A Method for GC–Olfactometry Panel Training

Odor-active compounds are commonly analyzed using gas chromatography–olfactometry (GC–O). However, there are only limited guidelines available for panelist training with this technique. In the current study, 29 volunteers were trained to detect, describe, and rate the intensity of odors. In addition, three GC–O methods, i.e., aroma extraction dilution method, detection frequency, and posterior intensity (PI), were used to evaluate the newly trained panelists’ ability to analyze key compounds of kvass (fermented nonalcoholic drink) aroma. A five-step approach is proposed for training as follows: (1) introduction of the method; (2) vocabulary training using standard compounds and learning the use of the scale; (3) training with the reference mixture A; (4) training with the real product of interest—the beverage kvass; and (5) monitoring and further training of the panel. Following these steps, all panelists learned how to perform GC–O analysis. Some variances among subjects were observed; however, the background of the trainees was found to be insignificant. Assessors for the “professional” GC–O panel were chosen for further training and included people with a sensory and food science background, but also ordinary consumers. The PI method, where subjects rate odor intensity after a peak eluted, was found to provide a sufficient amount of data for key compound analysis. The method enabled easy data handling, provided valuable feedback for panel monitoring, and aided in the selection process to decide which assessors would be suitable for further training and placement on a professional panel.     

Novel luciferase–opsin combinations for improved luminopsins

Previous work has demonstrated that fusion of a luciferase to an opsin, to create a luminescent opsin or luminopsin, provides a genetically encoded means of manipulating neuronal activity via both chemogenetic and optogenetic approaches. Here we have expanded and refined the versatility of luminopsin tools by fusing an alternative luciferase variant with high light emission, Gaussia luciferase mutant GLucM23, to depolarizing and hyperpolarizing channelrhodopsins with increased light sensitivity. The combination of GLucM23 with Volvox channelrhodopsin-1 produced LMO4, while combining GLucM23 with the anion channelrhodopsin iChloC yielded iLMO4. We found efficient activation of these channelrhodopsins in the presence of the luciferase substrate, as indicated by responses measured in both single neurons and in neuronal populations of mice and rats, as well as by changes in male rat behavior during amphetamine-induced rotations. We conclude that these new luminopsins will be useful for bimodal opto- and chemogenetic analyses of brain function.     

Fluid–attenuated inversion recovery (FLAIR) sequences for the assessment of acute stroke

Background and purpose Diffusion–weighted magnetic resonance (MR) imaging (DWI), and three–dimensional (3D) time–of–flight (TOF) MR angiography (MRA), are highly sensitive for the early detection of stroke and arterial occlusion. However, only a few studies have evaluated the sensitivity of conventional MR sequences that are usually included in the imaging protocol. The aim of this study was to evaluate interobserver and intertechnique reproducibility of Fluid–Attenuated Inversion Recovery (FLAIR) sequences for the diagnosis of early brain ischemia and arterial occlusion. Methods Over a 30–month period, brain MR examinations were performed in 34 patients within 12 hours after stroke onset. Imaging protocol included FLAIR sequences, DWI and 3D TOF MRA. Ten observers including radiologists and neurologists, performed separately a visual interpretation of FLAIR images for the detection of brain ischemia and arterial occlusion seen as an arterial high signal. DWI and 3D TOF MRA were used as reference and interpreted independently by two senior radiologists. Interobserver agreement was assessed for image quality, detectability and conspicuity of lesions whereas intertechnique agreement was only judged for lesion detectability. Results On FLAIR sequences, interobserver agreement for the detection of brain ischemia and arterial occlusion was excellent (κ = 0.81 and 0.87 respectively). The concordance between FLAIR and DWI sequences for the detection of brain ischemia and between FLAIR and 3D TOF MRA for the detection of arterial occlusion were judged as excellent for all observers (κ = 0.91 and 0.89 respectively). Conclusion Although DWI is the most sensitive technique with which to detect acute stroke, FLAIR imaging may also be useful to demonstrate both acute ischemia and arterial occlusion with an excellent interobserver reproducibility.     

