Remote sensing in Michigan for land resource management: Waterfowl habitat management at Pointe Mouillee

For many years the Pointe Mouillee State Game Area, located on the Lake Erie shoreline just south of Detroit, has been a prime waterfowl habitat. The usefulness of the site for this purpose has been impaired because of the gradual deterioration of the marshland and severe flooding and storms during the spring of 1973. Also, it has been proposed that a dredge spoils area be located in or near the marsh. To aid the future management of a diked refuge area of 148 hectares within the State Game Area, a detailed vegetation inventory was prepared by photointerpretation and a generalized vegetation inventory was obtained by processing multispectral scanner imagery. Also, an analysis was conducted to determine the magnitude of past losses of marshland and the possibilities of replacing this lost habitat. The analysis indicated that large additions to waterfowl habitat could be provided by changes in management of vegetation in existing sections of the State Game Area, through acquisition and conversion of adjacent land by the Michigan Department of Natural Resources, and by the proposed construction of a barrier dike offshore of Pointe Mouillee. Altogether, the various measures considered in this report could affect a total area of nearly 13 sq. km

Biomarkers of cerebral injury and inflammation in pediatric tuberculous meningitis

Background Tuberculous meningitis (TBM) leads to death or disability in half the affected individuals. Tools to assess severity and predict outcome are lacking. Neuro-specific biomarkers could serve as markers of the severity and evolution of brain injury, but have not been widely explored in TBM. We examined biomarkers of neurological injury (neuromarkers) and inflammation in pediatric TBM and their association with outcome. Methods Blood and cerebrospinal fluid (CSF) of children with TBM and hydrocephalus taken on admission and over 3 weeks were analysed for neuromarkers S100B, neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and multiple inflammatory markers. Results were compared with 2 control groups; patients with 1) a fatty filum (abnormal filum terminale of the spinal cord), and 2) pulmonary tuberculosis (pTB). Imaging was conducted on admission and at 3 weeks. Outcome was assessed at 6 months. Results Data were collected from 44 TBM cases (median age 3.3 [0.3–13.1] years), 11 fatty filum (median age 2.8 [0.8–8] years) and 9 pTB controls (median age 3.7 [1.3–11.8] years). Seven cases (16%) died and 16 (36%) had disabilities. Neuromarkers and inflammatory markers were elevated in CSF on admission and for up to 3 weeks, but not in serum. Initial and highest concentrations in week 1 of S100B and NSE were associated with poor outcome, as were highest concentration overall and an increasing profile over time in S100B, NSE and GFAP. Combined neuromarker concentrations increased over time in patients who died, whereas inflammatory markers decreased. Cerebral infarcts were associated with highest overall neuromarker concentrations and an increasing profile over time. Tuberculomas were associated with elevated IL-12p40, IP-10 and MCP-1 concentrations, whereas infarcts were associated with elevated TNF-α, MIP-1α, IL-6 and IL-8. Conclusion CSF neuromarkers are promising biomarkers of injury severity and are predictive of mortality. An increasing trend suggested ongoing brain injury, even though markers of inflammation declined with treatment. These findings could offer novel insight into the pathophysiology of TBM

Low-Threshold AlGaN-based UVB VCSELs enabled by post-growth cavity detuning

The performance of vertical-cavity surface-emitting lasers (VCSELs) is strongly dependent on the spectral detuning between the gain peak and the resonance wavelength. Here, we use angle-resolved photoluminescence spectroscopy to investigate the emission properties of AlGaN-based VCSELs emitting in the ultraviolet-B spectral range with different detuning between the photoluminescence peak of the quantum-wells and the resonance wavelength. Accurate setting of the cavity length, and thereby the resonance wavelength, is accomplished by using doping-selective electrochemical etching of AlGaN sacrificial layers for substrate removal combined with deposition of dielectric spacer layers. By matching the resonance wavelength to the quantum-wells photoluminescence peak, a threshold power density of 0.4 MW/cm2 was achieved, and this was possible only for smooth etched surfaces with a root mean square roughness below 2 nm. These results demonstrate the importance of accurate cavity length control and surface smoothness to achieve low-Threshold AlGaN-based ultraviolet VCSELs

The pharmacokinetics of enteral antituberculosis drugs in patients requiring intensive care

