Detecting changes in surface moisture and water table position with spectral changes in surface vegetation in northern peatlands

Due to warmer and drier conditions, wildland fire has been increasing in extent into peatland ecosystems during recent decades. As such, there is an increasing need for broadly applicable tools to detect surface peat moisture, in order to ascertain the susceptibility of peat burning, and the vulnerability of deep peat consumption in the event of a wildfire. In this thesis, a field portable spectroradiometer was used to measure surface reflectance of two Sphagnum moss dominated peatlands. Relationships were developed correlating spectral indices to surface moisture as well as water table position. Spectral convolutions were also applied to the high resolution spectra to represent spectral sensitivity of earth observing sensors. Band ratios previously used to monitor surface moisture with these sensors were assessed. Strong relationships to surface moisture and water table position are evident for both the narrowband indices as well as broadened indices. This study also found a dependence of certain spectral relationships on changes in vegetation cover by leveraging an experimental vegetation manipulation. Results indicate broadened indices employing the 1450-1650 nm region may be less stable under changing vegetation cover than those located in the 1200 nm region.

INFLUENCE OF 24-HOUR SLEEP DEPRIVATION ON CARDIOVASCULAR AND NEURAL CONTROL AT REST AND DURING ACUTE STRESS IN HUMANS

Recent epidemiological studies report a consistent association between short sleep and incidence of hypertension, as well as short sleep and cardiovascular disease-related mortality. While the association between short sleep and hypertension appears to be stronger in women than men, the mechanisms underlying the relations between sleep deprivation, stress, risks of cardiovascular diseases, and sex remain unclear. We conducted two studies to investigate the underlying neural mechanisms of these relations. In study 1, we examined sympathetic neural and blood pressure responses to experimentally-induced sleep deprivation in men and women. We further investigated the influence of sleep deprivation on cardiovascular reactivity to acute stress. In study 2, we examined the neural and cardiovascular function throughout the ovarian cycle in sleep deprived women. Twenty-eight young healthy subjects (14men and 14 women) were tested twice in study 1, once after normal sleep (NS) and once after 24-h total sleep deprivation (TSD). We measured the blood pressure, heart rate (HR), muscle sympathetic nerve activity (MSNA) and forearm blood flow (FBF) during 10min baseline, 5min of mental stress (MS) and 2 min cold pressor test (CPT). We demonstrated that TSD increased resting arterial blood pressure to a similar extent in both men and women, but MSNA decreased only in men following TSD. This MSNA response was associated with altered baroreflex function in women and divergent testosterone responses to TSD between men and women. Regarding TSD and cardiovascular reactivity, TSD elicited augmented HR reactivity and delayed recovery during both MS and CPT in men and women, and responses between sexes were not statistically different. Fourteen young healthy women participated in study 2. Subjects were tested twice, once during their early follicular (EF) phase after TSD, once during their mid-luteal (ML) phase after TSD. Blood pressure, HR, MSNA, and FBF were recorded during 10min baseline, 5 min MS, and 2 min CPT. We observed an augmented resting supine blood pressure during EF compared to ML in sleep deprived women. In contrast, resting MSNA, as well as cardiovascular responses to stressors, were similar between EF and ML after TSD. In conclusion, we observed sex differences in MSNA responses to TSD that demonstrate reductions of MSNA in men, but not women. TSD elicited augmented HR reactivity and delayed HR recovery to acute stressors similarly in men and women. We also reported an augmented supine blood pressure during EF compared to ML in sleep deprived women. These novel findings provide new and valuable mechanistic insight regarding the complex and poorly understood relations among sleep deprivation, sex, stress, and risk of cardiovascular disease.

INTERACTIVE CONTROLS OF WATER TABLE POSITION AND PLANT FUNCTIONAL TYPES ON PEAT POREWATER CHARACTER IN NORTHERN BOG ECOSYSTEMS: IMPLICATIONS FOR CARBON CYCLING DYNAMICS

