To save 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 saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.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 saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved 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.
Mixed crop–livestock systems, the world's most widespread farming systems, promote farm resilience through diversification and allow for crop–livestock integration (CLI). Intensification and specialization challenge these systems. In Northwest Vietnam, the standard farm model is based on mixed crop–livestock family farms but is shifting towards more specialized farming systems. The aim of the current study was to identify the new balance between livestock and crops on farms in Northwest Vietnam and to examine the effects of specialization on CLI practices and production system intensification by identifying current CLI practices and performing a retrospective analysis of changes in these practices. One hundred farms were surveyed and 24 interviews on farm trajectories were conducted in Dien Bien district (Dien Bien province) between January and April 2022. Based on the level of CLI and farm diversification, seven types of farms were identified and classified into three categories: (B) mixed farms, (A) farms specializing in livestock and (C) farms specializing in crops. The study of farm trajectories revealed three main changes: the conversion of mixed crop–livestock farms into more specialized crop systems, a change from mixed crop–livestock to more specialized family livestock farms and a change in the management of large ruminant herds and their feed system from free grazing to forage-fed systems. Understanding these changes will help identify drivers and potential constraints to the development of new practices for the integration of crop and livestock farming.
Let $k \geqslant 2$ be an integer. We prove that factorisation of integers into k parts follows the Dirichlet distribution $\mathrm{Dir}\left({1}/{k},\ldots,{1}/{k}\right)$ by multidimensional contour integration, thereby generalising the Deshouillers–Dress–Tenenbaum (DDT) arcsine law on divisors where $k=2$. The same holds for factorisation of polynomials or permutations. Dirichlet distribution with arbitrary parameters can be modelled similarly.
The brief essay is a response to an article by the French sociologist Loïc Wacquant which critiques the concept of “racial capitalism” that has gained much prominence and currency in recent times. It offers a historical analysis of the emergence of “race” as a concept in the Euro-Atlantic sphere and points to the complexities in extending it beyond that space, into the Indian Ocean world for example. As a consequence, the ambitious claims made by some theorists of “racial capitalism” appear difficult to sustain.
The association between the consumption of dairy products and risk of CVD has been inconsistent. There is a lack of studies in populations with high intakes of dairy products. We aimed to examine the association between intake of dairy products and risk of incident major adverse coronary events and stroke in the Swedish Malmö Diet and Cancer cohort study. We included 26 190 participants without prevalent CVD or diabetes. Dietary habits were obtained from a modified diet history, and endpoint data were extracted from registers. Over an average of 19 years of follow-up, 3633 major adverse coronary events cases and 2643 stroke cases were reported. After adjusting for potential confounders, very high intakes of non-fermented milk (>1000 g/d) compared with low intakes (<200 g/d) were associated with 35 % (95 % CI (8, 69)) higher risk of major adverse coronary events. In contrast, moderate intakes of fermented milk (100–300 g/d) were associated with a lower risk of major adverse coronary events compared with no consumption. Intakes of cheese (only in women) and butter were inversely associated with the risk of major adverse coronary events. We observed no clear associations between any of the dairy products and stroke risk. These results highlight the importance of studying different dairy foods separately. Further studies in populations with high dairy consumption are warranted.
Why did British politicians on both sides of the Atlantic propose a confederal rather than incorporating union in 1754? This question has been difficult to answer because most scholars have focused on the Albany Plan of Union outside of its imperial context, seeing in the plan either evidence of nascent American nationalism, a point of divergence between American and British conceptions of empire, or a missed moment to establish parliamentary supremacy over America. I show instead that the British and American plans for confederal union in 1754 formed part of an intensely partisan and pan-imperial debate about the nature of the British imperial constitution. The failure to adopt a confederal imperial constitution in 1754 had more to do with the contingency of the outbreak of the Seven Years’ War than with diverging British and American visions of empire or nascent American nationalism.
