bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple positive solutions for a critical quasilinear equation via Morse theory
Authors: Cingolani Silvia , Vannella Giuseppina 
Published: December 2007

We deal with the existence of solutions for the quasilinear problem

(P_{\lambda })\:
\begin{cases}
−\mathrm{\Delta }_{p}u = \lambda u^{q−1} + u^{p^{ \ast }−1} & \text{in}\:\Omega , \\ u > 0 & \text{in}\:\Omega , \\ u = 0 & \text{on}\:\partial \Omega ,
\end{cases}

where

Ω

is a bounded domain in

\mathbb{R}^{N}

with smooth boundary,

N⩾p^{2}

,

1 < p⩽q < p^{ \ast }

,

p^{ \ast } = Np/ (N−p)

,

\lambda > 0

is a parameter. Using Morse techniques in a Banach setting, we prove that there exists

\lambda ^{ \ast } > 0

such that, for any

\lambda \in (0,\lambda ^{ \ast })

,

(P_{\lambda })

has at least

\mathcal{P}_{1}(\Omega )

solutions, possibly counted with their multiplicities, where

\mathcal{P}_{t}(\Omega )

is the Poincaré polynomial of

Ω

. Moreover for

p⩾2

we prove that, for each

\lambda \in (0,\lambda ^{ \ast })

, there exists a sequence of quasilinear problems, approximating

(P_{\lambda })

, each of them having at least

\mathcal{P}_{1}(\Omega )

distinct positive solutions.

Résumé
On s'interesse à l'existence de solutions pour l'équation quasi-linéaire

(P_{\lambda })\:
\begin{cases}
−\mathrm{\Delta }_{p}u = \lambda u^{q−1} + u^{p^{ \ast }−1} & \text{in}\:\Omega , \\ u > 0 & \text{in}\:\Omega , \\ u = 0 & \text{on}\:\partial \Omega ,
\end{cases}

où

Ω

est un domaine de

\mathbb{R}^{N}

avec frontière régulière,

N⩾p^{2}

,

1 < p⩽q < p^{ \ast }

,

p^{ \ast } = Np/ (N−p)

,

\lambda > 0

est un paramètre. Par des techniques de la théorie de Morse dans le cadre des espaces de Banach, un démontre l'existence de

\lambda ^{ \ast } > 0

tel que, pour tout

\lambda \in (0,\lambda ^{ \ast })

,

(P_{\lambda })

possède au moins

\mathcal{P}_{1}(\Omega )

solutions, considerées avec leur multiplicité, où

\mathcal{P}_{1}(\Omega )

est le polynôme de Poincaré de

Ω

. En outre, pour

p⩾2

, on démontre que, pour tout

\lambda \in (0,\lambda ^{ \ast })

, il existe une suite de problèmes quasi-linéaires qui approchent

(P_{\lambda })

, chacun desquels a au moins

\mathcal{P}_{1}(\Omega )

solutions positives différentes.
Stillbirth rates in Peruvian populations at high altitude
Authors: Gonzales Gustavo F. , Tapia Vilma , Carrillo Carlos E. 
Published: December 2007

AbstractObjectiveTo compare the stillbirth rates in 4 cities at different altitudes in Peru.MethodsThe stillbirth rates from a sample of 22,662 births recorded in the Perinatal Information System database were analyzed between 2005 and 2006 for the cities of Lima (150 m), Huancayo (3280 m), Cuzco (3430 m), and Puno (3850 m).ResultsStillbirths were higher at high altitude (> 3000 m) (OR 4.82; CI, 3.05–7.72) compared with low altitude. The effect of altitude was observed after controlling for socioeconomic (OR 4.29; CI, 2.61–6.93), demographic and biological (OR 4.18; CI, 2.65–6.77), maternal health care (OR 4.72; CI, 2.96–7.61), and fetal factors (OR 3.96; CI, 2.48–6.45). Inhabitants from the southern Andes demonstrated a protective effect on stillbirth rate compared with the central Andes, which may be due to an ancestry effect with longer multigenerational residence in the southern Andes population.ConclusionStillbirth rate is higher at high altitude compared with low altitude.
Obstructive sleep apnea in pregnancy and fetal outcome
Authors: Sahin Figen Kir , Koken Gulengul , Cosar Emine , Saylan Filiz , Fidan Fatma , Yilmazer Mehmet , Unlu Mehmet 
Published: December 2007

