Secondary forest succession differs through naturalised gorse and native kānuka near Wellington and Nelson

The dominant native woody species forming early successional vegetation on formerly forested sites in lowland New Zealand were kānuka (Kunzea ericoides) and mānuka (Leptospermum scoparium) (Myrtaceae). These have been replaced extensively by gorse (Ulex europaeus, Fabaceae), a naturalised species in New Zealand. Because gorse typically gives way to native broadleaved (angiosperm) forest in about 30 years, it is often considered desirable for facilitating native forest restoration. We tested three hypotheses, derived from the New Zealand literature, on gorse and kānuka: (1) kānuka stands have a different species composition and greater species richness than gorse stands at comparable successional stages; (2) differences between gorse and kānuka stands do not lessen over time; and (3) several native plant taxa are absent from or less common in gorse than in kānuka stands. We sampled 48 scrub or low-forest sites in two regions, Wellington and Nelson. Sites were classified into one of four predefined categories – young gorse, young kānuka, old gorse, old kānuka – based on canopy height of the succession and the dominant early-successional woody species. Few characteristics of the sites and surrounding landscapes differed significantly among site categories, and none consistently across regions. The vegetation composition of gorse and kānuka and their immediate successors differed in both regions, mainly in native woody species. Species richness was often lower in gorse and there were fewer smallleaved shrubs and orchids in gorse. Persistent differences at the older sites suggest the successional trajectories will not converge in the immediate future; gorse leads to different forest from that developed through kānuka. Gorse-dominated succession is therefore not a direct substitute for native successions. We suggest areas of early native succession should be preserved, and initiated in landscapes where successions are dominated by gorse or other naturalised shrubs.Research was funded by the Department of Conservation under science investigation number 3591

Restoring native ecosystems in urban Auckland: urban soils, isolation, and weeds as impediments to forest establishment

New Zealand urban environments are currently dominated by exotic plant species. Restoring native vegetation and its associated native biodiversity in these landscapes is desirable for both cultural and ecological reasons. We report on the first four years of an ongoing vegetation restoration experiment in Waitakere City, Auckland, that addresses four challenges to urban restoration: weeds, Anthropic Soils, attraction of frugivorous birds, and patch isolation. Nine commonly planted native species, grouped separately into wind- and bird-dispersed species, were planted across four sites increasingly isolated from native bush patches, using two site preparation methods. By year three, woody weeds >50 cm tall had established with an average density of 1.7 plant m across all sites. This was more than 17 times denser than all established wild native woody seedlings of any height. One of our establishment methods, sparse planting with mulch, resulted in higher native plant survival and faster plant growth. However, after 4 years, the more intensive method, dense planting and ripping of the soil, resulted in a denser canopy and a 2.8-fold reduction in woody weed establishment. The typically urban soils of all sites were highly modified, with substantial variation in compaction, ponding risk, and fertility over distances of 5-15 m. Several, but not all, species were detrimentally affected by soil compaction and ponding. Many bird-dispersed species, both native and non-native, colonised the experiment, although this did not differ between plots with planted wind-dispersed and bird-dispersed species, perhaps due to the small size of these plots. Site colonisation by native species was particularly high at sites ≤ 100 m from existing native vegetation, suggesting that even small patches of native vegetation in urban landscapes will be valuable as seed sources for accelerating native plant establishment at nearby receptive sites © New Zealand Ecological Society

Optimality Criteria for Probabilistic Numerical Methods

It is well understood that Bayesian decision theory and average case analysis are essentially identical. However, if one is interested in performing uncertainty quantification for a numerical task, it can be argued that standard approaches from the decision-theoretic framework are neither appropriate nor sufficient. Instead, we consider a particular optimality criterion from Bayesian experimental design and study its implied optimal information in the numerical context. This information is demonstrated to differ, in general, from the information that would be used in an average-case-optimal numerical method. The explicit connection to Bayesian experimental design suggests several distinct regimes in which optimal probabilistic numerical methods can be developed.Comment: Prepared for the proceedings of the RICAM workshop on Multivariate Algorithms and Information-Based Complexity, November 201

Creek habitats as sources for the spread of an invasive herb in a New Zealand mountain landscape