Guillain–Barré syndrome–like–onset neurosarcoidosis positive for immunoglobulin G anti-N-acetylgalactosaminyl-GD1a antibody

Anti-ganglioside antibodies have been reported in various peripheral neuropathies, including Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, Fisher syndrome, monoclonal gammopathy-associated neuropathy, and other idiopathic neuropathies. To our knowledge, there has been no report of anti-ganglioside-positive sarcoidosis. We report a 62-year-old man with acute weakness of the limbs and sensory disturbance of the right arm and trunk resembling GBS. Soluble interleukin-2 receptor and angiotensin-converting enzyme levels were elevated. Anti-ganglioside antibodies (immunoglobulin G anti-N-acetylgalactosaminyl-GD1a antibody [IgG anti-GalNAc-GD1a antibody]) were detected. Neurophysiological examination demonstrated axonal neuropathy. Bilateral hilar lymphadenopathy was demonstrated on a chest CT scan, and abnormal uptake of ⁶⁷Gallium was detected by scintigraphy. The ratio of CD4 to CD8 was elevated in bronchoalveolar lavage fluid. Noncaseating epithelioid cell granulomas were detected in a specimen obtained via transbronchial lung biopsy. Because intravenous immunoglobulin did not improve the symptoms, we commenced steroid pulse therapy followed by oral prednisolone therapy. After steroid therapy, he recovered fully. Because the findings in our patient fulfilled the criteria for neurosarcoidosis, we diagnosed his illness as probable neurosarcoidosis. To the best of our knowledge, this is the first patient with GBS–like–onset neurosarcoidosis positive for anti-IgG anti-GalNAc-GD1a antibody.     

Diabetes Type II: A Risk Factor for Depression–Parkinson–Alzheimer?

There is ample evidence that impairments in the hypothalamic–pituitary–adrenal (HPA) axis are of etiopathobiochemical importance in a subgroup of patients with “depression”, causing hypercortisolaemia as major metabolic effect. Chronic hypercortisolaemia causes insulin resistance. Therefore, it is not surprising that epidemiological studies demonstrate an association of “depression” with diabetes type II and vice versa. Chronic stress and hypercortisolaemia are conditions, which have been suggested to be causal for Alzheimer’s disease (AD) as brain insulin resistance is associated with β-Amyloid-accumulation and hyperphosphorylation of tau-protein. Depression is one of the significant symptomatology preceding AD. It is however, not known whether “depression” associated with hypercortisolaemia is the subgroup at risk for AD. In contrast to a subgroup of “depression” and to AD, in Parkinson’s disease (PD) there is only weak evidence for an association with diabetes type II and insulin resistance. As “depression” is preceding PD in up to half of such patients, it remains to be elucidated whether this is a subgroup of depressed patients, which is not associated with disturbances of the HPA axis and hypercortisolaemia. Improved clinical and biochemical/molecular knowledge about “depression” associated with AD and PD in comparison to “pure” depression might lead to improved therapeutic strategies and even drug development focusing subtypes of “depression”.     

Dense Encoder-Decoder–Based Architecture for Skin Lesion Segmentation

Cognitive Computation - Melanoma is one kind of dangerous cancer that has been increasing rapidly in the world. Initial diagnosis is essential to survival, but often the disease is diagnosed in the...     

Hemodynamic brain–computer interfaces for communication and rehabilitation

Functional near-infrared spectroscopy (NIRS) and functional magnetic resonance imaging (fMRI) are non-invasive methods for acquiring hemodynamic signals from the brain with the primary benefit of anatomical specificity of signals. Recently, there has been a surge of studies with NIRS and fMRI for the implementation of a brain–computer interface (BCI), for the acquisition, decoding and regulation of hemodynamic signals in the brain, and to investigate their behavioural consequences. Both NIRS and fMRI rely on the measurement of the task-induced blood oxygen level-dependent response. In this review, we consider fundamental principles, recent developments, applications and future directions and challenges of NIRS-based and fMRI-based BCIs.     

Psychometric properties of the Ndetei–Othieno–Kathuku (NOK) Scale: A mental health assessment tool for an African setting

Background: Research suggests that psychiatric conditions in children and adolescents are highly debilitating, with sparse resources for assessment and treatment in low- and middle-income countries (LMICs).

Objectives: The primary aim of this study was to evaluate the reliability, validity, and latent factor structure of an ethnographically-grounded assessment instrument for detecting common mental health complaints among rural Kenyan children and adolescents.

