The Quant Delusion: Financial Engineering in the Post-Lehman Dodd–Frank Landscape

The recent financial crisis and its aftershocks have reshaped the world of financial engineering, quantitative analysis, and derivatives trading. Government intervention, regulatory reform, and the refutation of fundamental axioms and model assumptions are three reshaping forces now confronting quantitative practitioners.Statistic

Ecohydrological characterisation of Whangamarino wetland

The Whangamarino wetland is internationally recognised and one of the most important lowland wetland ecosystems in the Waikato Region. The wetland’s hydrology has been altered by reduced river base levels, the installation of a weir to raise minimum water levels and the Lower Waikato Waipa Flood Control Scheme, which is linked via the (hypertrophic) Lake Waikare and affected by varying catchment land use practices. When water levels exceed capacity, the overflow is released into the Whangamarino wetland, which also receives flood waters from Whangamarino River. Water levels in the wetland are also affected at high stage, by a control structure near Meremere at the confluence of Waikato and Whangamarino Rivers, and at low stage by a weir a short distance upstream. The ecohydrology of a representative part of the wetland was studied to assess the linkage between wetland ecology and the natural and anthropogenic modification of the flood regime and land use. The primary goal of this research was to characterise the present state of the wetland, which will aid in developing future goals and approaches for restoration. The study focused on a 2.3 km transect extending from the Whangamarino River, through the wetland to adjacent farmed hillsides. Hydrological and meteorological data were retrieved and analysed from an automated weather station and seven water level sites along the transect. Historical water level records (over 46 years) were used to determine changes in the hydrological regime and the impact of the flood control scheme, through a flood inundation and frequency analysis. During a winter flood event, river water quality was assessed. Peat surface oscillation in the restiad bog was examined. Vegetation patterns were assessed and classified through ordination and statistical techniques. Peat, soil and foliage physical and chemical quality were measured. Atmospheric ammonia (NH3) deposition rates of N into the wetland were measured. Water levels in the inland 0–1.1 km of the transect line (restiad bog) were relatively stable and consistent, rising and falling through winter and summer. This area had rainfall as the primary water input and was independent from the Whangamarino River, except during large flood events where the fringe of the restiad bog was inundated. Closer to the Whangamarino River water levels were more variable and strongly responsive to the river’s hydrological regime. A flood inundation event in September 2010 impacted on wetland water level regimes up to 1.4 km from the river and had a return period of 3.3 years. Frequency analysis showed sites up to 500 m from the river will likely be inundated by floods every year. A 100 year flood was estimated to inundate 1.75 km from the river, but would not cover the entire wetland. River water samples collected during a flood event showed total suspended solids within the Whangamarino River peaking at 260 mg L-1, double the concentration from Pungarehu Canal (86 mg L-1). Nutrient concentrations (such as dissolved reactive phosphorus) followed a similar pattern to the flood hydrograph. Minimum water levels have increased since the development of the artificial weir, but before this occurred water table lowering may have encouraged manuka invasion towards the restiad bog. Increased flood inundation is now the most likely threat to continued wetland degradation and manuka invasion into the restiad bog, due to the change in water levels and the deposition of sediment and nutrients. Nutrients, heavy metals, isotopes (δ15N) and physical soil characteristics (such as bulk density) increased from the start of the manuka belt (1100 m) and were greatest near the Whangamarino River (2300 m). A gradient was observed in peat and soil chemistry patterns, with increasing fertility and a change from bog to swamp-type environments along the transect line towards the river. A mineralised swamp fringe belt was present next to the farmland (0–50 m). From 50–1100 m a restiad bog (dominated by Empodisma minus) was present and changed to a manuka transition zone from 1100–1500 m. From 1500–1900 m, a swamp environment was present with a dominant canopy of manuka changing to Coprosma tenuicaulis closer to the river. C. tenuicaulis appears to be acting as a buffer zone over 150 m, removing a large amount of nutrients and sediment from flood waters. The remaining 400 m (1900–2300 m) of the transect line was a marshland, with the highest nutrient and sediment abundances and the most variable water level patterns. This area was colonised primarily by Polygonum persicaria (willow weed). The major risk to the wetland is from continued flood inundation with nutrient and sediment rich waters. Recommendations for future management include restoring catchment water quality and better management of the flood control regime

Falling Incapacity Benefit claims in a former industrial city: policy impacts or labour market improvement?

