567 research outputs found
Alien Registration- Johnson, Lilli M. (Appleton, Knox County)
https://digitalmaine.com/alien_docs/15087/thumbnail.jp
The long-term effects of whole-tree harvest at final felling on soil properties in a Norway Spruce (Picea Abies (L) Karst.) Stand
Increased demand for forest-derived biomass has resulted in changes in harvest intensities in Finland. Conventional stem-only harvest (CH) has to some extent been replaced with whole-tree harvest (WTH). The latter involves a greater removal of nutrients from the forest ecosystem, as all the above ground biomass is exported from the site. This has raised concerns that WTH could result in large changes in the nutrient dynamics of a forest stand and could eventually lower its site productivity. Little empirical data exists to support this assumption as only a limited number of studies have been conducted on the topic. A majority of these discuss the short-term effects, thus the long-term consequences remain unknown.
The objective of this study was to compare differences in soil properties after CH and WTH in a fertile Norway spruce (Picea abies (L) Karst.) stand in Southern Finland. The site was clear-felled in August 2000 and spruce seedlings were planted in the following summer. Soil sampling in the form of systematic randomized sampling was carried out in May 2011. Changes in base saturation, cation exchange capacity, elemental pools (total and exchangeable) and acidity were studied in both organic and mineral horizons. The results indicate that WTH lowered effective cation exchange capacity and base saturation particularly in the humus layer. The pools of exchangeable Al and Fe were increased in the humus layer, whereas the amount of exchangeable Ca decreased in both layers. WTH also resulted in lower Ca/Al-ratios across the sampled layers. Treatment did not have a significant effect on pH, total pools of elements or on the C/N-ratio of the soil. The results suggest that although the stand possesses significant pools of nutrients at present, WTH, if continued, could have long-term effects on site productivity
Positron Emission Tomography Imaging Reveals Auditory and Frontal Cortical Regions Involved with Speech Perception and Loudness Adaptation
Considerable progress has been made in the treatment of hearing loss with
auditory implants. However, there are still many implanted patients that
experience hearing deficiencies, such as limited speech understanding or
vanishing perception with continuous stimulation (i.e., abnormal loudness
adaptation). The present study aims to identify specific patterns of cerebral
cortex activity involved with such deficiencies. We performed O-15-water
positron emission tomography (PET) in patients implanted with electrodes
within the cochlea, brainstem, or midbrain to investigate the pattern of
cortical activation in response to speech or continuous multi-tone stimuli
directly inputted into the implant processor that then delivered electrical
patterns through those electrodes. Statistical parametric mapping was
performed on a single subject basis. Better speech understanding was
correlated with a larger extent of bilateral auditory cortex activation. In
contrast to speech, the continuous multi-tone stimulus elicited mainly
unilateral auditory cortical activity in which greater loudness adaptation
corresponded to weaker activation and even deactivation. Interestingly,
greater loudness adaptation was correlated with stronger activity within the
ventral prefrontal cortex, which could be up-regulated to suppress the
irrelevant or aberrant signals into the auditory cortex. The ability to detect
these specific cortical patterns and differences across patients and stimuli
demonstrates the potential for using PET to diagnose auditory function or
dysfunction in implant patients, which in turn could guide the development of
appropriate stimulation strategies for improving hearing rehabilitation.
