Wealth Accumulation and Activity Choice Evolution Among Amazonian Forest Peasant Households

This paper examines investment and livelihood decisions among forest peasant households in the Amazonian floodplain. A dynamic household model of multiple asset accumulation and activity choice under risk and credit constraints is developed by incorporating natural resource use and human capital evolution. Asset portfolios and sectoral incomes are estimated and then simulated to investigate the endowment and lifecycle dependency as well as the convergence/divergence of asset accumulation and corresponding activity choices. Physical asset endowment (especially land) and different human capital evolutions across activities help to explain forest peasants' livelihood choices, distinctive asset portfolios, and divergent income outcomes over the lifecycle.

Smoothing Income against Crop Flood Losses in Amazonia: Rain Forest or Rivers as a Safety Net

This article examines the role of ex post labor supply in smoothing income in response to crop losses caused by large floods among riverine households in the Peruvian Amazon, where rich environmental endowments permit a variety of resource extractive activities and coping responses. The paper finds that households respond to crop losses primarily by intensifying fishing effort not by relying on gathering of non-timber forest products, hunting, or asset liquidation. This ex post labor adjustment helps to smooth total income against small crop losses but less well against large crop losses. Both relatively non-poor households with better fishing capital and poor young households with a physical labor advantage employ this natural insurance in rivers.

Using the TPACK Framework to Unite Disciplines in Online Learning

This paper builds on a previous case study in which a group of lecturers from various disciplines were interviewed about their practice as facilitators of online learning. The lecturers\u27 comments about their teaching practices revealed their awareness of specific types of teacher knowledge about online teaching. This was an unintended outcome of the previous study. Subsequently, as reported in this paper, the data were interrogated further using a new lens to investigate the extent to which these elements of teacher knowledge were evident throughout their practices. The technological, pedagogical and content knowledge (TPACK) theoretical framework enabled the researchers to identify the lecturers\u27 views about the content taught in online and blended environments, the pedagogy which guided teaching and course design, and the technology selected to facilitate students\u27 learning. This paper also considers practical issues about using the TPACK framework as a research tool as a lens through which to view online teachers\u27 knowledge about pedagogy, technology and content

Upper Devonian microvertebrates from the Canning Basin, Western Australia

A diverse microvertebrate fauna is described from the Virgin Hills and Napier formations, Bugle Gap Limestone Canning Basin, Western Australia. Measured sections at horse Spring and Casey Falls (Virgin Hills Formation) and South Oscar Range (Napier Formation) comprise proximal to distal slope carbonates ranging in age from the Late Devonian Frasnian to middle Famennian. A total of 18 chondrichthyan taxa are identified based on teeth, including the first record of Thrinacodus tranquillus, Cladoides wildungensis, Protacrodus serra and Lissodus lusavorichi from the Canning Basin. A new species, Diademodus dominicus sp. nov. is also described and provided the first record of this genus outside of Laurussia. In addition, the upper range of Australolepis seddoni has been extended to Late Devonian conodont Zone 11, making it the youngest known occurrence for this species. The Virgin Hills and Napier formations microvertebrate faunas show close affinities to faunas recovered from other areas of Gondwana, including eastern Australia, Iran, Morocco and South China, which is consistent with known conodont and trilobite faunas of the same age

New investigations at Kalambo Falls, Zambia:Luminescence chronology, site formation, and archaeological significance

AbstractFluvial deposits can provide excellent archives of early hominin activity but may be complex to interpret, especially without extensive geochronology. The Stone Age site of Kalambo Falls, northern Zambia, has yielded a rich artefact record from dominantly fluvial deposits, but its significance has been restricted by uncertainties over site formation processes and a limited chronology. Our new investigations in the centre of the Kalambo Basin have used luminescence to provide a chronology and have provided key insights into the geomorphological and sedimentological processes involved in site formation. Excavations reveal a complex assemblage of channel and floodplain deposits. Single grain quartz optically stimulated luminescence (OSL) measurements provide the most accurate age estimates for the youngest sediments, but in older deposits the OSL signal from some grains is saturated. A different luminescence signal from quartz, thermally transferred OSL (TT-OSL), can date these older deposits. OSL and TT-OSL results are combined to provide a chronology for the site. Ages indicate four phases of punctuated deposition by the dominantly laterally migrating and vertically aggrading Kalambo River (∼500–300 ka, ∼300–50 ka, ∼50–30 ka, ∼1.5–0.49 ka), followed by deep incision and renewed lateral migration at a lower topographic level. A conceptual model for site formation provides the basis for improved interpretation of the generation, preservation, and visibility of the Kalambo archaeological record. This model highlights the important role of intrinsic meander dynamics in site formation and does not necessarily require complex interpretations that invoke periodic blocking of the Kalambo River, as has previously been suggested. The oldest luminescence ages place the Mode 2/3 transition between ∼500 and 300 ka, consistent with other African and Asian sites where a similar transition can be found. The study approach adopted here can potentially be applied to other fluvial Stone Age sites throughout Africa and beyond