Background. There is a paucity of data on the pharmacokinetics of fixed-dose combination enteral antituberculosis treatment in critically ill patients. Objectives. To establish the pharmacokinetic profile of a fixed-dose combination of rifampicin, isoniazid, pyrazinamide and ethambutol given according to weight via a nasogastric tube to patients admitted to an intensive care unit (ICU). Methods. We conducted a prospective, observational study on 10 patients (mean age 32 years, 6 male) admitted to an ICU and treated for tuberculosis (TB). Serum concentrations of the drugs were determined at eight predetermined intervals over 24 hours by means of high-performance liquid chromatography. Results. The therapeutic maximum plasma concentration (Cmax) for rifampicin at time to peak concentration was achieved in only 4 patients, whereas 2 did not achieve therapeutic Cmax for isoniazid. No patient reached sub-therapeutic Cmax for pyrazinamide (6 were within and 4 above therapeutic range). Three patients reached sub-therapeutic Cmax for ethambutol, and 6 patients were within and 1 above the therapeutic range. Patients with a sub-therapeutic rifampicin level had a higher mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score (p=0.03) and a lower estimated glomerular filtration rate (GFR) (p=0.03). Conclusions. A fixed-dose combination tablet, crushed and mixed with water, given according to weight via a nasogastric tube to patients with TB admitted to an ICU resulted in sub-therapeutic rifampicin plasma concentrations in the majority of patients, whereas the other drugs had a more favourable pharmacokinetic profile. Patients with a sub-therapeutic rifampicin concentration had a higher APACHE II score and a lower estimated GFR, which may contribute to suboptimal outcomes in critically ill patients. Studies in other settings have reported similar proportions of patients with ‘sub-therapeutic’ rifampicin concentrations

The pharmacokinetics of enteral antituberculosis drugs in patients requiring intensive care

The original publication is available at http://www.samj.org.zaBackground. There is a paucity of data on the pharmacokinetics of fixed-dose combination enteral antituberculosis treatment in critically ill patients. Objectives. To establish the pharmacokinetic profile of a fixed-dose combination of rifampicin, isoniazid, pyrazinamide and ethambutol given according to weight via a nasogastric tube to patients admitted to an intensive care unit (ICU). Methods. We conducted a prospective, observational study on 10 patients (mean age 32 years, 6 male) admitted to an ICU and treated for tuberculosis (TB). Serum concentrations of the drugs were determined at eight predetermined intervals over 24 hours by means of highperformance liquid chromatography. Results. The therapeutic maximum plasma concentration (Cmax) for rifampicin at time to peak concentration was achieved in only 4 patients, whereas 2 did not achieve therapeutic Cmax for isoniazid. No patient reached sub-therapeutic Cmax for pyrazinamide (6 were within and 4 above therapeutic range). Three patients reached sub-therapeutic Cmax for ethambutol, and 6 patients were within and 1 above the therapeutic range. Patients with a sub-therapeutic rifampicin level had a higher mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score (p=0.03) and a lower estimated glomerular filtration rate (GFR) (p=0.03). Conclusions. A fixed-dose combination tablet, crushed and mixed with water, given according to weight via a nasogastric tube to patients with TB admitted to an ICU resulted in sub-therapeutic rifampicin plasma concentrations in the majority of patients, whereas the other drugs had a more favourable pharmacokinetic profile. Patients with a sub-therapeutic rifampicin concentration had a higher APACHE II score and a lower estimated GFR, which may contribute to suboptimal outcomes in critically ill patients. Studies in other settings have reported similar proportions of patients with ‘sub-therapeutic’ rifampicin concentrations.Publishers' Versio

Structural and luminescence imaging and characterisation of semiconductors in the scanning electron microscope

The scanning electron microscopy techniques of electron backscatter diffraction (EBSD), electron channelling contrast imaging (ECCI) and hyperspectral cathodoluminescence imaging (CL) provide complementary information on the structural and luminescence properties of materials rapidly and non-destructively, with a spatial resolution of tens of nanometres. EBSD provides crystal orientation, crystal phase and strain analysis, whilst ECCI is used to determine the planar distribution of extended defects over a large area of a given sample. CL reveals the influence of crystal structure, composition and strain on intrinsic luminescence and/or reveals defect-related luminescence. Dark features are also observed in CL images where carrier recombination at defects is non-radiative. The combination of these techniques is a powerful approach to clarifying the role of crystallography and extended defects on a materials' light emission properties. Here we describe the EBSD, ECCI and CL techniques and illustrate their use for investigating the structural and light emitting properties of UV-emitting nitride semiconductor structures. We discuss our investigations of the type, density and distribution of defects in GaN, AlN and AlGaN thin films and also discuss the determination of the polarity of GaN nanowires