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Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 native bird species (18% of the non-vagrant bird fauna and 25% of those species within the fox’s range), a smaller tally than for cats (343 species, including 297 within the fox’s Australian range, a subset of that of the cat). Most (81%) bird species eaten by foxes are also eaten by cats, suggesting that predation impacts are compounded. As with consumption by cats, birds that nest or forage on the ground are most likely to be consumed by foxes. However, there is also some partitioning, with records of consumption by foxes but not cats for 25 bird species, indicating that impacts of the two predators may also be complementary. Bird species ≥3.4 kg were more likely to be eaten by foxes, and those <3.4 kg by cats. Our compilation provides an inventory and describes characteristics of Australian bird species known to be consumed by foxes, but we acknowledge that records of predation do not imply population-level impacts. Nonetheless, there is sufficient information from other studies to demonstrate that fox predation has significant impacts on the population viability of some Australian birds, especially larger birds, and those that nest or forage on the ground.
Schizophrenia, which is linked to a range of physical health conditions, might share intrinsic inflammatory disease pathways with type-two diabetes mellitus (T2DM). Psychotropic medication has presented a major confounder in examining this association. First-episode psychosis (FEP) patients present an interesting cohort to study this potential association, being generally younger with less comorbidity, and with limited exposure to antipsychotic medication.
Aims
To assess whether FEP, which could be described as ‘developing schizophrenia’, is associated with prediabetes, or ‘developing diabetes’, to determine whether intrinsic disease links could cause the conditions to develop in unison.
Methods
Using PRISMA criteria, we searched Embase, Medline, PsychInfo, Web of Science, and Google Scholar to 6th January 2016. We assessed case-control studies with biochemical assessment of prediabetic states in FEP patients alongside matched controls.
Results
Twelve studies were included, involving 1137 participants. Several measurements examined prediabetes, including fasting plasma glucose, impaired glucose tolerance, and insulin resistance. Pooled analysis found FEP to be related to impaired glucose tolerance (mean difference 1.31 [0.37, 2.25]), insulin resistance (mean difference 0.30 [0.18, 0.42]), and the number of patients with impaired glucose tolerance (odds ratio 5.44 [2.63–11.27]).
Conclusion
Our findings suggest a potential link between prediabetic markers, in particular impaired glucose tolerance and insulin resistance, and FEP. However, we cannot establish causality, and the studies contributing to this review were at some risk of bias. Nevertheless, the findings might help to explain the increased prevalence of T2DM in patients with schizophrenia and could have implications for the management of schizophrenia patients.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
For outbreaks of gastrointestinal disease, rapid identification of the source is crucial to enable public health intervention and prevent further cases. Outbreak investigation comprises analyses of exposure information from cases and, if required, undertaking analytical epidemiological studies. Hypothesis generation has been reliant on empirical knowledge of exposures historically associated with a given pathogen. Epidemiology studies are resource-intensive and prone to bias, one of the reasons being the difficulties in recruiting appropriate controls. For this paper, the information from cases was compared against pre-defined background exposure information. As exemplars, three past outbreaks were used, one of common and two of rare exposures. Information from historical case trawling questionnaires was used to define background exposure having removed any exposures implicated with the outbreak. The case-background approach showed good sensitivity and specificity, identifying correctly all outbreak-related exposures. One additional exposure related to a retailer was identified and four food items where all cases had been exposed. In conclusion, the case-background method, a development of the case-case design, can be used to assist with hypothesis generation or when a case-control study may not be possible to carry out.
Current policy emphasises the importance of ‘living well’ with dementia, but there has been no comprehensive synthesis of the factors related to quality of life (QoL), subjective well-being or life satisfaction in people with dementia. We examined the available evidence in a systematic review and meta-analysis. We searched electronic databases until 7 January 2016 for observational studies investigating factors associated with QoL, well-being and life satisfaction in people with dementia. Articles had to provide quantitative data and include ⩾75% people with dementia of any type or severity. We included 198 QoL studies taken from 272 articles in the meta-analysis. The analysis focused on 43 factors with sufficient data, relating to 37639 people with dementia. Generally, these factors were significantly associated with QoL, but effect sizes were often small (0.1–0.29) or negligible (<0.09). Factors reflecting relationships, social engagement and functional ability were associated with better QoL. Factors indicative of poorer physical and mental health (including depression and other neuropsychiatric symptoms) and poorer carer well-being were associated with poorer QoL. Longitudinal evidence about predictors of QoL was limited. There was a considerable between-study heterogeneity. The pattern of numerous predominantly small associations with QoL suggests a need to reconsider approaches to understanding and assessing living well with dementia.