The Secundinus stone, with its combination of carved phallus and text, was found in 2022 in excavations within the stone fort at Vindolanda. We consider comparanda for the imagery from Vindolanda, Britannia and further afield, and textual parallels particularly from Pompeii. We offer several possible interpretations of the object and prefer an analysis which takes the text, SECVNDINVS CACOR, as it is carved. This interpretation would add an otherwise unattested verbal form to the Latin scato-sexual vocabulary.
To date, the predominant means for computing the probability density function (p.d.f.) for the free surface elevation of a nonlinear, irregular water wave field, free of assumptions involving narrow-bandedness and small directionality, is the approximate Gram–Charlier series solution of Longuet-Higgins (J. Fluid Mech., vol. 17, 1963, pp. 459–480, hereafter LH63). In this paper we re-visit the derivation of this p.d.f. to second order in the wave steepness, utilizing both moment and cumulant generating functions. We show that LH63's approximate solution based on the cumulant generating function, in fact, matches that derived from the moment generating function. Moreover, through a change of variables coupled with complex analysis, it is shown that the approximation employed by LH63 is unnecessary, and the second-order p.d.f. stemming from the cumulant generating function can be represented exactly in terms of the Airy function. The new second-order p.d.f. predicts increased probability of extreme positive surface elevations typical of e.g. rogue waves, relative to both second- and third-order solutions of LH63. This heavy positive tail is inherent, and is explained through comparison of the asymptotic limits of the p.d.f.s for large surface elevations. A semi-theoretical method is also proposed for remedying non-physical spurious oscillations that arise in the negative tail, based on the envelope of the Airy function with negative arguments. This modified negative tail is valid for irregular wave fields having skewness less than or equal to 0.2. The new p.d.f.s are compared against those based on data sets generated from second-order irregular wave theory as well as a fully nonlinear, spectrally accurate numerical wave model. Good accuracy is collectively demonstrated for directionally spread irregular seas in both finite and infinite water depths for a range of directional spreading.
In multispecies electrolyte solutions, even in the absence of an external electric field, differences in ion diffusivities induce an electric potential and generate additional fluxes for each species. This electro-diffusion process is well-described by the advection Nernst–Planck equation. This study aims to analyse the long-time behaviour of the governing equation under electroneutrality and zero current conditions, and to investigate how the diffusion-induced electric potential and shear flow enhance the effective diffusion coefficients of each species in channel domains. The exact solutions of the effective equation with certain special parameters, as well as the asymptotic analyses for ions with large diffusivity discrepancies, are presented. Furthermore, there are several interesting properties of the effective equation. First, it is a generalization of the Taylor dispersion, with a nonlinear diffusion tensor replacing the scalar diffusion coefficient. Second, the effective equation exhibits a scaling relation, revealing that the system with a weak flow is equivalent to the system with a strong flow under scaled physical parameters. Third, in the case of injecting an electrolyte solution into a channel containing well-mixed buffer solutions or electrolyte solutions with the same ion species, if the concentration of the injected solution is lower than that of the pre-existing solution, then the effective equation simplifies to a multi-dimensional diffusion equation. However, when introducing the electrolyte solution into a channel filled with deionized water, the ion–electric interaction results in several phenomena not present in the advection–diffusion equation, including upstream migration of some species, spontaneous separation of ions, and non-monotonic dependence of the effective diffusivity on Péclet numbers. Finally, the dependence of effective diffusivity on concentration and ion diffusivity suggests a method to infer the concentration ratio of each component and ion diffusivity by measuring the effective diffusivity.
In this paper, we study the hydrostatic approximation for the Navier-Stokes system in a thin domain. When we have convex initial data with Gevrey regularity of optimal index $\frac {3}{2}$ in the x variable and Sobolev regularity in the y variable, we justify the limit from the anisotropic Navier-Stokes system to the hydrostatic Navier-Stokes/Prandtl system. Due to our method in the paper being independent of $\varepsilon $, by the same argument, we also obtain the well-posedness of the hydrostatic Navier-Stokes/Prandtl system in the optimal Gevrey space. Our results improve upon the Gevrey index of $\frac {9}{8}$ found in [15, 35].
This study evaluated the significance of positron emission tomography/computed tomography (PET/CT) in detecting recurrences or other primary malignancies in patients treated for oro- and hypopharyngeal squamous cell carcinoma.
Method
A retrospective analysis of the follow up of 132 patients was performed and 370 PET/CT scans were assessed for their accuracy.
Results
All asymptomatic clinical occult recurrences were detected by PET/CT and accounted for 28 per cent of recurrences. Asymptomatic patients with metastases detected by PET/CT had a significant survival benefit compared to patients diagnosed in a symptomatic stage. For locoregional recurrence, no significant difference in overall survival could be demonstrated. In total, 33 primary malignancies were discovered, of which 48 per cent were first detected by PET/CT. The specificity and negative predictive value of the PET/CT scans had ranges of 85–100 and 83–100 per cent, respectively.
Conclusion
The role of PET/CT scans in detecting primary malignancies, clinical occult recurrences and especially asymptomatic metastases was observed.
Consider the family of automorphic L-functions associated with primitive cusp forms of level one, ordered by weight k. Assuming that k tends to infinity, we prove a new approximation formula for the cubic moment of shifted L-values over this family which relates it to the fourth moment of the Riemann zeta function. More precisely, the formula includes a conjectural main term, the fourth moment of the Riemann zeta function and error terms of size smaller than that predicted by the recipe conjectures.
Soil moisture deficit is the major constraint for sesame crop production during its main rainfed and summer cultivation seasons. In summer cultivation, the crop frequently gets exposed to soil moisture deficit at various crop growth stages. Therefore, it is essential to identify the traits along with promising genotypes adapted to soil moisture deficit. A set of 35 sesame genotypes with checks was used to quantify the variation in morpho-physiological, yield, and quality traits under irrigated (WW) and deficit soil moisture stress (WS) conditions in the summer seasons of 2021 and 2022. The analysis of variance revealed the presence of high variability among the genotypes for various measured traits. The mean performance indicated that WS negatively affects the growth, development, yield and quality traits. Moreover, the correlation, path analysis and D2 analysis studies suggested that the traits, viz. leaf area (LA), total dry matter (TDM), canopy temperature (CT), number of branches per plant (NBP) and number of seeds per capsule (NSC) were significantly associated with seed yield under both the conditions. Quality traits like palmitic acid and oleic acid correlated positively with seed yield, particularly under WS. Furthermore, the genotypes with lower canopy temperatures were found to be better seed yielders under WS. In addition, mean performance and cluster analysis suggested that the genotypes: IC- 205776, JSCDT-112, JCSDT-26, IC-205610, and IC-204300, secured higher seed yield along with superior agronomical traits and net photosynthetic rate. These selected genotypes were most promising and could be used in future sesame crop improvement programmes.
Border Carbon Adjustments (BCAs) may play an important role in lowering the economic costs of greenhouse gas mitigation and in overcoming political-economy constraints on the use of carbon taxes or equivalent measures. A carbon tax plus a full BCA could deal with the competitiveness challenges arising from carbon taxes by using the WTO's National Treatment principle to apply equal levies on domestic production and on imports, and by symmetrically rebating the carbon tax on exports in the manner of a value-added tax (VAT) export rebate. This approach would shift the base for carbon taxation from production to demand and potentially achieve substantial reductions in the cost of cutting emissions. It would avoid the massive measurement and compliance problems associated with BCAs based on foreign emission intensities. By contrast, import-only BCAs distort prices of importables relative to exportables; create divisive trade conflicts and deterioration in the terms of trade for developing countries; and likely require development of complex sets of import preferences.