Landscapes typically comprise various habitats that differ in their susceptibility to invasion by exotic species. Highly invasible habitats such as riparian corridors can act as a conduit for rapid movement across the landscape and as a propagule source to facilitate spread into adjacent, less invasible habitats. If this is so, there should be a decline in invader frequency and/or abundance with distance away from the source; the local abundance of invasive species in the source habitat should be positively correlated with local abundance in the adjacent habitat; and, having accounted for variation in local source population size, the slope of the decline in invader abundance with distance away from the source habitat should reflect the ease with which adjacent habitat can be invaded. Here, we test these predictions to assess whether creek habitats function as a source to facilitate the spread of the invasive plant Hieracium lepidulum Stenstr. (Asteraceae) in upland catchments of the South Island, New Zealand, by surveying H. lepidulum abundance in creek margin and adjacent beech forest and subalpine habitat in 17 creek catchments. Our results imply that propagule pressure from populations in creek margins and other disturbed areas is driving catchment-wide H. lepidulum invasion, but forest and subalpine habitats currently differ in the way H. lepidulum spreads from source populations. Our results suggest that H. lepidulum invasion is at an earlier stage in subalpine areas, that there are few barriers to invasion across this habitat, and that subalpine habitats will become more heavily invaded than forests. These findings can be used to underpin monitoring strategies and management prioritisation for this invader

The role of early childhood psychological factors in determining risk for enuresis at school age in a UK cohort

There is evidence for a link between psychological factors and bedwetting, but the direction of this association is unclear. Using data on 8769 children from the Avon Longitudinal Study of Parents and Children, we examined whether difficult temperament (Toddler Temperament Scale at 24 months; Emotionality Activity Sociability Questionnaire at 38 months) and psychological problems (Revised Rutter Parent Scale for Preschool Children at 42 months) are linked to bedwetting at school age. We examined the association between these risk factors and different patterns of bedwetting from 4 to 9 years using multinomial regression. Difficult temperament and psychological problems in early childhood were associated with increased odds of bedwetting at 4–9 years. The strongest associations were most often found for the pattern of bedwetting that was both frequent (at least twice a week) and persistent (up to age 9) e.g. the temperament traits of ‘adaptability’ and ‘mood’ were associated with a 33 % increase (95 % confidence interval = 1.14–1.55) and a 27 % increase (1.10–1.47) respectively in the odds of persistent and frequent bedwetting per one standard deviation increase in risk score. Early behaviour problems (e.g. conduct problems [1.43 (1.25, 1.63)] and hyperactivity [1.29 (1.11, 1.50), p < 0.001]) were also associated with frequent and persistent bedwetting, but there was less evidence that early emotional difficulties were risk factors for bedwetting. Adjustment for confounders did not alter these conclusions. The presence of difficult temperament and behaviour problems in early childhood might help to identify children who will continue to experience bedwetting at school age. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00787-015-0756-7) contains supplementary material, which is available to authorized users

Perioperative lumbar drain placement: An independent predictor of tension pneumocephalus and intracranial complications following anterior skull base surgery

Objective: To measure the effect of routine perioperative lumbar drain placement during anterior skull base surgery on the frequency of: 1) tension pneumocephalus and 2) total intracranial complications. Design: Retrospective review of a series of patients (n = 161) who underwent the transglabellar/subcranial approach to lesions of the anterior skull base between December 1995 and November 2009. A retrospective cohort (n = 45) underwent routine lumbar drain placement at the time of skull base surgery. The remainder of the series did not undergo routine perioperative lumbar drain placement. Intervention: Transglabellar/subcranial surgical approach to the anterior skull base, with or without routine perioperative lumbar drain placement. Results: Routine placement of perioperative lumbar drains was an independent predictor of tension pneumocephalus ( P =.022, odds ratio = 11.22 [1.218–103.3]). In addition, this practice was also associated with an increased risk of intracranial complications overall ( P =.025, odds ratio = 2.623 [1.104–6.233]). Conclusion: Routine placement of perioperative lumbar drain may be associated with an increased risk of tension pneumocephalus and intracranial complications during surgery of the anterior cranial base. Laryngoscope, 2011Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84402/1/21409_ftp.pd

Omega-3 and Omega-6 Fatty acids and risk of psychotic outcomes in the ALSPAC birth cohort