Evaluation of a Spyware Detection System Using Thin Client Computing

In previous work, we introduced a bait injection system designed to delude and detect crimeware by forcing it to reveal itself during the exploitation of monitored information. Although effective as a technique, our original system was practically limited, as it was implemented in a personal VM environment. In this paper, we extend our system by applying it to thin-clien to demonstrate how the approach can be used in a large-scale deployment. Adapting our system to such an environment revealed a number of challenging issues, such as scalability, portability, and choice of physical communication means. We provide implementation details, as well as experimental results that demonstrate the scalability and effectiveness of our system

Exact spinor-scalar bound states in a QFT with scalar interactions

We study two-particle systems in a model quantum field theory, in which scalar particles and spinor particles interact via a mediating scalar field. The Lagrangian of the model is reformulated by using covariant Green's functions to solve for the mediating field in terms of the particle fields. This results in a Hamiltonian in which the mediating-field propagator appears directly in the interaction term. It is shown that exact two-particle eigenstates of the Hamiltonian can be determined. The resulting relativistic fermion-boson equation is shown to have Dirac and Klein-Gordon one-particle limits. Analytic solutions for the bound state energy spectrum are obtained for the case of massless mediating fields.Comment: 12 pages, RevTeX, 1 figur

Comparing open and minimally invasive surgical procedures for oesophagectomy in the treatment of cancer: the ROMIO (Randomised Oesophagectomy: Minimally Invasive or Open) feasibility study and pilot trial

Localised oesophageal cancer can be curatively treated with surgery (oesophagectomy) but the procedure is complex with a risk of complications, negative effects on quality of life and a recovery period of 6-9 months. Minimal-access surgery may accelerate recovery.The ROMIO (Randomised Oesophagectomy: Minimally Invasive or Open) study aimed to establish the feasibility of, and methodology for, a definitive trial comparing minimally invasive and open surgery for oesophagectomy. Objectives were to quantify the number of eligible patients in a pilot trial; develop surgical manuals as the basis for quality assurance; standardise pathological processing; establish a method to blind patients to their allocation in the first week post surgery; identify measures of postsurgical outcome of importance to patients and clinicians; and establish the main cost differences between the surgical approaches.Pilot parallel three-arm randomised controlled trial nested within feasibility work.Two UK NHS departments of upper gastrointestinal surgery.Patients aged ≥ 18 years with histopathological evidence of oesophageal or oesophagogastric junctional adenocarcinoma, squamous cell cancer or high-grade dysplasia, referred for oesophagectomy or oesophagectomy following neoadjuvant chemo(radio)therapy.Oesophagectomy, with patients randomised to open surgery, a hybrid open chest and minimally invasive abdomen or totally minimally invasive access.The primary outcome measure for the pilot trial was the number of patients recruited per month, with the main trial considered feasible if at least 2.5 patients per month were recruited.During 21 months of recruitment, 263 patients were assessed for eligibility; of these, 135 (51%) were found to be eligible and 104 (77%) agreed to participate, an average of five patients per month. In total, 41 patients were allocated to open surgery, 43 to the hybrid procedure and 20 to totally minimally invasive surgery. Recruitment is continuing, allowing a seamless transition into the definitive trial. Consequently, the database is unlocked at the time of writing and data presented here are for patients recruited by 31 August 2014. Random allocation achieved a good balance between the arms of the study, which, as a high proportion of patients underwent their allocated surgery (69/79, 87%), ensured a fair comparison between the interventions. Dressing patients with large bandages, covering all possible incisions, was successful in keeping patients blind while pain was assessed during the first week post surgery. Postsurgical length of stay and risk of adverse events were within the typical range for this group of patients, with one death occurring within 30 days among 76 patients. There were good completion rates for the assessment of pain at 6 days post surgery (88%) and of the patient-reported outcomes at 6 weeks post randomisation (74%).Rapid recruitment to the pilot trial and the successful refinement of methodology indicated the feasibility of a definitive trial comparing different approaches to oesophagectomy. Although we have shown a full trial of open compared with minimally invasive oesophagectomy to be feasible, this is necessarily based on our findings from the two clinical centres that we could include in this small preliminary study.Current Controlled Trials ISRCTN59036820.This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 48. See the NIHR Journals Library website for further project information

Impact of flipper-banding on breeding success of African penguins Spheniscus demersus at Robben Island: comparisons among silicone rubber bands, stainless-steel bands and no bands

From 2001 to 2006, two new designs of flipper bands made from silicone rubbers were tested on African penguins Spheniscus demersus at 365 nests on Robben Island, South Africa. We compared, over six years, the breeding success, from hatching to fledging, of three different groups of penguins: those with rubber bands (117 nests), with conventional stainless-steel bands (103 nests) and without bands (145 nests). There were no significant differences in breeding success between the three groups, suggesting that neither the currently used steel bands, nor either of the new rubber-band designs, were harmful during the seasons investigated. The rubber bands caused less wear of feathers and less drag on a model penguin than the steel bands. In captivity, the behaviours of African penguins fitted with rubber bands were not noticeably different to those of unbanded birds