AbstractObjectiveTo simultaneously investigate the polysomnography (PSG) and nonstress test (NST) records of pregnant women with obstructive sleep apnea (OSA) to observe NST changes during maternal desaturation and determine maternal and fetal outcomes.MethodsA prospective observational study of pregnant women assessed by questionnaire for symptoms of OSA. Women with self‐reported frequent snoring or apnea were offered PSG and NST.ResultOSA was diagnosed in 4 (11.4%) of the 35 pregnant women who underwent PSG. Three (75%) had fetal heart decelerations accompanying maternal desaturation. The neonates of women diagnosed with OSA had lower mean Apgar scores and birth weights compared with neonates of women without OSA. Three neonates from the women diagnosed with OSA were admitted to the newborn healthcare unit.ConclusionOSA in pregnancy has important maternal and fetal outcomes. Pregnant women should be assessed for symptoms of OSA and suspected cases should be offered PSG.
A symbolic approach to polyhedral scene analysis by parametric calotte propagation
Authors: Li Hongbo , Zhao Lina , Chen Ying 
Published: December 2007

SUMMARYPolyhedral scene analysis studies whether a 2D line drawing of a 3D polyhedron is realizable in space, and if so, it gives the results of parameterizing the space of all possible realizations. For generic 2D data, symbolic computation with Grassmann–Cayley algebra is needed in the analysis. In this paper, we propose a method called parametric calotte propagation to solve the realization and parameterization problems for general polyhedral scenes at the same time. In algebraic manipulation, parametric propagation is more efficient than elimination. In applications, it can lead to linear construction sequences for nonspherical polyhedra whose resolvable sequences do not exist.
Land, family and the transmission of property in a rural society of South Bohemia, 1651–1840
Authors: ZEITLHOFER HERMANN 
Published: December 2007

ABSTRACTThis article deals with the changing patterns of transmission of land and houses in pre-industrial rural Bohemia. By linking different sources, such as land registers, census-like lists and a family reconstitution, this study focuses on both the demographic and the economic factors that influenced peasant transmission strategies as well as on the consequences of changing transmission patterns for access to land-ownership in the local society. The results of this study show that patterns of land transmission changed profoundly after about 1720. Between 1651 and 1720 many houses with or without land were sold to non-kin as well as to kin although in both cases a customary and not a market price was paid. Imperfect market mechanisms are also indicated by the frequency of exchanges of houses between families. After around 1720 transmissions of property from father to son progressively became the dominant pattern. The chances of women (both widows and daughters and their husbands) to become property-holders diminished and it became extremely difficult for persons not born into house-owning families to acquire any houses or land.
Remarriage in a stem family system in early modern Japan
Authors: KUROSU SATOMI 
Published: December 2007

ABSTRACTDrawing data from the local population registers in two northeastern Japanese agricultural villages in the period 1716–1870, this study examines the patterns and covariates of remarriage in a rural community with strong adherence to a stem family organization. Event history analysis is applied separately for males and females, and for two types of previous marriage (uxorilocal and virilocal). Controlling for demographic and economic factors, coresiding parents and children had differential impacts on remarriage for these subgroups. Men and women were tightly bound to the fates of their natal and marital households within the larger context of local economic conditions.
Remarriage, gender and social class: a longitudinal study of remarriage in southern Sweden, 1766–1894
Authors: LUNDH CHRISTER 
Published: December 2007

ABSTRACTRemarriage was common in Sweden in pre-industrial times, especially among men, although over the nineteenth century the number of remarriages declined. This article analyses remarriages in southern Sweden between 1766 and 1894. Data are derived from family reconstitutions in five rural parishes in southern Sweden, which makes it possible to follow individual widows and widowers from the year of the death of the spouse. The focus here is on the influence of individual characteristics, household composition, food prices and time period on an individual widow's or widower's probability of remarriage. For some variables the effect was quite general, for example the negative effect on remarriage of the individual's age and the decrease in the likelihood of remarriage in the nineteenth century. The influence of other variables was not this straightforward. Socioeconomic status interacted with all variables, especially gender, food prices and the presence of minor or adult children in the household.
Rural land and credit markets, the permanent income hypothesis and proto-industry: evidence from early modern Zurich
Authors: PFISTER ULRICH 
Published: December 2007

