571 research outputs found
Cretaceous-Tertiary findings, paradigms and problems
The asteroid hypothesis has stimulated numerous studies of the paleontological record at Cretaceous/Tertiary time as well as of geological indicators of environmental crisis preserved in the rock record. Both extinctions and geological anomalies often occur at times that do not appear to be synchronous or instantaneous. The record includes paleontological indicators of dinosaurs, terrestrial flora, marine planktonic organisms, and shallow water marine macrofauna and geological phenomena include occurrences of iridium and other platinum metals, trace elements, clay mineralogy, shocked minerals, soot, microspherules, and isotopes of osmium, strontium and carbon. These findings are reviewed in the context of the alternate hypotheses of an exogenic cause, involving either a single asteroid impact or multiple commentary impacts, and an endogenic cause, involving intense global volcanism and major sea level regression
Benthic Filter Feeding: A Natural Eutrophication Control
The importance of the benthic filter feeding community as a natural control on eutrophication is considered. The important environmental factors favorable for such a control are relatively shallow water depths and a dense benthic filter feeding commmunity of small animals. The criteria are summarized in the equivalence of the water recycling time, ĎĎ, for the benthic community and the time constant, ĎĎ, for phytoplankton growth. The criteria are applied specifically to the conditions that exist in South San Francisco bay
Credibility and adjustment: gold standards versus currency boards
It is often maintained that currency boards (CBs) and gold standards (GSs) are alike in that they are stringent monetary rules, the two basic features of which are high credibility of monetary authorities and the existence of automatic adjustment (non discretionary) mechanism. This article includes a comparative analysis of these two types of regimes both from the perspective of the sources and mechanisms of generating confidence and credibility, and the elements of operation of the automatic adjustment mechanism. Confidence under the GS is endogenously driven, whereas it is exogenously determined under the CB. CB is a much more asymmetric regime than GS (the adjustment is much to the detriment of peripheral countries) although asymmetry is a typical feature of any monetary regime. The lack of credibility is typical for peripheral countries and cannot be overcome completely even by âhardâ monetary regimes.http://deepblue.lib.umich.edu/bitstream/2027.42/40078/3/wp692.pd
Tidal propagation in strongly convergent channels
Simple firstâ and secondâorder analytic solutions, which diverge markedly from classical views of cooscillating tides, are derived for tidal propagation in strongly convergent channels. Theoretical predictions compare well with observations from typical examples of shallow, âfunnelâshapedâ tidal estuaries. A scaling of the governing equations appropriate to these channels indicates that at first order, gradients in crossâsectional area dominate velocity gradients in the continuity equation and the friction term dominates acceleration in the momentum equation. Finite amplitude effects, velocity gradients due to wave propagation, and local acceleration enter the equations at second order. Applying this scaling, the firstâorder governing equation becomes a firstâorder wave equation, which is inconsistent with the presence of a reflected wave. The solution is of constant amplitude and has a phase speed near the frictionless wave speed, like a classical progressive wave, yet velocity leads elevation by 90°, like a classical standing wave. The secondâorder solution at the dominant frequency is also a unidirectional wave; however, its amplitude is exponentially modulated. If inertia is finite and convergence is strong, amplitude increases along channel, whereas if inertia is weak and convergence is limited, amplitude decays. Compact solutions for secondâorder tidal harmonics quantify the partially canceling effects of (1) time variations in channel depth, which slow the propagation of low water, and (2) time variations in channel width, which slow the propagation of high water. Finally, it is suggested that phase speed, alongâchannel amplitude growth, and tidal harmonics in strongly convergent channels are all linked by morphodynamic feedback
Effectiveness of community based safe motherhood promoters in improving the utilization of obstetric care. The case of Mtwara Rural District in Tanzania
In Tanzania, maternal mortality ratio remains unacceptably high at 578/100,000 live births. Despite a high coverage of antenatal care (96%), only 44% of deliveries take place within the formal health services. Still, "Ensure skilled attendant at birth" is acknowledged as one of the most effective interventions to reduce maternal deaths. Exploring the potential of community-based interventions in increasing the utilization of obstetric care, the study aimed at developing, testing and assessing a community-based safe motherhood intervention in Mtwara rural District of Tanzania. This community-based intervention was designed as a pre-post comparison study, covering 4 villages with a total population of 8300. Intervention activities were implemented by 50 trained safe motherhood promoters (SMPs). Their tasks focused on promoting early and complete antenatal care visits and delivery with a skilled attendant. Data on all 512 deliveries taking place from October 2004 to November 2006 were collected by the SMPs and cross-checked with health service records. In addition 242 respondents were interviewed with respect to knowledge on safe motherhood issues and their perception of the SMP's performance. Skilled delivery attendance was our primary outcome; secondary outcomes included antenatal care attendance and knowledge on Safe Motherhood issues. Deliveries with skilled attendant significantly increased from 34.1% to 51.4% (rho < 0.05). Early ANC booking (4 to 16 weeks) rose significantly from 18.7% at baseline to 37.7% in 2005 and 56.9% (rho < 0.001) at final assessment. After two years 44 (88%) of the SMPs were still active, 79% of pregnant women were visited. Further benefits included the enhancement of male involvement in safe motherhood issues. The study has demonstrated the effectiveness of community-based safe motherhood intervention in promoting the utilization of obstetric care and a skilled attendant at delivery. This improvement is attributed to the SMPs' home visits and the close collaboration with existing community structures as well as health services
A qualitative exploration of the experiences of veterans who are serving sentences in custody
The focus on veterans in research is not a novel topic; however, the majority of studies are related to trauma, employment, mental health, suicide, and substance misuse. The Criminal Justice System involvement with veterans is a topic that has yet to be examined to a great extent. This study, conducted with adult male prisoners, elicited information from six veterans regarding their experiences of being in the armed forces, leaving the armed forces and becoming involved in the Criminal Justice System. Responses were evaluated using Interpretative Phenomenological Analysis (IPA) and three main themes were identified: âyouâre baptised into the armyâ, âthem and us,â and âoperational mind setâ; each of which comprised a number of superordinate themes. The research highlights that, although it is important to acknowledge the heterogenic nature of this group, it is equally important to note that much of their thinking and behaviour may be similar to those that have not had these experiences. As such, there is a need to reduce the notion that they are separate and different to other prisoners, requiring different treatment. The study highlights that many of the Offending Behaviour Programmes and interventions already available to prisoners would be appropriate for this group. The current research supports the merit in creating a service in prisons that will allow for ex-servicemen to meet together and access the support that is available to them. The implications of the research are discussed further
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