Northern wetlands, and particularly peatlands, have been shown to store around 30% of the world's soil carbon and thus play a significant role in the carbon cycle of our planet. Changes in climate are altering peatland hydrology and vegetation communities. These changes are possibly resulting in declines in the ability of peatlands to sequester carbon because losses through carbon oxidation and mineralization are likely to increase relative to C inputs from net primary production in a warmer, drier climate. However, the consequences of interactive effects of altered hydrology and vegetation on carbon storage are not well understood. This research evaluated the importance of plant species, water table, and their interactive effects on porewater quality in a northern peatland with an average pH of 4.54, ranging from 4.15 to 4.8. We assessed the effects of plant functional group (ericaceous shrubs, sedges, and bryophytes) and water table position on biogeochemical processes. Specifically, we measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), potential enzyme activity, organic acids, anions and cations, spectral indexes of aromaticity, and phenolic content. Our results indicate that acetate and propionate concentrations in the sedge-dominated communities declined with depth and water table drawdown, relative to the control and ericaceous treatments. DOC increased in the lowered water table treatments in all vegetation community types, and the peat porewater C:N ratio declined in the sedge-dominated treatments when the water table was lowered. The relationship between DOC and ferrous iron showed significant responses to vegetation type; the exclusion of Ericaceae resulted in less ferrous iron per unit DOC compared to mixed species treatments and Ericaceae alone. This observation was corroborated with higher mean oxidation redox potential profiles (integrating 20, 40, and 70 cm) measured in the sedge treatments, compared with the mixed and Ericaceae species treatments over a growing season. Enzymatic activities did not show as strong of a response to treatments as expected; the oxidative enzyme peroxidase and the hydrolytic enzyme phosphatase were the only enzymes to respond to water table, where the potential activity of both enzymes increased with water table drawdown. Overall, there were significant interactive effects between changes in vegetation and water table position on peat porewater composition. These data suggest that vegetation effects on oxidation reduction potentials and peat porewater character can be as important as water table position in northern bog ecosystems.

Impact of coil position and electrophysiological monitoring on determination of motor thresholds to transcranial magnetic stimulation

OBJECTIVE: We compared motor and movement thresholds to transcranial magnetic stimulation (TMS) in healthy subjects and investigated the effect of different coil positions on thresholds and MEP (motor-evoked potential) amplitudes. METHODS: The abductor pollicis brevis (APB) 'hot spot' and a standard scalp position were stimulated. APB resting motor threshold (APB MEP-MT) defined by the '5/10' electrophysiological method was compared with movement threshold (MOV-MT), defined by visualization of movements. Additionally, APB MEP-MTs were evaluated with the '3/6 method,' and MEPs were recorded at a stimulation intensity of 120% APB MEP-MT at each position. RESULTS: APB MEP-MTs were significantly lower by stimulation of the 'hot spot' than of the standard position, and significantly lower than MOV-MTs (n=15). There were no significant differences between the '3/6' and the '5/10' methods, or between APB MEP amplitudes by stimulating each position at 120% APB MEP-MT. CONCLUSIONS: Coil position and electrophysiological monitoring influenced motor threshold determinations. Performing 6 instead of 10 trials did not produce different threshold measurements. Adjustment of intensity according to APB MEP-MT at the stimulated position did not influence APB MEP amplitudes. SIGNIFICANCE: Standardization of stimulation positions, nomenclature and criteria for threshold measurements should be considered in design and comparison of TMS protocols.

A Surface Displacement Analysis for Volcan Pacaya from October 2001 through March 2013 by Means of 3-D Modeling of Precise Position GPS Data

Volcán Pacaya is one of three currently active volcanoes in Guatemala. Volcanic activity originates from the local tectonic subduction of the Cocos plate beneath the Caribbean plate along the Pacific Guatemalan coast. Pacaya is characterized by generally strombolian type activity with occasional larger vulcanian type eruptions approximately every ten years. One particularly large eruption occurred on May 27, 2010. Using GPS data collected for approximately 8 years before this eruption and data from an additional three years of collection afterwards, surface movement covering the period of the eruption can be measured and used as a tool to help understand activity at the volcano. Initial positions were obtained from raw data using the Automatic Precise Positioning Service provided by the NASA Jet Propulsion Laboratory. Forward modeling of observed 3-D displacements for three time periods (before, covering and after the May 2010 eruption) revealed that a plausible source for deformation is related to a vertical dike or planar surface trending NNW-SSE through the cone. For three distinct time periods the best fitting models describe deformation of the volcano: 0.45 right lateral movement and 0.55 m tensile opening along the dike mentioned above from October 2001 through January 2009 (pre-eruption); 0.55 m left lateral slip along the dike mentioned above for the period from January 2009 and January 2011 (covering the eruption); -0.025 m dip slip along the dike for the period from January 2011 through March 2013 (post-eruption). In all bestfit models the dike is oriented with a 75° westward dip. These data have respective RMS misfit values of 5.49 cm, 12.38 cm and 6.90 cm for each modeled period. During the time period that includes the eruption the volcano most likely experienced a combination of slip and inflation below the edifice which created a large scar at the surface down the northern flank of the volcano. All models that a dipping dike may be experiencing a combination of inflation and oblique slip below the edifice which augments the possibility of a westward collapse in the future.