ABSTRACTThe study documents fluctuations of proto-industrial income, of occupation, debt and presence on land markets across the life course for rural households in a major proto-industrial region during the seventeenth and eighteenth centuries. These fluctuations are interpreted on the basis that a major objective of households is to equalize their income across different stages of their development. The permanent income hypothesis is then extended to take into account land purchases and debt-contracting that result from the need to adjust land and capital to fluctuations in the size of the family labour force across the family cycle and from endeavours to improve the family's welfare by increasing the labour to land ratio. The empirical material presented shows marked fluctuations of income from proto-industrial work across the life course and suggests the existence of permanent income-cum-accumulation strategies to cope with these fluctuations.
On factorials which are products of factorials
Authors: LUCA FLORIAN 
Published: December 2007

AbstractIn this paper, we look at the Diophantine equation
(0.1)
Under the ABC conjecture, we show that it has only finitely many nontrivial solutions. Unconditionally, we show that the set of n for which the above equation admits an integer solution a1,. . .,at is of asymptotic density zero.
On motivic principal value integrals
Authors: VEYS WILLEM 
Published: December 2007

AbstractInspired byp-adic (and real) principal value integrals, we introduce motivic principal value integrals associated to multi-valued rational differential forms on smooth algebraic varieties. We investigate the natural question whether (for complete varieties) this notion is a birational invariant. The answer seems to be related to the dichotomy of the Minimal Model Program.
Geometric collections and Castelnuovo–Mumford regularity
Authors: COSTA L. , MIRÓ–ROIG R. M. 
Published: December 2007

AbstractThe paper begins by overviewing the basic facts on geometric exceptional collections. Then we derive, for any coherent sheaf $\cF$ on a smooth projective variety with a geometric collection, two spectral sequences: the first one abuts to $\cF$ and the second one to its cohomology. The main goal of the paper is to generalize Castelnuovo–Mumford regularity for coherent sheaves on projective spaces to coherent sheaves on smooth projective varieties X with a geometric collection σ. We define the notion of regularity of a coherent sheaf $\cF$ on X with respect to σ. We show that the basic formal properties of the Castelnuovo–Mumford regularity of coherent sheaves over projective spaces continue to hold in this new setting and we show that in case of coherent sheaves on $\PP^n$ and for a suitable geometric collection of coherent sheaves on $\PP^n$ both notions of regularity coincide. Finally, we carefully study the regularity of coherent sheaves on a smooth quadric hypersurface $Q_n \subset \PP^{n+1}$ (n odd) with respect to a suitable geometric collection and we compare it with the Castelnuovo–Mumford regularity of their extension by zero in $\PP^{n+1}$.
Stable sandwich classification theorem for classical-like groups
Authors: ZHANG ZUHONG 
Published: December 2007

AbstractLet H denote a subgroup of the unitary group U(R, Λ) which is normalized by EU(J, ΓJ) for some form ideal (J, ΓJ) of a commutative form ring (R, Λ). We prove that H satisfies a “sandwich” property, i.e., there exists a form ideal (I ΓI) such that

for some form ideal (I : J7, Ω). This answers a conjecture of Bak (1967) in the stable case.
Sectorial forms and unbounded subnormals
Authors: ATHAVALE AMEER , CHAVAN SAMEER 
Published: December 2007

AbstractWe use the theory of sectorial sesquilinear forms to characterize the closure of the Creation Operator of Quantum Mechanics in the classical set-up. Further, we bring that theory to bear upon the class of unbounded cyclic subnormal operators that admit analytic models; in particular, we provide a sufficient condition for the existence of complete sets of eigenvectors for certain sectorial operators related to unbounded subnormals. The relevant theory is illustrated in the context of a class of analytic models of which the classical Segal–Bargmann space is a prototype. The framework of sectorial sesquilinear forms is also shown to be specially useful for treating questions related to the existence, uniqueness and stability of certain parabolic evolution equations naturally associated with such analytic models.
The second Johnson homomorphism and the second rational cohomology of the Johnson kernel
Authors: SAKASAI TAKUYA 
Published: December 2007