This article provides an in-depth study of Incapacity Benefit (IB) claims in a major city and of the factors behind their changing level. It relates to the regime prior to the introduction of the Employment and Support Allowance (ESA) in 2008. Glasgow has had one of the highest levels of IB in Britain with a peak of almost one fifth of the working age population on IB or Severe Disablement Allowance (SDA). However, over the past decade the number of IB claimants in Glasgow, as in other high claiming areas, has fallen at a faster rate than elsewhere, and Glasgow now has twice the national proportion of working-age people on IB/SDA rather than its peak of three times. The rise in IB in Glasgow can be attributed primarily to deindustrialisation; between 1971 and 1991, over 100,000 manufacturing jobs were lost in the city. Policy response was belated. Lack of local statistics on IB led to a lengthy delay in official recognition of the scale of the issue, and targeted programmes to divert or return IB claimants to work did not begin on any scale until around 2004. Evidence presented in the article suggests that the reduction in claims, which has mainly occurred since about 2003, has been due more to a strengthening labour market than to national policy changes or local programmes. This gives strong support to the view that excess IB claims are a form of disguised unemployment. Further detailed evaluation of ongoing programmes is required to develop the evidence base for this complex area. However, the study casts some doubt on the need for the post-2006 round of IB reforms in high-claim areas, since rapid decline in the number of claimants was already occurring in these areas. The article also indicates the importance of close joint working between national and local agencies, and further development of local level statistics on IB claimants

Minimum drain setback distances to protect New Zealand wetlands: tool development

This report documents the development of a Wetland Drain Setback Tool (WDST) for New Zealand freshwater wetlands. The purpose of this tool is to assess the potential effects of historical and new drains on wetland ecosystems and provide guidance on appropriate setback distances to protect these ecosystems from adverse effects due to lowered water levels. The WDST directly supports the implementation of the National Environmental Standards for Freshwater (NES-F), which were established in 2020 to protect and restore wetlands. These standards prohibit earthworks or modifications to the water cycle within or near wetlands unless exempted for specific reasons like wetland restoration. However, there is a lack of national guidance on acceptable water level declines for different wetland types. The specific goals of this project were to develop and evaluate the viability of the WDST for New Zealand conditions and recommend subsequent steps for its development. The project involved five key steps: 1. Development of a conceptual model to evaluate how drain systems affect wetland hydrology. 2. Representation of the drain-wetland model in numerical software. 3. Collection of site-specific data to refine and validate the numerical modeling approach. 4. Application of conceptual and numerical models to a hypothetical drain development scenario. 5. Development of two national-scale datasets on hydraulic conductivity and Land Surface Recharge to provide input data in the absence of site measurements. The conceptual model simplifies wetland hydrology affected by drainage, reducing the need for complex modeling at each wetland. Numerical modeling was done using COMSOL Multiphysics, integrating complex governing equations like groundwater flow. Site-specific data collection and model calibration were carried out at wetlands in different regions. Satisfactory model calibrations were achieved, indicating the suitability of the drainage model for predicting water level responses. A hypothetical land development scenario near a wetland on the Kāpiti Coast was tested to demonstrate how the WDST could be applied. Various scenarios indicated lateral setback distances to ensure minimal change in wetland water levels. Overall, the report concludes that a national tool to estimate drainage effects near wetlands is feasible. It recommends further refinement, including verification at additional wetlands and data collection for input parameters. The tool could potentially be developed into a web-based application, supported by technical guidance material, to assist users in protecting wetland ecosystems through appropriate drainage setback distances

