A field investigation of planimetric knickpoint morphology from rock-bed sections of Niagara Escarpment fluvial systems (Ontario)

This study was an initial attempt to understand the impact of parents, peers, the media, and sex education curricula on shaping adolescents\u27 knowledge and attitudes about dating relationships and sexuality. In addition, participants\u27 descriptions of what constitutes a good date and a bad date were investigated. One hundred participants (48 females, 52 males) aged thirteen to sixteen participated: half of the sample were early adolescents (13-14 years) and the other half were middle adolescents (15-16 years). All participants were asked to describe experienced or hypothetical good and bad dates. For good dates, respondents identified engaging in fun, recreational activities, whereas bad dates were defined by the absence of such activities. In addition, gender differences were found with regard to the importance and validity that participants placed on parents, peers, media, and sex education as sources of dating information. With respect to the amount of information provided by each source, females received more information than males from music videos. Females also rated parents and television as more accurate sources of dating information than did males. With respect to the influence of each source on participants\u27 choice of dating partner, females rated parents, peers, and television as greater sources of influence on their choice of dating partner than did males. Lastly, females perceived more pressure to date from peers and television than males, and believed that they shared more similar attitudes and values about dating with their peers than males. An examination of the relative impact of each of the external sources revealed that males believed that dating partners were a source of information that was easy to access, comfortable, and provided the most accurate information about dating and sexuality issues. In conclusion, females credited external sources of information (e.g. parents, peers, and television) as sources of dating information whereas males credited dating partners (a non-threatening source) as sources of dating information

Surrogacy and Citizenship: A Conjunctive Solution to a Global Problem

People around the world are turning to surrogacy when they are unable to conceive by traditional means. When surrogacy turns traditional notions of parentage upside down, however, countries struggle to find efficient regulations that protect their own citizens, while still recognizing the increasingly global nature of modern society. Children born through surrogacy arrangements between Thai surrogate mothers and Australian intended parents have been confronted with the consequences of inadequate regulation. This note argues that in addition to revising surrogacy legislation to reflect the increasingly transient nature of society, countries must make mirror citizenship reform so children born through surrogacy are able to easily become citizens of their intended parents\u27 home country

Relevance of intermittent rivers and streams in agricultural landscape and their impact on provided ecosystem services—a Mediterranean case study

Ecosystem services (ES), as an interconnection of the landscape mosaic pieces, along with temporal rivers (IRES) are an object of research for environmental planners and ecological economists, among other specialists. This study presents (i) a review on the importance of IRES and the services they can provide to agricultural landscapes; (ii) a classification tool to assess the impact of IRES to provide ES by agricultural landscapes; (iii) the application of the proposed classification to the Caia River in order to identify the importance of this intermittent river for its surrounding agricultural landscape. The classification of the ES follows the Common International Classification of Ecosystem (CICES) classification that was adapted for the purposes of this study. Firstly, the list of ES provided by agricultural landscape was elaborated. In the next step, we assessed the potential of IRES to provide ES. Next, IRES impacts to ES within the agricultural landscape were evaluated according to observations from the conducted field monitoring in the study area. This study focuses on the relevance of the intermittent Caia River-a transboundary river in Spain and Portugal-and its ephemeral tributaries in the agricultural landscape. Our study estimates that each hydrological phase of IRES increases the ES provided by the agricultural landscape. However, the dry phase can potentially have negative impacts on several services. The intensification of the agricultural sector is the main provision of the water resource within the Caia River basin, but we were able to identify several other ES that were positively impacted. The present study is in line with the conclusions of other authors who state that IRES constitute a valuable resource which should not be underestimated by society.Agência financiadora COST Action CA15113 Slovak Research and Development Agency APVV-16-0278 UID/SOC/04020/2013info:eu-repo/semantics/publishedVersio

Novel strategies in tendon and ligament tissue engineering: Advanced biomaterials and regeneration motifs

Tendon and ligaments have poor healing capacity and when injured often require surgical intervention. Tissue replacement via autografts and allografts are non-ideal strategies that can lead to future problems. As an alternative, scaffold-based tissue engineering strategies are being pursued. In this review, we describe design considerations and major recent advancements of scaffolds for tendon/ligament engineering. Specifically, we outline native tendon/ligament characteristics critical for design parameters and outcome measures, and introduce synthetic and naturally-derived biomaterials used in tendon/ligament scaffolds. We will describe applications of these biomaterials in advanced tendon/ligament engineering strategies including the utility of scaffold functionalization, cyclic strain, growth factors, and interface considerations. The goal of this review is to compile and interpret the important findings of recent tendon/ligament engineering research in an effort towards the advancement of regenerative strategies

The Moderating Effect of Tenure and Gender on the Relationship Between Organizational Justice and Affective Commitment

Employees’ emotional commitment to their organizations has powerful implications for the performance and retention of their workforces. Organizational justice is an established antecedent of affective commitment; however, the intricacies of the relationships between the four dimensions of organizational justice (distributive, procedural, interpersonal, and informational) and affective commitment have been insufficiently explored in existing literature. The present study explored the relative strengths of the relationships between the four types of organizational justice and affective commitment. It was hypothesized that all types of organizational justice would positively relate to employees’ affective commitment. Tenure and gender were also hypothesized to interact with organizational justice such that longer-tenure employees and women would experience a stronger relationship between all types of organizational justice and affective commitment than shorter-tenure employees and men, respectively. A total of 152 survey responses were analyzed to test these hypotheses. Consistent with the hypotheses, all four dimensions of organizational justice were positively related to affective commitment with informational and procedural justice having the strongest relationships, followed by interpersonal and distributive justice. However, no moderation effects were found, suggesting that justice practices of organizations can be executed similarly regardless of the tenure or gender of employees

Particle Path Length Distributions in Meandering Gravel-bed Streams: Results from Physical Models

In gravel-bed rivers with well-defined pool-bar morphology, the path length of transported bed particles must be, at least during channel-forming flows, equal to the length scale of the morphology. This is the basis for some methods for estimating bed material transport rates. However, previous data, especially from field tests, are often strongly positively skewed with mean much shorter than the pool-bar spacing. One possible explanation is that positively skewed distributions occur only in channels lacking distinct pool-bar topography or only at lower discharges in pool-bar channels. A series of flume experiments using fluorescent tracers was used to measure path length distributions in low-sinuosity meandering channels to assess the relation with channel morphology and flow conditions. At channel-forming flows, 55 to 75 per cent of the tracer grains were deposited on the first point bar downstream of the point of tracer input, with 15 per cent passing beyond the first bar. Path length distributions are symmetrical with mean equal to the pool-bar spacing and can be described with a Cauchy distribution. In some cases there was a secondary mode close to the point of tracer introduction; this bimodal distribution fits a combined gamma-Cauchy distribution. Only when discharge was reduced below the channel-forming flow were frequency distributions unimodal and positively skewed with no relation to the pool-bar spacing. Thus, path length distributions become more symmetrical, and mean path length increases to coincide with pool-bar spacing, as flow approaches channel-forming conditions. This is a substantial modification of existing models of particle transfer in gravel-bed rivers

Bed Particle Path Length Distributions and Channel Morphology in Gravel-bed Streams

The path length (downstream displacement over a given time period) of individual bed particles in gravel-bed rivers is central to morphological methods for measuring bed load transport rate and is also fundamental to understanding the bed load transport process and the development of channel morphology. Previous studies of particle movement using tracers report predominantly strongly positively skewed frequency distributions of path length with modes close to the point of entrainment. However, gravel-bed rivers often have regularly spaced erosion (scour pools) and deposition (channel bars) sites that are several channel widths apart and it is reasonable to expect that particle path length would reflect this morphological scale, at least during flows large enough to create and modify the morphology. Here, we synthesize and re-analyze results from published bed load tracing experiments in gravel-bed rivers to identify the variety of possible path length distributions for differing channel morphology, channel dimensions, bed particle size, and particle mobility (i.e. flow magnitude) and to look for occurrences of path length coinciding with the length scale of the morphology. The results show that path length distributions may be positively skewed, symmetrical, and uni-, bi-, or multi-modal and may include modes that coincide with known or expected pool–bar spacing. Primary path length modes equivalent to possible pool–bar spacing are more probable at higher non-dimensional bed shear stress, from which it is inferred that both particle mobility and channel morphology exert an influence on particle path lengths and that particle movement is unlikely to be stochastic except at relatively low particle mobility. Existing data are inadequate for more than a preliminary analysis of this problem consequently there is a need for new data collected explicitly and systematically to confirm these preliminary results, isolate the effect of the several variables that influence the characteristics of path length frequency distributions and identify the conditions under which path length coincides with the length scale of the dominant morphology

Bed-load Path Length and Point Bar Development in Gravel-bed River Models

Low-sinuosity meandering gravel-bed flume experiments were employed to investigate spatial patterns of deposition, which point to patterns of channel development related to the pool and bar morphology. At channel-forming discharges, fluorescent bedload tracers indicate that deposition is typically focused around the point bar apex, downstream of the apex (contributing to downstream bar migration), and at the bar head/riffle surface. Seven flume experimental runs illustrate a sequence of point bar development related to the spatial patterns of tracer deposition, and the related path length distribution. At early stages of bar formation, transport is from the scour zone across the point bar head to the bar apex and bar margin downstream of the apex. As the point bar develops, bedload transport across the bar decreases, as transport along the channel thalweg increases and sediment is deposited along the bar margin. Deposition cells appear to move from downstream to upstream of the bar apex as this sequence of bar formation progresses. At low (non-channel-forming) discharges, transport occurs to the bar head/riffle surface with very little material being transported to the apex region or point bar interior. The implication is that there is an inherent connection between the loci of particle deposition and point bar formation, largely controlled by the morphology of the channel

L'utilisation de transpondeurs passifs pour l'estimation du transport sédimentaire : premiers retours d'expérience

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