AbstractThe Johnson kernel is the subgroup of the mapping class group of a surface generated by Dehn twists along bounding simple closed curves, and has the second Johnson homomorphism as a free abelian quotient. In terms of the representation theory of the symplectic group, we give a complete description of cup products of two classes in the first rational cohomology of the Johnson kernel obtained by the rational dual of the second Johnson homomorphism.
On decomposition numbers and Alvis–Curtis duality
Authors: ACKERMANN BERND , SCHROLL SIBYLLE 
Published: December 2007

AbstractWe show that for general linear groups GLn(q) as well as for q-Schur algebras the knowledge of the modular Alvis–Curtis duality over fields of characteristic ℓ, ℓ ∤ q, is equivalent to the knowledge of the decomposition numbers.
The elimination of Chagas' disease from Brazil
Authors: MASSAD E. 
Published: December 2007

SUMMARYOn 9 June 2006 the Pan American Health Organization (PAHO) presented the Minister of Health of Brazil with the International Elimination of Transmission of Chagas' Disease Certificate. This act was the culmination of an intensive process that began in 1991 with the Southern Cone Initiative, a joint agreement between the governments of Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay and Peru, to control Chagas' disease by the elimination of the main vector, Triatoma infestans. This initiative has been highly successful and the prevalence area of the vector diminished rapidly in the last years. As a consequence, the current seroprevalence in children aged between 0 and 5 years is of the order of 10−5, a clear indication that transmission, if it is occurring, is only accidental. In this review I calculate the basic reproduction number, R0, for Chagas' disease and demonstrate that its relatively low value (1·25) explains why vectorial transmission was interrupted relatively easily. In addition, I used a mathematical model to forecast how long the remaining cases of the disease, as well as the additional vertically transmitted cases will last.
The seasonality of human cryptosporidiosis in New Zealand
Authors: LAKE I. R. , PEARCE J. , SAVILL M. 
Published: December 2007

SUMMARYIn New Zealand human cryptosporidiosis demonstrates spring and autumn peaks of incidence with the spring peak being three times greater in magnitude than the autumn peak. The imbalance between the two peaks is notable, and may be associated with the high livestock density in New Zealand. In the summer and autumn the cryptosporidiosis rate was positively associated with temperatures in the current and previous month, highlighting the importance of outdoor recreation to transmission. No associations between spring incidence and weather were found providing little support for the importance of drinking-water pathways. Imported travel cases do not appear to be an important factor in the aetiology of cryptosporidiosis in New Zealand.
Mining pesticide use data to identify best management practices
Authors: Oakley Emily , Zhang Minghua , Miller Paul Richard 
Published: December 2007

AbstractThis paper reports on the initial findings of an ongoing research project to capture differences in pest management strategies and decision-making among growers using the California Pesticide Use Reports (PUR) database. Analysis was performed for prunes in Sutter and Yuba counties to identify on-farm innovation by analyzing the PUR for best management practices to reduce pesticide use. Results showed that large variations in pesticide use were present in 2000, with a range of less than 5 kg to more than 41 kg of pesticide applied per hectare (ha) crop planted in Sutter County and a range of less than 2 kg to close to 30 kg per ha crop planted in Yuba County. Among the 42 growers selected cultivating more than 80 ha, five growers in Sutter County and three growers in Yuba County in 2000 were identified as low pesticide use growers. The results indicated a surprising number of low to no fungicide users and an even higher number of growers using no herbicides in both counties. Twenty-nine viable low pesticide use growers were identified overall among the total 294 growers in the Sutter and Yuba counties. However, there were no spatial patterns of where these low pesticide use growers' fields were located. The transition from higher-risk active ingredients (AIs) to reduced-risk AIs used by many of the low pesticide users suggests intentional substitution. Initial yield data indicate that quantity and quality were not adversely affected by low use growers employing reduced-risk pesticides, fewer (AIs) per field, and lower rates per chemical than their moderate to high use counterparts. Diverse collaborators consisting of university researchers, environmental and community organizations, state government scientists, and growers worked together throughout the entire project, beginning with defining the research parameters, then interpreting the results, and finally suggesting practical applications for the outcomes. The paper also highlights the effectiveness of using such collaborative research relationships to explore low pesticide use alternatives, to directly exchange research findings with growers, and to encourage a farmer-to-farmer extension model.
Work: A necessary sacrifice or a suffered chore? Labor and farm continuity in alternative agriculture in France
Authors: Macombe Catherine 
Published: December 2007

