Migrant entry channels and family - related migratory patterns in Europe: a theoretical and empirical investigation

Despite the quantitative relevance of family-related migration in most European countries, few studies have attempted to shed light on how migration policies affect family-level migration strategies. The nature of this knowledge gap is both theoretical and empirical. Conceptually, framing the intersections between the macro-level institutional frameworks underpinned by immigration policies, the meso-level functioning of social networks and the micro-level family decision-making is a challenging task. From an empirical perspective, sound analysis of the family and migratory patterns vis-à-vis the institutional frameworks regulating admission, settlement and the right to family reunification is jeopardised by the lack of data sources that keep track of immigration status on entry (and the subsequent status changes), of the family history prior to migration, and of the patterns and timing of household formation in the country of destination. This paper attempts to address these knowledge gaps. Its overarching aim is to contribute to a better understanding of how admission channels shape household composition and the patterns and timing of family migratory processes. The paper begins with a conceptual review and synthesis of the links between immigration policies, migratory processes and household decision-making strategies. The following empirical analysis is based on the 2008 Ad-Hoc Module on migrant workers of the EU Labour Force Survey for eleven EU receiving countries (Austria, France, Germany, Greece, Ireland, Italy, Netherlands, Portugal, Spain and United Kingdom). A set of indicators is used to describe the migrant household composition and timing of families’ migratory pattern. Results reveal distinctive family-related migration patterns and migrant household composition by route of entry, suggesting that selective admission policies define the composition of the migrant families at different stages of the migratory experience, disrupting the cohabitation of spouses and, even more often, of different generations. One major feature of the association is its strong gendered connotation

Rich Information in the Acoustic Signals from Feeding and Grazing in Ruminants

Because of their impact on productivity and the environment, feeding behaviour, ingestion and rumination are critical to understand intake in grazing ruminants. Many systems, mainly mechanical, have been developed to measure ingestive behaviour. However, these systems have problems, including mechanical failure and the inability to distinguish between the complex jaw movements of prehension and ingestion (Laca et al., 1994). The sounds generated by these behaviours are rich in information that holds potential not only to distinguish and count behaviours, but also identify aspects of the nature of the foods ingested

The Sound of Chewing

Acoustic biotelemetry has been proposed as a way to count ingestive bites and chews of grazing animals. Recent work has indicated the possibility that detailed analysis of \u27sounds of chewing\u27 contains information about other characteristics of the ingestive process that can be used to study grazing behaviour of free ranging animals (Laca & Wallis DeVries, 2000), or to monitor stall-fed animals in more detail

Resource heterogeneity and foraging behaviour of cattle across spatial scales

BackgroundUnderstanding the mechanisms that influence grazing selectivity in patchy environments is vital to promote sustainable production and conservation of cultivated and natural grasslands. To better understand how patch size and spatial dynamics influence selectivity in cattle, we examined grazing selectivity under 9 different treatments by offering alfalfa and fescue in patches of 3 sizes spaced with 1, 4, and 8 m between patches along an alley. We hypothesized that (1) selectivity is driven by preference for the forage species that maximizes forage intake over feeding scales ranging from single bites to patches along grazing paths, (2) that increasing patch size enhances selectivity for the preferred species, and that (3) increasing distances between patches restricts selectivity because of the aggregation of scale-specific behaviours across foraging scales.ResultsCows preferred and selected alfalfa, the species that yielded greater short-term intake rates (P < 0.0001) and greater daily intake potential. Selectivity was not affected by patch arrangement, but it was scale dependent. Selectivity tended to emerge at the scale of feeding stations and became strongly significant at the bite scale, because of differences in bite mass between plant species. Greater distance between patches resulted in longer patch residence time and faster speed of travel but lower overall intake rate, consistent with maximization of intake rate. Larger patches resulted in greater residence time and higher intake rate.ConclusionWe conclude that patch size and spacing affect components of intake rate and, to a lesser extent, the selectivity of livestock at lower hierarchies of the grazing process, particularly by enticing livestock to make more even use of the available species as patches are spaced further apart. Thus, modifications in the spatial pattern of plant patches along with reductions in the temporal and spatial allocation of grazing may offer opportunities to improve uniformity of grazing by livestock and help sustain biodiversity and stability of plant communities

Vi è un'alternativa alla paratiroidectomia nei pazienti con calcolosi renale da iperparatiroidismo primitivo? Tre casi clinici

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The Proportion of the Ungrazed Area of the Pasture (PUP) Determines When Forage Intake and Diet Quality Decline in Grazing Systems

Grazing management has to deal with the spatial and temporal heterogeneity of pastures. In this context it is desirable to have a grazing management strategy that can be applied in a wide range of pasture conditions to control daily forage intake, diet quality and thus, animal performance. Sward height has been extensively studied and has been found not to be universally applicable to control the animal response as its relationship with intake changes with sward structure (Prache and Peyraud, 2001; Sollenberger and Burns, 2001) . Selective grazing is a universal phenomenon where, independently of pasture condition, cattle prefer the more nutritious and easily ingested top stratum of the pasture before consuming the deeper strata that impose a lower diet quality and greater restrictions on selective grazing. This study tested the hypothesis that forage intake and diet quality significantly decreases when the top selected stratum is removed across the entire area of the pasture (i.e. the proportion of pasture ungrazed)