Governor Forrest Anderson’s Leadership & Political Acumen -- Alec Hansen “In the Crucible of Change”

Montana Governor Forrest Anderson was perhaps the most experienced and qualified person ever to be elected as Governor of Montana. Having previously served as a county attorney, a member of the legislature, a Supreme Court Justice, and twelve years as Attorney General, Anderson roared to a large victory in 1968 over the Incumbent GOP Governor Tim Babcock. Though the progressive change period in Montana began a few years earlier, Anderson’s 1968 win catapulted progressive policy-making into the mainstream of Montana political and governmental affairs. He used his unique skills and leadership to craftily architect the reorganization of the executive branch which had been kept weak since statehood so that the peoples’ government would not be able to challenge corporations who so dominated Montana. Anderson, whose “Pay More, What For?” campaign slogan strongly separated him from Tim Babcock and the GOP on the sales tax issue, not only beat back the regressive sales tax in the 1968 election, but oversaw its demise at the polls in 1971, shaping politics in Montana for decades to come. Anderson also was a strong proponent of the concept of a new Montana Constitution and contributed strategically to its calling and passage. Anderson served only one term as Governor for health reasons, but made those four years a launch pad for progressive politics and government in Montana. In this film, Alec Hansen, Special Assistant to Governor Anderson, provides an insider’s perspective as he reflects on the unique way in which Governor Anderson got things done at this critical period “In the Crucible of Change.” Alec Hansen is best known in Montana political and governmental circles as the long-time chief of the Montana League of Cities and Towns, but he cut his teeth in public service with Governor Forrest Anderson. Alec was born in Butte in 1941, attended local schools graduating from Butte High in 1959. After several years working as a miner and warehouseman for the Anaconda Company in Butte, he attended UM and graduated in History and Political Science in 1966. He joined the U.S. Navy and served with amphibious forces in Vietnam. After discharge from the Navy in 1968, he worked as a news and sports reporter for The Montana Standard in Butte until in September of 1969 he joined Governor Anderson as a Special Assistant focused on press, communications and speech-writing. Alec has noted that drafts were turned into pure Forrest Anderson remarks by the man himself. He learned at the knee of “The Fox” for the rest of Anderson’s term and continued with Governor Tom Judge for two years before returning to Butte to work for the Anaconda Company as the Director of Communications for Montana operations. In 1978, after Anaconda was acquired by the Atlantic Richfield Company, Alec went to work in February for U.S. Senator Paul Hatfield in Washington D.C., leaving after Hatfield’s primary election loss in June 1978. He went back to work for Gov. Judge, remaining until the end of 1980. In 1981 Alec worked as a contract lobbyist and news and sports reporter for the Associated Press in Helena. In 1982, the Montana League of Cities and Towns hired him as Executive Director, a position he held until retirement in 2014. Alec and his wife Colleen, are the parents of two grown children, with one grandson.

Palliative care in heart failure: a position statement from the palliative care workshop of the Heart Failure Association of the European Society of Cardiology

Heart failure is a serious condition and equivalent to malignant disease in terms of symptom burden and mortality. At this moment only a comparatively small number of heart failure patients receive specialist palliative care. Heart failure patients may have generic palliative care needs, such as refractory multifaceted symptoms, communication and decision making issues and the requirement for family support. The Advanced Heart Failure Study Group of the Heart Failure Association of the European Society of Cardiology organized a workshop to address the issue of palliative care in heart failure to increase awareness of the need for palliative care. Additional objectives included improving the accessibility and quality of palliative care for heart failure patients and promoting the development of heart failure-orientated palliative care services across Europe. This document represents a synthesis of the presentations and discussion during the workshop and describes recommendations in the area of delivery of quality care to patients and families, education, treatment coordination, research and policy.

