7,850 research outputs found
Managing Agricultural Price Risk in Developing Countries
We survey the experience of risk management in developing country agricultural supply chains. We focus on exposure, instruments, impediments to access and developing country futures markets. We draw on lessons from experience over the past two decades.Commodities, Risk Management, Developing Countries
A Simulation Study of Automated Material Handling Systems in Semiconductor Fabs
A critical aspect of semiconductor manufacturing is the design and analysis of material handling and production control polices to optimize fab performance. As wafer sizes have increased, semiconductor fabs have moved toward the use of automated material handling systems (AMHS). However, the behavior of AMHS and the effects of AMHS on fab productivity are not well understood. The first aspect of the research involves the development of a design and analysis methodology for evaluating the throughput capacity of AMHS. A set of simulation experiments is used to evaluate the throughput capacity of an AMHS and the effects on fab performance measures. This research utilizes two simulations of SEMATECH fab data of actual production fabs. The AMHS vehicle utilization point at which fab performance is degraded is studied. Results show a large increase in lot cycle time at a vehicle utilization of 75%, far below the maximum 100% utilization. These results stress the importance of using a performance indicator that takes into account the performance of the entire fab and not only the AMHS. The second aspect of this research involves the study of AMHS and tool dispatching rules. The hypothesis of this study is that fab performance is affected by both the choice of AMHS and tool dispatching rules as well as their interaction. A full factorial design experiment is conducted to test this hypothesis. Results show that for each fab tested the vehicle rules, machine rules, and their interactions are significant using an ANOVA test on average lot cycle time and other fab performance measures. Additional analyses are conducted to identify robust combinations of AMHS and tool dispatching rules among those tested. The overall results of this study indicate that AMHS and tool dispatching rules effect fab performance and must be considered together when trying to optimize fab performance
Pediatric thyroid disease: when is surgery necessary, and who should be operating on our children?
Surgical diseases of the thyroid in the pediatric population represent a diverse set of both benign and malignant conditions. Overall, incidence is rare. Benign conditions include Graves' disease, toxic adenomas, congenital hyperthyroidism, and goiter. Differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC), with its related familial cancer syndromes, are the most common malignancies. Near-total or total thyroidectomy is the appropriate surgery for thyroid cancer, with/out central lymph node dissection. Emerging practice guidelines from professional societies are helpful, although they generally have not addressed surgical management of the pediatric patient. Thyroidectomy in children is associated with a higher rate of complications, such as recurrent laryngeal nerve injury and hypoparathyroidism, as compared to the surgery in adults. Therefore, it is essential that pediatric thyroidectomy be performed by high-volume thyroid surgeons, regardless of specialty. Case volume to support surgical expertise usually must be borrowed from the adult experience, given the relative paucity of pediatric thyroidectomies at an institutional level. These surgeons should work as part of a multidisciplinary team that includes pediatric endocrinologists and anesthesiologists, pediatricians, nuclear medicine physicians, and pathologists to afford children the best clinical outcomes
Optical Studies of Twenty Longer-Period Cataclysmic Binaries
We obtained time-series radial velocity spectroscopy of twenty cataclysmic
variable stars, with the aim of determining orbital periods P_orb. All of the
stars reported here prove to have P_orb > 3.5 h. For sixteen of the stars,
these are the first available period determinations, and for the remaining four
(V709 Cas, AF Cam, V1062 Tau, and RX J2133+51) we use new observations to
improve the accuracy of previously-published periods. Most of the targets are
dwarf novae, without notable idiosyncracies. Of the remainder, three (V709 Cas,
V1062 Tau, and RX J2133+51) are intermediate polars (DQ Her stars); one (IPHAS
0345) is a secondary-dominated system without known outbursts, similar to LY
UMa; one (V1059 Sgr) is an old nova; and two others (V478 Her and V1082 Sgr)
are long-period novalike variables. The stars with new periods are IPHAS 0345
(0.314 d); V344 Ori (0.234 d); VZ Sex (0.149 d); NSVS 1057+09 (0.376 d); V478
Her (0.629 d); V1059 Sgr (0.286 d); V1082 Sgr (0.868 d); FO Aql (0.217 d); V587
Lyr (0.275 d); V792 Cyg (0.297 d); V795 Cyg (0.181 d); V811 Cyg (0.157 d); V542
Cyg (0.182 d); PQ Aql (0.247 d); V516 Cyg (0.171 d); and VZ Aqr(0.161 d).
Noteworthy results on individual stars are as follows. We see no indication of
the underlying white dwarf star in V709 Cas, as has been previously claimed;
based on the non-detection of the secondary star, we argue that the system is
farther away that had been thought and the white dwarf contribution is probably
negligible. V478 Her had been classified as an SU UMa-type dwarf nova, but this
is incompatible with the long orbital period we find. We report the first
secondary-star velocity curve for V1062 Tau. In V542 Cyg, we find a late-type
contribution that remains stationary in radial velocity, yet the system is
unresolved in a direct image, suggesting that it is a hierarchical triple
system.Comment: P.A.S.P., in press. 34 pages and 8 figure
Japan and the East Asian financial crisis: patterns, motivations and instrumentalisation of Japanese regional economic diplomacy
At first sight, the East Asian financial crisis represents an instance of Japan failing the test of regional leadership - as evidenced by its abandonment of initial proposals for an Asian Monetary Fund (AMF) in the face of US and Chinese opposition in 1997. However, if a second look is taken, and one which is sensitised to the fundamental characteristics of its diplomacy, then Japan can be seen as far more effective in augmenting its regional leadership role than previously imagined. Indeed, this article demonstrates that Japanese policy-makers have resurrected, over the longer term and in different guises, AMF-like frameworks which provide a potential springboard for further regional cooperation. Hence, the aims of this article are twofold. The first is to demonstrate the overall efficacy of Japanese regional economic diplomacy, and its ability to control outcomes through steering East Asia towards enhanced monetary cooperation. The second is to explain the reasons behind Japan's distinctive policy approach towards the financial crisis and general lessons for understanding its foreign policy. The article seeks to do so by asking three fundamental questions about the 'what', 'why' and 'how' of Japan's regional role: 'what' in terms of the dominant behavioural patterns of Japan's economic diplomacy; 'why' in terms of the motivations for this behaviour; and 'how' in terms of Japan's instrumentalisation of its regional policy
FDTL voices : drawing from learning and teaching projects
This publication draws on insights and experiences from individuals and teams within learning and teaching development projects in higher education. It considers lessons learnt from the processes, outcomes and tangible outputs of the projects across the spectrum of the FDTL initiative, with the intention that colleagues can draw on and benefit from this experience. The overriding theme at the heart of every FDTL project has been the desire to achieve some form of positive and meaningful change at the level of the individual, institution or discipline. The continuing legacy of the programme has been to create wider community involvement as projects have engaged with the higher education sector on multiple levels - personal, institutional, practice, and policy. This publication has remained throughout a collaborative endeavour, supported by Academy colleagues. It is based around the four themes emerging from the initiative as a whole: ⢠Sectoral/Organisational Change ⢠Conceptual Change ⢠Professional and Personal Development Partnership and ⢠Project Managemen
Potential value of triple drug therapy with ivermectin, diethylcarbamazine, and albendazole (IDA) to accelerate elimination of lymphatic filariasis and onchocerciasis in Africa
Phosphorylation stoichiometries of human eukaryotic initiation factors.
Eukaryotic translation initiation factors are the principal molecular effectors regulating the process converting nucleic acid to functional protein. Commonly referred to as eIFs (eukaryotic initiation factors), this suite of proteins is comprised of at least 25 individual subunits that function in a coordinated, regulated, manner during mRNA translation. Multiple facets of eIF regulation have yet to be elucidated; however, many of the necessary protein factors are phosphorylated. Herein, we have isolated, identified and quantified phosphosites from eIF2, eIF3, and eIF4G generated from log phase grown HeLa cell lysates. Our investigation is the first study to globally quantify eIF phosphosites and illustrates differences in abundance of phosphorylation between the residues of each factor. Thus, identification of those phosphosites that exhibit either high or low levels of phosphorylation under log phase growing conditions may aid researchers to concentrate their investigative efforts to specific phosphosites that potentially harbor important regulatory mechanisms germane to mRNA translation
Breaking barriers, building community: improving student engagement with preparation for studying online multidisciplinary science by distance learning - a case study
Developing an online learning community can help to improve student success. This presents a challenge as the student cohort is often time-limited and shifting in composition before a module starts. The continued evaluation and development of an online preparatory website for the new, year one module S112 - Science: concepts and practice is reported. Evaluation of the site in 2017-18 showed high levels of student satisfaction with the resources, though very little engagement with the asynchronous forum. Therefore, improvements before the October 2018 module start centred on increasing student engagement on the forum: Firstly, tutors moderating the forums were tasked with developing several optional scientific tasks for staged release to generate student discussion. Secondly, volunteer peer mentors from the 2017-18 presentation were recruited and trained as âstudent buddiesâ to provide non-academic advice and support.Student engagement increased markedly prior to the October 2018 module. The clearest emergent theme from tutors who moderated the forums was that students were seeking to establish a study community, rather than obtain subject-specific advice. Student response to the buddies was positive, with students more willing to ask questions of the buddies than of the tutor moderators. Data for S112 show that registrations at module start increased by 23.5% from 2017 to 2018, and early withdrawals (14 days after module start) dropped by 2%.Our results provide ideas for building online student engagement, particularly in scenarios where students may come and go, and have little available time: for example, bridging gaps in time or academic readiness, whether by blended or distance learning
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