This paper presents a simple mathematical formula for correcting radio-echo-sounding data from an ice sheet or glacier for the effects of varying refractive index. The method requires some knowledge of the variation of refractive index with depth. In rare cases this may be known from direct measurement, but it can be estimated from the density profile. If even this is unknown, we show that the corrections can be estimated to an accuracy of about 3% of the depth to bubble close-off (i.e. to about ±12 m for dry-snow conditions), and that the size of the refraction correction for a glacier or ice sheet with a flat bed is typically 6–10 m under these conditions.
The Ca II K line serves as an important tool in determining the physics of the photosphere-chromosphere region of the solar atmosphere (Cram 1983). To date detailed analyses have centred on the study of line intensity profiles.
Little is understood about the evolution of structural and functional brain changes during the course of uncontrolled focal status epilepticus in humans.
Methods:
We serially evaluated and treated a nine-year-old girl with refractory focal status epilepticus. Long-term EEG monitoring, MRI, MRA, SPECT, intraoperative visualization of affected cortex, and neuropathological examination of a biopsy specimen were conducted over a three year time span. Imaging changes were correlated with simultaneous treatment and EEG findings.
Results:
The EEG monitoring showed almost continuous spike discharges emanating initially from the right frontocentral area. These EEG abnormalities were intermittently suppressed by treatment with anesthetics. Over time, additional brain areas developed epileptiform EEG abnormalities. Serial MRI studies demonstrated an evolution of changes from normal, through increased regional T2 signal to generalized atrophy. An MRAdemonstrated dilatation of the middle cerebral artery stem on the right compared to the left with a broad distribution of flow-related enhancement. An 18FDG-PET scan showed a dramatically abnormal metabolic profile in the same right frontocentral areas, which modulated in response to treatment during the course of the illness. A right frontotemporal craniotomy revealed a markedly hyperemic cortical focus including vascular shunting. A sample of resected cortex showed severe gliosis and neuronal death.
Conclusions:
The co-registration of structural and functional imaging and its correlation with operative and pathological findings in this case illustrates the relentless progression of regional and generalized abnormalities in intractable focal status epilepticus that were only transiently modified by exhaustive therapeutic interventions. Increased flow through large vessels appeared to be shunted and did not translate into increased microvascular perfusion.
The purpose of this study was to test the hypothesis that orbitofrontal cortical volume would be reduced following anterior cingulotomy for obsessive-compulsive disorder (OCD). Whole brain cortical parcellation was performed on magnetic resonance imaging (MRI) data from nine patients, before and 9(±6) months following anterior cingulotomy. No significant volumetric reductions were found in the orbitofrontal cortex. Exploratory findings of reduced volume in ventral temporo-fusiform and posterior cingulate regions were consistent with chance differences, in the face of multiple comparisons. Therefore, though the circumscribed lesions of anterior cingulotomy have recently been associated with corresponding volumetric reductions in the caudate nucleus, no comparable volumetric reductions are evident in cortical territories. Taken together, these results are most consistent with a model of cingulo-striatal perturbation as a putative mechanism for the efficacy of this procedure. While limitations in sensitivity may have also contributed to these negative findings, the methods employed have previously proven sufficient to detect cortical volumetric abnormalities in OCD. The current results may reflect a relatively diffuse pattern of cortico-cortical connections involving the neurons at the site of cingulotomy lesions. Future functional neuroimaging studies are warranted to assess possible cortical or subcortical metabolic changes associated with anterior cingulotomy, as well as predictors of treatment response.
The modern therapeutic approach to most psychiatric diseases involves a combination of well-supervised psychotherapy, pharmacotherapy, and electroconvulsive therapy. Patients who fail to adequately respond to these modern treatment methods and remain severely disabled may be considered for surgical intervention. Cingulotomy, capsulotomy, subcaudate tractotomy, and limbic leucotomy are the most common psychosurgical procedures performed today, with response rates in the 35% to 65% range. Modern stereotactic techniques have reduced complication rates, but controversy remains regarding the optimal surgical procedure. The major psychiatric diagnostic categories that might respond to surgery include treatment-refractory major affective disorders, obsessive-compulsive disorder, and chronic anxiety states. Surgery should be considered as one part of an entire treatment plan and must be followed by an appropriate psychiatric rehabilitation program. It should only be carried out by an expert multidisciplinary team consisting of a neurologist a neurosurgeon, and a psychiatrist with experience in these disorders. Surgical intervention remains a reasonable therapeutic option for select patients with a disabling psychiatric disease and may be underutilized.
Depressive symptoms are prominent psychopathological features of Huntington's disease (HD), making a negative impact on social functioning and well-being.
Method
We compared the frequencies of a history of depression, previous suicide attempts and current subthreshold depression between 61 early-stage HD participants and 40 matched controls. The HD group was then split based on the overall HD group's median Hospital Anxiety and Depression Scale-depression score into a group of 30 non-depressed participants (mean 0.8, s.d. = 0.7) and a group of 31 participants with subthreshold depressive symptoms (mean 7.3, s.d. = 3.5) to explore the neuroanatomy underlying subthreshold depressive symptoms in HD using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI).
Results
Frequencies of history of depression, previous suicide attempts or current subthreshold depressive symptoms were higher in HD than in controls. The severity of current depressive symptoms was also higher in HD, but not associated with the severity of HD motor signs or disease burden. Compared with the non-depressed HD group DTI revealed lower fractional anisotropy (FA) values in the frontal cortex, anterior cingulate cortex, insula and cerebellum of the HD group with subthreshold depressive symptoms. In contrast, VBM measures were similar in both HD groups. A history of depression, the severity of HD motor signs or disease burden did not correlate with FA values of these regions.
Conclusions
Current subthreshold depressive symptoms in early HD are associated with microstructural changes – without concomitant brain volume loss – in brain regions known to be involved in major depressive disorder, but not those typically associated with HD pathology.
Fully updated and containing significant new material on photography, laser profiling and image processing, the third edition of this popular textbook covers a broad range of remote sensing applications and techniques across the Earth, environmental and planetary sciences. It focuses on physical principles, giving students a deeper understanding of remote sensing systems and their possibilities, while remaining accessible to those with less mathematical training by providing a step-by-step approach to quantitative topics. Boxed examples, additional photos and numerous colour images engage students and show them how the theory relates to the many real-world applications. Chapter summaries, review questions and additional problems allow students to check their understanding of key concepts and practise handling real data for themselves. Supplementary online material includes links to freely available software, animations, computer programs, colour images and other web-based resources of interest.
In Chapter 3 we discussed principally the interaction of electromagnetic radiation with the surface and bulk of the material being sensed. However, the radiation also has to make at least one journey through at least part of the Earth's atmosphere, and two such journeys in the case of systems that detect reflected radiation, whether artificial or naturally occurring. Each time radiation passes through the atmosphere it is attenuated to some extent. In addition, as we have already seen in Section 3.1.2 and Figure 3.5, the atmosphere has a refractive index that differs from unity so that radiation travels through it at a speed different from the free-space speed of 299 792 458 m s−1. These phenomena must be considered if the results of a remotely sensed measurement are to be corrected for the effects of atmospheric propagation, or if they are to be used to infer the properties of the atmosphere itself. We have already considered them in general terms in discussing the radiative transfer equation (Section 3.4). In this chapter we shall relate them more directly to the constituents of the atmosphere.
Composition and structure of the gaseous atmosphere
At sea level, the principal constituents of the dry atmosphere are molecules of nitrogen (about 78% by volume), oxygen (21%) and the inert gas argon (1%). There is also a significant but variable (typically 0.1% to 3%) amount of water vapour, often specified by the relative humidity H.
There are many books that explain the subject of remote sensing to those whose backgrounds are primarily in the environmental sciences. This is an entirely reasonable fact, since they continue to be the main users of remotely sensed data. However, as the subject grows in importance, the need for a significant number of people to understand not only what remote sensing systems do, but how they work, will grow with it. This was already happening in 1990, when the first edition of Physical Principles of Remote Sensing appeared, and since then increasing numbers of physical scientists, engineers and mathematicians have moved into the field of environmental remote sensing. It is mainly for such readers that this book, like its previous editions, has been written. That is to say, the reader for whom I have imagined myself to be writing is educated to a reasonable standard (although not necessarily to first degree level) in physics, with a commensurate mathematical background. I have however found it impossible to be strictly consistent about this, because of the wide range of disciplines within and beyond physics from which the material has been drawn, and I trust that readers will be understanding when they find the treatment either too simple or over their heads.
In Chapter 1 we noted that electromagnetic radiation is fundamental to remote sensing as we have defined it: the information about the sensed object is carried by this radiation. We therefore need to develop an understanding of the essential characteristics of this radiation and of how it interacts with its surroundings. This is a large topic and it is covered in this chapter and the next two. In this chapter we consider electromagnetic radiation in its simplest form, when it is propagating in (travelling through) a vacuum, usually termed ‘free space’. This is practically useful, because for much of its journey towards the sensor the radiation is propagating in a medium that approximates to free space, and it also allows us to develop some of the essential ideas that describe electromagnetic radiation without too much confusing detail.
A particularly important part of this chapter deals with thermal radiation. As we noted in Chapter 1, most passive remote sensing systems detect thermal radiation (in the infrared or microwave regions) or they detect reflected solar radiation. Solar radiation is itself, as explained in this chapter, essentially just another form of thermal radiation, so by developing an understanding of thermal radiation we are able to describe many of the characteristics of the radiation detected by passive systems.