Patent foramen ovale and neurosurgery in sitting position: a systematic review

We have conducted a systematic review of air embolism complications of neurosurgery in the sitting position and patent foramen ovale (PFO) closure. It assesses the risk and benefit of PFO closure before neurosurgery in the sitting position. The databases Medline, Embase, and Cochrane Controlled Trial Register were systematically searched from inception to November 2007 for keywords in both topics separately. In total, 4806 patients were considered for neurosurgery in sitting position and 5416 patients underwent percutaneous PFO closure. The overall rate of venous air embolism during neurosurgery in sitting position was 39% for posterior fossa surgery and 12% for cervical surgery. The rate of clinical and transoesophageal echocardiography detected paradoxical air embolism was reported between 0% and 14%. The overall success rate for PFO closure using new and the most common closure devices was reported 99%, whereas the average risk of major complications is <1%. On the basis of our systematic review, we recommend screening for PFO and considering closure in cases in which the sitting position is the preferred neurosurgical approach. Our proposed management including the time of PFO closure according to available data is presented. However, the conclusions from our systematic review may be limited due to the lack of level A evidence and from using data from observational cohort studies. Thus, definite evidence-based recommendations require prospective evaluation of the issue in well-designed studies.

Transesophageal echocardiography for verification of the position of the electrocardiographically-placed central venous catheter

OBJECTIVE: Compare changes in P-wave amplitude of the intra-atrial electrocardiogram (ECG) and its corresponding transesophageal echocardiography (TEE)-controlled position to verify the exact localization of a central venous catheter (CVC) tip. DESIGN: A prospective study. SETTING: University, single-institutional setting. PARTICIPANTS: Two hundred patients undergoing elective cardiac surgery. INTERVENTIONS: CVC placement via the right internal jugular vein with ECG control using the guidewire technique and TEE control in 4 different phases: phase 1: CVC placement with normalized P wave and measurement of distance from the crista terminalis to the CVC tip; phase 2: TEE-controlled placement of the CVC tip; parallel to the superior vena cava (SVC) and measurements of P-wave amplitude; phase 3: influence of head positioning on CVC migration; and phase 4: evaluation of positioning of the CVC postoperatively using a chest x-ray. MEASUREMENTS AND MAIN RESULTS: The CVC tip could only be visualized in 67 patients on TEE with a normalized P wave. In 198 patients with the CVC parallel to the SVC wall controlled by TEE (phase 2), an elevated P wave was observed. Different head movements led to no significant migration of the CVC (phase 3). On a postoperative chest-x-ray, the CVC position was correct in 87.6% (phase 4). CONCLUSION: The study suggests that the position of the CVC tip is located parallel to the SVC and 1.5 cm above the crista terminalis if the P wave starts to decrease during withdrawal of the catheter. The authors recommend that ECG control as per their study should be routinely used for placement of central venous catheters via the right internal jugular vein.

A standardized protocol for the prevention of clinically relevant venous air embolism during neurosurgical interventions in the semisitting position

OBJECTIVE: We report the results and complications associated with standardized intraoperative management designed for the prevention of hemodynamically relevant venous air embolism during surgery performed in the semisitting position. METHODS: A protocol for preoperative evaluation and intraoperative monitoring was developed and applied in 187 consecutive patients who underwent surgery in the semisitting position between 1999 and 2004. The protocol included preoperative transesophageal echocardiography examination (TEE), intraoperative TEE monitoring, catheterization of the right atrium and a combination of fluid input, positive end expiratory pressure, and standardized positioning aiming at a positive pressure in the transverse and sigmoid sinuses. Data were collected retrospectively from the charts and intraoperative anesthesiological protocols of the patients for the incidence of clinically relevant air embolism (i.e., TEE-diagnosed air embolism plus a decrease in end tidal CO2 or hemodynamic changes) and other complications related to the semisitting position. RESULTS: Three cases (1.6%) of relevant venous air embolism occurred in 187 patients. Only 1 case (0.5%) was hemodynamically relevant, with temporary arterial blood pressure decrease and heart rate increase. Pneumatocephalus leading to lethargy was a frequent postoperative finding, which resolved spontaneously in all except 1 patient with epileptic seizure and oculomotor nerve palsy attributable to space-occupying subdurally trapped air, which had to be treated surgically. There was no permanent morbidity or mortality related to the semisitting position. CONCLUSION: Fear of massive venous air embolism is one reason for dramatic decline in the use of the semisitting position in neurosurgical practice. We found that strict adherence to a standardized protocol using TEE monitoring before and during surgery; exclusion of patients with patent foramen ovale; and a combination of positive end expiratory pressure, fluid input, and a standardized position aiming a positive pressure in the transverse and sigmoid sinuses helped to greatly minimize this complication to a rate of 0.5% for hemodynamically relevant events.