Background Long chain polyunsaturated fatty acid (PUFA) levels have been implicated in the pathology of psychotic disorders. We investigated the relationship between childhood PUFA levels and later psychotic experiences (PE's) in a large birth cohort. Methods Plasma levels of Ω-3 and Ω-6 fatty acids (FA's) were assayed at ages 7 and 16 years. PE's were assessed at ages 12 and 18 years using a semi-structured interview. Primary outcome was any PE's at 18 years; sensitivity analyses examined incident PE's between ages 12 and 18 years, persistent PE's (at 12 and 18) and psychotic disorder at 18 years. Genetic instruments for Ω-3 and Ω-6 were derived and used in a multivariable Mendelian Randomization analysis. Results Higher levels of Ω-6 FA's AA, OA and AdA at age 7 years were weakly associated with a reduced risk for PE's at 18 years, however, effect sizes were small and attenuated after adjusting for confounders (strongest evidence for OA; adjusted OR, 0.842; 95% CI, 0.711, 0.998; p, 0.048). Total Ω-6 levels at age 16 years were associated with an increased odds of psychotic disorder at age 18 years. However, there was no association between Ω-6/Ω-3 ratio and psychosis outcomes, nor with genetic instruments of total Ω-3 or Ω-6 levels. Conclusions There is no strong evidence that total plasma Ω-3 FA levels or Ω-6/Ω-3 ratios in childhood and mid-adolescence are associated with increased risk for PE's or psychotic disorder, but very marginal evidence that alterations in the Ω-6 pathway at developmental time points might influence risk2

Olfactory groove meningioma: Discussion of clinical presentation and surgical outcomes following excision via the subcranial approach

Objectives/Hypothesis: To describe surgical outcomes and radiographic features of olfactory groove meningiomas treated by excision through the subcranial approach. Special emphasis is placed on paranasal sinus and orbit involvement. Study Design: Retrospective review of a series of patients. Methods: Nineteen patients underwent excision of olfactory groove meningioma (OGM) via the transglabellar/subcranial approach between December 1995 and November 2009. Nine patients had previously undergone prior resection at outside institutions, and four had prior radiotherapy in addition to a prior excision. Transglabellar/subcranial surgical approach to the anterior skull base was performed. Results: Tumor histology included three World Health Organization (WHO) grade III lesions, one WHO grade II lesion, and 15 WHO grade I lesions. Fourteen patients had evidence of extension into the paranasal sinuses, with the ethmoid sinus being most commonly involved. Kaplan‐Meier estimates of mean overall and disease‐free survival were 121.45 months and 93.03 months, respectively. The mean follow‐up interval was 41.0 months, and at the time of data analysis three patients had recurrent tumors. Seven (36.8%) patients experienced a major complication in the perioperative period; there were no perioperative mortalities. Orbit invasion was observed in four patients, with optic nerve impingement in 11 patients. Of these, three patients had long‐term diplopia. No patients experienced worsening of preoperative visual acuity. Conclusions: Olfactory groove meningiomas demonstrate a propensity to spread into the paranasal sinuses, particularly in recurrent cases. Given a tendency for infiltrative recurrence along the skull base, this disease represents an important area of collaboration between neurosurgery and otolaryngology. The subcranial approach offers excellent surgical access for excision, particularly for recurrences that involve the paranasal sinuses and optic apparatus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87044/1/22174_ftp.pd

Bayesian numerical methods for nonlinear partial differential equations

The numerical solution of differential equations can be formulated as an inference problem to which formal statistical approaches can be applied. However, nonlinear partial differential equations (PDEs) pose substantial challenges from an inferential perspective, most notably the absence of explicit conditioning formula. This paper extends earlier work on linear PDEs to a general class of initial value problems specified by nonlinear PDEs, motivated by problems for which evaluations of the right-hand-side, initial conditions, or boundary conditions of the PDE have a high computational cost. The proposed method can be viewed as exact Bayesian inference under an approximate likelihood, which is based on discretisation of the nonlinear differential operator. Proof-of-concept experimental results demonstrate that meaningful probabilistic uncertainty quantification for the unknown solution of the PDE can be performed, while controlling the number of times the right-hand-side, initial and boundary conditions are evaluated. A suitable prior model for the solution of PDEs is identified using novel theoretical analysis of the sample path properties of Matérn processes, which may be of independent interest

Uncertainties of the Inclusive Higgs Production Cross Section at the Tevatron and the LHC

We study uncertainties of the predicted inclusive Higgs production cross section due to the uncertainties of parton distribution functions (PDF). Particular attention is given to bbH Yukawa coupling enhanced production mechanisms in beyond SM scenarios, such as MSSM. The PDF uncertainties are determined by the robust Lagrange Multiplier method within the CTEQ global analysis framework. We show that PDF uncertainties dominate over theoretical uncertainties of the perturbative calculation (usually estimated by the scale dependence of the calculated cross sections), except for low Higgs masses at LHC. Thus for the proper interpretation of any Higgs signal, and for better understanding of the underlying electroweak symmetry breaking mechanism, it is important to gain better control of the uncertainties of the PDFs.Comment: LaTeX, JHEP, 19 pages, 14 figure