AbstractSystems advocating alternative agriculture would appear to be handicapped by the amount and the minutiae of human labor required. Is this really a threat to the continuity of farms associated with these systems? We do not believe that this directly hampers the survival of a farm. We advance the theory that continuity is not just down to chance; the farmer at the time chooses to prolong the life of the farm and more especially to look for a successor. We have shown through a study conducted in central France (Auvergne) that the main guarantee of organizational sustainability, that which sustains the business as a viable entity when another person takes over, is when a farmer thinks of his farm as an entity-cum-project supporting a meaningful life plan. A farmer might also see his farm solely as capital or as heritage, but neither of these last two attitudes is sufficient for him to ensure the spirit of his enterprise is passed on. There is a particularly large number of farmers in the first category (entity-cum-project) who adopt alternative farming practices, which are meaningful. It also seems to be the case that the manner of working is closely linked to the moral principles of farmers who use alternative systems. Moreover, the same objective amount of work that might be thought excessive in a system that puts strong emphasis on high productivity, is regarded as normal in an alternative system. Farmers often approach extension advisors to help reorganize their working conditions. We maintain that alternative systems have peculiarities with regard to work that make this type of advice difficult. Our aim is to help advisors clearly construct the input they give to the various types of farmers. We put forward a typology of possible practices as regards advice on work, according to assessments farmers have made about the amount of work they do and their way of working. The large number of hours devoted to an alternative farming activity and the nature of that activity, whether demanding or linked to practices thought archaic, are not always a handicap to the continuity of an alternative system. On the contrary, these features can be its hallmark.
Periphyton in rice–fish culture system: A case study from Arunachal Pradesh, India
Authors: Das D.N. , Saikia S.K. , Das A.K. 
Published: December 2007

AbstractThe farmers of the Apatani tribe in Arunachal Pradesh, India have been raising a concurrent crop of fish successfully in their mountain valley rice plots for the past 40 years. They follow indigenous rice agronomy, ignoring the use of fertilizers, pesticides and even supplementary feed for the fish reared in the system. However, the yield levels of fish, ranging from 250 to 500 kg ha−1season−1, clearly support the role of other available resources within their wet rice fields. The investigation revealed that the rice itself provided the substrates for colonization and growth of periphyton. The colonized periphytic contents (1406–13513 no. cm−2stem−1) on rice stems and other natural fish feeds within the system seem to have direct effect in this regard. The Apatani technique of rice–fish integration may be considered as one of the periphyton-based aquaculture (PBA) systems which deserve further research attention.
Evaluation of different pig slurry composts as fertilizer of horticultural crops: Effects on selected chemical and microbial properties
Authors: Ros Margarita , García Carlos , Teresa Hernandez Maria 
Published: December 2007

AbstractThe excessive use of mineral fertilizers affects soil quality, gives rise to environmental problems and consumes energy. In contrast, organic amendment may improve soil quality at the same time as providing nutrients to plant. The aim of the work was to study the effects on crop yield and soil microbial activity of the successive addition of mineral fertilizers and fresh pig slurry before each successive crop compared with one sole application of different pig slurry composts (solid fraction of a pig slurry (CSFPS) and fresh pig slurry plus wood shavings (1:1 v/v; CPS+WS) before planting the first crop. Compost-treated soils exhibited higher organic carbon content than inorganically fertilized soils, throughout the experimental period. However, N content in the former soils was lower than in the latter after the second crop. Nevertheless, yields obtained with repeated additions of fresh pig slurry or with a sole application of pig slurry composts were similar to those obtained with repeated mineral fertilization. After the horticultural crops, organically treated soils generally showed higher values of both microbial biomass and metabolic microbial activity (measured as basal respiration and dehydrogenase activity) than the soil receiving mineral fertilization. Subsequently, the organically amended soils showed higher protease, phosphatase and β-glucosidase activities than the inorganically fertilized soil and similar levels of urease activity. From this study it can be concluded that both fresh and composted pig slurry can be used as an alternative for mineral fertilizer in growing horticultural crops and maintaining soil quality.