Defects, band bending and ionization rings in MoS2

Chalcogen vacancies in transition metal dichalcogenides are widely acknowledged as both donor dopants and as a source of disorder. The electronic structure of sulphur vacancies in MoS2 however is still controversial, with discrepancies in the literature pertaining to the origin of the in-gap features observed via scanning tunneling spectroscopy (STS) on single sulphur vacancies. Here we use a combination of scanning tunnelling microscopy (STM) and STS to study embedded sulphur vacancies in bulk MoS2 crystals. We observe spectroscopic features dispersing in real space and in energy, which we interpret as tip position- and bias-dependent ionization of the sulphur vacancy donor due to tip induced band bending (TIBB). The observations indicate that care must be taken in interpreting defect spectra as reflecting in-gap density of states, and may explain discrepancies in the literature.Comment: 7 pages, 5 figure

Robotic arm-assisted bi-unicompartmental knee arthroplasty maintains natural knee joint anatomy compared with total knee arthroplasty : a prospective randomized controlled trial

Aims The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. Methods An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups. Results The pre- to postoperative changes in joint anatomy were significantly less in patients undergoing bi-UKA in all three planes in both the femur and tibia, except for femoral sagittal component orientation in which there was no difference. Overall, for the six parameters of alignment (three femoral and three tibial), 47% of bi-UKAs and 24% TKAs had a change of < 2° (p = 0.045). The change in HKAA towards neutral in varus and valgus knees was significantly less in patients undergoing bi-UKA compared with those undergoing TKA (p < 0.001). Alignment was neutral in those undergoing TKA (mean 179.5° (SD 3.2°)) while those undergoing bi-UKA had mild residual varus or valgus alignment (mean 177.8° (SD 3.4°)) (p < 0.001). Conclusion Robotic-assisted, cruciate-sparing bi-UKA maintains the natural anatomy of the knee in the coronal, sagittal, and axial planes better, and may therefore preserve normal joint kinematics, compared with a mechanically aligned TKA. This includes preservation of coronal joint line obliquity. HKAA alignment was corrected towards neutral significantly less in patients undergoing bi-UKA, which may represent restoration of the pre-disease constitutional alignment (p < 0.001)

Significant differences in rates of aseptic loosening between two variations of a popular total knee arthroplasty design

Purpose: The NexGen Legacy Posterior Stabilised (LPS) prosthesis (Zimmer Biomet, Warsaw, IN, USA) has augmentable and non-augmentable tibial baseplate options. We have noted an anecdotal increase in the number of cases requiring early revision for aseptic loosening since adopting the non-augmentable option. The purpose of this study was to ascertain our rates of aseptic tibial loosening for the two implant types within five years of implantation and to investigate the causes for any difference observed. Methods: A database search was performed for all patients who underwent primary total knee arthroplasty (TKA) using the NexGen LPS between 2009 and 2015. Kaplan–Meier curves were plotted to assess for differences in revision rates between cohorts. We collected and compared data on gender, age, body mass index, component alignment and cement mantle quality as these were factors thought to affect the likelihood of aseptic loosening. Results: Two thousand one hundred seventy-two TKAs were included with five year follow-up. There were 759 augmentable knees of which 14 were revised and 1413 non-augmentable knees of which 48 were revised. The overall revision rate at five years was 1.84% in the augmentable cohort and 3.4% in the non-augmentable cohort. The revision rate for aseptic loosening was 0.26% in the augmentable group and 1.42% in the non-augmentable group (p = 0.0241). Conclusions: We have identified increased rates of aseptic loosening in non-augmentable components. This highlights the effect that minor implant changes can have on outcomes. We recommend that clinicians remain alert to implant changes and publish their own results when important trends are observed

Gatehouse Family 1856-57 Index: Royal Society Collection

Pittwater Church of England 1857. Deed of trust of land on Nonsuch Farm conveyed by Alfred James Gatehouse to himself and Robert Blyth and John Walker, as trustees for a chapel of the Church of England. Signed by A. J. Gatehouse, but not witnessed. Lease from George Henry Gatehouse of Grindstone Bay to Charles Allen Galt of Spring Bay, farmer, of Rosedale, a farm of 500 acres at £100 p.a.for ten years, 1856. RS 9

Acetyl-CoA synthetase 2 promotes acetate utilization and maintains cancer cell growth under metabolic stress

A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment