Carrier animals pose a food safety risk because they can transmit S. enterica to finished food products in the processing plant or by contamination of the environment. Environmental contamination has become increasingly important as non-animal foods (plant-based) have been implicated as sources of S. enterica. The prevalence of S. enterica in swine is high and yet carrier animals remain healthy. S. enterica has developed a highly sophisticated set of virulence factors that allow it to adapt to host environments and to cause disease. It is assumed that S. enterica also has developed unique ways to maintain itself in animals and yet not cause disease. Here we describe our research to understand persistence. Specifically, data are presented that demonstrates that detection of most carrier animals requires specific stresses that cause S. enterica to be shed from pigs. As well, we describe a phenotypic phase variation process that appears to be linked to the carrier state and a complex set of factors that control phenotypic phase variation. Finally, we describe how the composition of the gut bacterial microbiome may contribute to persistence and at the least how S. enterica might alter the composition of the gut bacterial microbiome.
In this paper we study the averaging formula for Nielsen coincidence numbers of pairs of maps (f,g): M→N between closed smooth manifolds of the same dimension. Suppose that G is a normal subgroup of Π = π1(M) with finite index and H is a normal subgroup of Δ = π1(N) with finite index such that Then we investigate the conditions for which the following averaging formula holds
where is any pair of fixed liftings of (f, g). We prove that the averaging formula holds when M and N are orientable infra-nilmanifolds of the same dimension, and when M = N is a non-orientable infra-nilmanifold with holonomy group ℤ2 and (f, g) admits a pair of liftings on the nil-covering of M.
We prove that the averaging formula for Nielsen numbers holds for continuous maps on infra-nilmanifolds: Let M be an infra-nilmanifold and ƒ: M → M be a continuous map. Suppose MK is a regular covering of M which is a compact nilmanifold with π1(MK = K. Assume that f*(K) ⊂ K. Then ƒ has a lifting . We prove a question raised by McCord, which is for any with an essential fixed point class, fix =1. As a consequence, we obtain the following averaging formula for Nielsen numbers
We prove that the averaging formula for Nielsen numbers holds for continuous maps on infra-solvmanifolds of type (R): Let M be such a manifold with holonomy group Ψ and let f: M → M be a continuous map. The averaging formula for Nielsen numbers
is proved. This is a workable formula for the difficult number N(f).
To determine the influence of early pain relief for patients with suspected appendicitis on the diagnostic performance of surgical residents.
A prospective randomized, double-blind, placebo-controlled trial was conducted for patients with suspected appendicitis. The patients were randomized to receive placebo (normal saline intravenous [IV]) infusions over 5 minutes or the study drug (morphine 5 mg IV). All of the clinical evaluations by surgical residents were performed 30 minutes after administration of the study drug or placebo. After obtaining the clinical probability of appendicitis, as determined by the surgical residents, abdominal computed tomography was performed. The primary objective was to compare the influence of IV morphine on the ability of surgical residents to diagnose appendicitis.
A total of 213 patients with suspected appendicitis were enrolled. Of these patients, 107 patients received morphine, and 106 patients received placebo saline. The negative appendectomy percentages in each group were similar (3.8% in the placebo group and 3.2% in the pain control group, p=0.62). The perforation rates in each group were also similar (18.9% in the placebo group and 14.3% in the pain control group, p=0.75). Receiver operating characteristic analysis revealed that the overall diagnostic accuracy in each group was similar (the area under the curve of the placebo group and the pain control group was 0.63 v. 0.61, respectively, p=0.81).
Early pain control in patients with suspected appendicitis does not affect the diagnostic performance of surgical residents.
Particles ranging in size from a few nanometers to tens of micrometers have a strong tendency to adsorb at interfaces between two immiscible fluids (e.g., water and oil or air). The driving force for this strong interfacial attachment is a reduction in interfacial area, and thus, interfacial energy. To design and engineer the structure and properties of materials constructed by such colloidal systems, it is imperative to understand the behavior of particles at fluid interfaces at the single-particle level and to establish the relationship between the microscopic behavior of interfacial particles and the bulk properties of particle-laden interfaces. In this article, we present background information on the behavior of particles at fluid–fluid interfaces and highlight recent advances in understanding the effects of particle shape and surface wettability on the behavior of particles at the interfaces. We also discuss recent advances in using interfacial attachment to direct the assembly of nanomaterials to create hierarchical structures with designed properties.