Methods: The Ndetei–Othieno–Kathuku Scale (NOK) was delivered to 2 282 children aged 10 to 18 years old. Exploratory factor analysis identified four latent factors. This structure was confirmed in subsequent confirmatory factor analyses. External validity was explored by investigating associations among NOK factors and Youth Self-Report DSM-oriented scales.

Results: Findings suggest the NOK possesses good internal reliability and a four-factor latent structure corresponding to depression, anxiety, somatic complaints, and a mixed factor. Significant associations ranging from small to medium effect sizes were noted between NOK factors and YSR DSM-oriented scales.

Conclusions: Exploratory findings suggest that the NOK possesses adequate psychometric properties among this population. This ethnographically-grounded instrument may be uniquely suited to screening for mental health complaints among Kenyan children and adolescents.     

A double-barrel superficial temporal artery-to-superior cerebellar artery (STA–SCA) and STA-to-posterior cerebral artery (STA–PCA) bypass for revascularization of the basilar apex

Basilar apex aneurysms are challenging lesions for both microsurgical and endovascular therapy. In patients in whom direct clipping and coil embolization are not options, cerebral revascularization and occlusion of the basilar artery is a possible treatment strategy. We report a patient with a large basilar apex aneurysm treated by double-barrel anastomoses of the superficial temporal artery to the superior cerebellar artery (STA–SCA) and the STA to the posterior cerebral artery (STA-PCA) followed by occlusion of the basilar artery below the SCAs. A double-barrel bypass augments blood flow to the brainstem. We report a novel bypass option for augmenting blood flow to the basilar apex and brainstem.     

Translation into Arabic and validation of the Schedule for the Assessment of Insight–Expanded Version (SAI-E) for use in Tunisia

Background

The Schedule for the Assessment of Insight–Expanded Version (SAI-E) consists of 11 items that encompass: awareness of having a mental illness, ability to rename psychotic phenomena as abnormal, and compliance with treatment.

Aims

To translate into Arabic and validate the Tunisian version of this instrument.

Method

The Arabic translation of the SAI-E was obtained by the “forward/backward translation” method. Adaptations were made after a pilot study involving 20 outpatients with schizophrenia and after taking account the opinions of 15 experts in psychiatry.For validation, 150 outpatients suffering from schizophrenia were recruited by a random drawing in the psychiatric department in Sousse (Tunisia).For factor analysis, principal components analysis and Varimax rotation were adopted. Convergent validity was assessed by correlating the translated scale with the G12 item (lack of judgment and awareness of the disease) of the positive and Negative Syndrome Scale (PANSS).Internal consistency was assessed by Cronbach alpha coefficient and inter-rater reliability was assessed by the use of intra-class correlation coefficient (ICC).

Results

Regarding construct validity, factor analysis revealed three factors that were responsible for 70.2% of the variance.As for concurrent validity, we found a negative correlation between the score of the SAI-E and that of the G12 item of the PANSS (r = − 0.82 and p < 10⁻³).The study of internal consistency between the 11 items was found to be good (α = 0.82). The test–retest reliability was satisfactory (r = 0.8, p < 10⁻³), and so was inter-rater reliability (ICC = 0.84).

Conclusion

In the Tunisian cultural context, the SAI-E presented three factors with good consistency and an inter-rater reliability compatible with the insight dimensions that are intended to be evaluated.     

Season–of–birth as a risk factor for the seasonality of suicidal behaviour

Despite implicating the same biological systems, the relationship between suicide seasonality and season–of–birth has not been examined previously. The purpose of this study was to investigate the interaction between season–of–birth and the seasonality of suicidal behaviour. All adult suicides (N = 2923) and deliberate self harm (DSH) hospitalizations (N = 33321) in Western Australia (1970–96) were examined. A variable population at risk approach was used to determine season–of–birth. Seasonality was established by spectral analysis. We found that DSH has a significant season–of–birth (p = 0.047) and seasonality of occurrence, both peaking in spring. Individuals born in the 90 days centred on the peak birth period, however, show no DSH seasonality. In contrast, suicide has no season–of–birth (p = 0.53). We also found a season–of–birth effect among the DSH group that eliminates any seasonality of DSH among the high–risk by birth group. Further work is needed to identify the possible biological and environmental determinants of this interaction.