What's a brain: neuroanatomy and neurochemistry of anxiety disorders in dogs

This review deals with the neurocircuitry of fear and anxiety disorders, with the focus on neuroanatomy and neurochemistry. This knowledge is required to correctly diagnose and treat dogs with anxiety-related behavioral disorders. Research to date has shown the involvement of the frontal cortex, the amygdala, the thalamus and the hippocampus as core regions in regulating fear. Imbalances (hyper- or hypoactivation) in this fear circuitry can trigger inappropriate fear responses, i.e. anxiety disorders. Serotonin, dopamine and norepinephrine are the main neurotransmitters of emotion in the brain, but gamma-aminobutyric acid (GABA), glutamate, and the hypothalamic-pituitary-adrenal (HPA) axis producing glucocorticoids are also important in the neurochemistry of anxiety

Functional brain imaging : a brief overview of imaging techniques and their use in human and canine anxiety research

When used in combination with specific radioactive markers, functional imaging modalities such as Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) enable the visualization of several neurotransmitter receptors and transporters, as well as of the perfusion and metabolism of the brain. This paper gives an overview of the functional imaging techniques, as well as of the studies that have been performed on humans and canines with anxiety disorders. Thus far, most of the research in this field has been focused on brain perfusion and the serotonergic and dopaminergic neurotransmitters, and less on gamma-aminobutyric acid (GABA), glutamate, norepinephrine and the hypothalamic-pituitary-adrenal (HPA) axis

Nuclear medicine: investigation of renal function in small animal medicine

Kidney function investigations in veterinary medicine are traditionally based on blood analysis (blood urea nitrogen (BUN) and serum creatinine concentration) and / or urinalysis (urine specific gravity, protein-to-creatinine ratio or fractional excretion). Morphologic information is usually obtained by abdominal radiography or ultrasonography. However, when more specific information on the functionality of the kidneys is needed, nuclear medicine offers various tracers that specifically represent glomerular filtration rate, effective renal plasma flow or functional renal mass, sometimes combining functional and morphologic data. These procedures can be based on blood sampling techniques (non-imaging methods), or data can be obtained using a gamma-camera (imaging methods). The most commonly used radionuclides for the examination of kidney function in small animal medicine are discussed in this review

Human alignment of neural network representations

Today's computer vision models achieve human or near-human level performance across a wide variety of vision tasks. However, their architectures, data, and learning algorithms differ in numerous ways from those that give rise to human vision. In this paper, we investigate the factors that affect the alignment between the representations learned by neural networks and human mental representations inferred from behavioral responses. We find that model scale and architecture have essentially no effect on the alignment with human behavioral responses, whereas the training dataset and objective function both have a much larger impact. These findings are consistent across three datasets of human similarity judgments collected using two different tasks. Linear transformations of neural network representations learned from behavioral responses from one dataset substantially improve alignment with human similarity judgments on the other two datasets. In addition, we find that some human concepts such as food and animals are well-represented by neural networks whereas others such as royal or sports-related objects are not. Overall, although models trained on larger, more diverse datasets achieve better alignment with humans than models trained on ImageNet alone, our results indicate that scaling alone is unlikely to be sufficient to train neural networks with conceptual representations that match those used by humans.Comment: Accepted for publication at ICLR 202

Improving neural network representations using human similarity judgments

Deep neural networks have reached human-level performance on many computer vision tasks. However, the objectives used to train these networks enforce only that similar images are embedded at similar locations in the representation space, and do not directly constrain the global structure of the resulting space. Here, we explore the impact of supervising this global structure by linearly aligning it with human similarity judgments. We find that a naive approach leads to large changes in local representational structure that harm downstream performance. Thus, we propose a novel method that aligns the global structure of representations while preserving their local structure. This global-local transform considerably improves accuracy across a variety of few-shot learning and anomaly detection tasks. Our results indicate that human visual representations are globally organized in a way that facilitates learning from few examples, and incorporating this global structure into neural network representations improves performance on downstream tasks.Comment: Published as a conference paper at NeurIPS 202

Week 96 Extension Results of a Phase 3 Study Evaluating Long-Acting Cabotegravir with Rilpivirine for HIV-1 Treatment

BACKGROUND: ATLAS (NCT02951052), a phase 3, multicenter, open-label study, demonstrated that switching to injectable cabotegravir (CAB) with rilpivirine (RPV) long-acting dosed every 4 weeks was noninferior at week (W) 48 to continuing three-drug daily oral current antiretroviral therapy (CAR). Results from the W 96 analysis are presented. METHODS AND DESIGN: Participants completing W 52 of ATLAS were given the option to withdraw, transition to ATLAS-2M (NCT03299049), or enter an Extension Phase to continue long-acting therapy (Long-acting arm) or switch from CAR to long-acting therapy (Switch arm). Endpoints assessed at W 96 included proportion of participants with plasma HIV-1 RNA less than 50 copies/ml, incidence of confirmed virologic failure (CVF; two consecutive HIV-1 RNA ≥200 copies/ml), safety and tolerability, pharmacokinetics, and patient-reported outcomes. RESULTS: Most participants completing the Maintenance Phase transitioned to ATLAS-2M (88%, n = 502/572). Overall, 52 participants were included in the W 96 analysis of ATLAS; of these, 100% (n = 23/23) and 97% (n = 28/29) in the Long-acting and Switch arms had plasma HIV-1 RNA less than 50 copies/ml at W 96, respectively. One participant had plasma HIV-1 RNA 50 copies/ml or higher in the Switch arm (173 copies/ml). No participants met the CVF criterion during the Extension Phase. No new safety signals were identified. All Switch arm participants surveyed preferred long-acting therapy to their previous daily oral regimen (100%, n = 27/27). CONCLUSION: In this subgroup of ATLAS, 98% (n = 51/52) of participants at the Extension Phase W 96 analysis maintained virologic suppression with long-acting therapy. Safety, efficacy, and participant preference results support the therapeutic potential of long-acting CAB+RPV treatment for virologically suppressed people living with HIV-1

Calculating thermal conductivity in a transient conduction regime: theory and implementation

We present a molecular dynamics method addressed to the calculation of the lattice thermal conductivity during the transient regime of approach to equilibrium from an initial condition of nonuniform temperature profile. We thoroughly assess the basics, the robustness, and the accuracy of the method, in particular by showing that its results are basically independent of most of the arbitrary simulation parameters. In addition, the method here presented is computationally light, thus paving the way for the investigation of large systems. This feature is fully exploited to investigate the thermal transport properties of disordered and nanostructured silicon samples, providing a clear atomistic picture on the ability of grain boundaries and lattice disorder to affect thermal conductivity by improved scattering of vibrational modes with long mean free path