The dehydrogenated microstructure of the lithium borohydride-yttrium hydride (LiBH4-YH3) composite obtained at 350°C under 0.3 MPa of hydrogen and static vacuum was investigated by transmission electron microscopy combined with a focused ion beam technique. The dehydrogenation reaction between LiBH4 and YH3 into LiH and YB4 takes place under 0.3 MPa of hydrogen, which produces YB4 nano-crystallites that are uniformly distributed in the LiH matrix. This microstructural feature seems to be beneficial for rehydrogenation of the dehydrogenation products. On the other hand, the dehydrogenation process is incomplete under static vacuum, leading to the unreacted microstructure, where YH3 and YH2 crystallites are embedded in LiBH4 matrix. High resolution imaging confirmed the presence of crystalline B resulting from the self-decomposition of LiBH4. However, Li2B12H12, which is assumed to be present in the LiBH4 matrix, was not clearly observed.
Social support programs for dementia caregivers were widely used in order to reduce care burden. We investigated which types of social supports can reduce psychological and non-psychological burdens of dementia caregivers, and explored the mechanism of those social supports.
We evaluated 731 community-dwelling dementia patients and their caregivers from the National Survey of Dementia Care in South Korea. We investigated the five types of social supports (emotional support, informational support, tangible support, positive social interaction, affectionate support) using the Medical Outcomes Study Social Support Survey in each caregiver. The mechanisms of specific types of social support on psychological/non-psychological burden were examined using path analysis.
Positive social interaction and affectionate support reduced psychological burden via direct and indirect paths. Tangible support reduced the non-psychological burden via direct and indirect paths. Informational support and emotional support were not helpful for reducing psychological or non-psychological burden. A maximum of 20% of psychological burden could be relieved by positive social interaction and 10.3% of that could be reduced by affectionate support. Tangible support was associated with a 15.1% maximal improvement in non-psychological burden.
In order to reduce caregiver burden in dementia effectively, psychosocial interventions should be tailored to target type of caregiver burden.
The most favoured nation (MFN) clauses in preferential trade agreements (PTAs) under GATT Article XXIV or under GATS Article V entrench the preferential trade relations between the PTA parties because the trade liberalization in future PTAs with third parties will be constrained by the existing PTA MFN clauses. Trade liberalization based on PTA MFN clauses cannot be considered part of the internal trade liberalization required by GATT Article XXIV:8 or GATS Article V:1. The exclusionary effects caused by trade liberalization through PTA MFN clauses increase the burden on trade with third parties. As a result, PTA MFN clauses do not meet the necessity test under the Appellate Body's decision in Turkey–Textiles, as reasonable alternatives to the PTA MFN clauses are available. For these reasons, PTA MFN clauses fail the requirements for legal defences under GATT Article XXIV or GATS Article V for their violations of the general MFN clauses under GATT Article I and GATS Article II. For those products or services subject to existing PTA MFN clauses, any preferential liberalization based on PTA MFN clauses should be accorded non-discriminatorily to all WTO members in accordance with GATT Article I or GATS Article II.
Among the different porous materials, bulk metallic glass (BMG) foams are of special interest due to their high strength combined with large elastic limit. Large surface areas and, therefore, high reactivity in chemical applications can be achieved by properly adjusting the pore characteristics. Pore size and pore size distribution are the key factors for determining the overall performance of open-cell porous materials used for functional applications, such as filtration or catalysis. As a result, the control of these factors is a necessary requirement for material design and application. In this work, BMG foams are produced by powder metallurgy through the selective dissolution of a fugitive phase. The work is focused on the manufacturing processes needed to properly control pore size and pore size distribution. The results reveal that customized hybrid BMG porous structures can be produced through the controlled milling of the BMG-composite powders.
In this paper, we have observed an atomic-scale structure and compositional variation at the interface of the InGaN/GaN multi-quantum wells (MQW) by both scanning transmission electron microscopy (STEM) using high-angle annular dark-field mode and atom probe tomography (APT). The iso-concentration analysis of APT results revealed that the roughness of InGaN/GaN interface increased as the MQW layers were filled up, and that the upper interface of MQW (GaN/InGaN to the p-GaN side) was much rougher than that of the lower interface (InGaN/GaN tot he n-GaN side). On the basis of experimental results, it is suggested that the formation of interface roughness can affect the quantum efficiency of InGaN-based light-emitting diodes.
The “LEXT” confocal laser scanning microscope has been used for the three-dimensional (3D) imaging of the surface of specimens, especially in materials science fields, by the penetration of near-infrared (NIR) light without mechanical cutting, deposition, or other specimen pretreatment. Noninvasive investigation of various biological tissues such as human spinal dura mater, rat aorta, and cornea without the dehydration process was successfully carried out with the “LEXT,” in order to access both surface and internal topographic images of the biological structures at a good status of the wet tissue such as in vivo, especially in measuring tissue thickness. The confocal NIR laser microscopy offers the viable means to visualize tissue architecture and its thickness in microdomain to integrate 3D images efficiently. We believe that the “LEXT” has a good application for biological researchers to study biomaterials, and it would be useful as a diagnostic tool in the near future.