Beyond hearing restoration, our study also reveals a potential role of the
frontal cortex in suppressing irrelevant or aberrant activity within the
auditory cortex, and thus may be relevant for understanding and treating
tinnitus
The megalithic building of S.Erasmo di Cesi: architecture, astronomy, and landscape
Abstract. One of the most enigmatic megalithic buildings of Italy is the structure which lies on the S. Erasmo hill near Cesi, in Umbria, a huge complex encompassing an area of around 8000 square meters and enclosed by refined cyclopean walls. Although its date is uncertain, suggested dates comprise the Iron Age and archaic period, down to the third century B.C. The building’s function is also uncertain. Usually identified as a fortified structure, in fact there is a megalithic platform at the southern end of the enclosure which could have served as foundation of a temple or palace and, from the top of Monte Torre Maggiore, a complex of temples dating from the fourth century B.C. overlooks the hill. Similar combinations of megalithic buildings resting half-way to temples placed on high peaks are known to exist. In order to clarify the function of this structure and its position in relation to the surrounding landscape, with particular attention to its visibility and to the directions of visibility from the complex, as well as to the possible astronomical alignments, we present a multi-disciplinary approach to the study of the S. Erasmo complex, which includes the mapping of the sky at the various possible epochs of construction, the creation of a digital model of the landscape in forms of digital maps using Geographic Information System technologies, and a 3D model using various 3D software packages
Effect of Deep Brain Stimulation on Regional Cerebral Blood Flow in Patients with Medically Refractory Tourette Syndrome
A model-based approach for vulnerability analysis of IoT security protocols: The Z-Wave case study
IoT (Internet of Things) devices are extensively used in security-critical services, as for example home door opening, gas monitoring, alarm systems, etc. Often, they use communication protocols with no standardisation and no security guarantee. Unsecured use of connected devices can cause threats or damages to the users, so security assurance, which can be ensured by the use of formal methods, must be guaranteed. Unfortunately practical usage of formal methods during the protocol design is very limited or missing at all. To address the problem of providing the designer with a user-friendly but rigorous design approach based on the use of formal methods, supporting security assurance already at the model level, but hiding the complexity of formal notations and verification techniques, in this paper we propose an approach, based on the Abstract State Machine formal method, for the specification and verification of security protocols. Specifically, we introduce a set of built-in primitives to model communication protocols and their security properties. Security verification can be carried out under the hypothesis of either a passive or an active attacker. The effectiveness of this approach is shown by means of its application to the Z-Wave protocol, claimed to be one of the most secure protocol for IoT devices communication thanks to the addition of the S2 Security class. We show the formal specification of the Z-Wave protocol and the security verification process
Multimorbidity and patterns of chronic conditions in a primary care population in Switzerland: a cross-sectional study
To characterise in details a random sample of multimorbid patients in Switzerland and to evaluate the clustering of chronic conditions in that sample.
100 general practitioners (GPs) each enrolled 10 randomly selected multimorbid patients aged ≥18 years old and suffering from at least three chronic conditions. The prevalence of 75 separate chronic conditions from the International Classification of Primary Care-2 (ICPC-2) was evaluated in these patients. Clusters of chronic conditions were studied in parallel.
The final database included 888 patients. Mean (SD) patient age was 73.0 (12.0) years old. They suffered from 5.5 (2.2) chronic conditions and were prescribed 7.7 (3.5) drugs; 25.7% suffered from depression. Psychological conditions were more prevalent among younger individuals (≤66 years old). Cluster analysis of chronic conditions with a prevalence ≥5% in the sample revealed four main groups of conditions: (1) cardiovascular risk factors and conditions, (2) general age-related and metabolic conditions, (3) tobacco and alcohol dependencies, and (4) pain, musculoskeletal and psychological conditions.
Given the emerging epidemic of multimorbidity in industrialised countries, accurately depicting the multiple expressions of multimorbidity in family practices' patients is a high priority. Indeed, even in a setting where patients have direct access to medical specialists, GPs nevertheless retain a key role as coordinators and often as the sole medical reference for multimorbid patients
Multifractal analysis for evaluating the representation of clouds in global kilometer-scale models
Clouds are one of the largest sources of uncertainty in climate predictions. Global km-scale models need to simulate clouds and precipitation accurately to predict future climates. To isolate issues in their representation of clouds, models need to be thoroughly evaluated with observations. Here, we introduce multifractal analysis as a method for evaluating km-scale simulations. We apply it to outgoing longwave radiation fields to investigate structural differences between observed and simulated anvil clouds. We compute fractal parameters which compactly characterize the scaling behavior of clouds and can be compared across simulations and observations. We use this method to evaluate the nextGEMS ICON simulations via comparison with observations from the geostationary satellite GOES-16. We find that multifractal scaling exponents in the ICON model are significantly lower than in observations. We conclude that too much variability is contained in the small scales (< 100 km) leading to less organized convection and smaller, isolated anvils
A process model of the formation of spatial presence experiences
In order to bridge interdisciplinary differences in Presence research and to establish connections between Presence and “older” concepts of psychology and communication, a theoretical model of the formation of Spatial Presence is proposed. It is applicable to the exposure to different media and intended to unify the existing efforts to develop a theory of Presence. The model includes assumptions about attention allocation, mental models, and involvement, and considers the role of media factors and user characteristics as well, thus incorporating much previous work. It is argued that a commonly accepted model of Spatial Presence is the only solution to secure further progress within the international, interdisciplinary and multiple-paradigm community of Presence research
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